ABSTRACT
Background and Objectives: In situ gel formation of Glycerol Monooleate [GMO] has been utilized to release many drugs. The aim of this research was to optimize, and in-vitro characterization of the controlled release and formulation of the matrices containing Olanzapine [OZ], GMO and Polyethylene glycol [PEG 300]
Methods and Materials: Response surface methodology [RSM] is a combination of mathematical and statistical techniques. In this study, Design-Expert software with Box-Behnken response surface methodology has been used to determine the relationships between variables and responses. GMO/water weight ratio [w/w] different and PEG 300/GMO [w/w] were in the range of 2-4% and 2-6% respectively. Percentage of loading; and release at 12 th and 168 th hr were calculated. In-vitro release studies of OZ from prepared gels were conducted in PBS [pH 6.8] and then analyzed by spectrophotometer at 265 nm
Results: The optimum formulation was obtained at weight ratio of water/GMO [w/w] and PEG [300]/GMO [w/w] at 0.28 and 0.2 respectively, and percentage of OZ was at 4%. The observed and predicted values for EE % were 86.8 %, 90.31% respectively those parameters for release at 12th hr were 16.1% and 15% and for release at 168th hr, were 59.8 % and 63.56% respectively
Conclusion: In this study we performed kinetic release profile of OZ with several models, from which Higuchi model showed the best fitting and correlation