Design of controlled release of Olanzapine by using Glycerol Monooleate in Sol-gel Systems

Backgrounds and This research is to develop new systems for drug release systems based on sol - gel systems. The objective of this study is to develop controlled release formulation of water insoluble Olanzapine (OZ), using Glycerol monooleate (GMO) and Polyethylene glycol (PEG 300). A Box- Behnken response surface methodology was applied to design gel system with 3 factors with an initial drug containing, weight ratio of GMO/water (w/w) and weight ratio of PEG 300/GMO (w/w). Therefore, in this study Design-Expert® software with Box- Behnken response surface methodology has been used specifically to determine the relationships between variables and responses. According to the results of experiments, a quadratic model as an appropriate equation has been selected to fit the percentage of loading. Percentage of release at 12th and 168th hr a cubic model is selected. Kinetic release profile of OZ was investigated with several models, from which Higuchi model showed the best fitting and highest correlation. Optimization of gel system was carried out based on statistical concept of experimental design. Validation test was carried out under optimum conditions of the parameters predicted by the polynomial model.