Release of indomethacin from a novel chitosan microsphere prepared by a naturally occurring crosslinker: Examination of crosslinking and polycation-anionic drug interaction
Fl. Mi et al., Release of indomethacin from a novel chitosan microsphere prepared by a naturally occurring crosslinker: Examination of crosslinking and polycation-anionic drug interaction, J APPL POLY, 81(7), 2001, pp. 1700-1711
Novel chitosan microspheres with lower cytotoxicity were fabricated in this
study and their drug release characteristics were investigated. Genipin, a
naturally occurring crosslinking reagent that has been used in herbal medi
cine and in the production of food dye, was used to prepare crosslinked chi
tosan microspheres by a water-in-oil dispersion method. The crosslinking me
chanism examined by FTIR and C-13-NMR suggests that the crosslinking of chi
tosan by genipin leads to the formation of secondary amide and heterocyclic
amino linkage. The polycation-anionic drug interaction between chitosan an
d indomethacin was pH dependent and could affect the dissolution property o
f indomethacin. By examination of the release profiles of tile crosslinked
chitosan microsphere, it was found that the release of indomethacin from th
e microsphere was sustainable and influenced by factors such as crosslinkin
g of microsphere and chitosan-indomethacin interaction, thus establishing c
rosslinked chitosan microsphere as a very promising polymeric carrier for d
rug release. (C) 2001 John Wiley & Sons, Inc.