Quasar™ C18 LC columns, based on ultra high purity silica and manufactured to tight specification, provides high efficiency separations and excellent peak shape for a wide range of compounds. Our methodology to yield high surface coverage enhances the pH stability and extends the working range. If data integrity and high productivity are top priorities for your lab, then this column can support your needs for any application.
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|Inner Diameter||4.6 mm|
|Particle Size||5.0 µm|
|Product Brand Name||Quasar|
Acetaminophen, aspirin and caffeine used in combination are an effective method of treating acute headaches and migraines. The combination of these substances is considered superior to acetaminophen alone in the treatment of headaches. There are other benefits due to the individual components of the tablets. Acetaminophen (also known as paracetamol) is the most common analgesic and antipyretic around the world. It is an effective treatment for acute primary headaches and can be combined with tramadol to treat cluster headaches. Acetaminophen has a very low risk of causing allergic reactions, thus can be used by those with bronchial asthma. Aspirin is a first-line therapy to treat moderate to severe primary headaches as well as reducing pain, fever and inflammation. However, it is not taken by children under twelve due to the risk of Reye syndrome. Caffeine is considered an effective treatment for various types of headaches, including post-dural puncture headaches and hypnic headaches. It also provides an increase in high energy exercise tolerance and reduces fatigue.
These drugs combined are commonly sold under the brand names Anadin Extra in the UK and Excedrin in the U.S. The United States Federal Drug Administration (FDA) recognize the combination of aspirin (250 mg), acetaminophen (250 mg), and caffeine (65 mg) as safe and effective and as an accepted concentration of active compounds in the tablets. Excedrin Migraine tablets contain this combination and in 2019 sold approximately 13.1 million units.
This application brief describes the use of a Quasar™ C18 column for the analysis of acetaminophen, aspirin and caffeine in accordance with the official Acetaminophen, Aspirin, and Caffeine Tablets USP monograph.
Amlodipine besylate belongs to a class of drugs known as dihydropyridine calcium channel blockers. It is primarily used to treat hypertension and angina as well as other conditions which arise as a result of coronary artery disease. As a calcium channel blocker, it prevents diffusion of calcium into cardiac muscle and the smooth muscle of the blood vessels. This causes vasodilation, lower heart contractility and therefore lower blood pressure. In addition, production of nitric oxide (a known vasodilator) increases. Amlodipine is listed on the World Health Organization’s (WHO) list of essential medicines as an antihypertensive medicine, meaning that it considered among the safest and most effective compounds needed to meet the requirements of a basic healthcare system. This application brief describes the use of a Quasar C18 column, using both fully porous and SPP stationary phases, to analyze amlodipine besylate in accordance with the official USP monograph.
Glucocorticoid steroids work by suppressing various aspects of the human immune system in conditions where hyperactivity can cause poor health through allergies, inflammation and autoimmune dysfunction. Betamethasone dipropionate belongs to this class of steroids. It is used for its high potency as an anti-inflammatory and immunosuppressant in the treatment of diseases such as eczema, dermatitis and psoriasis. Betamethasone dipropionate is classified as a ‘super-potent’ steroid in the treatment of psoriasis in comparison with betamethasone valerate (another common analogue of betamethasone) which is rated as upper mid-strength. This application brief describes the use of a Quasar C18 column for the analysis of betamethasone dipropionate in accordance with the official USP monograph.
In recent years there has been an increase in interest regarding 'AQ' columns due to their ability to retain polar analytes reproducibly under high aqueous conditions and with no phase collapse as a traditional C18 column would exhibit. There are two general approaches to the bonded phase chemistry of AQ columns. The first is to employ a polar or hydrophilic end-capping. The second method is to incorporate polar-embedded groups within the alkyl chains. These two methods provide a high degree of polar character to the final alkyl bonded phase, allowing full interaction with the alkyl chains upon wetting the silica surface with water. Additionally, the added polar functionality introduces a secondary separation mechanism (dipole-dipole interactions) to facilitate alternative selectivity for polar compounds. This application brief describes the use of Quasar™ C18, AQ and AQ Plus columns for the analysis of polar compounds, outlining the benefits of stationary phases offering alternative selectivity.
