Park S-B, Kang H-W, Haam S, Park H-Y, Kim W-S
Department of Chemical Engineering, College of Engineering and Bioproducts Research Center, Yonsei University, Seoul 120-749, South Korea.
J Microencapsul. 2004 Aug;21(5):485-97. doi: 10.1080/02652040410001729269.
Chitosan beads (CBs) incorporating Ca-alginate microspheres (CAMs), containing a drug, were prepared as an oral sustained delivery system. Stable and monodisperse Ca-alginate microspheres loaded with drug were obtained by a membrane emulsification method. The Ca-alginate microspheres were encapsulated in chitosan beads by the ionotropic gelation method with a polyelectrolyte complex reaction between two oppositely charged polyions. The surface and internal characteristics of the beads were improved by ionic cross-linking in tripolyphosphate (TPP) solution adjusted to pH 5.0. The release experiments were performed using lidocaine.HCl (cationic drug) and sodium salicylate (anionic drug) as model drugs. Initial release of drugs depended on the degree of swelling. Ca-alginate microspheres encapsulated in chitosan beads were superior to both drug-loaded CBs and CAMs beads for sustained release because they had a three-layer composition; a calcium alginate core bounded by an inter-phasic chitosan-alginate membrane, which itself was surrounded by a layer of chitosan-TPP.
含有药物的壳聚糖珠（CBs）包裹海藻酸钙微球（CAMs）被制备成一种口服缓释给药系统。通过膜乳化法获得了负载药物的稳定且单分散的海藻酸钙微球。海藻酸钙微球通过离子凝胶法，利用两种带相反电荷的聚离子之间的聚电解质复合反应被包裹在壳聚糖珠中。通过在pH值调至5.0的三聚磷酸钠（TPP）溶液中进行离子交联，改善了珠子的表面和内部特性。以盐酸利多卡因（阳离子药物）和水杨酸钠（阴离子药物）作为模型药物进行了释放实验。药物的初始释放取决于溶胀程度。包裹在壳聚糖珠中的海藻酸钙微球在缓释方面优于负载药物的CBs和CAMs珠子，因为它们具有三层结构：一个海藻酸钙核心被一个相间的壳聚糖-海藻酸盐膜包围，而该膜本身又被一层壳聚糖-TPP包围。
