以甲基丙烯酸甲酯为壁材,采用乳液聚合法制备了阿维菌素微囊悬浮剂。研究了聚合反应时间、芯壁比(芯材与壁材的质量比)和表面活性剂(十二烷基硫酸钠,SDS)用量对所制备微囊的包裹率、载药量和粒径的影响规律,并对其贮存稳定性和释放性能进行了测定。结果发现:所制备微囊的包裹率、载药量和粒径均与聚合反应时间呈正相关,包裹率和载药量在聚合反应3h后达到相对稳定,粒径在聚合反应1h后变化幅度明显减小;芯壁比对所制备微囊的载药量和粒径影响较为明显,随着芯壁比的增加,载药量增加、粒径减小,当芯壁比从1:5增大到1:2时,载药量由15.59%增加到30.33%,平均粒径(D50)由5.47减小到2.18μm,但芯壁比对微囊包裹率的影响不明显;SDS用量对所制备微囊的包裹率和载药量影响较小,对粒径的影响较大,当SDS的质量分数为8%时,微囊的D铀最小且更为均一。研究表明,反应时间等3个因素对阿维菌素微囊悬浮剂成囊均有一定的影响,当反应时间大于3h、芯壁质量比为1:3至1:2、SDS质量分数为6%至8%时,有利于形成粒径均一、形态规则、包裹率和载药量都较高,且具有良好的贮存稳定性和释放特性的阿维菌素微囊悬浮剂。
Abamectin capsule suspensions (CS) with methyl methacrylate as wall material were prepared by emulsion polymerization. The influence of polymerization time, ratio of core material to wall material ( core to wall) and percentage of SDS on the entrapment rate, drug-loading rate and mean size of CS was studied, stability at high and low temperature and the controlled release effect were also studied. The results showed that the entrapment rate, drug-loading rate and mean size of CS were positive correlation with the polymerization time. The entrapment rate and drug-loading rate were relatively steady when the polymerization time was more than 3 hours, and the change of mean particle size was obviously reduced when the polymerization time was more than 1 hours. The drug-loading rate and mean size were significantly affected by core to wall. As the core to wall increased from 1 : 5 to 1:2, the drug-loading rate increased from 15.59% to 30.33% and the Ds0 varied from 5.47μm to 2.18 μm. The influence of percentage of SDS on entrapment rate and drug-loading rate was not evident, but it was evident on mean particle size. When the percentage of SDS was 8%, the D50 of CS was smallest and the particles were more uniform. It indicated that each of the three factors had certain effects on the microencapsulation of abamectin. The acceptable abamectin capsule suspensions which had uniform mean size, regular shape, high entrapment rate and drug-loading rate, good stability at high and low temperature and good sustained release effect could be made when the polymerization time was more than 3 h, the core to wall was between 1:3 and 1:2 and the percentage of SDS was between 6% and 8 %.