The formation of solid dispersions is an effective method of increasing the dissolution rate of poorly soluble drugs, and hence, of improving their bioavailability. The carrier fusion method was used to prepare different solid dispersions of carbamazepine with two types of Gelucires (44/14 and 50/13). The physical characteristics of the binary systems were determined by hot-stage microscopy, differential scanning calorimetry, X-ray powder diffractometry and diffuse reflectance infrared Fourier transform spectroscopy. Finally, in vitro dissolution was evaluated. The dissolution kinetics showed that both Gelucires were able to effect a remarkable increase in the dissolution rate of carbamazepine, even with a small proportion of carrier. The improved dissolution of the drug could be attributed to the reduction in its particle size and its increased wettability when the polymer is dissolved.
