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.