RESUMO
Salbutamol sulfate beads were prepared using anionic and cationic polysaccharides, Gelrite and chitosan, respectively. Alginate beads were also prepared for comparison. The mean diameter, porosity, and drug content of the beads were determined. The beads were examined by scanning electron microscopy (SEM), DSC, and x-ray diffraction. The drug release from the beads was studied in 0.1 N HCl (pH 1.2), distilled water, and phosphate buffer (pH 7.4). The physical examination of the beads indicated the presence of drug crystals with no interaction between the drug and polymers. The drug release was dependent on the ionic properties of the polymers and the pH of the release media. In acidic pH, chitosan beads showed a rapid drug release, whereas a sustained drug release was obtained from Gelrite beads. In contrast, the drug release in phosphate buffer was rapid from Gelrite, and chitosan showed a sustained drug release. The results of drug release from Gelrite were comparable to that from alginate beads. Gelrite is recommended as an anionic polysaccharide for sustained-release preparations.
