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.