Dissolution Profiles of a Few Sustained Release Preparations Containing .BETA.-Blockers.

Abstract

Dissolution profiles of a few sustained release preparations containing $-blockers were examined in media of various pH.Dissolution patterns of carteolol from Mikelan-LA tablets were found to be independent of pH values of media,while those from sustained release products containing pindolol depended on pH values of media.The latters consisted of pH-independent fast dissolving part and pH-dependent sustained release part.There were also difference in dissolution rates among brands.In Blocklin-L capsule,apparent dissolution rates of pindolol at pH 5.0-6.0 exceeded those at the first and second dissolution media of JP XII when UV absorbance was measured.Its dissolution rates measured by HPLC were found to be smaller than those measured by UV absorbance.Some material(s) was likely to be dissolved in dissolution media from capsule ingredients which exhibited UV absorption only at pH 5.0-6.0.