Modeling drug release from bioerodible microspheres using a cellular automaton

Area of Science:

• Biomedical Engineering
• Materials Science
• Computational Chemistry

Background:

• Conventional mathematical models for drug release from microspheres often rely on curve fitting, limiting generalizability.
• Understanding polymer erosion and drug diffusion dynamics is crucial for optimizing drug delivery systems.

Purpose of the Study:

• To develop a novel three-dimensional cellular automaton model for simulating drug release from biodegradable microspheres.
• To independently model polymer erosion and drug diffusion processes.
• To provide a more generalizable and insightful approach compared to conventional methods.

Main Methods:

• A 3D cellular automaton model was developed, utilizing millions of cells representing polymer, drug, pores, and solvent.
• Polymer erosion was simulated based on cell life expectancy and solvent proximity.
• Drug diffusion was modeled as random diffusion from drug-containing cells to solvent-containing cells.

Main Results:

• Simulations showed good correlation with experimental drug release data at different pH levels.
• The model successfully captured key drug release phases, including burst and sustained release.
• Graphical outputs from the model were comparable to Scanning Electron Microscopy (SEM) images.

Conclusions:

• The cellular automaton model offers a powerful tool for understanding and simulating drug release phenomena from biodegradable microspheres.
• This approach provides valuable insights into the interplay of erosion and diffusion in drug delivery systems.
• The model demonstrates potential for improved prediction and design of drug delivery devices.