Predicting Microstructure Development During Casting of Drug Eluting Coatings

Published

September 19, 2010

Author(s)

David M. Saylor, Jonathan E. Guyer, Daniel Wheeler, James A. Warren

Abstract

We have devised a novel diffuse interface formulation to model the development of chem- ical and physical inhomogeneities, i.e. microstructure, during the process of casting drug eluting coatings. These inhomogeneities, which depend on the coating constituents and manufacturing conditions, can have a profound affect on the rate and extent of drug release and, therefore, the ability of coated medical devices to function successfully. By deriving the model equations in a time-dependent reference frame, we find that it is computationally viable to probe a wide, physically relevant range of material and process quantities. To illus- trate the application of the model, we have evaluated the impact of manufacturing solvent, coating thickness, and evaporation rate on microstructure development. Our results suggest that modifying these process conditions can have a strong and nearly discontinuous effect on coating microstructure and, therefore, drug release. Further, we demonstrate that the model can be applied to processes that involve the incremental application of the coating in layers or passes. This new model formulation, which can also be used to predict the kinetics of drug release, provides a tool to elucidate and quantify the relationships between process variables, microstructure, and performance. Establishing these relationships can reduce empiricism in materials selection and process design, providing a facile and efficient means to tailor the underlying microstructure and achieve a desired drug release behavior.

Citation

Journal of Controlled Release

Volume

7

Pub Type

Journals

Download Paper

DOI Link

Keywords

microstructure, coating, modeling, simulation, di¿usion, stent

Citation

Saylor, D. , Guyer, J. , Wheeler, D. and Warren, J. (2010), Predicting Microstructure Development During Casting of Drug Eluting Coatings, Journal of Controlled Release, [online], https://doi.org/10.1016/j.actbio.2010.09.019 (Accessed December 8, 2024)