Abstract

SOLUBILITY ENHANCEMENT STUDIES OF FEBUXOSTAT BY EMPLOYING POLOXAMER 188

Soumya Reddy* and P. Tripura Sundari

ABSTRACT

Aim: Febuxostat (FBX) is a non purine selective inhibitor of xanthine oxidase/xanthine reductase. It belongs to BCS class II with low solubility and high permeability. Because of low solubility the bioavailability of the drug is hampered, food also interferes with the absorption of drug and decreases the Cmax by 38-49%. The bioavailability of a drug is a function of dissolution rate of the drug which is controlled by the surface area of the drug. In the category of poorly soluble drugs the change in surface area of the drug will show considerable changes in the solubility and dissolution of the drug. Materials and methods: In the present study, the attempts were made to improve the bioavailability of FBX by solid dispersions technique by employing Poloxamer 188 as carrier molecule. Different ratios on weight basis viz (1:1, 1:2, 2:1, 3:1, 4:1) coded as (FBXP1, FBXP2, FBXP3, FBXP4, FBXP5) with Poloxamer 188 were prepared. Results and Discussion: The drug release studies were characterized in liquid state by phase solubility studies and in solid state by Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), Powdered X ray diffraction studies (PXRD) and Scanning electron microscopy (SEM). The aqueous solubility of FBX was favored by the presence of carriers. Solid state characterization indicated that FBX was present as fine amorphous form in the carrier polymeric molecules. Conclusion: In contrast to the solution rate of pure FBX the drug in carriers considerably improved the dissolution rate, this can be attributed to the increased wettability and dispersibility as well as decreased crystallinity and increased amorphous fraction of drug.

Keywords: Febuxostat, solid dispersions, Poloxamer 188, Phase solubility, drug release studies.