Junyaprasert V B, Mitrevej A, Sinchaipanid N, Boonme P, Wurster D E
Department of Pharmacy, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand.
Drug Dev Ind Pharm. 2001 Jul;27(6):561-6. doi: 10.1081/ddc-100105181.
Microcapsules of vitamin A palmitate were prepared by gelatin-acacia complex coacervation. The effects of colloid mixing ratio, core-to-wall ratio, hardening agent, concentration of core solution, and drying method on the coacervation process and the properties of the microcapsules were investigated. The microcapsules of vitamin A palmitate were prepared using different weight ratios of gelatin and acacia, that is, 2:3, 1:1, and 3:2 under controlled conditions. The other factors studied were 1:1, 1:2, and 1:3 core-to-wall ratios; 30, 60, and 120 min of hardening time; 2, 5, and 10 ml of formaldehyde per 280 g of coacervation system as a hardening agent; and 30%, 40%, and 50% w/w vitamin A palmitate in corn oil as a core material. The drying methods used were air drying, hot air at 40 degrees C, and freeze-drying. The results showed that spherical microcapsules were obtainedfor all conditions except for 30 min of hardening time, which did not result in microcapsules. The optimum conditions for free-flowing microcapsules with a high percentage of entrapped drug were 1:1 gelatin-to-acacia ratio and 1:2 core-to-wall ratio when hardening with 2 ml formaldehyde for 60 min and using 40% w/w vitamin A palmitate in corn oil as the core concentration. In addition, drying the microcapsules by freeze-drying provided microcapsules with excellent appearance.
采用明胶-阿拉伯胶复凝聚法制备了棕榈酸视黄酯微胶囊。研究了胶体混合比例、芯壁比、固化剂、芯溶液浓度和干燥方法对复凝聚过程及微胶囊性能的影响。在控制条件下，使用不同重量比的明胶和阿拉伯胶，即2:3、1:1和3:2，制备了棕榈酸视黄酯微胶囊。研究的其他因素包括1:1、1:2和1:3的芯壁比；30、60和120分钟的固化时间；每280克复凝聚体系中加入2、5和10毫升甲醛作为固化剂；以及玉米油中30%、40%和50%（w/w）的棕榈酸视黄酯作为芯材。使用的干燥方法有空气干燥、40℃热风干燥和冷冻干燥。结果表明，除固化时间为30分钟未得到微胶囊外，所有条件下均得到了球形微胶囊。对于包封率高且能自由流动的微胶囊，最佳条件是明胶与阿拉伯胶比例为1:1，芯壁比为1:2，用2毫升甲醛固化60分钟，并使用玉米油中40%（w/w）的棕榈酸视黄酯作为芯材浓度。此外，通过冷冻干燥微胶囊可得到外观优异的微胶囊。
