Abstract: Sodium alginate microspheres are traditional sustained releasing materials；gel strength enhancement and capillary porosity increment are effective ways to improve their sustained releasing ability. Atomic adsorption spectrometry along with micro appearance characterization and swelling experiments are used to explore the feasibility of sustained releasing of Cu2+ of sodium alginate/palygorskite microspheres. Palygorskite improves the gel strength of the microspheres as well as their sustained releasing ability. Comparing with the sodium alginate microspheres，the composite ones prepared with proposed method had better adsorption ability (from 91.82% to 94.60%). In addition，the cumulative releasing percentage within 2 hours decreased from 66.35% to 22.78%. Thus，palygorskite/sodium alginate composite microspheres can be an ideal carrier for long term sustained releasing drugs.

Key words: sustained releasing microspheres, copper, palygorskite, sodium alginate

摘要： 海藻酸钠微球是传统缓控释制剂，提高凝胶强度和增大毛细孔隙率是改善其缓控释性能的有效途径。本文以原子吸收分光光度法辅以微观形貌表征（SEM）和溶胀实验等分析方法，探讨了凹土/海藻酸钠复合微球用于以生命体中微量元素（Cu2+）控释的可行性，并进行了缓释机理分析。实验结果表明，凹土具有显著改善微球的凝胶强度和缓释性能的作用；与海藻酸钠微球相比，复合微球的吸附率由91.82%提高到94.60%，在2 h之内的释放率由66.35%降低到22.78%，表明凹土/海藻酸钠复合微球可作为理想的长效缓释药物的载体。

关键词: 缓释微球, 铜, 凹土, 海藻酸钠