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Preparation and Release Behavior of Ethylcellulose Microcapsules Containing Theophylline Dispersed in Cellulose Triacetate Matrices
Author(s) -
Wu JenChin,
Jean WenJiunn,
Chen Hui
Publication year - 1993
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.199300004
Subject(s) - cellulose triacetate , chemistry , theophylline , distilled water , cellulose , coacervate , chromatography , solvent , ethyl cellulose , scanning electron microscope , chemical engineering , nuclear chemistry , organic chemistry , polymer , composite material , materials science , medicine , engineering , endocrinology
Using 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 equation.