Evaluation of parameters involved in preparation and release of drug loaded in crosslinked matrices of alginate.

Parameters affecting the characteristics of the drug loaded crosslinked sodium alginate matrix films and the release of metoclopramide hydrochloride and cisapride from these matrices were studied. It was shown that the release rate is influenced by the crosslinking technique of the matrix film, crosslinker type and concentration, drug physico-chemical properties especially solubility and the molecular weight, acidity of the release medium, concentration and the loaded quantity of the drug in the matrix. The crosslinking process of the matrix film was shown to be an interfacial phenomenon and the nature of crosslinking depends on the crosslinker type and concentration. This work also showed that crosslinked alginate in a matrix form has limitation in practical use due to the effect of acidic medium on the crosslinking of the matrix film and hence, the rate of drug release.