Zusammenfassung
The aim of this work was to characterize and investigate the potential
of chitosan/cashew gum (CH/CG) gel for the controlled release of
pilocarpine hydrochloride. Gels were prepared by reacetylation of CH
with acetic anhydride, characterized by infrared spectroscopy, thermal
analysis, and X-ray diffraction. Swellings in water and in phosphate
buffers were also investigated. The release of pilocarpine for CH and
CH/CG gels was shown to be similar in the first 100 min, where about
60% of the pilocarpine was released. After this time, addition of CG to
the gels decreases pilocarpine release rate in the medium. CH gel
release was found to be dependent on pH values, a non-Fickian mechanism
was observed for the release at pH 2 and 7.4, while at pH 9.8, a Fickian
(diffusion) mechanism took place. On the other hand the release of
pilocarpine in CH/CG matrix occurred by Fickian mechanism, independent
of the pH value. (c) 2005 Wiley Periodicals, Inc.
Nutzer