ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Precautions in using global kinetic and thermodynamic models for characterization of drug release from multivalent supports

Gheorghe Maria and Ionela Luta

Department of Chemical & Biochemical Engineering, University Politehnica of Bucharest, P.O. Box 35-107, Bucharest, Romania

E-mail: gmaria99m@hotmail.com

Abstract: Building-up a detailed kinetic model for drug release from various supports is a difficult task, especially when chemical reactions take place, accompanied by adsorption-desorption and diffusion steps. Often, semi-empirical release models derived from theoretical formulations of the transport process and system characteristics are employed. Their parameters have limited validity as they are dependent on the support, drug-ligand properties, and release conditions. However, they are often used for a quick simulation and design of drug delivery systems with a controlled release correlating the model parameters with the system characteristics and release conditions. Detailed information allows elaboration of an extended mechanistic model; the bias in the predictions introduced on various levels of model simplification is presented in this paper. A case study of a chemically activated ligand release in human plasma from a multivalent dendrimeric support is approached, pointing out the imprecision introduced by the gradual simplification of an extended model as well as the low reliability of the prediction when using various semi-empirical global models.

Keywords: drug release – dendrimers – isothermal kinetics – model reduction

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-011-0041-2

Chemical Papers 65 (4) 542–552 (2011)