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