Effect of different polymeric dispersions on In-vitro dissolution rate and stability of celecoxib class II drug

Abstract

Solid dispersions can play a significant role in the enhancement of drug dissolution and stability. Still, the polymeric effect can vary according to the possibility of intermolecular forces with the drug. The objective of this study was to evaluate the effect of several polymers on enhancement in-vitro dissolution behavior of celecoxib; in addition to comparing prepared dispersions with selected commercial products. Solid dispersions of celecoxib were prepared with different ratios between the drug and selected polymer (Soluplus®, polyvinyl pyrrolidine, Chitosan, polyethylene glycol). Physicochemical characterizations were performed using Powder X-ray diffraction, Differential Scanning Calorimetry, Fourier Transform Infra-Red analysis and Scanning Electron Microscopy. Dispersions were subjected to in-vitro drug release studies. Results revealed enhancement in dissolution rate for all dispersions prepared except for Chitosan-based dispersions that showed clear retardation in the drug release. Prepared dispersions from other polymers succeeded to match with release profile of two commercially marketed products (Celebrex® and Flamex®). Further Characterization of Chitosan dispersions revealed presence celecoxib in its crystalline form entrapped inside Chitosan carrier with the presence of two hydrogen bonding between Chitosan and celecoxib. Although both Polyvinylpyrrolidone, and polyethylene glycol dispersions showed a great enhancement in drug release; both failed to maintain stability. Sticky paste formation occurred to dispersions, and recrystallization took place in polyethylene glycol dispersions.