Dissolution Enhancement in Nano/Micro-Sized Dispersions of Piroxicam with the Novel Polymer Soluplus® and Polyvinyl Pyrrolidone

Abstract

Piroxicam, a Non-Steroidal Anti-Inflammatory Drug (NSAID), belongs to the class II of the biopharmaceutical classification system (BCS) and thus exhibits poor bioavailability. In an effort to tackle this issue, we report here the comparative properties of the solid dispersions of piroxicam made from a novel graft copolymer of polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol (Soluplus) and the linear polymer polyvinyl pyrrolidone (K 25), both the dispersions synthesized identically using solvent evaporation method. The absence of crystallinity of drug in the solid dispersions was confirmed by Powder X-Ray Diffractometry, and Differential Scanning Calorimetry (DSC). FTIR analysis showed the presence of intermolecular hydrogen bonding between the piroxicam and the polymers. The morphology and the particle size of the dispersions were analyzed with an FESEM. The results obtained from these analyses confirm that the drug is present in amorphous state in the dispersions. The in vitro dissolution characteristics of the tablets made from these powders were studied using the USP paddle dissolution apparatus (type II). The dissolution profiles show that the nanodispersions have higher dissolution rate than that of pure drug.

Keywords: Piroxicam, solid dispersions, dissolution enhancement, polyvinyl pyrrlidone, Soluplus