Dynamics of controlled release of heparin from swellable crosslinked starch microspheres.

The microspheres of crosslinked starch have been prepared and characterized by IR spectral analysis and SEM technique. The prepared microspheres were loaded with an anticoagulant drug 'heparin' and the kinetics of in-vitro release of heparin was investigated spectrophotometrically at physiological pH (7.4) and body temperature (37 degrees C). The influence of percent loading of heparin, chemical architecture of the microspheres and pH of the release medium were examined on the release profiles of the drug. The chemical stability of heparin was tested in phosphate buffer saline (pH 7.4) and the release was also studied in various simulated biological fluids.