Brazilian Journal of Chemical Engineering
On-line version ISSN 0104-6632
OLIVEIRA, B. F; SANTANA, M. H. A. and RE, M. I.. Spray-dried chitosan microspheres cross-linked with d, l-glyceraldehyde as a potential drug delivery system: preparation and characterization. Braz. J. Chem. Eng. [online]. 2005, vol.22, n.3, pp. 353-360. ISSN 0104-6632. http://dx.doi.org/10.1590/S0104-66322005000300004.
Chitosan microspheres of a small particle size and with good sphericity were prepared by a spray-drying method followed by treatment with a cross-linking agent. Owing to restrictions on the use of cross-linked chitosan microspheres in the pharmaceutical field, d,l-glyceraldehyde, a biocompatible reatant was used. The parameters studied affecting extent of cross-linking were cross-linking time and concentration of the cross-linking agent. Glutaraldehyde, the aldehyde most frequently employed as chemical cross-linking agent for proteins, was also used as a control. The cross-linked spray-dried chitosan microspheres were analyzed with respect to their morphological aspects, particle size, zeta potential and water uptake capacity. It was found that an increase either in d,l-glyceraldehyde concentration or in duration of cross-linking caused a decrease in both the swelling capacity and the zeta potential of the chitosan microspheres. Compared to glutaraldehyde, d,l-glyceraldehyde appears to be a good cross-linking agent for chitosan microspheres with the advantage that it is nontoxic.
Keywords : Glyceraldehyde; Chitosan microspheres; Cross-linking; Spray drying.