Solubility and Dissolution Enhancement of Carvedilol by Solid Dispersion Technique Using Gelucire 50/13

Solid dispersions in water-soluble carriers have attracted considerable interest as a means of improving the dissolution rate and hence possibly bioavailability, of a range of hydrophobic drugs. Inclusion behavior of gelucire 50/13 was studied towards carvedilol, an antihypertensive agent in order to develop mucoadhesive oral dosage form with enhanced dissolution rate and bioavailability, following gelucire carvedilol solid dispersion. The present work was investigated to examine the release of carvedilol from various molecular weight fractions of gelucire solid dispersions. Solid dispersions of carvedilol were prepared in different molar ratios of drug: carrier by using solvent evaporation and melting methods. The physical mixture and solid dispersion (s) were characterized for drug-carrier interaction, drug content, solubility and dissolution rate. The release rate of carvedilol from the resulting complexes was determined from dissolution studies by use of USP dissolution apparatus 2 (paddle method). The physical state and drug: gelucire interaction of solid dispersions and physical mixtures were characterized by X-ray diffraction (XRD), Infra Red Spectroscopy (IR) and Differential Scanning Calorimetry (DSC). The dissolution rate of carvedilol was increased significantly in all of the solid dispersion systems compared to that of the pure drug and physical mixtures. The solid dispersion prepared in the molar ratio of 1:2 by the solvent evaporation method was found to have the fastest dissolution profile.