Engineering Diffusion-Controlled Drug Delivery Systems to Achieve a Desired Drug Release Profile: Mathematical...

Area of Science:

• Biomaterials Science
• Pharmaceutical Engineering
• Computational Modeling

Background:

• Drug delivery devices offer localized treatment with reduced systemic side effects.
• Designing diffusion-controlled systems for predictable drug release profiles is a significant challenge due to time-varying release rates.

Purpose of the Study:

• To develop a mathematical framework for the rational design of diffusion-controlled drug delivery systems.
• To enable the achievement of desired therapeutic drug release profiles.

Main Methods:

• A continuum-scale mathematical model was developed for diffusion-controlled drug release from spherical microcapsules.
• Functionally graded polymers with spatially varying diffusivity and non-uniform initial drug distribution were modeled.
• An inverse optimization procedure using a hybrid imperialist competitive algorithm was employed to identify design variables.

Main Results:

• Achieving a constant (zero-order) drug release rate is possible by optimizing initial drug distribution and diffusivity.
• More complex, general release profiles necessitate the simultaneous optimization of spatially varying diffusivity and initial drug loading.

Conclusions:

• The proposed framework successfully integrates mathematical modeling and optimization for rational drug delivery system design.
• This approach enables the creation of diffusion-controlled systems capable of producing tailored therapeutic release behaviors.