Release kinetics of drugs from rosin-glycerol ester microcapsules prepared by solvent evaporation technique

Rosin-glycerol ester microcapsules containing sulphadiazine were prepared by solvent evaporation technique. The goodness of fit of the release data was tested with first order, Higuchi matrix model and Hixon-Crowell cube root law. All these models were sufficiently linear. Application of the differential rate treatment showed that release from most of the microcapsules followed first order equation. Whereas up to 40-50 per cent of release, a zero order, membrane controlled kinetics was observed, the release is apparently first order under nonsteady, state conditions.