Binary inclusion complexes of diflunisal with ß-cyclodextrin and hydroxypropyl-ß-cyclodextrin: Preparation and characterization.

ABSTRACT

Low aqueous solubility and bioavailability is the limiting factor to achieve desired therapeutic efficacy for variety of new and existing drug moieties. The goal of the present study was to explore the effects of ß-cyclodextrin (ßCD) and hydroxypropyl-ß-cyclodextrin (HPßCD) on the solubility and dissolution profile of diflunisal (DIF) prepared by using two different methods (physical mixing and solvent evaporation) at DIF-cyclodextrins weight ratios of 11, 12 and 14. The phase solubility studies demonstrated that DIF solubility increased proportionally with an increase in ßCD and HPßCD concentration. The inclusion complexes were subjected to characterization of scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and X-ray diffractometry (XRD). Solvent evaporation yielded higher DIF solubility than physical mixing method. HPßCD-DIF inclusion complexes yielded higher dissolution profile than ßCD complexes when prepared under same experimental design. FTIR, DSC and XRD confirmed the successful inclusion of DIF into cyclodextrin (ßCD/HPßCD) by both preparation methods with enhanced water solubility and drug release in comparison with pure drug.