Enhancement of Dissolution Properties of Efavirenz by Solid Dispersion Technique using Sylysia
The objective of present study was to enhance the dissolution rate of Efavirenz(EFV) by using solid dispersion technique. Solid dispersions in water soluble carriers have attracted considerable interest as a means of improving the dissolution rate, and hence possibly bioavailability of a range of hydrophobic drugs. The poor solubility of Efavirenz leads to poor dissolution and hence variation in bioavailability.Efavirenz (EFV) is an antihuman immunodeficiency virus (antiHIV) drug that works by inhibiting the non-nucleoside reverse transcriptase of HIV and is used as a part of the highly active antiretroviral therapy.In the present investigation solid dispersions(SD) were prepared by employing different grades of silica gel(Sylysia).They were prepared by solvent evaporation and kneading method in two different mass ratios 1:1 and 1:2. Comparision of both methods was also investigated. Physicochemical characterisation of disperse systems was carried out using differential scanning calorimetry(DSC), X-ray diffraction(XRD), FTIR. Dissolution tests were conducted and evaluated on the basis of cumulative percentage drug release.The prepared solid dispersions were also evaluated for precompression parameters like angle of repose,bulk &tapped density,drug content,Carr’s index and Hausner’s ratio.Improved dissolution was observed in 1:1 ratio disperse system of kneading method compared to solvent evaporation method. Physicochemical characterisation results suggested that EFV existed in amorphous form in all dispersion systems which show that dissolution can be enhanced.