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Statins are a group of medicines that can help lower the level of low-density lipoprotein (LDL) cholesterol in the blood and help prevent cardiovascular disease. LDL cholesterol is often referred to as "bad cholesterol", and statins reduce its production in the liver by competitively inhibiting HMG CoA reductase, an enzyme involved in cholesterol synthesis. The origin of simvastatin can be found as far back as the 1950’s, when scientists at Merck were researching the biosynthesis of cholesterol. But it was the isolation of HMG CoA reductase by Japanese biochemist Akira Endo whose research into the relationship between fungi and cholesterol biosynthesis was the springboard for the development of the synthetic statin Simvastatin, marketed under the trade name of Zocor. This application brief describes the robust HPLC analysis of the polar compound Simvastatin using a gradient which reaches 100% aqueous conditions.
Omeprazole belongs to a class of drugs known as Proton Pump Inhibitors (PPI’s). It is used in the treatment of conditions relating to overactive stomach acid such as gastroesophageal reflux disease, peptic ulcers and Zollinger-Ellison syndrome. The World Health Organization regards omeprazole among its ‘List of Essential Medicines’ which outlines the most effective and safest medicines required by a countries healthcare system to meet its needs. Omeprazole is a very commercially important drug, being ranked as the 7th most prescribed drug in the USA in 2017 with over 58 million prescriptions. This application brief describes the use of a Quasar C8 column for the analysis of omeprazole in accordance with the United States Pharmacopoeia (USP) monograph.
In 1906, English biochemist Sir Frederick Gowland Hopkins also discovered that certain food factors were important to health. All the vitamins we recognise today were discovered during the early 20th century. There are two groups of vitamins, fat soluble and water soluble. Both types are regarded as essential for normal growth and our overall well being. Vitamin B2 (Riboflavin) and vitamin B3 (Niacinamide) are water soluble vitamins, naturally occurring in a number of food stuffs including milk and eggs. Both vitamins are used as dietary supplements and can help lower cholesterol, prevent migraines. Hydrophilic interaction liquid chromatography (HILIC), as first suggested by Alpert in 1990 provides an alternative approach to effectively separate small polar compounds, on polar stationary phases, which are not well retained under reversed phase conditions. Water is the strongest solvent in HILIC and as mobile phases typically contain low levels of water the resulting methods are ideally suited for MS applications. This application brief illustrates the efficient separation of vitamin B2 and B3 applying the HILIC mode of separation using the Quasar SPP HILIC column.
The medication known as Plavix is an antiplatelet drug which prevents platelets in your blood from sticking together to form an unwanted blood clot, that could block an artery. It is used to lower the risk of having a stroke, or serious heart problem after you've had a heart attack, or aid with circulation problems as it helps to keep blood flowing smoothly in the body. The patent expired in 2012 and the drug is now also sold under many generic brands. Plavix tablets contain the active ingredient clopidogrel hydrogen sulphate, which is readily analysed by HPLC. This application brief describes use of a Quasar C8 column in the analysis of Plavix.
The aerobic mold which yielded cephalosporin C was found in the sea near a sewage outfall nearby Cagliari harbour, Sardinia, by the Italian pharmacologist Giuseppe Brotzu in July 1945. Since their discovery and subsequent commercialization in 1964, the cephalosporins today are broad-spectrum ß-lactam antibiotics used for the treatment of a number of bacterial conditions including septicaemia, pneumonia and meningitis. The pharmacology of cephalosporins is similar to that of the penicillin class of compounds. This application brief describes use of a Quasar biphenyl column in the analysis of several cephalosporins, a mixture of first and second generation ß-lactam antibiotics.
Today, Warfarin is the most widely used anticoagulant in the world, used to thin the blood and prevent clots.1 It was discovered by chance when in the 1920’s cattle in the US were found to be bleeding to death having eaten mouldy hay from sweet clover crops.2 However, the exact identity of the substance causing the haemorrhaging was to remain unknown for many years. Over the coming years studies of the spoiled hay eventually led to the extraction of a compound which was later named dicoumarol. It was observed that this dicoumarol could not act as an anticoagulant on its own. It was only after it was metabolised byfungi that it exhibited anticoagulant properties. This explained why only spoiled hay caused the outbreak in the cattle. After further research, the synthesis of a more potent anticoagulant from dicoumarol, warfarin, was produced. Warfarin first commercial use was as a rat poison in 1948, followed by license for human use in 1953. This application brief illustrates the analysis of warfarin, Figure 1, using the Quasar AQ liquid chromatography phase.
Naproxen is a nonsteroidal anti-inflammatory drugs (NSAIDs) used to treat certain types of arthritis and other acute inflammatory conditions. It was first released to the prescription drug market in 1976 under the name Naprosyn. Then a few years later its counterpart salt, naproxen sodium, was released for prescription use and is used predominately in formulations today. The HPLC analysis of Naproxen on a porous silica C18 column is well documented in the literature. However, with the current trend in liquid chromatography being towards higher kinetic efficiency and shorter analysis time the subsequent development in column technology has realised that, without the need to change instrumentation. This application brief will illustrate the application of a superficially porous particles (SPP) column for the analysis of naproxen.
