The purpose of the present study was to prepare an acceptable nanosuspension of ritonavir by increasing the aqueous solubility, dissolution and hence oral bioavailability. Ritonavir is having low aqueous solubility and high permeability which can be considered as drug belonging to class-II according to BCS. In this study nanosuspension technology was tailored to increase solubility and dissolution rate of ritonavir. Ritonavir Nanosuspension was prepared by Pearl milling technique using zirconium oxide beads as milling media, poloxamer 407 as a stabilizer. The prepared nanosuspension was characterized using DSC (Differential Scanning Colorimetry) and XRD (X-Ray Difractometry). The nanosuspension was further evaluated for drug release, redispersability, assay and for stability. The solubility and dissolution studies revealed that there was a considerable increase in the solubility and dissolution rate of ritonavir in nanosuspension formulation as compared to pure drug. Human acceptability studies of prepared placebo nanosuspensions were found to be acceptable when evaluated for organoleptic properties like odour, taste, smell and other characteristics like appearance and pourability.
