Formulation Development of Orlistat Nanocrystals: In Vitro Characterization and in Vivo Studies

Abstract

Poor solubility of orlistat limits its luminal concentration and hence needs to be administered in higher doses, leading to drug related side effects. The aim of the present research was to investigate nanocrystallization approach to increase the solubility of orlistat using melt extrusion and high-pressure homogenization (HPH) methods. The effect of factors like type and amount of polymer, homogenization pressure and time, and number of cycles on orlistat solubility was investigated. A ~10-fold increase in the solubility of orlistat was attained using OPo11N with a subsequent increase in the dissolution rate of the drug. Poloxamer 188-orlistat nanocrystals (OPo11N) as compared to pure orlistat led to a decrease in T90%(20 mins for OPo11N and 51 mins for marketed sample). In vivo studies in female Sprague Dawley (SD) rats showed that post one month of oral administration the total cholesterol and low-density lipoproteins of female SD rats remained unchanged compared to the control group. The triglycerides content and high-density lipoproteins levels were significantly increased with increase in the treatment time i.e. 12 weeks compared to the group treated with pure orlistat drug. In conclusion, the NC approach could serve as an effective formulation strategy for solubility enhancement of orlistat.