Chitosan/starch fibers and their properties for drug controlled release

Fibers of chitosan and starch, with salicylic acid (SA) as model drug incorporated in different concentrations, were obtained by spinning their solution through a viscose-type spinneret into a coagulating bath containing aqueous tripolyphosphate (TPP) and ethanol. Chemical, morphological and mechanical properties characterization was carried out, as well as the studies of the factors that influence the drug releasing from chitosan/starch fibers. These factors included the component ratio of chitosan and starch, the loaded amount of SA, the pH and the ionic strength of the release solution and others. The diameter of the fibers is around 15+/-3 microm. The best values of the tensile strength at 12.21 cN/tex and breaking elongation at 25.13% of blend fibers were obtained when the starch content was 30 wt%; the water-retention value (WRV) of blend fibers increased as the composition of starch was raised. The results of controlled release tests showed that the amount of SA released increased with an increase in the proportion of starch present in the fiber. Moreover, the release rate of drug decreased as the amount of drug loaded in the fiber increased, but the cumulative release amount is increasing. The chitosan/starch fibers were also sensitive to pH and ionic strength. The release rate was being accelerated by a lower pH and a higher ionic strength, respectively. All the results indicated that the chitosan/starch fiber was potentially useful in drug delivery systems.