Altrenogest has been widely used in synchronization of estrus of pigs, but the existing preparations are inconvenient to use for they have to be administered individually. In order to simplify its administration and improve its stability, altrenogest microcapsules were successfully prepared by intra-liquid desiccation using ethyl cellulose as the capsule material in this study. The average particle size of the optimal altrenogest microcapslue was 76.8 µm which is less than 200 µm, so they are suitable for use in animal feed. The yields, encapsulation levels and drug loading capacity were 20 %, 84 % and 53 %, respectively. The drug release in artificial gastric juice was relatively rapid with 50 % in the first hour and 60 % by hour 2 and the release curve fit the power function equation. Extended exposure (10 d) to light (4500 lux), high humidity (95 %) and high temperature (60 ℃) did not change the concentration of encapsulated drug. The prepared altrenogest microcapsules are suitable as a feed additive and could simplify the use of this drug for the synchronization of estrus for swine production.

Altrenogest已广泛用于同步猪的发情，但现有的制剂需要单独施用，使用不方便。为了简化其给药过程并提高其稳定性，本研究以乙基纤维素为胶囊材料，采用液内干燥法成功制备了丙烯孕酮微胶囊。最佳的双烯孕素微胶囊的平均粒径为76.8 µm，小于200 µm，因此适合在动物饲料中使用。产率、包封率和载药量分别为20%、84%和53%。人工胃液中药物释放较快，第一小时释放50%，第二小时释放60%，释放曲线符合幂函数方程。长时间暴露于光（4500勒克斯）、高湿度（95%）和高温（60℃）下（10天）不会改变包封药物的浓度。制备的丙孕素微胶囊适合作为饲料添加剂，并且可以简化该药物在猪生产同步发情中的使用。