Glutaraldehyde cross-linked chitosan microspheres for controlled release of centchroman

摘要

Glutaraldehyde cross-linked chitosan microspheres were prepared for controlled release of centchroman,a nonsteroidal contraceptive.The cross-linked microspheres with low-molecular-weight(LMW)chitosan(260 kg mol~(-1))have shown maximum degree of swelling(287 wt %)but were found to be poor in loading and release behavior for centchroman.The microspheres with medium-molecular-weight(MMW)chitosan(1134 kg mol~(-1))have shown 250 wt% degree of swelling and 37.5 wt% loading of centehroman,but microspheres with high-molecular-weight(HMW)chitosan(2224 kg mol~(-1))have shown a low degree of swelling(150 wt %)and centehroman loading(30 wt %).The microspheres with MMW chitosan have released 82 wt % of loaded centehroman in a controlled release manner within a period of 70 h in comparison to low-(260 kg mol~(-1))and high-MW(2224 kg mol~(-1))chitosan microspheres.The chitosan microspheres with 62 wt % degree of deacetylation(DDA)were more efficient in the controlled release of centehroman in comparison to chitosan microspheres with low(48 wt %)and high-DDA(75 wt %).The fractional release of centehroman(M_tM_(infinity))from chitosan microspheres was used to predict the mechanism of drug release and to determine the diffusion constant(D)of centehroman.