Drug dissolution is a test to measure the amount of active ingredients released in a specific dosage form. Drug effectiveness depends highly on bioavailability, which is how well a substance becomes completely available for its intended destination. The active ingredients from a dosage must dissolve to a large extent before they can be absorbed into the body. Once absorbed into the gastrointestinal lumen, the active ingredient then proceeds into the circulatory system where it binds to a receptor. The major determinant of a drug’s dissolution rate is the solubility of the drug in an aqueous medium. Other factors that can increase or decrease drug dissolution include viscosity of the gastrointestinal fluid, the radius of the drug particle, polymorphism, and the pH of the gastrointestinal fluid. The United States Pharmacopoeia (USP) describes apparatus and dissolution media for evaluating the dissolution rate of drugs. Using aspirin as a model, experiments have been performed that evaluated the effect of pH on dissolution of a coated aspirin tablet. Solubility was shown to increase with increasing pH and the time for maximum dissolution was shortest for the higher pH values. Concentrations were determined by UV spectrophotometry. Future work will evaluate the mechanism for stirring the dissolution medium, and sampling techniques on both uncoated release and extended-release aspirin tablets. Additionally, a method using High Performance Liquid Chromatography for the analysis will be developed. The results of these experiments will be used to develop experiments that can be performed in analytical chemistry courses to demonstrate the principles of drug dissolution.

Dissolution's role in drug development

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.