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Activation of β adrenergic receptors on airway smooth muscle leads to the activation of adenylate cyclase and to an increase in the intracellular concentration of 3,5-cyclic adenosine monophosphate (cyclic AMP). The increase in cyclic AMP is associated with the activation of protein kinase A, which in turn, inhibits the phosphorylation of myosin and lowers intracellular ionic calcium concentrations, resulting in muscle relaxation.
Levosalbutamol relaxes the smooth muscles of all airways, from the trachea to the terminal bronchioles. Increased cyclic AMP concentrations are also associated with the inhibition of the release of mediators from mast cells in the airways. Levosalbutamol acts as a functional agonist that relaxes the airway irrespective of the spasmogen involved, thereby protecting against all bronchoconstrictor challenges.
While it is recognized that β adrenergic receptors are the predominant receptors on bronchial smooth muscle, data indicate that there are beta receptors in the human heart, 10–50% of which are β adrenergic receptors. The precise function of these receptors has not been established. However, all β adrenergic agonist drugs can produce a significant cardiovascular effect in some patients, as measured by pulse rate, blood pressure, and restlessness symptoms, and/or electrocardiographic (ECG). | 1 | Enantiopure drugs |
As magmatic gas travelling upward encounters meteoric water in an aquifer, steam is produced. Latent magmatic heat can also cause meteoric waters to ascend as a vapour phase. Extended fluid-rock interaction of this hot mixture can leach constituents out of the cooling magmatic rock and also the country rock, causing volume changes and phase transitions, reactions and thus an increase in ionic strength of the upward percolating fluid. This process also decreases the fluid's pH. Cooling can cause phase separation and mineral deposition, accompanied by a shift toward more reducing conditions. At the surface expression of such hydrothermal systems, low-temperature volcanic gases (<400 °C) are either emanating as steam-gas mixtures or in dissolved form in hot springs. At the ocean floor, such hot supersaturated hydrothermal fluids form gigantic chimney structures called black smokers, at the point of emission into the cold seawater.
Over geological time, this process of hydrothermal leaching, alteration, and/or redeposition of minerals in the country rock is an effective process of concentration that generates certain types of economically valuable ore deposits. | 0 | Greenhouse Gases |
The 2001 Heart Outcomes and Prevention Evaluation trial seemed to show ramipril possessed cardioprotective qualities which extended beyond its qualities as an antihypertensive. However, the trial and the interpretation of its results have been criticised.
The Acute Infarction Ramipril Efficacy (AIRE) trial showed a 27% reduction in mortality for patients receiving ramipril for chronic heart failure following a myocardial infarction.
Ramipril was found to have similar results as telmisartan, an angiotensin II receptor blocker. | 1 | Enantiopure drugs |
Like other β-lactam antibiotics, dicloxacillin acts by inhibiting the synthesis of bacterial cell walls. It inhibits cross-linkage between the linear peptidoglycan polymer chains that make up a major component of the cell wall of Gram-positive bacteria. | 1 | Enantiopure drugs |
Escitalopram has FDA approval for the treatment of major depressive disorder in adolescents and adults, and generalized anxiety disorder in adults. In European countries and the United Kingdom, it is approved for depression (MDD) and anxiety disorders; these include: general anxiety disorder (GAD), social anxiety disorder (SAD), obsessive-compulsive disorder (OCD), and panic disorder with or without agoraphobia. In Australia it is approved for major depressive disorder. | 1 | Enantiopure drugs |
Thalidomide is a classical example highlighting the alleged role of chirality in drug toxicity. Thalidomide was a racemic therapeutic and prescribed to pregnant women to control nausea and vomiting. The drug was withdrawn from world market when it became evident that the use in pregnancy causes phocomelia (clinical conditions where babies are born with deformed hand and limbs). Later in late 1970s studies indicated that the (R)- enantiomer is an effective sedative, the (S)-enantiomer harbors teratogenic effect and causes fetal abnormalities. Later studies established that under biological conditions the (R)-thalidomide, good partner, undergoes an in vivo metabolic inversion to the (S)-thalidomide, evil partner and vice versa. It is a bidirectional chiral inversion. Hence the argument that the thalidomide tragedy could have been avoided by using a single enantiomer is ambiguous and pointless.
The salient features are presented in the table below. | 1 | Enantiopure drugs |
Since the start of the Industrial Revolution, atmospheric concentration have been increasing, causing global warming and ocean acidification. In October 2023 the average level of in Earth's atmosphere, adjusted for seasonal variation, was 422.17 parts per million by volume (ppm). Figures are published monthly by the National Oceanic & Atmospheric Administration (NOAA). The value had been about 280 ppm during the 10,000 years up to the mid-18th century.
Each part per million of in the atmosphere represents approximately 2.13 gigatonnes of carbon, or 7.82 gigatonnes of .
It was pointed out in 2021 that "the current rates of increase of the concentration of the major greenhouse gases (carbon dioxide, methane and nitrous oxide) are unprecedented over at least the last 800,000 years".
It has been estimated that 2,400 gigatons of CO₂ have been emitted by human activity since 1850, with some absorbed by oceans and land, and about 950 gigatons remaining in the atmosphere. Around 2020 the emission rate was over 40 gigatons per year.
Some fraction (a projected 20–35%) of the fossil carbon transferred thus far will persist in the atmosphere as elevated levels for many thousands of years after these carbon transfer activities begin to subside. | 0 | Greenhouse Gases |
Chlorprothixene may increase the plasma-level of concomitantly given lithium. In order to avoid lithium intoxication, lithium plasma levels should be monitored closely.
If chlorprothixene is given concomitantly with opioids, the opioid dose should be reduced (by approx. 50%), because chlorprothixene amplifies the therapeutic actions and side effects of opioids considerably.
Avoid the concomitant use of chlorprothixene and tramadol (Ultram). Seizures may be encountered with this combination.
Consider additive sedative effects and confusional states to emerge, if chlorprothixene is given with benzodiazepines or barbiturates. Choose particular low doses of these drugs.
Exert particular caution in combining chlorprothixene with other anticholinergic drugs (tricyclic antidepressants and antiparkinsonian agents): Particularly the elderly may develop delirium, high fever, severe obstipation, even ileus and glaucoma . | 1 | Enantiopure drugs |
Water's Lewis base character makes it a common ligand in transition metal complexes, examples of which include metal aquo complexes such as to perrhenic acid, which contains two water molecules coordinated to a rhenium center. In solid hydrates, water can be either a ligand or simply lodged in the framework, or both. Thus, consists of [Fe(HO)] centers and one "lattice water". Water is typically a monodentate ligand, i.e., it forms only one bond with the central atom. | 0 | Greenhouse Gases |
Flutamide was first synthesized in 1967 by Neri and colleagues at Schering Plough Corporation. It was originally synthesized as a bacteriostatic agent, but was subsequently, and serendipitously found to possess antiandrogen activity. The code name of flutamide during development was SCH-13521. Clinical research of the medication began in 1971, and it was first marketed in 1983, specifically in Chile under the brand name Drogenil and in West Germany under the brand name Flugerel. Flutamide was not introduced in the United States until 1989; it was specifically approved by the U.S. Food and Drug Administration for the treatment of metastatic prostate cancer in combination with a gonadotropin-releasing hormone (GnRH) analogue. The medication was first studied for the treatment of hirsutism in women in 1989. It was the first "pure antiandrogen" to be studied in the treatment of hirsutism. Flutamide was the first NSAA to be introduced, and was followed by nilutamide in 1989 and then bicalutamide in 1995. | 1 | Enantiopure drugs |
On 23 November 2007, the use and trade of pseudoephedrine in Mexico was made illegal as it was argued that it was extremely popular as a precursor in the synthesis of methamphetamine. | 1 | Enantiopure drugs |
Dexrazoxane has been used to protect the heart against the cardiotoxic side effects of chemotherapeutic drugs such as anthracyclines, such as daunorubicin or doxorubicin or other chemotherapeutic agents. However, in July 2011 the European Medicines Agency (EMA) released a statement restricting use only in adult patients with cancer who have received > 300 mg/m doxorubicin or > 540 mg/m epirubicin and general approval for use for cardioprotection. That showed a possibly higher rate of secondary malignancies and acute myelogenous leukemia in pediatric patients treated for different cancers with both dexrazoxane and other chemotherapeutic agents that are associated with secondary malignancies. On July 19, 2017, based on evaluation of the currently available data the European Commission issued an EU-wide legally binding decision to implement the recommendations of the Committee for Medicinal Products for Human Use (CHMP) on dexrazoxane and lifted its 2011-contraindication for primary prevention of anthracycline-induced cardiotoxicity with dexrazoxane in children and adolescents where high doses (≥ 300 mg/m) of anthracyclines are anticipated.
