Mehta Tejal1*, Patel Kunal2
Elementary Osmotic Pumps (EOP) consists of osmotic core (coated with a semipermeable membrane (SPM) and a small orifice is created in the membrane. The objective of the present study was to develop an optimized EOP tablets containing inclusion complex of Nicardipine Hydrochloride (NH) using central composite design. Amount of osmotic agent (X1) and size of delivery orifice (X2) were selected as independent variables. Formulations were prepared by direct compression method and evaluated for % Cumulative Drug Release (% CDR) at 540min. as dependent variables. Amount of osmotic agent and size of delivery orifice had a significant effect on % CDR. The results of multiple linear regression analysis revealed that EOP tablets should be prepared using an optimum concentration of osmotic agent and size of delivery orifice to achieve a zero order drug release. Contour plots as well as response surface plots were constructed to show the effects of X1 and X2 on % CDR. A model was validated for accurate prediction of % CDR by performing checkpoint analysis. The computer optimization process, contour plots and response surface plots predicted at the concentration of independent variables X1 and X2 (50mg and 0.8mm respectively), for maximized response. The drug release from the developed formulation was found independent of pH and agitational intensity. The above optimized batch was also evaluated by different pharmacokinetic models. Stability study of optimized batch was conducted at accelerated conditions for six month and it was found to be stable.
