Establishment of a BioequivalenceIndicating Dissolution Specification for Candesartan Cilexetil Tablets Using a Convolution Model

The aim of the present work was to establish a bioequivalence-indicating dissolution specification for candesartan cilexetil tablets.The discriminating power of the selected medium (0.25% Polysorbate 20 in pH 6.5 phosphate buffer) was assessed relative to that of 0.35% Polysorbate 20 in pH 6.5 phosphate buffer, a medium recommended by the U.S. FDA.Plasma concentration-time profiles of candesartan cilexetil tablets were derived from in vitro dissolution data by a convolution model.In solubility studies, 0.25% Polysorbate 20 in pH 6.5 phosphate buffer provided sink conditions for candesartan cilexetil 16-mg tablets.The method was more sensitive to the concentration of Polysorbate 20 than to paddle rotation speed and was able to distinguish depressed dissolution of mismanufactured tablets in samples taken at 20-and 30-min intervals.Verification of the model performed on innovator samples revealed the closeness of the predicted C max and AUC 0-α values to the reported values.A two-point dissolution specification is proposed for post-approval changes, and a one-point dissolution specification for quality control release of production batches.