Dexrazoxane was designated by the US FDA as an orphan drug for "prevention of cardiomyopathy for children and adults 0 through 16 years of age treated with anthracyclines". This decision allows virtually all children to receive dexrazoxane starting with the first dose of anthracycline at the discretion of the treating provider. The label change by the agency announcing dexrazoxane as an approved cardio-oncology protectant has been followed by a review by the agency. Currently, the only FDA and EMA approved cardioprotective treatment for anthracycline cardioprotection is dexrazoxane, which provides effective primary cardioprotection against anthracycline-induced cardiotoxicity without reducing anthracycline activity and without enhancing secondary malignancies.
The United States Food and Drug Administration has also approved a dexrazoxane for use as a treatment of extravasation resulting from IV anthracycline chemotherapy. Extravasation is an adverse event in which chemotherapies containing anthracylines leak out of the blood vessel and necrotize the surrounding tissue. | 1 | Enantiopure drugs |
Chiral purity is a measure of the purity of a chiral drug. Other synonyms employed include enantiomeric excess, enantiomer purity, enantiomeric purity, and optical purity. Optical purity is an obsolete term since today most of the chiral purity measurements are done using chromatographic techniques (not based on optical principles). Enantiomeric excess tells the extent (in %) to which the chiral substance contains one enantiomer over the other. For a racemic drug the enantiomeric excess will be 0%. There are number of chiral analysis tools such as polarimetry, NMR spectroscopy with the use of chiral shift reagents, chiral GC (gas chromatography), chiral HPLC (high performance liquid chromatography), chiral TLC (thin-layer chromatography) and other chiral chromatographic techniques, that are employed to evaluate chiral purity. Assessing the purity of a unichiral drug or enantiopure drug is of great importance from a drug safety and efficacy perspective. | 1 | Enantiopure drugs |
Levofloxacin is a broad-spectrum antibiotic that is active against both Gram-positive and Gram-negative bacteria. Like all quinolones, it functions by inhibiting the DNA gyrase and topoisomerase IV, two bacterial type IIA topoisomerases. Topoisomerase IV is necessary to separate DNA that has been replicated (doubled) prior to bacterial cell division. With the DNA not being separated, the process is stopped, and the bacterium cannot divide. DNA gyrase, on the other hand, is responsible for supercoiling the DNA, so that it will fit in the newly formed cells. Both mechanisms amount to killing the bacterium. Levofloxacin acts as a bactericide.
As of 2011, the mechanism of action for the drug's musculoskeletal complications were not clear. | 1 | Enantiopure drugs |
Carbon Action is an investor-led initiative which shows how companies in investment portfolios are managing carbon emissions and energy efficiency.
Over 300 investors with US$25 trillion in assets under management ask the world's highest emitting companies to take three specific actions in response to climate change:
* Make emissions reductions (year-on-year)
* Publicly disclose emission reduction targets
* Make ROI-positive investments in projects
CDP launched a new research series at the beginning of 2015, taking a sector by sector approach. | 0 | Greenhouse Gases |
Despite being generally inert, carbon tetrachloride can undergo various reactions. Hydrogen or an acid in the presence of an iron catalyst can reduce carbon tetrachloride to chloroform, dichloromethane, chloromethane and even methane. When its vapours are passed through a red-hot tube, carbon tetrachloride dechlorinates to tetrachloroethylene and hexachloroethane.
Carbon tetrachloride, when treated with HF, gives various compounds such as trichlorofluoromethane (R-11), dichlorodifluoromethane (R-12), chlorotrifluoromethane (R-13) and carbon tetrafluoride with HCl as the by-product:
This was once one of the main uses of carbon tetrachloride, as R-11 and R-12 were widely used as refrigerants.
An alcohol solution of potassium hydroxide decomposes it to potassium chloride and potassium carbonate in water:
When a mixture of carbon tetrachloride and carbon dioxide is heated to 350 degrees C, it gives phosgene: A similar reaction with carbon monoxide instead gives phosgene and tetrachloroethylene:
Reaction with hydrogen sulfide gives thiophosgene:
Reaction with sulfur trioxide gives phosgene and pyrosulfuryl chloride:
Reaction with phosphoric anhydride gives phosgene and phosphoryl chloride:
Carbon tetrachloride reacts with dry zinc oxide at 200 degrees Celsius to yield zinc chloride, phosgene and carbon dioxide: | 0 | Greenhouse Gases |
As the name suggests, eslicarbazepine acetate is the acetate ester prodrug of eslicarbazepine. Eslicarbazepine itself is the pharmacologically more active of the two stereoisomers of licarbazepine. More specifically, it is (S)-(+)-licarbazepine.
;Related drugs and active metabolites for comparison: | 1 | Enantiopure drugs |
The FDA label contains warnings that rasagiline may cause severe hypertension or hypotension, may make people sleepy, may make motor control worse in some people, may cause hallucinations and psychotic-like behavior, may cause impulse control disorder, may increase the risk of melanoma, and upon withdrawal may cause high fever or confusion.
Side effects when the drug is taken alone include flu-like symptoms, joint pain, depression, stomach upset, headache, dizziness, and insomnia. When taken with L-DOPA, side effects include increased movement problems, accidental injury, sudden drops in blood pressure, joint pain and swelling, dry mouth, rash, abnormal dreams and digestive problems including vomiting, loss of appetite, weight loss, abdominal pain, nausea, constipation. When taken with Parkinson's drugs other than L-DOPA, side effects include peripheral edema, fall, joint pain, cough, and insomnia. | 1 | Enantiopure drugs |
Levosalbutamol, also known as levalbuterol, is a short-acting β adrenergic receptor agonist used in the treatment of asthma and chronic obstructive pulmonary disease (COPD). Evidence is inconclusive regarding the efficacy of levosalbutamol versus salbutamol or salbutamol-levosalbutamol combinations, though levosalbutamol is believed to have a better safety profile due to its more selective binding to β receptors (primarily in the lungs) versus β (primarily in heart muscle).
The drug is the (R)-(−)-enantiomer of its prototype drug salbutamol. It is available in some countries in generic formulations from pharmaceutical companies including Cipla, Teva, and Dey, among others. | 1 | Enantiopure drugs |
The atmospheric abundance of CFC-115 rose from 8.4 parts per trillion (ppt) in year 2010 to 8.7 ppt in 2020 based on analysis of air samples gathered from sites around the world. | 0 | Greenhouse Gases |
Moexipril was an angiotensin converting enzyme inhibitor (ACE inhibitor) used for the treatment of hypertension and congestive heart failure. Moexipril can be administered alone or with other antihypertensives or diuretics.
It works by inhibiting the conversion of angiotensin I to angiotensin II.
It was patented in 1980 and approved for medical use in 1995. Moexipril is available from Schwarz Pharma under the trade name Univasc. | 1 | Enantiopure drugs |
Nebulized meropenem (inhaled route) is researched, but is not approved, for prevention of bronchiectasis exacerbation. | 1 | Enantiopure drugs |
It is also available in combination with hydrochlorothiazide, under the brand name Lotensin HCT, and with amlodipine (Lotrel). | 1 | Enantiopure drugs |
The compound was protected by a patent which was assigned to the German pharmaceutical company Hoechst AG (since merged into Aventis) on 29 October 1991. The patent was scheduled to expire on 29 October 2008. On 11 September 2007, in an appeal by the Indian company Lupin Ltd., the United States Court of Appeals for the Federal Circuit reversed a district court trial verdict and found that Aventis's patent on ramipril was invalid for "obviousness", opening this drug to generic manufacturers. | 1 | Enantiopure drugs |
Since there is a frequent large pharmacokinetic and pharmacodynamic differences between enantiomers of a chiral drug it is not surprising that enantiomers may result in stereoselective toxicity. They can reside in the pharmacologically active enantiomer (eutomer) or in the inactive one (distomer). The toxicologic differences between enantiomers of have also been demonstrated. The following are examples of some of the chiral drugs where their toxic/undesirable side-effects dwell almost in the distomer. This would seem to be a clear cut case of going for a chiral switch. | 1 | Enantiopure drugs |
Levetiracetam has not been found to be useful for treatment of neuropathic pain, nor for treatment of essential tremors. Levetiracetam has not been found to be useful for treating all developmental disorders within the autism spectrum; studies have only proven to be an effective treatment for partial, myoclonic, or tonic-clonic seizures associated with autism spectrum disorder. | 1 | Enantiopure drugs |
Squibb developed the first ACE inhibitor, captopril, but it had adverse effects such as a metallic taste (which, as it turned out, was due to the sulfhydryl group). Merck developed enalapril as a competing product.
