Degradation Kinetics of Diltiazem

AbstractThe kinetics of degradation of diltiazem hydrochloride in aqueous buffered solutions (pH 1-7) were studied. Diltiazem was found to undergo hydrolysis to desacetyldiltiazem. The decomposition of diltiazem followed pseudo-first order kinetics under the experimental conditions. The drug was relatively stable over the pH range 3-6 with optimum stability at pH 5. The extrapolated shelf-life at this pH was 42.0 days compared to 15.8 day at pH 2.