Effects of starch pre-gelatinization on the physicochemical and tableting properties of a co-processed excipient for direct compression

Background: Development of new molecules as excipients is costly and time consuming, hence a shift towards modifying already existing excipient via co-processing. Objective: The study aimed to evaluate the effects of starch pre-gelatinization on co-processed Ipomoea batatas starch in directly compressed diclofenac and paracetamol tablet formulations. Methods: Starch from Ipomoea batatas was extracted following standard procedure. Co-processing was carried out by co-dispersion of native starch (Excipient X) or pre-gelatinized starch (Excipient Y) with lactose and polyvinylpyrrolidone. The resulting excipients were subjected to physicochemical evaluation and interaction studies using Fourier transform infrared (FTIR). Tablet formulations of diclofenac and paracetamol were prepared by direct compression and evaluated for mechanical and in vitro dissolution properties. Results: Excipients X and Y exhibited excellent flow properties. Swelling and hydration capacities (9.10 mL and 5.98 g/g, respectively) were significantly higher in Excipient Y than in Excipient X (9.10 mL and 5.98 g/g, respectively) but the moisture content of Excipient X was more than two times (17.52%) that of Excipient Y (7.94%). FTIR revealed no interaction between the co-processed excipients and the drugs. Excipient Y impacted better mechanical properties on the tablets and superior disintegration properties in both tablet formulations. In vitro drug release was faster from tablets produced with Excipient Y than those produced with Excipient X. Conclusion: Co-processed pre-gelatinized Ipomoea batatas starch elicited superior mechanical, disintegration and drug release properties over its native counterpart in directly compressed diclofenac and paracetamol tablets.