Enalaprilat was developed first, partly to overcome these limitations of captopril. The sulfhydryl moiety was replaced by a carboxylate moiety, but additional modifications were required in its structure-based design to achieve a potency similar to captopril. Enalaprilat, however, had a problem of its own in that it had poor oral availability. This was overcome by the Merck researchers through the esterification of enalaprilat with ethanol to produce enalapril.
Merck introduced enalapril to market in 1981; it became Merck's first billion dollar-selling drug in 1988. The patent expired in 2000, opening the way for generics. | 1 | Enantiopure drugs |
Side effects are mild, usually at the start of treatment; they include:
*Cough
*Fatigue
*Weakness/Asthenia
*Headache
*Disturbances of mood and/or sleep
Less often
*Taste impairment
*Epigastric discomfort
*Nausea
*Abdominal pain
*Rash
Reversible increases in blood urea and creatinine may be observed. Proteinuria has occurred in some patients. Rarely, angioneurotic edema and decreases in hemoglobin, red cells, and platelets have been reported. | 1 | Enantiopure drugs |
R-410A cannot be used in R-22 service equipment because of higher operating pressures (approximately 40 to 70% higher).
While R-410A has negligible fractionation potential, it cannot be ignored when charging. | 0 | Greenhouse Gases |
Because of the multiple carbon–fluorine bonds, and the high electronegativity of fluorine, the carbon in tetrafluoromethane has a significant positive partial charge which strengthens and shortens the four carbon–fluorine bonds by providing additional ionic character. Carbon–fluorine bonds are the strongest single bonds in organic chemistry. Additionally, they strengthen as more carbon–fluorine bonds are added to the same carbon. In the one carbon organofluorine compounds represented by molecules of fluoromethane, difluoromethane, trifluoromethane, and tetrafluoromethane, the carbon–fluorine bonds are strongest in tetrafluoromethane. This effect is due to the increased coulombic attractions between the fluorine atoms and the carbon because the carbon has a positive partial charge of 0.76. | 0 | Greenhouse Gases |
Levofloxacin is a third-generation fluoroquinolone, being one of the isomers of ofloxacin, which was a broader-spectrum conformationally locked analog of norfloxacin; both ofloxacin and levofloxaxin were synthesized and developed by scientists at Daiichi Seiyaku. The Daiichi scientists knew that ofloxacin was racemic, but tried unsuccessfully to separate the two isomers; in 1985 they succeeded in separately synthesizing the pure levo form and showed that it was less toxic and more potent than the other form.
It was first approved for marketing in Japan in 1993, for oral administration, and Daiichi marketed it there under the brand name Cravit. Daiichi, working with Johnson & Johnson as it had with ofloxacin, obtained FDA approval in 1996 under the brand name Levaquin to treat bacterial sinusitus, bacterial exacerbations of bronchitis, community-acquired pneumonia, uncomplicated skin infections, complicated urinary tract infections, and acute pyelonephritis.
Levofloxacin is marketed by Sanofi-Aventis under a license agreement signed with Daiichi in 1993, under the brand name "Tavanic".
Levofloxacin had reached blockbuster status by this time; combined worldwide sales of levofloxacin and ofloxacin for J&J alone were in 2009.
The term of the levofloxacin United States patent was extended by the U.S. Patent and Trademark Office 810 days under the provisions of the Hatch Waxman Amendment so that the patent would expire in 2010 instead of 2008. This extension was challenged by generic drug manufacturer Lupin Pharmaceuticals, which did not challenge the validity of the patent, but only the validity of the patent extension, arguing that the patent did not cover a "product" and so Hatch-Waxman was not available for extensions. The federal patent court ruled in favor of J&J and Daiichi, and generic versions of levofloxacin did not enter the U.S. market until 2009. | 1 | Enantiopure drugs |
Water vapor plays a key role in lightning production in the atmosphere. From cloud physics, usually clouds are the real generators of static charge as found in Earth's atmosphere. The ability of clouds to hold massive amounts of electrical energy is directly related to the amount of water vapor present in the local system.
The amount of water vapor directly controls the permittivity of the air. During times of low humidity, static discharge is quick and easy. During times of higher humidity, fewer static discharges occur. Permittivity and capacitance work hand in hand to produce the megawatt outputs of lightning.
After a cloud, for instance, has started its way to becoming a lightning generator, atmospheric water vapor acts as a substance (or insulator) that decreases the ability of the cloud to discharge its electrical energy. Over a certain amount of time, if the cloud continues to generate and store more static electricity, the barrier that was created by the atmospheric water vapor will ultimately break down from the stored electrical potential energy. This energy will be released to a local oppositely charged region, in the form of lightning. The strength of each discharge is directly related to the atmospheric permittivity, capacitance, and the source's charge generating ability. | 0 | Greenhouse Gases |
Fluoroalkanes are generally inert and non-toxic.
Fluoroalkanes are not ozone depleting, as they contain no chlorine or bromine atoms, and they are sometimes used as replacements for ozone-depleting chemicals.
The term fluorocarbon is used rather loosely to include any chemical containing fluorine and carbon, including chlorofluorocarbons, which are ozone depleting. Fluoroalkanes are sometimes confused with fluorosurfactants, which significantly bioaccumulate.
Perfluoroalkanes do not bioaccumulate; those used in medical procedures are rapidly excreted from the body, primarily via expiration with the rate of excretion as a function of the vapour pressure; the half-life for octafluoropropane is less than 2 minutes, compared to about a week for perfluorodecalin.
Low-boiling perfluoroalkanes are potent greenhouse gases, in part due to their very long atmospheric lifetime, and their use is covered by the Kyoto Protocol. The global warming potential (compared to that of carbon dioxide) of many gases can be found in the IPCC 5th assessment report, with an extract below for a few perfluoroalkanes.
The aluminium smelting industry has been a major source of atmospheric perfluorocarbons (tetrafluoromethane and hexafluoroethane especially), produced as by-product of the electrolysis process. However, the industry has been actively involved in reducing emissions in recent years. | 0 | Greenhouse Gases |
Side effects reported for trandolapril include nausea, vomiting, diarrhea, headache, dry cough, dizziness or lightheadedness when sitting up or standing, hypotension, or fatigue. | 1 | Enantiopure drugs |
Out of the available endocrine-disrupting compounds looked at, flutamide has a notable effect on anogenital distance in rats.) | 1 | Enantiopure drugs |
Dexchlorpheniramine is an antihistamine, or an antagonist of the histamine H receptor. A study found that dexchlorpheniramine had a K value of 20 to 30 μM for the muscarinic acetylcholine receptors using rat brain tissue. | 1 | Enantiopure drugs |
As a type of emergency contraception, levonorgestrel is used after unprotected intercourse to reduce the risk of pregnancy. However, it can serve different hormonal purposes in its different methods of delivery. It is available for use in a variety of forms: | 1 | Enantiopure drugs |
1,1,2-Trichloro-1,2,2-trifluoroethane, also called trichlorotrifluoroethane (often abbreviated as TCTFE) or CFC-113, is a chlorofluorocarbon. It has the formula . This colorless, volatile liquid is a versatile solvent. | 0 | Greenhouse Gases |
Since the late 1970s, the use of CFCs has been heavily regulated because of their destructive effects on the ozone layer. After the development of his electron capture detector, James Lovelock was the first to detect the widespread presence of CFCs in the air, finding a mole fraction of 60 ppt of CFC-11 over Ireland. In a self-funded research expedition ending in 1973, Lovelock went on to measure CFC-11 in both the Arctic and Antarctic, finding the presence of the gas in each of 50 air samples collected, and concluding that CFCs are not hazardous to the environment. The experiment did however provide the first useful data on the presence of CFCs in the atmosphere. The damage caused by CFCs was discovered by Sherry Rowland and Mario Molina who, after hearing a lecture on the subject of Lovelocks work, embarked on research resulting in the first publication suggesting the connection in 1974. It turns out that one of CFCs most attractive features—their low reactivity—is key to their most destructive effects. CFCs lack of reactivity gives them a lifespan that can exceed 100 years, giving them time to diffuse into the upper stratosphere. Once in the stratosphere, the suns ultraviolet radiation is strong enough to cause the homolytic cleavage of the C-Cl bond. In 1976, under the Toxic Substances Control Act, the EPA banned commercial manufacturing and use of CFCs and aerosol propellants. This was later superseded in the 1990 amendments to the Clean Air Act to address stratospheric ozone depletion.
