Evaluation of the effects of co-processed Manihot Esculenta starch on the tablet properties of directly compressed diclofenac and paracetamol formulations

Abstract

Advancements in tablet manufacture has increased the demand for versatile excipients with multifunctional applications. Co-processing is fast evolving into the tool for development of these excipients with unique functional properties. The aim of this study is to evaluate the effect of co-processed Manihot esculenta starch and povidone on tablet properties of diclofenac and paracetamol formulations. Starch extracted from Manihot esculenta tubers was modified either by pre-gelatinization or gelatinization and then co-processed by co-dispersion with povidone to yield EXP-A and EXP-B respectively. The developed excipients were assessed for their flow properties, moisture contents, swelling indices, hydration capacities and particle densities. The co-processed excipients and a physical mixture of the excipients were incorporated into diclofenac and paracetamol tablet formulations by direct compression. The tablets were evaluated for uniformity of weight, hardness, friability, disintegration time and in vitro drug release. Possible drug-excipient interaction was also investigated by Fourier Transform Infrared Spectroscopy (FT-IR). Results showed that EXP-B possessed better flow properties, higher swelling index and hydration capacity and lower moisture content than EXP-A. All the tablets had uniform weights, tablet hardness was between 4.5 and 11 kp; tablets containing higher amounts of EXP-A or EXP-B had higher hardness. Friability was between 0.45 and 4.02 with tablets containing EXP-A having lower values than the other batches. Disintegration time was between 1.45 and 12.77 min with tablets containing unmodified starch in both formulations having the least values. Dissolution profile was similar for tablets containing co-processed excipients. Co-processing starch from Manihot esculenta tubers with povidone produced robust tablets which may be better suited for modified-release tablet formulations.