The origin of statins dates back to the mid 1970’s when the Japanese biochemist, Akira Endo, isolated a factor from the fungus Penicillium citrinum which he identified as a competitive inhibitor of 3-hydroxy-3-methylglutarylcoenzyme A reductase (HMG-CoA reductase). This substance, which he named compactin or mevastatin, was the first statin to be administered to humans. Statins competitively inhibit HMG-CoA reductase, an enzyme involved in cholesterol synthesis, especially in the liver. Used to prevent cardiovascular disease and to lower cholesterol levels, atorvastatin is one of a number of synthetic statins routinely produced. It is now the most commonly prescribed statin medication. This application brief describes the robust HPLC analysis of the polar compound atorvastatin using a gradient which reaches 100% aqueous mobile phase conditions.
Prednisolone, Prednisone and Cortisone are commonly used steroids to treat a range of inflammatory conditions and autoimmune disorders. These synthetic derivatives of hydrocortisone were developed and approved for medicinal use as early as the 1940’s. American chemists first identified Cortisone as having a therapeutic benefit in the treatment of rheumatoid arthritis and it was commercialized by Merck in 1948. The first commercially feasible synthesis of prednisone was carried out in 1955 in the laboratories of the Schering Corporation. A C18 HPLC column can be used for the analysis of these synthetic steroids, but they are not well retained, and resolution is incomplete. This application brief will look at the differences in chromatography between the Quasar C18 and AQ phase chemistries for the analysis prednisolone, prednisone and cortisone.
Fluconazole is an azole anti-fungal medication used primarily in the treatment of a wide range of fungal infections. Examples include thrush, urinary tract infections and the prevention of fungal infections in immunocompromised patients undergoing chemotherapy. The mechanism of action can be described as fungistatic, the growth and replication of fungi is inhibited by fluconazole rather than directly attacked. This process is achieved by inhibiting enzymes which are important in the production of fungal membranes, allowing the immune system ample opportunity to target and degrade the pathogen. Fluconazole has generic status and is thus globally produced and prescribed. It is on the World Health Organization’s (WHO) list of essential medicines, which serves as a model of the safest and most effective medications needed by a health system. This application brief describes the use of a Quasar C18, on both porous silica and SPP silica phases, for the analysis of fluconazole in accordance with the official USP monograph.
Metformin belongs to a class of drugs known as biguanides and contains the active ingredient metformin hydrochloride. Metformin oral tablets are used, in combination with diet and exercise, to treat high blood glucose levels in patients with type 2 diabetes mellitus. Tablets are often used as monotherapy, or in combination with other anti-diabetic agents or insulin.
This application brief describes the use of a Quasar C18 column for the analysis of metformin hydrochloride RS in accordance with Dissolution Test 3 in the United States Pharmacopoeia (USP) monograph for metformin hydrochloride tablets.
Paracetamol, also known as acetaminophen, is an analgesic/antipyretic drug, that reduces fever and pain and is ubiquitous in treating these symptoms. Providing relief for these common symptoms combined with the fact that paracetamol is very well tolerated (in comparison with other analgesics such as aspirin) go towards explaining why it is so widely used. Paracetamol has generic status with many manufacturers making it a commercially important compound. Despite being so widely used the mechanism of action of paracetamol is not fully known. It has been shown to interact with same enzymes as non-steroidal anti-inflammatory drugs, but exclusively in the central nervous system as oppose to the periphery. This application brief describes the use of a Quasar C8 for the analysis of paracetamol adapted from the official USP monograph.
Vitamin C, also known as ascorbic acid and L-ascorbic acid, is a water soluble vitamin found in various foods including peppers, kiwifruit, oranges and kale. It is regarded as an essential nutrient to prevent scurvy, involved in the repair of tissue and also thought to lower cancer risk. It is required for the functioning of several enzymes and is important for immune system function. Since it’s isolation in 1928 it was the first vitamin to be commercially produced. Today it is widely available as a dietary supplement. This application brief describes use of a Quasar biphenyl column in the analysis of vitamin C.
Ciprofloxacin was the first fluoroquinolone brought to the market, in 1987, and represented an important medical breakthrough driving further research into this new class of antibiotics. It was developed in 1981 by Bayer and is currently the most potent of available fluoroquinolones. A broad-spectrum antibiotic it is used to treat several bacterial infections. Literature citations reference the use of a C18 HPLC column. However, due to the aromatic functionality with ciprofloxacin it makes it an ideal candidate for the application of a phenyl based stationary phase. This application brief describes use of a Quasar biphenyl column in the analysis of the synthetic antibiotic ciprofloxacin.
Ibuprofen belongs to the class of compounds known as Nonsteroidal Anti-inflammatory Drugs (NSAIDS) which are used in the treatment of pain, fever and various types of inflammation. NSAIDS work by inhibiting the synthesis of a wide range of prostaglandins produced as a response to injury, strain or illness. Since its introduction in 1969, its tolerability and effectiveness have made it one of the most popularly prescribed/taken medications in the world, with over 24 million prescriptions in the U.S. alone. Ibuprofen has generic status with many manufacturers, making it a very commercially important compound. Projections have estimated a global market value of ibuprofen to be 294.4 million USD in 2020, with an estimated value of 447.6 million USD by 2026. This application brief describes the use of a Quasar C18, on both porous silica and SPP silica phases for the analysis of ibuprofen in accordance with the official USP monograph, specifically, the chromatographic purity section.
Opiates, originally derived from the opium poppy, have been used for thousands of years for both recreational and medicinal purposes.