Contramid® : High-amylose starch for controlled drug delivery

Contramid® is a novel pharmaceutical excipient obtained by chemically and physically modifying a high-amylose corn starch. When a compressed tablet of Contramid® powder is placed in an aqueous medium, the material forms a hard gel displaying sponge-like viscoelastic properties. When observed by x-ray tomography, the gel reveals a membrane at its surface which governs the slow release of medication. Basic starch properties responsible for Contramid®'s slow release behavior are reviewed and used to explain the mechanism of self-assembly behind the controlled drug delivery technology. Characteristics of Contramid® such as diffusion and enzymatic susceptibility are also presented.