Dissolution enhancement.

Objective: The main objective of the current research work was development and characterization of self-micro emulsifying drug delivery system of cilnidipine which is poorly water-soluble drug. The improved solubility could offer improved dissolution as well as oral bioavailability. Method: Component excipients were selected based on the preliminary studies, capryol 90 and triacetin (1:1) selected as an oil, tween 80 selected as surfactant, transcutol p selected as co-surfactant based on the maximum solubility and better emulsification efficiency. The ternary phase diagram was constructed to identify the optimum composition of the formulation. Simplex centroid mixture design was applied for selection of optimized batch of SMEDDS. Capryol 90 and triacetin, tween 80 and transcutol p were taken as an independent variables X1, X2 & X3 respectively, while emulsification time (Y1) and % drug release at 2 minutes (Y2) were taken as dependent variables. Optimized SMEDDS was evaluated based on % transmittance, emulsification time, globule size, PDI, % drug release, and cloud point. After that, SMEDDS were filled in capsule and short-term stability study was done and SMEDDS compared with pure drug for dissolution profile. Result and Discussion: Optimized batch containing capryol 90 and triacetin (1:1), tween 80 and transcutol p at a concentration of 10%, 67% and 23% respectively. The solubility of cilnidipine is increased by using capryol 90 and triacetin (1:1) as an oily phase. All the evaluation parameters of the optimized SMEDDS were met the acceptance criteria. Optimized batch of SMEDDS showed > 90% drug release within 2 minutes. Dissolution was improved as compared to the pure drug. Conclusion: A self-micro emulsifying drug delivery system of cilnidipine was developed successfully. Present work demonstrated for improving the dissolution of cilnidipine. This may lead to improved oral bioavailability of cilnidipine for the treatment of hypertension. Keywords: Cilnidipine, SMEDDS, Solubility, Dissolution enhancement.