Enhancement of Dissolution Rate of Efavirenz by Solid Dispersion Technique

Efavirenz is an HIV-1 specific, non-nucleoside reverse transcriptase inhibitor (NNRTI).It is an antiretroviral agent indicated for the treatment of human immunodeficiency virus type 1 (HIV-1) infection, which is not soluble in water and lower absorption in gastric fluid. In order to improve the solubility and oral absorption of the drug in gastric fluid and to enhance its dissolution rate, solid dispersion method is designed and evaluated. Solid dispersions of Efavirenz were prepared using PEG 6000. The effect of fusion-solvent methods of preparation of solid dispersion on dissolution behavior was also investigated. Dissolution studies indicated a significant increase in dissolution of Efavirenz when dispersed in PEG6000. Solid dispersions containing Efavirenz / PEG 6000, 1: 8, showed a 2-fold increase in dissolution after 180 min in the 0.1 N HCl systems.