Date of Award
Master of Science in Chemical Sciences (MSCB)
Dr. Marina Koether
Dr. Michael Van Dyke
Dr. Huggins Msimanga
Aspartame (C14H18N2O5) is a well-known artificial sweetener that has been around since the 1900s and is considered 200 times sweeter than sugar. Its main purpose is to serve as a sugar substitute in “diet” food and beverages. It is also consumer friendly by having a high availability, and an affordable price. Additionally, aspartame is found in many pharmaceutical drugs to mask the bitter taste of the active pharmaceutical ingredient (API). For instance, lozenges are solid intraoral dosage forms intended to slowly release the API into the oral cavity. Aspartame is used in lozenges to impart a sweet taste while an API is administered orally. Since both the API and aspartame are uniformly distributed in the lozenge, aspartame can be used as a surrogate for some API’s, such as menthol, when studying the kinetics of dissolution.
In this study, aspartame was analyzed in Halls and Ricola lozenges and other tabletop sweeteners such as NJoy, Natra, Equal powder and tablets. The dissolution test is one of the essential assays required to be passed before a drug product can be released for sale. The API must meet the listed requirement of percent dissolved in a certain time as found on the United States Pharmacopeia Monograph (USP) for that drug. The rate of dissolution is determined by a dissolution profile which shows the percent dissolved versus time. Dissolution tests measured the amount of lozenge dissolved versus time while different parameters such as stirring rate, temperature, dissolution media, and different pH’s were applied. Kinetic parameters such as activation energy, zero-order kinetics, and dissolution rate constants were determined. Aspartame was quantified by both a visible and UV method, and ultimately by ultra-HPLC. Dissolution profiles, kinetics, and figures of merit from the different assays are reported.
Available for download on Monday, May 10, 2027