Formulation and Characterization of Carvedilol In situ Gels for Oral Delivery-In vitro and In vivo Pharmacokinetic Studies

Abstract

Abstract The purpose of the study is to develop floating in situ gelling oral delivery system of carvedilol. Before formulating into in situ gels, carvedilol was first made into solid dispersions to enhance its solubility. The solvent evaporation method was employed for making solid dispersions. Drug content, solubility, dissolution, SEM, DSC, and XRD studies were done for solid dispersions. In situ gel formulations were prepared using the optimized solid dispersion formulation. Sodium alginate and HPMC K100M were used as gelling agent and viscosity enhancing agent respectively. In vitro characterizations like gelling capacity, floating time, drug content, viscosity, and % cumulative drug release studies were done. In vivo pharmacokinetic parameters like Cmax, Tmax, half-life, AUC, AUMC, and MRT were studied. FTIR studies ruled out any drug-excipient interactions. The drug release pattern showed a burst effect in the first 30 minutes then followed by a steady release for 12 hours. Stability data indicated that the formulation remained stable with no significant changes in drug content, viscosity, and percent cumulative drug release upon storage. In vivo pharmacokinetic study results were found to be satisfactory. A stable, sustained release, liquid oral floating in-situ gelling systems of carvedilol were successfully formulated and evaluated. GRAPHICAL ABSTRACT