Preliminary investigations in matrix-based tablet formulations of diltiazem hydrochloride containing succinic acid-treated methylcellulose.

The feasibility of using succinic acid-treated methylcellulose in matrix-based tablets of diltiazem hydrochloride was investigated in this study. A 2(3) factorial design was employed to investigate the effect of ratio of methylcellulose to succinic acid, amount of ethyl alcohol, and drying time on the percentage drug dissolved in 300 min. The tablets were prepared by wet granulation technique. The ratio of methylcellulose to succinic acid was found to significantly influence the swelling and gelling characteristics of the polymer. Carbonyl peak was found in the infrared (IR) spectra of the samples modified using succinic acid, suggesting the presence of an ester group. The results of an ANOVA test revealed that the significance of the ratio of methylcellulose to succinic acid and drying time was greater in magnitude than that of amount of alcohol in controlling the drug release in 300 min. The results of F-test revealed that the zero-order model fits well to the in vitro dissolution data. The characteristics of methylcellulose can be changed by reacting it with succinic acid and the resultant product can be used as a hydrophilic matrixing agent.