Fibers of alginate and polyethylene glycol (PEG), 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 CaCl(2) and ethanol. Chemical, morphological, and mechanical properties characterization were carried out, as well as the studies of the factors that influence the drug releasing from alginate/PEG fibers. These factors included the component ratio of alginate and PEG, the loaded amount of SA, the pH, and the ionic strength of the release solution and others. The best values of the tensile strength at 13.41 cN/tex and breaking elongation at 23.13% of blend fibers were obtained when the PEG content was 5 wt %; the water swelling ratio (WSR) of blend fibers increased as the composition of PEG was raised. The results of controlled release tests showed that the amount of SA released increased with an increase in the proportion of PEG 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 alginate/PEG fibers were also sensitive to pH and ionic strength. For pH 7.4 the drug release was faster compared to pH 1.0, being simultaneously accelerated by a higher ionic strength. All the results indicated that the alginate/PEG fiber was potentially useful in drug delivery systems.
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