Improved dissolution rate of valdecoxib inclusion complexes with hydroxypropyl-β-cyclodextrin

Abstract

Valdecoxib is a hydrophobic molecule that is practically insoluble in aqueous media and exhibits an exceedingly slow intrinsic dissolution rate. The present study was emphasized on improving the solubility and dissolution rate of drug by forming inclusion complex with hydroxypropyl-β -cyclodextrin. The inclusion complexes were prepared by physical mixture, kneading and common solvent methods. Phase solubility studies indicated the formation of a 1:1 M complex in solution. Drug excipient interactions were characterized using Fourier transformed infrared spectroscopy and differential scanning calorimetry studies. Differential scanning calorimetry studies indicated the formation of solid inclusion complex of valdecoxib hydroxypropyl-β -cyclodextrin at 1:2 M ratio in kneading and common solvent method. Solid inclusion complexes of valdecoxib hydroxypropyl-β -cyclodextrin (1:2 M) prepared by kneading and common solvent method exhibited higher rates of dissolution and dissolution efficiency values both in 0.1N HCl and 0.1N HCl with 0.25% sodiumlauryl sulphate.