Development and validation of a HPLC/PDA method for simultaneous quantification of amlodipine besylate and valsartan in dissolution media

Valsartan, an angiotensin blocker, is often combined with amlodipine (a calcium channel antagonist) in the current treatment of hypertension. There is a generic brand-name drug Exforge® which has been proven to be clinically effective. However, its price is high, making it quite difficult to access, especially in low- and middle-income countries. Therefore, research and development of generic drugs is essential.