Optimization of Pregelatinized Taro Boloso-I Starch as a Direct Compression Tablet Excipient

Background. Tablets are still the most preferred means of drug delivery. The search for new and improved direct compression tablet excipients is an area of research focus. This is because the direct compression method overcomes the drawbacks of granulation methods of tablet production. It exempts several treatment steps associated with the granulation methods. The requirements for the powders to be directly compressible include flowability, low friction tendency, compressibility, and fast disintegration capacity. Taro Boloso-I is a new variety of Colocasia esculenta (L. Schott) yielding 67% more than a previously reported variety (Godare) in Ethiopia. This study is aimed at enhancing the flowability while keeping the compressibility and compactibility of the pregelatinized Taro Boloso-I starch. Methods. Central composite design was used for the optimization of two factors which were the temperature and duration of pregelatinization against 4 responses. The responses were angle of repose, Hausner's ratio, Heckel's yield pressure, and tablet breaking force. Results and Discussions. An increase in the temperature resulted in decrease in both the angle of repose and the Hausner ratio and that of time decreased angle of repose as well. The Heckel yield pressure was observed to increase with increasing levels of both temperature and time. The pregelatinized starch prepared by heating 15% slurry of Taro Boloso-I starch at the pregelatinization temperature of 66.22 degrees C for 20 min showed desired flow property and compressibility. Conclusions. Pregelatinized Taro Boloso-I starch could be regarded as a potential direct compression excipient in terms of flowability, compressibility, and compactibility. The PGTBIS could perform better as filler and binder in direct compression tablets than the Starch 1500 (R) in terms of compactibility.