Misirli Y, Oztürk E, Kurşaklioğlu H, Denkbaş E B
Hacettepe University, Beytepe, Ankara, Turkey.
J Microencapsul. 2005 Mar;22(2):167-78. doi: 10.1080/02652040400026368.
Mitomycin-C loaded and chitosan-coated alginate microspheres were prepared for use in chemoembolization studies. In this respect, first alginate microspheres were prepared by using a spraying method using an extrusion device with a small orifice and following suspension cross-linking in an oil phase. Chitosan-coating onto the alginate microspheres was achieved by polyionic complex formation between alginate and chitosan. CaCl(2) was used as a cross-linker for alginate microspheres. The obtained chitosan-coated alginate microspheres were spherical shaped and approximately 100-400 microm average size. The microspheres were evaluated based on their swellability and the swelling ratio was changed between 50-280%. CaCl(2) concentration, stirring rate, chitosan molecular weight, chitosan concentration and time for coating with chitosan were selected as the effective parameters on microsphere size and swelling ratio. Equilibrium swellings were achieved in approximately 30 min. On the other hand, chitosan molecular weight, chitosan concentration and time for coating with chitosan were found as the most effective parameters on both drug loading ratio and release studies. Maximum drug loading ratio of 65% was achieved with high molecular weight (HMW) chitosan, highest chitosan concentration (i.e. 1.0% v/v) and shortest time for coating with chitosan (i.e. 1 h) values.
制备了负载丝裂霉素 - C并包覆壳聚糖的海藻酸钠微球,用于化学栓塞研究。在这方面,首先使用带有小孔的挤压装置通过喷雾法制备海藻酸钠微球,然后在油相中进行悬浮交联。通过海藻酸钠和壳聚糖之间形成聚离子复合物,实现壳聚糖对海藻酸钠微球的包覆。氯化钙用作海藻酸钠微球的交联剂。所获得的壳聚糖包覆的海藻酸钠微球呈球形,平均尺寸约为100 - 400微米。基于微球的溶胀性对其进行评估,溶胀率在50 - 280%之间变化。选择氯化钙浓度、搅拌速率、壳聚糖分子量、壳聚糖浓度和壳聚糖包覆时间作为影响微球尺寸和溶胀率的有效参数。在大约30分钟内达到平衡溶胀。另一方面,发现壳聚糖分子量、壳聚糖浓度和壳聚糖包覆时间是对药物负载率和释放研究最有效的参数。使用高分子量(HMW)壳聚糖、最高壳聚糖浓度(即1.0% v/v)和最短壳聚糖包覆时间(即1小时)时,实现了65%的最大药物负载率。