By 1987, in response to a dramatic seasonal depletion of the ozone layer over Antarctica, diplomats in Montreal forged a treaty, the Montreal Protocol, which called for drastic reductions in the production of CFCs. On 2 March 1989, 12 European Community nations agreed to ban the production of all CFCs by the end of the century. In 1990, diplomats met in London and voted to significantly strengthen the Montreal Protocol by calling for a complete elimination of CFCs by 2000. By 2010, CFCs should have been completely eliminated from developing countries as well.
Because the only CFCs available to countries adhering to the treaty is from recycling, their prices have increased considerably. A worldwide end to production should also terminate the smuggling of this material. However, there are current CFC smuggling issues, as recognized by the United Nations Environmental Programme (UNEP) in a 2006 report titled "Illegal Trade in Ozone Depleting Substances". UNEP estimates that between 16,000–38,000 tonnes of CFCs passed through the black market in the mid-1990s. The report estimated between 7,000 and 14,000 tonnes of CFCs are smuggled annually into developing countries. Asian countries are those with the most smuggling; as of 2007, China, India and South Korea were found to account for around 70% of global CFC production, South Korea later to ban CFC production in 2010. Possible reasons for continued CFC smuggling were also examined: the report noted that many of the refrigeration systems that were designed to be operated utilizing the banned CFC products have long lifespans and continue to operate. The cost of replacing the equipment of these items is sometimes cheaper than outfitting them with a more ozone-friendly appliance. Additionally, CFC smuggling is not considered a significant issue, so the perceived penalties for smuggling are low. In 2018 public attention was drawn to the issue, that at an unknown place in east Asia an estimated amount of 13,000 metric tons annually of CFCs have been produced since about 2012 in violation of the protocol. While the eventual phaseout of CFCs is likely, efforts are being taken to stem these current non-compliance problems.
By the time of the Montreal Protocol, it was realised that deliberate and accidental discharges during system tests and maintenance accounted for substantially larger volumes than emergency discharges, and consequently halons were brought into the treaty, albeit with many exceptions. | 0 | Greenhouse Gases |
Spirapril, sold under the brand name Renormax among others, is an ACE inhibitor antihypertensive drug used to treat hypertension. It belongs to dicarboxy group of ACE inhibitors.
It was patented in 1980 and approved for medical use in 1995. | 1 | Enantiopure drugs |
Meropenem rapidly reduces serum concentrations of valproic acid. As a result, people who use valproic acid for epilepsy are at increased risk of seizures during treatment with meropenem. In situations where the use of meropenem cannot be avoided, prescription of an additional anticonvulsant should be considered. | 1 | Enantiopure drugs |
As the tartrate salt, levorphanol is marketed by Hikma Pharmaceuticals USA Inc. and Virtus Pharmaceuticals in the U.S., and Canada under the brand name Levo-Dromoran. | 1 | Enantiopure drugs |
Fluoroform, or trifluoromethane, is the chemical compound with the formula . It is a hydrofluorocarbon as well as being apart of the haloforms, a class of compounds with the formula (X = halogen) with C symmetry. Fluoroform is used in diverse applications in organic synthesis. It is not an ozone depleter but is a greenhouse gas. | 0 | Greenhouse Gases |
Side effects seen more often with levomilnacipran than with placebo in clinical trials included nausea, dizziness, sweating, constipation, insomnia, increased heart rate and blood pressure, urinary hesitancy, erectile dysfunction and delayed ejaculation in males, vomiting, tachycardia, and palpitations. | 1 | Enantiopure drugs |
Flutamide has been found to be effective in the treatment of female pattern hair loss in a number of studies. In one study of 101 pre- and postmenopausal women, flutamide alone or in combination with an oral contraceptive produced a marked decrease in hair loss scores after 1 year of treatment, with maximum effect after 2 years of treatment and benefits maintained for another 2 years. In a small study of flutamide with an oral contraceptive, the medication caused an increase in cosmetically acceptance hair density in 6 of 7 women with diffuse scalp hair loss. In a comparative study, flutamide significantly improved scalp hair growth (21% reduction in Ludwig scores) in hyperandrogenic women after 1 year of treatment, whereas cyproterone acetate and finasteride were ineffective. | 1 | Enantiopure drugs |
1,1,2,2-Tetrafluoroethane (also called R-134 or HFC-134) is a hydrofluorocarbon, a fluorinated alkane. It is an isomer of the more-used 1,1,1,2-tetrafluoroethane (R-134a). It is used as a foam expansion agent and heat transfer fluid. | 0 | Greenhouse Gases |
Tetrafluoromethane is a potent greenhouse gas that contributes to the greenhouse effect. It is very stable, has an atmospheric lifetime of 50,000 years, and a high greenhouse warming potential 6,500 times that of CO.
Tetrafluoromethane is the most abundant perfluorocarbon in the atmosphere, where it is designated as PFC-14. Its atmospheric concentration is growing. As of 2019, the man-made gases CFC-11 and CFC-12 continue to contribute a stronger radiative forcing than PFC-14.
Although structurally similar to chlorofluorocarbons (CFCs), tetrafluoromethane does not deplete the ozone layer because the carbon–fluorine bond is much stronger than that between carbon and chlorine.
Main industrial emissions of tetrafluoromethane besides hexafluoroethane are produced during production of aluminium using Hall-Héroult process. CF also is produced as product of the breakdown of more complex compounds such as halocarbons. | 0 | Greenhouse Gases |
Gestonorone caproate has been available widely in Europe, including in the United Kingdom, and has also been marketed in Japan, China, Mexico, and certain other countries. However, it has been discontinued in most countries and its availability is more limited today; it appears to remain marketed only in the Czech Republic, Japan, Mexico, and Russia. It has not been marketed in the United States, Canada, and many other countries. | 1 | Enantiopure drugs |
Preparations of levocetirizine are sold under the following brand names:
* Xyzal in Australia, Austria, Bulgaria, Croatia, Cyprus, Czech Republic, Finland, France, Hong Kong, Hungary, India, Ireland (also Rinozal), Italy, Japan, Lithuania, Netherlands, Poland, Portugal, Romania, Taiwan, Thailand, Turkey, The Philippines, Serbia, Singapore, Slovakia, Slovenia, South Africa, Switzerland and UK. In May 2007, the US Food and Drug Administration approved Xyzal, where it is co-marketed by Sanofi-Aventis.
* Xazal in Spain.
* Zobral in Cyprus.
* Levobert in India.
* Xusal in Germany and Mexico.
* Xozal in Greece.
* Degraler in Chile.
* Allevo in Egypt.
* Zilola, Histisynt, and Xyzal (UCB) in Hungary.
* Alcet, Curin, and Seasonix in Bangladesh.
* Vozet and Uvnil in India.
* T-Day Syrup in Pakistan.
* Curin in Nepal.
* Zenaro in the Czech Republic and Slovakia.
* Xuzal and Zival in Chile.
* Cezera, Levosetil, Robenan, and Xyzal in Serbia.
* Rinozal and Xyzal in Ireland.
* Xycet in Morocco. | 1 | Enantiopure drugs |
Dichloromethane is the most important halomethane-based solvent. Its volatility, low flammability, and ability to dissolve a wide range of organic compounds makes this colorless liquid a useful solvent. It is widely used as a paint stripper and a degreaser. In the food industry, it was previously used to decaffeinate coffee and tea as well as to prepare extracts of hops and other flavorings. Its volatility has led to its use as an aerosol spray propellant and as a blowing agent for polyurethane foams. | 0 | Greenhouse Gases |
Levomethamphetamine is the levorotatory (L-enantiomer) form of methamphetamine. Levomethamphetamine is a sympathomimetic vasoconstrictor that is the active ingredient in some over-the-counter (OTC) nasal decongestant inhalers in the United States. | 1 | Enantiopure drugs |
Like methane itself, halomethanes are tetrahedral molecules. The halogen atoms differ greatly in size and charge from hydrogen and from each other. Consequently, most halomethanes deviate from the perfect tetrahedral symmetry of methane.
The physical properties of halomethanes depend on the number and identity of the halogen atoms in the compound. In general, halomethanes are volatile but less so than methane because of the polarizability of the halides. The polarizability of the halides and the polarity of the molecules makes them useful as solvents. The halomethanes are far less flammable than methane. Broadly speaking, reactivity of the compounds is greatest for the iodides and lowest for the fluorides. | 0 | Greenhouse Gases |
Greenhouse gases are infrared active, meaning that they absorb and emit infrared radiation in the same long wavelength range as what is emitted by the Earth's surface, clouds and atmosphere.
