Rofecoxib-beta-cyclodextrin inclusion complex for solubility enhancement.

Complex formation of rofecoxib and beta-cyclodextrin in aqueous solution and in solid state and the possibility of improving the solubility and dissolution rate of rofecoxib via complexation with cyclodextrin were investigated. Phase solubility studies indicated the formation of an 1:1 complex in solution and the value of apparent stability constant was 769 M(-1). Solid inclusion complexes of rofecoxib and cyclodextrin were prepared by the kneading method in different molar ratios. Differential scanning calorimetry studies indicated the formation of solid inclusion complexes of rofecoxib and cyclodextrin at different molar ratios and the solid complexes exhibited a higher rate of dissolution than the physical mixture and the pure drug.