Patent Evaluation: Dextrin and concanavalin-A matrix as a drug delivery system

Abstract

Novelty: A controlled drug delivery system is provided for the release of an unconjugated drug immobilised in a biocompatible matrix. The system may be used to treat disorders such as diabetes or bacterial infections. Insulin may be immobilised in the matrix with dextran (containing glucose moieties) and concanavalin-A (glucose receptor). The binding of dextran to concanavalin-A is reversed with increased concentrations of free glucose in the physiological environment. The free glucose displaces dextran-glucose from this receptor causing a conformational change in the matrix and the desired release of insulin.

Biology: In witro studies using nitrofurantoin were performed and results presented in figures.

Chemistry: Syntheses are not provided as the compounds are known. The system is based on a lectin, such as concanavelin-A. This is in the form of glucose moieties of dextran which is the basis of the matrix in which the drug is immobilised. The mamx may be enclosed inside a non-erodible material such as an acrylic permanent gel covalently cross-linked in situ to prevent escape of the concanavelin.