Preparation and characterization of stearic acid-grafted chitosan oligosaccharide polymeric micelles.
- Author:
Yi-qing YE
1
;
Fu-qiang HU
;
Hong YUAN
Author Information
- Publication Type:Journal Article
- MeSH: Chitosan; administration & dosage; chemistry; Drug Carriers; Drug Delivery Systems; Hydrogen-Ion Concentration; Methotrexate; administration & dosage; chemistry; Micelles; Oligosaccharides; administration & dosage; chemistry; Particle Size; Polymers; Polyphosphates; Solubility; Stearic Acids; administration & dosage; chemistry
- From: Acta Pharmaceutica Sinica 2004;39(6):467-471
- CountryChina
- Language:Chinese
-
Abstract:
AIMTo prepare the micelles of stearic acid-grafted chitosan oligosaccharide and investigate the drug release from micelles.
METHODSMediated by a 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), stearic acid (SA) was covalently attached to chitosan oligosaccharide (CSO), and the graft polymer (CSO-SA) was obtained. The critical aggregation concentration (CAC) of the CSO-SA was determined by measuring the fluorescence intensity of pyrene as a fluorescent probe. The effect of various pH dispersed media and concentration of tripolyphosphate sodium (TPP) on the micellar size distribution and zeta-potential measured by light scattering and electrophoretic mobility, was investigated. In buffers of different pH, the release profiles of methotrexate (MTX) from micelles were evaluated.
RESULTSThe CAC value of CSO-SA in deionized water was 0.05 g x L(-1). The mean diameter of CSO-SA micelles was 26.7 nm and the zeta potential was (55.9 +/- 0.1) mV. With the increase of TPP concentration, the size and MTX encapsulation of CSO-SA micelles increased, while the zeta-potential decreased. With the decrease of pH value of dispersed media, the size and zeta-potential of CSO-SA micelles increased, and the MTX encapsulation in CSO-SA micelles decreased. While the enhancement of drug release from the micelles was observed.
CONCLUSIONThe graft polymer of CSO-SA provides polymeric micelles, which possessed a low CAC value in aqueous media. The drug release in vitro from CSO-SA micelles was affected by the pH of delivery media.