ENHANCEMENT OF SOLUBILITY AND DISSOLUTION PROFILE OF NEVIRAPINE BY SOLID DISPERSION TECHNIQUE

Abstract

Solid dispersions (SDs) of nevirapine (NVP) were prepared with the objective of dissolution enhancement by solvent evaporation technique by
using polymers like PEG 6000 and PVP (k 30). The Fourier transform‐IR (FTIR) studies indicated the possibility of hydrogen bonding with the
polymer. Powder‐XRD and DSC were used to characterize the solid dispersions, indicated a transformation of drug from crystalline to
microcrystalline form. In vitro dissolution studies of SDs performed in 0.1 N HCl and pH 6.8 phosphate buffer solution showed a significant increase
in dissolution rates of NVP comparing to physical mixtures and pure drug. Comparatively, SD of NVP: PEG 6000 and NVP: PVP (K30) in various
weight ratios (1:2, 1:4, 1:6) were prepared by solid dispersion method exhibited a higher release rate than the conventional method. Improved
dissolution of model drug may be attributed to the modification in drug crystalline in SDs as was evident from our analytical studies. The dissolution
pattern of the NVP from all the SDs followed predominantly, first order kinetics. This study reflects the vital role of polymers as a novel approach to
improve the solubility of NVP, which could minimize the variable dissolution rates with increase in oral bioavailability.