99% of the Earths dry atmosphere (excluding water vapor) is made up of nitrogen () (78%) and oxygen () (21%). Because their molecules contain two atoms of the same element, they have no asymmetry in the distribution of their electrical charges, and so are almost totally unaffected by infrared thermal radiation, with only an extremely minor effect from collision-induced absorption. A further 0.9% of the atmosphere is made up by argon (Ar), which is monatomic, and so completely transparent to thermal radiation. On the other hand, carbon dioxide (0.04%), methane, nitrous oxide and even less abundant trace gases account for less than 0.1% of Earths atmosphere, but because their molecules contain atoms of different elements, there is an asymmetry in electric charge distribution which allows molecular vibrations to interact with electromagnetic radiation. This makes them infrared active, and so their presence causes greenhouse effect. | 0 | Greenhouse Gases |
Levamlodipine (INN), also known as levoamlodipine or S-amlodipine is a pharmacologically active enantiomer of amlodipine. Amlodipine belongs to the dihydropyridine group of calcium channel blocker used as an antihypertensive and antianginal agent. It was approved by the U.S. FDA in December 2019 and is currently marketed under the brand name Conjupri. | 1 | Enantiopure drugs |
Hexafluoroethane's solid phase has two polymorphs. In the scientific literature, different phase transition temperatures have been stated. The latest works assign it at 103 K (−170 °C). Below 103 K it has a slightly disordered structure, and over the transition point, it has a body centered cubic structure. The critical point is at 19.89 °C (293.04 K) and 30.39 bar.
Table of densities:
Vapor density is 4.823 (air = 1), specific gravity at 21 °C is 4.773 (air = 1) and specific volume at 21 °C is 0.1748 m/kg. | 0 | Greenhouse Gases |
, GOSAT-GW, the successor of GOSAT-2 and GCOM-W "Shizuku", is under development for launch in JFY2024 on the last flight of the H-IIA launch vehicle. | 0 | Greenhouse Gases |
An enantiopure drug is a pharmaceutical that is available in one specific enantiomeric form. Most biological molecules (proteins, sugars, etc.) are present in only one of many chiral forms, so different enantiomers of a chiral drug molecule bind differently (or not at all) to target receptors. Chirality can be observed when the geometric properties of an object is not superimposable with its mirror image. Two forms of a molecule are formed (both mirror images) from a chiral carbon, these two forms are called enantiomers. One enantiomer of a drug may have a desired beneficial effect while the other may cause serious and undesired side effects, or sometimes even beneficial but entirely different effects. The desired enantiomer is known as an eutomer while the undesired enantiomer is known as the distomer. When equal amounts of both enantiomers are found in a mixture, the mixture is known as a racemic mixture. If a mixture for a drug does not have a 1:1 ratio of its enantiomers it is a candidate for an enantiopure drug. Advances in industrial chemical processes have made it economical for pharmaceutical manufacturers to take drugs that were originally marketed as a racemic mixture and market the individual enantiomers, either by specifically manufacturing the desired enantiomer or by resolving a racemic mixture. On a case-by-case basis, the U.S. Food and Drug Administration (FDA) has allowed single enantiomers of certain drugs to be marketed under a different name than the racemic mixture. Also case-by-case, the United States Patent Office has granted patents for single enantiomers of certain drugs. The regulatory review for marketing approval (safety and efficacy) and for patenting (proprietary rights) is independent, and differs country by country. | 1 | Enantiopure drugs |
Zuclopenthixol is available in three major preparations:
* As zuclopenthixol decanoate (Clopixol Depot, Cisordinol Depot), it is a long-acting intramuscular injection. Its main use is as a long-acting injection given every two or three weeks to people with schizophrenia who have a poor compliance with medication and suffer frequent relapses of illness. There is some evidence it may be more helpful in managing aggressive behaviour.
* As zuclopenthixol acetate (Clopixol-Acuphase, Cisordinol-Acutard), it is a shorter-acting intramuscular injection used in the acute sedation of psychotic inpatients. The effect peaks at 48–72 hours providing 2–3 days of sedation.
* As zuclopenthixol dihydrochloride (Clopixol, Cisordinol), it is a tablet used in the treatment of schizophrenia in those who are compliant with oral medication.
It is also used in the treatment of acute bipolar mania. | 1 | Enantiopure drugs |
Chlorprothixene has a strong sedative activity with a high incidence of anticholinergic side effects. The types of side effects encountered (dry mouth, massive hypotension and tachycardia, hyperhidrosis, substantial weight gain etc.) normally do not allow a full effective dose for the remission of psychotic disorders to be given. So cotreatment with another, more potent, antipsychotic agent is needed.
Chlorprothixene is structurally related to chlorpromazine, with which it shares, in principle, all side effects. Allergic side effects and liver damage seem to appear with an appreciable lower frequency. The elderly are particularly sensitive to anticholinergic side effects of chlorprothixene (precipitation of narrow angle glaucoma, severe obstipation, difficulties in urinating, confusional and delirant states). In patients >60 years the doses should be particularly low.
Early and late extrapyramidal side effects may occur but have been noted with a low frequency (one study with a great number of participants has delivered a total number of only 1%). | 1 | Enantiopure drugs |
Volcanic gases are gases given off by active (or, at times, by dormant) volcanoes. These include gases trapped in cavities (vesicles) in volcanic rocks, dissolved or dissociated gases in magma and lava, or gases emanating from lava, from volcanic craters or vents. Volcanic gases can also be emitted through groundwater heated by volcanic action.
The sources of volcanic gases on Earth include:
* primordial and recycled constituents from the Earth's mantle,
* assimilated constituents from the Earth's crust,
* groundwater and the Earth's atmosphere.
Substances that may become gaseous or give off gases when heated are termed volatile substances. | 0 | Greenhouse Gases |
In 2021, dextrorphan was identified in >75% of sludge samples taken from 12 wastewater treatment plants in California. The same study associated dextrorphan with estrogenic activity by using predictive modelling, before observing it in in vitro. | 1 | Enantiopure drugs |
In vivo, when alacepril undergoes deacetylation, it loses a molecule similar to the amino acid phenylalanine which transforms it into captopril. Captopril then provides its blood pressure lowering effect through two way. First, it inhibits the conversion of angiotensin 1, a precursor molecule, to angiotensin II, a vasoconstrictor that narrows blood vessels. Secondly, captopril prevents the breakdown of bradykinin, a vasodilator peptide that naturally relaxes blood vessels. | 1 | Enantiopure drugs |
The synthesis of the all-important dipeptide-like side chain involves alkylation of the tert-butyl ester of -alanine (2) with ethyl 2-bromo-4-phenylbutanoate (1); the presominane of the desired isomer is attributable to asymmetric induction from the adjacent chiral center. Reaction of the product with hydrogen chloride then cleaves the tert-butyl group to give the half acid (3). Coupling of that acid to the secondary amine on tetrahydroisoquinoline (4) gives the corresponding amine. The tert-butyl ester in this product is again cleaved with hydrogen chloride to afford moexipril (5). | 1 | Enantiopure drugs |
Unichiral indicates configurationally homogeneous substance (i.e. made up of chiral molecules of one and the same configuration). Other commonly used synonyms are enantiopure drugs and enantiomerically pure drugs. Monochiral drugs has also been suggested as another synonym. Professor Eliel, Wilen, and Gal expressed their deep concern over the misuse of the term "homochiral" in articles to denote enantiomerically pure drugs, which is incorrect. Homochiral means objects or molecules of the same handedness. Hence should be used only for comparison of two or more objects of like "chirality". For instance, left hands of different individuals, or say R-naproxen and R-ibuprofen.
Globally drug companies and regulatory agencies have an inclination towards the development of unichiral drugs as a consequence of the increased understanding of the differing biological properties of individual enantiomers of a racemic therapeutics. Most of these unichiral drugs are the consequence of chiral switch approach. The table below list selected unichiral drugs used in drug therapy.
A company may go in for developing a racemic drug against an enantiomer by providing adequate reasoning. The rationale why a company might pursue developing racemic drugs could include expensive separation of enantiomers, eutomer racemizes in solution (e.g. oxazepam), activities of the enantiomeric pair are different but supplementary, distomer is inactive, but separation is exorbitant. Insignificant/low toxicity of the distomer, high therapeutic index, mutually beneficial, pharmacological activities of both the enantiomers, and if the development of an enantiomer takes huge amount of time for a drug of emergency need e.g., cancer, AIDS, etc. | 1 | Enantiopure drugs |
Oral exemestane 25 mg/day for 2–3 years of adjuvant therapy was generally more effective than 5 years of continuous adjuvant tamoxifen in the treatment of postmenopausal women with early-stage estrogen receptor-positive/unknown receptor status breast in a large well-designed trial. Preliminary data from the open-label TEAM trial comparing exemestane with tamoxifen indicated in 2009 that exemestane 25 mg/day is also effective in the primary adjuvant treatment of early-stage breast cancer in postmenopausal women.
