DISSOLUTION BEHAVIOR OF GRISEOFULVIN SOLID DISPERSIONS USING POLYETHYLENE-GLYCOL, TALC, AND THEIR COMBINATION AS DISPERSION CARRIERS

Griseofulvin solid dispersions were prepared using polyethylene glycol 6000 (PEG), talc, and their combination as carriers by the solvent me thod. The dissolution of griseofulvin from these dispersions was studi ed. It was found that in these carriers the drug dissolution rate was a function of drug loading. The dissolution rate from dispersions prep ared using PEG was similar to that from PEG/talc dispersions, especial ly at a low percentage of drug loading. Dispersions of PEG and PEG/tal c provided dissolution rates faster than those from dispersions of tal c. The incorporation of talc in PEG yielded dispersions with propertie s of less tackiness and ease for handling. Dissolution kinetics, based on the Hixson-Crowell equation, was used to determine the characteris tics of griseofulvin particles in dispersions. Linear relationships we re obtained for PEG and PEG/talc dispersions that indicated the presen ce of a uniformly sized monoparticulate system, whereas deviation from linearity was observed for talc dispersions. This appeared to be a mu ltiparticulate system in which particles were present as free form and adsorbed form on the surface of talc.