PHYSICOCHEMICAL AND TABLET PROPERTIES OF CO-PROCESSED STARCH WITH DIFFERENT GRADES OF PVP AS DIRECT COMPRESSION EXCIPIENT

Abstract

Co-processed excipients with combination of two or more existing excipients at sub-particle level interaction
will provide a means of developing high functionality excipients it is one of the most widely method for
preparing directly compressible excipients. The main aim of this study was to evaluate the flowability
compressibility, compactibility tablet ability and disintegration properties of tablets produced by direct
compression of co-processed maize starch and polyvinyl pyrollidone using metronidazole as active ingredient.
Different excipients were produced by co-fusion of maize starch and polyvinyl pyrollidone. Subsequently, the
co-processed excipients were assessed for physicochemical parameters mean particle size, angle of repose, flow
rate bulk, tapped densities Carr’s index, Hausner’s ratio, moisture content. The co-processed excipients (49%)
were mixed with metronidazole (50%) and magnesium stearate (1% w/w) and directly compressed into 400mg
tablets using a single punch tableting machine at 7 MT. The tablets formed were kept for 24hr to allow for
elastic recovery and subsequently evaluated for weight uniformity, disintegration time and in-vitro drug release.
Results obtained showed that maize starch has poor flow characteristics but improved when co-processed with
different grades PVP based of indices of angle of repose (27°-45°) and Hausner’s ratio (0.76-1.6). All batches of
tablets released 50% and 90 % of the drug in less than 10 and 15min respectively. The results indicate that the
batches of co-processed maize starch and PVP exhibit excellent powder characteristics (compressibility and
flowability) and good disintegrant properties (disintegration time of less than 4 minutes).