(751e) Theoretical Prediction of Drug Released Into GI Tract From Spherical Nanoparticles: Analysis of the Affect of Finite Dissolution Rate and Rate of Absorption

The significance of controlled release drug delivery systems lies in their ability to deliver the drug at a steady rate thus reducing the dosage interval and providing a prolonged pharmacodynamic effect. Mathematical modeling of these drug delivery systems could help us understand the underlying mass transport mechanisms involved in the control of drug release. Mathematical modeling also plays an important role in providing us with valuable information such as the amount of drug released during a certain period of time or when the next dosage needs to be administered. Thus, potentially reducing the number of in-vitro and in-vivo experiments which in some cases are infeasible. There is a large spectrum of published mathematical models and approaches describing drug release from various types of controlled drug delivery devices. Most of these models focus on drug release into a perfect sink condition. However in a real system absorption and elimination process of the drug occur in parallel to drug release process especially when the drug delivery system is expected to stay within the human body for a period of few weeks or even months. Various physiological factors such as gastrointestinal tract (GI) pH, stomach emptying, (GI) motility, presence of food etc., affect the rate of absorption which inturn affects the drug release process. As the physiological parameters are not taken into consideration during model development discrepancies arise in the drug release behavior in vitro and in vivo. In this work a mathematical model is developed for drug release from spherical nanoparticles consisting of slowly dissolving drug particles. The affect of absorption rate and slow dissolution rate on drug release behavior is studied.