Lee H Y, Chan L W, Heng P W S
National University of Singapore, Singapore.
J Microencapsul. 2005 May;22(3):275-80. doi: 10.1080/02652040500100378.
Spherical and discrete calcium alginate microspheres had been produced by the emulsification technique. The microencapsulation process was highly efficient, but drug release from microspheres was rapid. A more orderly chain arrangement of the polymeric chains would give rise to a stronger and less permeable matrix capable of sustaining drug release. Therefore, the potential of using partially cross-linked alginate in the production of microspheres by emulsification was explored. The size and roundness of the microspheres, its drug content and drug release property were determined. The more viscous alginate solutions when reacted with more calcium salt added resulted in larger microspheres produced. Microspheres made from partially cross-linked alginate exhibited lower drug content and higher T75% values in drug release studies. This was due to decreased flexibility of the polymer chains which were partially held together by calcium ions, reducing subsequent interaction with the calcium ions resulting in lower drug entrapment efficiency and a more permeable microsphere matrix.
通过乳化技术制备了球形且离散的海藻酸钙微球。微囊化过程效率很高，但微球中的药物释放很快。聚合物链更有序的链排列会产生更强且渗透性更低的基质，能够维持药物释放。因此，研究了在乳化法制备微球过程中使用部分交联海藻酸盐的可能性。测定了微球的大小和圆度、其药物含量和药物释放特性。当与添加的更多钙盐反应时，更粘稠的海藻酸盐溶液会产生更大的微球。在药物释放研究中，由部分交联海藻酸盐制成的微球显示出较低的药物含量和较高的T75%值。这是由于聚合物链的柔韧性降低，聚合物链被钙离子部分固定在一起，减少了随后与钙离子的相互作用，导致较低的药物包封效率和更具渗透性的微球基质。
