Substituted amylose as a matrix for sustained-drug release: a biodegradation study.

Substituted amylose polymers are prepared by reacting amylose chains with a suitable substituent such as 1,2-epoxypropanol (glycidol). Substituted amylose polymers are introduced as novel excipients for controlled release of bioactive materials. Since substituted amylose polymers are amylose-based polymers, they are subject to biodegradation by alpha-amylase enzymes present in the gastro-intestinal tract; thus, gamma spectroscopy is used to follow the release of the natural abundant rhenium (VII) oxide used as a drug model, and to test their resistance to alpha-amylase enzymatic degradation. Two substituted amylose solid dosage forms were prepared: (i) matrix system and (ii) dry-coated tablets. Matrix systems and dry-coated tablets maintained their structure, and controlled the release of [186Re] showing no significant degradation of tablets by alpha-amylase.