Student Research Projects

Analysis of the Kinetics and Products of the Hydrolysis Reaction of Methylene Blue

Student Keane Dye, '16
Faculty Mentor(s)
Department Chemistry
Course Chemistry 480: Instrumental Methods of Analysis

Abstract

Methylene blue has been utilized for numerous medicinal purposes over the past century. In our research it been studied as a model drug for release from poly acrylic acid and poly allylamine hydrochloride (PAH /PAA) thin films. Despite the use of methylene blue in these studies it is still not fully understood how methylene blue is delivered under physiological conditions, or what the final product upon release. This project studied the kinetics of a possible reaction of methylene blue in basic solution, specifically its hydrolysis at standard physiological conditions (pH and temperature). Additionally we attempted to isolate and determine the hydrolysis product by UV-visible spectroscopy and Gas Chromatography-Mass Spectroscopy (GC-MS). The kinetic studies show that methylene blue is not readily hydrolyzed under physiological conditions. However, under strongly basic conditions nearly all of the methylene blue is converted into the hydrolyzed product, thiazine dye methylene violet, in less than 24 hours. GC-MS analysis is consistent with this product. These results demonstrate that PAA/PAH films may serve as time-release drug delivery system. This research may be applied to areas of medical research attempting to develop reliable transdermal drug delivery systems utilizing a variety of structurally diverse pharmaceutical compounds.