Abstract

STUDIES ON SOLUBILITY AND DISSOLUTION ENHANCEMENT OF ENTACAPONE BY SOLID DISPERSION TECHNIQUE

Amaresh, K. M. Lokamatha Swamy*, Amit Kumar, Annu P., Shravan L. Nargund, Vinayak K.

ABSTRACT

The bioavailability of entacapone after oral administration is very low (35%) and subject to large inter-individual variation. Hence, the present study was planned to enhance the oral bioavailability of entacapone solid dispersion technique using various water soluble carriers. Solid dispersions (SDs) of entacapone were prepared using various water soluble carriers by kneading method at different drug to carrier ratios. The compatibility between the drug and carriers was performed by FTIR studies. The drug content and percentage yield of PMs and SDs were estimated. In vitro dissolution studies of pure entacapone, PMs and SDs were carried out. FTIR studies indicated no chemical interaction between entacapone and various carriers. Solubility studies showed that the solubility of entacapone increased linearly as a function of concentration of water soluble carriers. All SDs of entacapone prepared with different drug to carrier ratios were found to be fine and free flowing. The percentage yield of all batchesof SDs was found satisfactory. The in vitro dissolution studies indicated significant increase in dissolution rate of entacapone from SDs compared to drug alone and their corresponding PMs.. Best fit model is first order kinetics compared to Hixson-Crowell’s cube root model. All SDs of entacapone prepared with various water soluble carriers were significantly improved the solubility and dissolution rate and thus enhances the oral bioavailability with better therapeutic effect and patient compliance. Hence, the developed SDs of entacapone can be utilised for formulation of suitable dosage form such as tablets or filled in hard gelatin capsules for oral administration.

Keywords: Solid dispersions, Entacapone, Urea, Mannitol, Sorbitol and Polaxamer-407.