Interim phase III trial results in 2011 showed that adding everolimus to exemestane therapy against advanced breast cancer can significantly improve progression-free survival compared with exemestane therapy alone.
A Phase III trial was reported in 2011, concluding that the use of exemestane in postmenopausal women at an increased risk for breast cancer reduced the incidence of invasive breast cancer. In 4,560 women, after 35 months, the administration of exemestane at a dose of 25 mg/day resulted in a 65% reduction in the risk of breast cancer compared with placebo; annual incidence rates were 0.19% and 0.55%, respectively (hazard ratio: 0.35; 95% CI [0.18-0.70]; p = 0.002). | 1 | Enantiopure drugs |
Mezlocillin is a broad-spectrum penicillin antibiotic. It is active against both Gram-negative and some Gram-positive bacteria. Unlike most other extended spectrum penicillins, it is excreted by the liver, therefore it is useful for biliary tract infections, such as ascending cholangitis. | 1 | Enantiopure drugs |
In June 2010, it was revealed that a phase II study of armodafinil as an adjunctive therapy in adults with schizophrenia had failed to meet the primary endpoints, and the clinical program was subsequently terminated. However, a study published later that year showed that patients with schizophrenia treated with armodafinil showed fewer of the negative symptoms of schizophrenia. | 1 | Enantiopure drugs |
In the sugarcane industry, the organic waste is usually burned in the power cogeneration process. When contaminated by chloride, this waste burns, releasing methyl chloride in the atmosphere. | 0 | Greenhouse Gases |
Cloxacillin is an antibiotic useful for the treatment of a number of bacterial infections. This includes impetigo, cellulitis, pneumonia, septic arthritis, and otitis externa. It is not effective for methicillin-resistant Staphylococcus aureus (MRSA). It can be used by mouth and by injection.
Side effects include nausea, diarrhea, and allergic reactions including anaphylaxis. Clostridium difficile diarrhea may also occur. It is not recommended in people who have previously had a penicillin allergy. Use during pregnancy appears to be relatively safe. Cloxacillin is in the penicillin family of medications.
Cloxacillin was patented in 1960 and approved for medical use in 1965. It is on the World Health Organization's List of Essential Medicines. It is not commercially available in the United States. | 1 | Enantiopure drugs |
Fosinopril is an angiotensin converting enzyme (ACE) inhibitor used for the treatment of hypertension and some types of chronic heart failure. Fosinopril is the only phosphonate-containing ACE inhibitor marketed, by Bristol-Myers Squibb under the trade name Monopril. Fosinopril is a cascading pro-drug. The special niche for the medication that differentiates it from the other members of the ACE Inhibitor drug class is that was specifically developed for the use for patients with renal impairment. This was through manipulation of the metabolism and excretion, and is seen that fifty percent of the drug is hepatobiliary cleared, which can compensate for diminished renal clearance. The remaining fifty percent is excreted in urine. It does not need dose adjustment.
It was patented in 1980 and approved for medical use in 1991. | 1 | Enantiopure drugs |
There has been some controversy about AstraZenecas behaviour in creating, patenting, and marketing the drug. Esomeprazoles successful predecessor, omeprazole, is a mixture of two mirror-imaged molecules (esomeprazole which is the S-enantiomer, and R-omeprazole); critics said the company was trying to "evergreen" its omeprazole patent by patenting the pure esomeprazole and aggressively marketing to doctors that it is more effective than the mixture. | 1 | Enantiopure drugs |
The metabolism of drospirenone is extensive. It is metabolized into the acid form of drospirenone by opening of its lactone ring. The medication is also metabolized by reduction of its double bond between the C4 and C5 positions and subsequent sulfation. The two major metabolites of drospirenone are drospirenone acid and 4,5-dihydrodrospirenone 3-sulfate, and are both formed independently of the cytochrome P450 system. Neither of these metabolites are known to be pharmacologically active. Drospirenone also undergoes oxidative metabolism by CYP3A4. | 1 | Enantiopure drugs |
Arformoterol is indicated for the maintenance treatment of bronchoconstriction in people with chronic obstructive pulmonary disease (COPD). | 1 | Enantiopure drugs |
Chemically, levocetirizine is the active levorotary enantiomer of cetirizine, also called the l-enantiomer of cetirizine. It is a member of the diphenylmethylpiperazine group of antihistamines. | 1 | Enantiopure drugs |
Ampicillin has been used extensively to treat bacterial infections since 1961. Until the introduction of ampicillin by the British company Beecham, penicillin therapies had only been effective against gram-positive organisms such as staphylococci and streptococci. Ampicillin (originally branded as "Penbritin") also demonstrated activity against gram-negative organisms such as H. influenzae, coliforms, and Proteus spp. | 1 | Enantiopure drugs |
Tetrafluoromethane, like other fluorocarbons, is very stable due to the strength of its carbon–fluorine bonds. The bonds in tetrafluoromethane have a bonding energy of 515 kJ⋅mol. As a result, it is inert to acids and hydroxides. However, it reacts explosively with alkali metals. Thermal decomposition or combustion of CF produces toxic gases (carbonyl fluoride and carbon monoxide) and in the presence of water will also yield hydrogen fluoride.
It is very slightly soluble in water (about 20 mg⋅L), but miscible with organic solvents. | 0 | Greenhouse Gases |
Parkinsons disease is characterized by the death of cells that produce dopamine, a neurotransmitter. An enzyme called monoamine oxidase (MAO) breaks down neurotransmitters. MAO has two forms, MAO-A and MAO-B. MAO-B is generally believed to break down dopamine; however, recent evidence suggests that MAO-A may mostly or entirely be responsible for dopamine metabolism. Rasagiline prevents the breakdown of dopamine by irreversibly binding to MAO-B. Dopamine is therefore more available, somewhat compensating for the diminished quantities made in the brains of people with Parkinsons.
Selegiline was the first selective MAO-B inhibitor. It is partly metabolized to levomethamphetamine (l-methamphetamine), one of the two enantiomers of methamphetamine, in vivo. While these metabolites may contribute to selegilines ability to inhibit reuptake of the neurotransmitters dopamine and norepinephrine, they have also been associated with orthostatic hypotension and hallucinations in some people. Rasagiline metabolizes into 1(R')-aminoindan which has no amphetamine-like characteristics and has neuroprotective properties in cells and in animal models.
It is selective for MAO type B over type A by a factor of fourteen. | 1 | Enantiopure drugs |
The effects of enrichment can be most simply attained in a greenhouse (see for its agricultural use). However, for experimentation, the results obtained in a greenhouse would be doubted due to it introducing too many confounding variables. Open-air chambers have been similarly doubted, with some critiques attributing, e.g., a decline in mineral concentrations found in these -enrichment experiments to constraints put on the root system. The current state-of-the art is the FACE methodology, where is put out directly in the open field. Even then, there are doubts over whether the results of FACE in one part of the world applies to another. | 0 | Greenhouse Gases |
Delapril is a prodrug; it is converted into two active metabolites, 5-hydroxy delapril diacid and delapril diacid. These metabolites bind completely to and inhibit angiotensin-converting enzyme (ACE), hence blocking angiotensin I to angiotensin II conversion. The resulting vasodilation prevents the vasoconstrictive effects of angiotensin II. Angiotensin II-induced aldosterone secretion by the adrenal cortex is also decreased by Delapril, leading to increases in excretion of sodium and therefore increases water outflow. | 1 | Enantiopure drugs |
Levonorgestrel has been studied in combination with androgens such as testosterone and dihydrotestosterone as a hormonal contraceptive for men. | 1 | Enantiopure drugs |
Side effects of dextromethorphan at normal therapeutic doses can include:
A rare side effect is respiratory depression. | 1 | Enantiopure drugs |
The compound is used as a calibrant in gas chromatography when the analytical technique uses mass spectrometry as a detector to identify and quantify chemical compounds in gases or liquids. When undergoing ionization in the mass spectrometer, the compound decomposes in a repeatable pattern to form fragments of specific masses, which can be used to tune the mass response and accuracy of the mass spectrometer. Most commonly used ions are those with approximate mass of 69, 131, 219, 414 and 502 atomic mass units. | 0 | Greenhouse Gases |
The following table lists pharmaceuticals that have been available in both racemic and single-enantiomer form. These single-enantiomer drug switched from the respective racemic drug are referred to as chiral switch.
The following are cases where the individual enantiomers have markedly different effects:
*Thalidomide: Thalidomide is racemic. One enantiomer is effective against morning sickness, whereas the other is teratogenic. However, the enantiomers are converted into each other in vivo. As a result, dosing with a single-enantiomer form of the drug will still lead to both the enantiomers eventually being present in the patients serum and thus would not prevent adverse effects—at best, it might reduce them if the rate of in vivo' conversion can be slowed.
