Development and optimization of a novel oral controlled delivery system for tamsulosin hydrochloride using response surface methodology

The purpose of this study was to develop and optimize oral controlled-release formulations for tamsulosin hydrochloride using a combination of two cellulose ester derivatives, hydroxypropyl methylcellulose (HPMC) and hydroxypropyl methylcellulose phthalate (HPMCP), with Surelease ® as a coating material. A three-factor, three-level Box-Behnken design was used to prepare systematic model formulations, which were composed of three formulation variables, the content of HPMC ( X 1 ) and HPMCP ( X 2 ) and the coating level ( X 3 ), as independent variables. The response surface methodology (RSM) and multiple response optimization utilizing the polynomial equation were used to search for the optimal coating formulation with a specific release rate at different time intervals. The drug release percentages at 2, 3 and 5 h were the target responses and were restricted to 15–30% ( Y 1), 50–65% ( Y 2) and 80–95% ( Y 3), respectively. The optimal coating formulation was achieved with 10% HPMC and 20% HPMCP at a coating level of 25%, and the observed responses coincided well with the predicted values from the RSM optimization technique. The drug release from pellets coated with the optimized formulation showed a controlled-release pattern (zero-order), in comparison with a commercial product (Harunal ® capsule). In conclusion, a novel, oral, controlled-release delivery system for tamsulosin hydrochloride was successfully developed by incorporating HPMC and HPMCP as coating additives into Surelease ® aqueous ethylcellulose dispersion.