The Effect of Configuration to Interaction Energy Between The Segments of Chitosan and Ascorbic Acid Molecule: Theoretical Study of Drug Release Control

Abstract

Polymer systems plays an important role in drug delivery, which can control the time release of the drug, reduce the rate of degradation of the drug, and can reduce the toxic properties of the drug. Chitosan is a polymer of N-acetyl glucosamine that is biocompatible, biodegradable, and have active groups that can be used as a drug carrier matrix to control the release rate of the drug in the human body. The related research has been conducted experimentally by applying chitosan as a matrix to control the release rate of ascorbic acid by in vitro in an aqueous medium. So that, this study aimed to describe the interactions that occur between segments of chitosan and ascorbic acid theoretically using ab initio computational methods. Software used is Gaussian03, while the level of theory and basis set calculations determined is HF-SCF / 6-31G (d, p). The results for the nine configuration interaction calculations indicate hydrogen bonds between ascorbic acid molecules and chitosan segment. The interaction energy obtained is different for each configuration. It can be used as a basis for explaining the gradual release of ascorbic acid molecule from chitosan matrix. Ascorbic acid molecules that bound to the matrix of chitosan with lower energy will be easier to release on the medium that used.