Formulation and Optimization of Immediate Release Cajanus Cajan Starch-Based Tablets Containing Metronidazole

Starch is found almost in all organs of plants as a carbohydrate reserve. It is considered one of the most commonly used pharmaceutical additives, mainly in tablet dosage forms; it used as a tablet binder when incorporated through the wet granulation process or as a disintegrant. Cajanus cajan has a high level of carbohydrate, which makes it another potential choice as a source for starch. This study aims to investigate and optimize the effect of Cajanus cajan starch concentrations as well as wet massing granulation time on physicochemical properties of metronidazole tablets. The hardness, friability percentage, and disintegration time of prepared tablets were determined, and the central composite design was employed in the optimization process. Then the tablets of optimized batch were compared against those tablets in which maize starch and sodium starch glycolate were used instead of Cajanus cajan starch. The results indicated that metronidazole tablets containing the upper level of starch paste (Cajanus cajan and/or maize starch paste) exhibited better percentage friability, hardness, and disintegration time than those formulated with lower levels and those without starch paste. The study showed that experimental design is a useful technique for optimizing Cajanus cajan starch-based tablets, which enabled a better understanding of how different variables could affect the responses. In addition, the study demonstrated that incorporation of Cajanus cajan starch in tablets formulation led to improvement of its physical properties compared to the formulations of maize starch and sodium starch glycolate respectively.