Development of Dissolution Medium for Candesartan Cilexetil by RP-HPLC Method

The present study deals with the dissolution of an angiotensin II receptor antagonist drug, candesartan. Candesartan cilexetil is a poorly water-soluble prodrug. The in vitro dissolution testing of Candesartan cilexetil in water and buffer solutions is not possible. In the present study, an attempt was made to develop a dissolution medium for in vitro testing of the drug. A Kromacil C18, 5µm column having 150x4.6 mm internal diameter in isocratic mode with mobile phase containing mixture of buffer (pH 4.5) and acetonitrile in ratio of 45:55 was used. The flow rate was 1.5 mL/min and effluents were monitored by UV at 257 nm. The selection of the medium was made on the basis of solubility data of Candesartan cilexetil in different dissolution medium at 37 °C. Solubility data revealed that phosphate buffer (pH 6.5) consisting of 0.35% w/v tween 20 could be a suitable dissolution medium. Key words: Candesartan, solubility, buffer, dissolution.