Optimization of Freeze Drying Condition of Prednisoloneacetate Solid Lipid Nanparticles Using Box-behnken Design

INTRODUCTION Nanoparticulate carrier system was used to target, improve bioavailability, control the drug release and avoid the enzymatic degradation. Among the nanoparticulates i.e. SLNs are attractive and face the challenges of stability. The major obstacle with the SLNs was agglomeration in order to avoid this problem freeze drying was attempted. In this laboratory process which involves freezing of sample followed by lyophilization. Freeze drying process involves freezing of liquid SLNs in order to remove the bound water which will produce highly concentrated product, but in some conditions there is a possibility of agglomeration of particles to avoid this cryoprotectants were added. The widely used cryoprotectants were sucrose, mannitol, glucose and trehalose and the concentration of these optimized by trial and error method or by any suitable statistical design. In the present study tristearin loaded prednisolone acetate SLNs was stabilized by cremophor RH40: Ethanol and it was freeze dried to improve the shelf life. In order to reduce the number of experimentation and to save the time and money to dry the SLNs Box-Behnken design was opted. The % and type of cryoprotectant and freeze drying temperature was considered important in freeze drying process hence these were optimized using Box-Behnken design.