Optimized preparation of insulin-lauryl sulfate complex loaded poly (lactide-co-glycolide) nanoparticles using response surface methodology.

Insulin-lauryl sulfate (INS-SDS) complex loaded poly (lactic acid-co-glycolic acid) (PLGA) nanoparticles were prepared by spontaneous emulsion solvent diffusion method. To improve the insulin entrapment efficiency (E.E), a five-level-two-factor central composite design and surface response methodology (RSM) was used to determine the optimum levels of PLGA/INS complex weight ratio and PVA/ acetone volume ratio, two important variables during nanoparticles fabrication. A quadratic model to express the E.E as a function of the two studied factors was developed. Only 10 experimental runs were necessary and the obtained model was adequate (P < 0.05). By partial derivative resolution of regression model, the optimum weight ratio of PLGA/INS complex and volume ratio of PVA/acetone was determined as 25/1 and 10/1, respectively. This preparing condition resulted E.E of insulin as high as 91% during nanoparticles production. Validation of the model was accomplished by experiments carried out on optimized formulation conditions. The experimental results were in good agreement with those predicted by the model. The results indicated that RSM represents an effective and potential technique for formulation optimization.