Abstract: To prepare naringenin self-microemulsion asymmetric membrane osmotic pump capsule and investigate its drug release behavior in vitro.The solidification of self-microemulsion was studied by using spherical crystallization technique.Cellulose acetate concentration,time for immersed in polymer solution and quenching liquid of the mold were selected as independent variables.The optimal preparation process of the asymmetric membrane osmotic pump capsule shell was determined by using the star design-effect-surface optimization method,taking the envelope thickness and 24h drug cumulative release as the dependent variables.The optimal preparation technologies of asymmetric membrane osmotic pump capsule shell were determined as follows:The cellulose acetate concentration was 9.44%.The time of the mold in the polymer solution and the quenching liquid was 3.77 and 15.86 min respectively.The cumulative drug release was 96.27%,and capsule shell thickness was 0.275 mm in the optimal preparation technology of asymmetric membrane osmotic pump capsule shell.The drug delivery behavior in vitro conforms to the zero-order drug delivery equation (R=0.999 7).Naringenin self-microemulsion asymmetric membrane osmotic pump capsule can slow down the release of drugs and solve the incomplete release of osmotic pump preparations made from insoluble drugs.

Key words: naringenin, self-microemulsifying, asymmetric membrane, osmotic pump capsule, central composite design