Finasteride is an antiandrogenic compound or ‘testosterone blocker’ which is used as a treatment for an enlarged prostate and can treat male hair loss. It inhibits the production of the enzyme Type-II 5a-reductase which converts testosterone into the more active metabolite 5a-dihydrotestosterone (DHT). DHT is responsible for the development and enlargement of the prostate and can contribute to hair loss by shortening hair follicles and causing them to fall out more quickly. By suppressing production of DHT, finasteride directly targets the molecule responsible for stimulation of prostatic growth. Finasteride is commonly sold under the brand name Proscar and in 2016 was the 75th most prescribed drug in the USA. This application brief describes the use of a Quasar C18 column to analyze finasteride in accordance with the official Finasteride Tablets USP monograph.
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.
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.
Clotrimazole is an azole anti-fungal medication used primarily in the treatment of a wide range of fungal dermal infections. Examples include thrush, athlete’s foot and ringworm. It has limited oral absorption and is commonly available in various topical preparations, including creams, lotions, and solutions. As well as its anti-fungal activity, clotrimazole has become a drug of interest in the treatment of sickle cell disease, malaria and some cancers. Clotrimazole 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 PerkinElmer Quasar™ C18 (150 x 4.6 mm, 5 µm) column in comparison with a GL Sciences Inertsil ODS-3 (150 x 4.6 mm, 5 µm) column for the analysis of clotrimazole, conducted by a pharmaceutical company in Chile.
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.
Retinol, one of the main forms of vitamin A, is regularly used in the treatment and protection of skin. By inducing the biosynthesis of collagen and promoting skin cell production, retinol helps to reduce the signs of early UV-induced skin aging. Retinol is also an anti-oxidant, allowing it to neutralize free radicals that may damage healthy skin cells. HPLC with UV detection is commonly used to assess and quantify retinol in a variety of samples.3 This application brief describes the use of a Quasar C18 column for the rapid analysis of retinol.
The most commonly used LC reversed-phase alkyl bonded stationary phase is octadecyl carbon chain (C18)-bonded silica, which is denoted as USP classification L1. C18 columns have a broad applicability from pharmaceuticals to food and environmental analyses. However, not all C18 columns are alike. Simply swapping a C18 column from one manufacturer to another can result in differences in retention time, resolution and even selectivity. Differences can arise due to variations in hydrophobicity, silanol activity, packing quality, particle size distribution, and silica purity, to name a few.
This technical note provides details of a comparative study between twenty-four silica-based C18 phases, from a number of manufacturers covering the following areas:
The most commonly used LC reversed-phase alkyl bonded stationary phase is octadecyl carbon chain (C18)-bondedsilica, which is denoted as USP classification L1. C18 columns have a broad applicability from pharmaceuticals to food and environmental analyses. However, not all C18 columns are alike. Simply swapping a C18 column from one manufacturer to another can result in differences in retention time, resolution and even selectivity. Differences can arise due to variations in hydrophobicity, silanol activity, packing quality, particle size distribution, and silica purity, to name a few.1
This technical note provides details of a comparative study between PerkinElmer Quasar™ C18 and GL Sciences Inertsil ODS-3 silica-based columns (150 x 4.6 mm, 5 µm), covering the following areas:
Salbutamol (also known as albuterol) is a bronchodilating agent which is ubiquitously used in the treatment of asthma and chronic obstructive pulmonary disorder (COPD). It is a polar hydrophilic compound (see Figure 1) which can be problematic when analyzing using reverse phase HPLC. Polar compounds can elute very close to the solvent front. It is therefore ideal for an eluting compound to have a capacity factor (k) between 1 and 10. Polar compounds with poor retention can have k values close to zero. Analyses with this level of retention are not reproducible and so it is important to increase the affinity that polar compounds have for the stationary phase. The technical note investigates the impact on retention of salbutamol by changing the chemistry of the stationary phase. When analyzing salbutamol in accordance with the British Pharmacopeia, the monograph stipulates the use of 'end-capped octadecylsilyl silica gel for chromatography (5 µm)'. This definition does not specify the type of end capping giving scope to the evaluation of different stationary phase whilst still adhering to BP requirements. Salbutamol sulfate was analyzed according to the British Pharmacopeia monograph: Salbutamol Pressurised Inhalation, Suspension. This analysis was performed on four Quasar columns: C18, AQ, AQ Plus and SPP C18/PFP in order to obtain the maximum improvement in the retention of salbutamol.