OXPRENOLOL RELEASE FROM BIOADHESIVE GELATIN POLY(ACRYLIC ACID) MICROSPHERES/

Drug release from gelatin/poly(acrylic acid) oxprenolol-loaded microsp heres has been evaluated using an in situ sink immersion method and a wetting method. The kinetics of drug release were analysed by applying the empirical exponential equation and by the calculation of the appr oximate contribution of the diffusional and relaxational mechanisms to the anomalous release process by fitting the data to the coupled Fick ian/Case II equation. The influence of glutaraldehyde cross-linking ag ent concentration, the poly(acrylic acid) content, the pH of the relea se medium and the particle size of the heads on the drug release kinet ics were evaluated and discussed.