中文摘要：

将海藻酸钠／明胶／盐酸四环素共混液滴入含有CaCl2的壳聚糖醋酸溶液中，制备出SA／GT质量配比分别为10／0．6、10／0．8、10／1．0的SA／CS／GT复合水凝胶载药微球，考察了模拟肠液和胃液中不同原料配比对载药性能的影响。结果表明，在配比为10／0．8下微球具有最大载药量，模拟肠液中水凝胶微球释放药物周期较长。因此，SA／CS／GT2三元复合水凝胶微球由于其良好的控制释放和降解性能，将是口服释药系统的一种优良载体。

英文摘要：

In this study, the compound of sodium alginate（SA）, gelatin hydrochloride（GT）, and tetracycline hydrochloride （TC）, a model antibiotic drug, is dropped into chitosan（CS） at ambient temperature. Polymeric blend hydrogel drug-loaded microspheres of sodium alginate/gelatin/chitosan/tetracycline hydrochloride, with three kinds of SA/GT ratios,are prepared by solidifying with calcium chloride （CaCl2）. The effects of different ratios on the release property of TC are discussed under simulated gastrointestinal pH conditions （2. 0,7. 4）. The highest TC envelopment is obtained from 10/0. 8 SA/GT ratio. It is also observed from release results that TC release from the micropheres through the external medium is much higher at pH （2.0） than that at pH（7. 4）. Then the sodium alginate/gelatin/chitosan blend hydrogel microspheres will be a new medicinal carrier for its good controlled release and degradation property.