*Ethambutol: Whereas the (S,S)-(+)-enantiomer is used to treat tuberculosis, the (R,R)-(–)-ethambutol may cause blindness.
*Steroid receptor sites also show stereoisomer specificity.
*Penicillin's activity is stereodependent. The antibiotic must mimic the -alanine chains that occur in the cell walls of bacteria in order to react with and subsequently inhibit bacterial transpeptidase enzyme.
*Propranolol: -propranolol is a powerful adrenoceptor antagonist, whereas -propranolol is not. However, both have local anesthetic effect.
*Methorphan: The -isomer of methorphan, levomethorphan, is a potent opioid analgesic, while the -isomer, dextromethorphan, is a dissociative cough suppressant.
*Carvedilol: (S)-(–)-isomer interacts with adrenoceptors with 100 times greater potency as β adrenoreceptor blocker than (R)-(+)-isomer. However, both the isomers are approximately equipotent as α adrenoreceptor blockers.
*Amphetamine and methamphetamine: The -isomers of these drugs are strong central nervous system (CNS) stimulants, while the -isomers lack appreciable CNS stimulant effects, but instead stimulate the peripheral nervous system. For this reason, the -isomer of methamphetamine is available as an over-the-counter nasal inhaler in some countries, while the -isomer is banned from medical use in all but a few countries in the world, and highly regulated in those countries which do allow it to be used medically.
*Ketamine: This drug is available as a mixture of both (S)-(+)-ketamine, also known as esketamine, and (R)-(–)-ketamine, also known as arketamine. Pure esketamine is also available. The two have different dissociative and hallucinogenic properties, with esketamine being more potent in isolation as a dissociative. The two enantiomers have inverse effects on the rate of glucose metabolism in the frontal cortex.
*Dihydroxy-3, 4 phenylalanine (Dopa): Dopa is a racemic mixture where one enantiomer, L-Dopa, is used as a treatment for Parkinson's Disease, and the other enantiomer, D-Dopa is considered to be toxic. D-Dopa can cause headaches, abdominal pains, nausea, vomiting, and dizziness. | 1 | Enantiopure drugs |
*April 8, 1971: Oxacillin Sodium Injectable
**Applicant: Sandoz
*July 27, 1973: Bactocill Capsule
**Applicant: GlaxoSmithKline
*March 10, 1980: Oxacillin Sodium Capsule
**Applicant: Ani Pharms Inc
*May 15, 1980: Oxacillin Sodium for Solution
**Applicant: TEVA
*June 2, 1981: Bactocill for Solution
**Applicant: GlaxoSmithKline
*December 23, 1986: Oxacillin Sodium Powder
**Applicant: Sandoz
*September 29, 1988: Oxacillin Sodium Injectable
**Applicant: Watson Labs Inc
*October 26, 1988: Oxacillin Sodium Injectable
**Applicant: Watson Labs Inc
*October 26, 1989: Bactocill in Plastic Container Injectable
**Applicant: Baxter Healthcare
*March 30, 2012: Oxacillin Sodium Injectable
**Applicant: Sagent Pharms
*January 18, 2013: Oxacillin Sodium Injectable
**Applicant: Aurobindo Pharma LTD
*August 25, 2014: Oxacillin Sodium Injectable
**Applicant: Mylan Labs LTD
*December 11, 2015: Oxacillin Sodium Injectable
**Applicant: Hospira Inc
*July 31, 2017: Oxacillin Sodium Injectable
**Applicant: Wockhardt Bio/Ag | 1 | Enantiopure drugs |
It has also been used as an adjunct infusion during general anesthesia. In this application, it has been shown to decrease post-operative delirium, pain, nausea and opioid use. | 1 | Enantiopure drugs |
Catalytic engineered systems are designed to pass air from the atmosphere, either passively or actively, through catalytic systems which leverage energy from the sun, an artificial light, or heat to oxidize methane. These catalysts include thermocatalysts, photocatalysts, and radicals produced artificially through photolysis (using light to break apart a molecule). | 0 | Greenhouse Gases |
In the late 1960s, John Vane of the Royal College of Surgeons of England was working on mechanisms by which the body regulates blood pressure. He was joined by Sérgio Henrique Ferreira of Brazil, who had been studying the venom of a Brazilian pit viper, the jararaca (Bothrops jararaca), and brought a sample of the vipers venom. Vanes team found that one of the venom's peptides selectively inhibited the action of angiotensin-converting enzyme (ACE), which was thought to function in blood pressure regulation; the snake venom functions by severely depressing blood pressure. During the 1970s, ACE was found to elevate blood pressure by controlling the release of water and salts from the kidneys.
Captopril, an analog of the snake venom's ACE-inhibiting peptide, was first synthesized in 1975 by three researchers at the U.S. drug company E.R. Squibb & Sons Pharmaceuticals (now Bristol-Myers Squibb): Miguel Ondetti, Bernard Rubin, and David Cushman. Squibb filed for U.S. patent protection on the drug in February 1976, which was granted in September 1977, and captopril was approved for medical use in 1980. It was the first ACE inhibitor developed and was considered a breakthrough both because of its mechanism of action and also because of the development process. In the 1980s, Vane received the Nobel prize and was knighted for his work and Ferreira received the National Order of Scientific Merit from Brazil.
The development of captopril was among the earliest successes of the revolutionary concept of structure-based drug design. The renin–angiotensin–aldosterone system had been extensively studied in the mid-20th century, and this system presented several opportune targets in the development of novel treatments for hypertension. The first two targets that were attempted were renin and ACE. Captopril was the culmination of efforts by Squibb's laboratories to develop an ACE inhibitor.
Ondetti, Cushman, and colleagues built on work that had been done in the 1960s by a team of researchers led by John Vane at the Royal College of Surgeons of England. The first breakthrough was made by Kevin K.F. Ng in 1967, when he found the conversion of angiotensin I to angiotensin II took place in the pulmonary circulation instead of in the plasma. In contrast, Sergio Ferreira found bradykinin disappeared in its passage through the pulmonary circulation. The conversion of angiotensin I to angiotensin II and the inactivation of bradykinin were thought to be mediated by the same enzyme.
In 1970, using bradykinin potentiating factor (BPF) provided by Sergio Ferreira, Ng and Vane found the conversion of angiotensin I to angiotensin II was inhibited during its passage through the pulmonary circulation. BPF was later found to be a peptide in the venom of a lancehead viper (Bothrops jararaca), which was a “collected-product inhibitor” of the converting enzyme. Captopril was developed from this peptide after it was found via QSAR-based modification that the terminal sulfhydryl moiety of the peptide provided a high potency of ACE inhibition.
Captopril gained FDA approval on April 6, 1981. The drug became a generic medicine in the U.S. in February 1996, when the market exclusivity held by Bristol-Myers Squibb for captopril expired. | 1 | Enantiopure drugs |
Geostationary Carbon Cycle Observatory (GeoCarb) was an intended NASA Venture-class Earth observation mission that was designed to measure the carbon cycle. Originally intended to be mounted on a commercial geostationary communication satellite operated by SES S.A., a lack of hosting opportunities drove NASA to seek a standalone spacecraft to carry GeoCarb. GeoCarb was to be stationed over the Americas and make observations between 50° North and South latitudes. Its primary mission was to conduct observations of vegetation health and stress, as well as observe the processes that govern the carbon exchange of carbon dioxide, methane, and carbon monoxide between the land, atmosphere, and ocean.
GeoCarb was a joint collaboration between NASA's Ames Research Center, Goddard Space Flight Center, and Jet Propulsion Laboratory; the University of Oklahoma; Colorado State University; the Lockheed Martin Advanced Technology Center of Palo Alto, California; and SES Government Solutions (now SES Space & Defense) of Reston, Florida.
On 29 November 2022, NASA announced the cancellation of development of the GeoCarb mission, citing cost overruns and the availability of other options to measure and observe greenhouse gases, like the EMIT instrument on the ISS and the upcoming Earth System Observatory. | 0 | Greenhouse Gases |
In the United States, Valeant raised the cost of the medication from about US$500 to US$24,000 per month in 2016. | 1 | Enantiopure drugs |
The program motivates companies to disclose and reduce their environmental impacts by using the power of investors and companies. | 0 | Greenhouse Gases |
Henry Cavendish showed that water was composed of oxygen and hydrogen in 1781. The first decomposition of water into hydrogen and oxygen, by electrolysis, was done in 1800 by English chemist William Nicholson and Anthony Carlisle. In 1805, Joseph Louis Gay-Lussac and Alexander von Humboldt showed that water is composed of two parts hydrogen and one part oxygen.
