Author(s): Nagesh C*, Shankaraiah MM, Attimarad SL, Patil AM, Vijay Kumar
Ritonavir is indicated in combination with other antiretroviral agents for the treatment of HIV-infection. One of the major problems with this drug is its low solubility in biological fluids, which results into poor bioavailability after oral administration. Therefore, solid dispersions (SDs) of Ritonavir were prepared using PEG-4000, PEG-6000 and PEG-8000 to increase its aqueous solubility. Ritonavir SDs was prepared in 1:1, 1:2 and 1:4 ratios of the drug to polymer (by weight) by melting method and solvent evaporation method. The prepared solid dispersion was subjected for solubility, drug content, In vitro release and infrared (IR) spectroscopic studies, DSC and stability study. In vitro release profiles of all SDs were comparatively evaluated and also studied against pure Ritonavir. Faster dissolution was observed by solid dispersion containing 1:4(P6M4) ratio of drug: PEG-6000. The increase in dissolution rate of the drug may be due to increase in wettability, hydrophilic nature of the carrier and due to reduction in drug crystallinity.