This research paper deals with design, optimization and evaluation of SCOT of metformin hydrochloride. A full factorial design was employed to optimize the amount of solubility modulating agent (X1) and % PEG in CA (X2) and % wt. build up (X3) as independent variables that influence the drug release. SCOT tablets of metformin were prepared by wet granulation method and evaluated for cumulative % drug release at 2,8,16 hours as dependent variable. Fabricated SCOT tablets were evaluated for weight variation, thickness, hardness, friability, and in-vitro release studies. Sodium chloride as solubility modulating agent retards the drug release. The % wt. buildup had effect on drug release due to Increase in coating weight from (2-5%) which retards drug release due to increase in thickness of semi permeable membrane. The values of independent and dependent variables were subjected to least square fit analysis to establish a full model. The prediction profiler and counter plot was generated at the concentration of in dependent variables X1(10.2 mg/tab), X2 (5) and X3 (3.5%) for maximized response. The drug release from developed formulation was found independent of pH and agitation intensity. The in-vitro release of fabricated osmotic tablet was compared with marketed osmotic and matrix tablet. The in-vitro release kinetics of fabricated osmotic tablet was found similar to marketed osmotic tablet as both followed zero-order release kinetics, While Matrix tablets exhibited Higuchi model.