Gilbert Newton Lewis isolated the first sample of pure heavy water in 1933.
The properties of water have historically been used to define various temperature scales. Notably, the Kelvin, Celsius, Rankine, and Fahrenheit scales were, or currently are, defined by the freezing and boiling points of water. The less common scales of Delisle, Newton, Réaumur, and Rømer were defined similarly. The triple point of water is a more commonly used standard point today. | 0 | Greenhouse Gases |
Epicillin (INN) is a penicillin antibiotic. It is not approved by the FDA for use in the United States.
It is an aminopenicillin. | 1 | Enantiopure drugs |
The oral bioavailability of drospirenone is between 66 and 85%. Peak levels occur 1 to 6 hours after an oral dose. Levels are about 27 ng/mL after a single 4 mg dose. There is 1.5- to 2-fold accumulation in drospirenone levels with continuous administration, with steady-state levels of drospirenone achieved after 7 to 10 days of administration. Peak levels of drospirenone at steady state with 4 mg/day drospirenone are about 41 ng/mL. With the combination of 30 μg/day ethinylestradiol and 3 mg/day drospirenone, peak levels of drospirenone after a single dose are 35 ng/mL, and levels at steady state are 60 to 87 ng/mL at peak and 20 to 25 ng/mL at trough. The pharmacokinetics of oral drospirenone are linear with a single dose across a dose range of 1 to 10 mg. Intake of drospirenone with food does not influence the absorption of drospirenone. | 1 | Enantiopure drugs |
Armodafinil exhibits linear time-independent kinetics following single and multiple oral dose administration. Increase in systemic exposure is proportional over the dose range of 50–400 mg. No time-dependent change in kinetics was observed through 12 weeks of dosing. Apparent steady state for armodafinil was reached within 7 days of dosing. At steady state, the systemic exposure for armodafinil is 1.8 times the exposure observed after a single dose. The concentration-time profiles of the (R)-(−)-enantiomer following a single dose of 50 mg Nuvigil or 100 mg Provigil (modafinil being a 1:1 mixture of (R)-(−)- and (S)-(−)- enantiomers) are nearly superimposable. However, the C of armodafinil at steady state was 37% higher following administration of 200 mg Nuvigil than the corresponding value of modafinil following administration of 200 mg Provigil due to the more rapid clearance of the (S)-(+)-enantiomer. | 1 | Enantiopure drugs |
Infections of leg ulcers can be treated with flucloxacillin. With diabetic foot infections the dose is adjusted according to whether the infection appears mild, moderate or severe. | 1 | Enantiopure drugs |
Drospirenone, also known as 1,2-dihydrospirorenone or as 17β-hydroxy-6β,7β:15β,16β-dimethylene-3-oxo-17α-pregn-4-ene-21-carboxylic acid, γ-lactone, is a synthetic steroidal 17α-spirolactone, or more simply a spirolactone. It is an analogue of other spirolactones like spironolactone, canrenone, and spirorenone. Drospirenone differs structurally from spironolactone only in that the C7α acetyl thio substitution of spironolactone has been removed and two methylene groups have been substituted in at the C6β–7β and C15β–16β positions.
Spirolactones like drospirenone and spironolactone are derivatives of progesterone, which likewise has progestogenic and antimineralocorticoid activity. The loss of the C7α acetylthio group of spironolactone, a compound with negligible progestogenic activity, appears to be involved in the restoration of progestogenic activity in drospirenone, as SC-5233, the analogue of spironolactone without a C7α substitution, has potent progestogenic activity similarly to drospirenone. | 1 | Enantiopure drugs |
During World War II, various chloroalkanes were in standard use in military aircraft, although these early halons suffered from excessive toxicity. Nevertheless, after the war they slowly became more common in civil aviation as well. In the 1960s, fluoroalkanes and bromofluoroalkanes became available and were quickly recognized as being highly effective fire-fighting materials. Much early research with Halon 1301 was conducted under the auspices of the US Armed Forces, while Halon 1211 was, initially, mainly developed in the UK. By the late 1960s they were standard in many applications where water and dry-powder extinguishers posed a threat of damage to the protected property, including computer rooms, telecommunications switches, laboratories, museums and art collections. Beginning with warships, in the 1970s, bromofluoroalkanes also progressively came to be associated with rapid knockdown of severe fires in confined spaces with minimal risk to personnel.
By the early 1980s, bromofluoroalkanes were in common use on aircraft, ships, and large vehicles as well as in computer facilities and galleries. However, concern was beginning to be expressed about the impact of chloroalkanes and bromoalkanes on the ozone layer. The Vienna Convention for the Protection of the Ozone Layer did not cover bromofluoroalkanes under the same restrictions, instead, the consumption of bromofluoroalkanes was frozen at 1986 levels. This is due to the fact that emergency discharge of extinguishing systems was thought to be too small in volume to produce a significant impact, and too important to human safety for restriction. | 0 | Greenhouse Gases |
Drospirenone is an antagonist of the MR, the biological target of mineralocorticoids like aldosterone, and hence is an antimineralocorticoid. It has about 100 to 500% of the affinity of aldosterone for the MR and about 50 to 230% of the affinity of progesterone for the MR. Drospirenone is about 5.5 to 11 times more potent as an antimineralocorticoid than spironolactone in animals. Accordingly, 3 to 4 mg drospirenone is said to be equivalent to about 20 to 25 mg spironolactone in terms of antimineralocorticoid activity. It has been said that the pharmacological profile of drospirenone more closely resembles that of progesterone than other progestins due to its antimineralocorticoid activity. Drospirenone is the only clinically used progestogen with prominent antimineralocorticoid activity besides progesterone. For comparison to progesterone, a 200 mg dose of oral progesterone is considered to be approximately equivalent in antimineralocorticoid effect to a 25 to 50 mg dose of spironolactone. Both drospirenone and progesterone are actually weak partial agonists of the MR in the absence of mineralocorticoids.
Due to its antimineralocorticoid activity, drospirenone increases natriuresis, decreases water retention and blood pressure, and produces compensatory increases in plasma renin activity as well as circulating levels and urinary excretion of aldosterone. This has been shown to occur at doses of 2 to 4 mg/day. Similar effects occur during the luteal phase of the menstrual cycle due to increased progesterone levels and the resulting antagonism of the MR. Estrogens, particularly ethinylestradiol, activate liver production of angiotensinogen and increase levels of angiotensinogen and angiotensin II, thereby activating the renin–angiotensin–aldosterone system. As a result, they can produce undesirable side effects including increased sodium excretion, water retention, weight gain, and increased blood pressure. Progesterone and drospirenone counteract these undesirable effects via their antimineralocorticoid activity. Accumulating research indicates that antimineralocorticoids like drospirenone and spironolactone may also have positive effects on adipose tissue and metabolic health. | 1 | Enantiopure drugs |
The combination of piperacillin and tazobactam, commonly branded as Zosyn, improves their overall bactericidal activity as amino-benzylpenicillins and ureidopencillins work synergistically with β-lactamase inhibitors. Concurrent use or unregulated dosages of piperacillin results in increasing levels of piperacillin within the body, prolonging neuromuscular transmission blockages created by non-depolarizing muscle relaxants, and disruptions in urine tests for glucose. Some compounds that may interfere with the bactericidal activity of piperacillin include chloramphenicol, macrolides, and sulfonamides.
Following two studies conducted in 1986 and 2006, piperacillin was found to inhibit the removal of methotrexate in animal kidneys. Furthermore, in the presence of piperacillin-tazobactam, the decay time for methotrexate triples in comparison to the normal half-life, leaving the patient exposed to cytotoxic effects produced by the chemical agent. While penicillin antibiotics generally work synergistically with aminoglycosides by enhancing their penetration of bacterial membranes, they can also work adversely by inactivating them. A reformulation of ethylenediaminetetraacetic acid and piperacillin-tazobactam has produced results showing an increase in their affinity with amikacin and gentamicin in vitro, enabling the process of simultaneous Y-site infusion to occur. However, tobramycin was found to be incompatible as a combination through Y-site infusion. | 1 | Enantiopure drugs |
Lisinopril leaves the body completely unchanged in the urine. The half-life of lisinopril is 12 hours, and is increased in people with kidney problems. While the plasma half-life of lisinopril has been estimated between 12 and 13 hours, the elimination half-life is much longer, at around 30 hours. The full duration of action is between 24 and 30 hours.
Lisinopril is the only water-soluble member of the ACE inhibitor class, and thus has no metabolism by the liver. | 1 | Enantiopure drugs |