Preparation and Release Behavior of Ethylcellulose Microcapsules Containing Theophylline Dispersed in Cellulose Triacetate Matrices
作者:
Jen‐Chin Wu,
Wen‐Jiunn Jean,
Hui Chen,
期刊:
Journal of the Chinese Chemical Society
(WILEY Available online 1993)
卷期:
Volume 40,
issue 1
页码: 23-28
ISSN:0009-4536
年代: 1993
DOI:10.1002/jccs.199300004
出版商: WILEY‐VCH Verlag
关键词: Sustained release;Microencapsulation;Theophyl‐line;Cellulose triacetate matrix;Ethylcellulose
数据来源: WILEY
摘要:
AbstractUsing ethylcellulose and cellulose triacetate as co‐wall materials, sustained release microcapsules of theophylline were prepared. The solid drug dispersed in the cellulose triacetate matrices was first prepared by solvent evaporation; then the matrices were microencapsulated by means of coacervation‐phase separation of ethylcellulose from toluene solution on addition of petroleum ether.The shapes and surface characteristics of theophylline, matrices and microcapsules were examined with a scanning‐electron microscope. The release of theophylline from various particles into distilled water was studied. The microcapsules had good characteristics of sustained release. The period for theophylline to dissolve from ethylcellulose microcapsules containing cellulose triacetate matrices was larger than those from only ethylcellulose microcapsules with a similar ratio of core to wall. The half‐time increased with increasing content of cellulose triacetate. The release pattern which was analogous to that from only ethylcellulose microcapsules obeyed a first‐order
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