Preparation and characterization of galactosylated chitosan coated BSA microspheres containing 5-fluorouracil

In this paper, new sustained release microspheres with a surface coating of targeting moieties coating are presented. Bovine serum albumin (BSA) was used to prepare the microspheres loading with 5-fluorouracil (5-FU) by means of chemical crosslinking method and then the microspheres were coated with N-galactosylated chitosan by electrostatic interaction. The structure of coating layers on the surface of 5-FU-loaded BSA microspheres was characterized by attenuated total reflection Fourier (ATR-FTIR), electron spectroscopy for chemical analysis (ESCA), wide X-ray diffraction (WXRD) and transmission electron microscopy (TEM). The properties of the coated microspheres containing 5-FU were determined. The size was in the range of 0.60-0.65 mu m, zeta potential was 16.6 mv, and the encapsulation efficiency, drug loading, and the content of galactosyl groups were 40.3% (w/w), 2.9% (w/w), and 5.4% (w/w), respectively. In comparison with uncoated microspheres, the coated microspheres showed delayed release and less burst release in vitro. All results suggested the BSA microspheres preparation with galactosyl chitosan coating could be a promising method for targeted delivery to the liver. (C) 2007 Elsevier Ltd. All rights reserved.