Enhancement of solubility and dissolution rate of indomethacin with different polymers by compaction process

The purpose of this study was to develop a compaction technique to enhance the solubility, dissolution rate and other physicochemical properties of poorly water-soluble drug indomethacin (IM) with different polymers. The IM was compacted with the different polymers like hydroxy propyl methylcellulose (HPMC), Kollicoat IR, Chitosan, Polyvinyl Pyrrolidone without using any binder and solvent. Polymer and drug were dry-blended, compressed into slugs on a tablet press, and then milled into a granular powder. Dissolution testing of the milled compacted granules were performed in 750 ml dissolution medium at 37°C (n = 6) and at a stirring speed of 100 rpm using six-station USP type-I dissolution apparatus. The compaction processes enhanced drug dissolution rate relative to drug alone and physical mixtures of IM and polymers. The compaction method produced granules with comparable solubility, dissolution and flowability enhancement compared to raw IM. The mechanism for dissolution enhancement is believed to be a microenvironment polymer surfactant effect facilitated by keeping the polymers and drug particles in close proximity during drug dissolution. The compaction method may provide a lower cost, quicker, readily scalable alternative for formulating poorly water-soluble drug substances.