ABSTRACT
During the process of consistency evaluation, it was found that the consistency of drug release between generic and original brands in vitro was not sufficient to demonstrate their same release in vivo. The disintegration of tablets, as a premise for the release of tablet drugs, greatly affects the release of drugs, depending on the structure and properties of disintegrants. Hence the systematic research on disintegrants would be very important for the evaluation of generic consistency. In this experiment, the physicochemical properties and application of 11 different sodium carboxymethyl starch (CMS-Na) from 9 manufacturers were investigated. This provides the reference for selection of excipients for consistency evaluation. The particle morphology of CMS-Na was observed by scanning electron microscope. The particle size distribution was determined by dry particle size analyzer. The determination of pH and loss on drying was carried out according to the 2015 edition of Chinese pharmacopoeia method. The powder fluidity was evaluated with Carr's index, Hausner ratio and angle of repose. The disintegration performance of CMS-Na was evaluated through determining the water absorption and swelling. The disintegration effect of CMS-Na tablets was studied using lactose and microcrystalline cellulose as fillers. The results showed that pH values and weight loss on drying of all samples met the requirements, whereas the particle morphology, fluidity, water swell-ability and disintegration time had a large variation, which leads to the large differences the properties of CMS-Na depending on the sources. Therefore in order to ensure that the reproducibility of generic drugs from their name brand, our studies indicate that only a sizable choice of disintegrants could ensure good inter batch reproducibility.