Nowadays, HIV associated neurological disorder especially HIV-1 virus infection is enhanced. Current available HIV therapies only reduce the plasma viral level and do not kill the virus completely. Administered dosage form does not reach the central nervous system (CNS) completely by the conventional approach. The oral route of drug administration,causes gastrointestinal irritation, hepatic metabolism and slow onset of action and some methods are invasive, resulting in the patient's non compliance. To overcome these problems, an effective novel formulation that will directly reach the CNS or brain needs to be developed.This study aims to formulate intranasal nanosuspension of ritonavir. Ritonavir is widely used as an antiretroviral agent and it is a protease enzyme inhibitor which is poorly soluble in water. High pressure homogenization technique was used for preparation prepare and optimization of nanosuspension by using 2 factors 3 level full factorial design, which is further characterized for particle size, polydispersity index, zeta potential, pH, drug content, in vitro drug diffusion and ex vivo permeation study. For stability of nanosuspension, lyophilization of optimized formulation was done. A comparison study between plain drug, nanosuspension and the lyophilized formulation was carried out, and it showed a significant increase in drug release from the membrane.