OBJECTIVE To prepare a self-microemulsifying drug delivery system(SMEDDS) for the oral administration of nebivolol hydrochloride(NBH) and to conduct in vitro evaluation.

METHODS The solubility of NBH was determined using various oil phases, surfactants, and co-surfactants. The composition of the blank self-microemulsifying formulation was determined using pseudo-ternary phase diagrams. A centralcomposite design-response surface method was employed to screen and optimize the formulation variables, and an excess amount of NBH raw material was incorporated to determine the drug loading capacity.

RESULTS The optimized composition of the NBH-SMEDDS formulation consisted of medium-chain glycerides, capryl caproyl macrogol glycerides, and 2-(2-ethoxyethoxy) ethyl acetate at a ratio of 20∶48∶32, with a drug loading capacity of 20.05 mg. The particle size, self-emulsification time, and particle size distribution range of the formulation were in agreement with the predicted values. Dissolution testing demonstrated that the overall dissolution trend of NBH-SMEDDS in the medium was higher than that of NBH powder and NBH ordinary tablet. The stability of NBH-SMEDDS was found to be satisfactory under accelerated conditions for 1, 2, and 3 months.

CONCLUSION The SMEDDS shows potential for enhancing the in vitro dissolution of NBH and demonstrates good stability.