Development of Modified-Release Diclofenac Sodium Capsules Using Blends of Pectin-Clay Multiparticulate Hybrid Systems as Release Retardants

A combination of inorganic and organic hybrid systems is of high research interest as they provide novel hybrid systems for the improvement of existing properties, overcoming limitations of the parent materials, and for the optimization of their controlled release potential. This study sorted to develop and pharmaceutically assess the release profile of diclofenac sodium using cocoa pod husk (CPH) blended with different proportions of either talc or bentonite as multiparticulate composite release modifiers. Preformulation investigations of the multiparticulate hybrid systems included pH, swelling index, moisture content, elemental contents, and flow properties. The FTIR was also used to investigate the compatibilities between pectin and bentonite (PB), pectin and talc (PT), and diclofenac and pectin-talc (DPT), as well as diclofenac and pectin-bentonite (DPB). The diclofenac content, uniformity of the weight of capsules, in vitro drug release, and the kinetics and mechanism of release of diclofenac from the hybrid systems were also investigated using mathematical models. The pectin yield was 23.3%, with the water-holding capacities of pectin-talc (PT) and pectin-bentonite (PB) hybrid systems being 6.4% and 5.0%, respectively. The swelling indices of PT and PB were 110.0 and 130.0 in 0.1 M HCL at pH 1.2 and 130.0 and 149.0 in phosphate buffer at pH 6.8, respectively. This system was also found to exhibit excellent flow properties, and there were no diclofenac-excipient interactions. All formulated batches passed the pharmacopoeial and nonpharmacopoeial tests. They also demonstrated controlled release properties via different release kinetics and mechanisms. This study shows that the pectin-talc and pectin-bentonite multiparticulate composites could be used as release modifiers in pharmaceutical preparations.