Drug Release from Inert Spherical Matrix Systems Using Monte Carlo Simulations.

Area of Science:

• Pharmacokinetics and Drug Delivery
• Computational Modeling
• Materials Science

Background:

• Predicting drug release from matrix systems is crucial for understanding drug delivery.
• Computational approaches offer a way to model and predict these complex behaviors.
• This study focuses on inert spherical matrix systems of varying sizes.

Purpose of the Study:

• To investigate drug release dynamics from spherical matrix systems using computer simulations.
• To determine the influence of matrix size and drug load on drug release.
• To identify and characterize the drug percolation threshold in these systems.

Main Methods:

• A cubic lattice model was employed to simulate the spherical matrix.
• Drug and excipient particles were randomly distributed based on chosen ratios.
• Drug release was simulated as a diffusion process.

Main Results:

• The Weibull equation accurately described release profiles up to 90%.
• Anomalous release was observed near the percolation threshold; Fickian release occurred at drug loads >0.45.
• A model involving the error function described the relationship between trapped drug and initial drug load, enabling determination of the percolation threshold.

Conclusions:

• The determined drug percolation threshold aligns with predictions from percolation theory.
• Computational simulations provide valuable insights into drug release mechanisms from matrix devices.