DEVELOPMENT OF ENZYMATICALLY DEGRADABLE PROTECTIVE COATINGS FOR USE IN TRIGGERED DRUG DELIVERY SYSTEMS - DERIVATIZED STARCH HYDROGELS

Starch is a common polysaccharide which consists of glucopyranose residues in an α-D-(1-4) linkage that yields D-glucose upon hydrolysis. Saturated aqueous solutions of soluble starch are easily reacted in the presence of glycidyl methacrylate to produce methacrylate grafted starch. Grafted starch solutions were polymerized to produce hydrogels, with and without the addition of an unsaturated acid. The grafted starch solutions and the resulting hydrogels are both shown to be degraded by the enzyme α-amylase. These acidic hydrogels are potentially useful as enzymatically degradable protective coatings in self-regulated drug delivery system applications. The pH of an acidic starch hydrogel required by this self-regulated drug delivery system does indicate that an adequately acidic hydrogel can be produced. © 1990.