Effects of the characteristics of chitosan on controlling drug release of chitosan coated PLLA microspheres

Citation
Sh. Chiou et al., Effects of the characteristics of chitosan on controlling drug release of chitosan coated PLLA microspheres, J MICROENC, 18(5), 2001, pp. 613-625
Citations number
31
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Pharmacology & Toxicology
Journal title
JOURNAL OF MICROENCAPSULATION
ISSN journal
0265-2048 → ACNP
Volume
18
Issue
5
Year of publication
2001
Pages
613 - 625
Database
ISI
SICI code
0265-2048(200107)18:5<613:EOTCOC>2.0.ZU;2-6
Abstract
Chitosan has been shown to be a biomaterial with good biocompatibility, and is highly biodegradable. This study investigated the effect of post-coatin g PLLA microspheres with different chitosans on the initial burst and contr olling the drug release of the microspheres. Without chitosan, 19.2% of enc apsulated lidocaine would release from PLLA microspheres within the first h our. (R-1), and the time of 50% release. (T-50) was 25 h. After the microsp heres were coated with chitosan of viscosity. (eta) 384 +/- 10 cp, R-1 and T-50 could be reduced and prolonged to 14.6% and 90 h, respectively, for al l tested molecular weights (Mw) of chitosan. In the case of the same Mw of chitosan being applied, the efficacy of reducing the initial burst of drug release was higher for a lower degree of deacetylation (D.D.). With chitosa n in acetic acid solution, coating the microspheres with high Mw and high v iscosity could most effectively reduce the initial burst and control drug r elease of PLLA microspheres. For example, the microspheres coated with chit osan solution of Mw 800 kDa and eta of 1479 cp, R-1 and T-50 could be reduc ed and prolonged to 7.4% and 245 h, respectively. The study indicated that manipulating the viscosity of the chitosan solution was the most important factor in contributing to controlling the drug release of chitosan post-coa ted PLLA microspheres.