Title: Using agglomerate breaking to model the performance of dry powder inhaler formulations

Author (Invited): Valeriu Damian-Iordache, GlaxoSmithKline

Abstract:

Modeling the delivery of dry powders to the lungs is a complex multi-scale, multi-physics problem. This talk briefly describes the issues related to the delivery of drugs to the lungs and set up the modeling problem. I'll will then show the intrinsic multi-scale nature of the problem both in time and space and show that a brute force modeling approach is not computationally feasible. A few key observations will suggest a computationally tractable approximation and modeling strategy based on agglomerate formation and breaking. The forward simulation combines an ODE based model for the evolution of the inter-particulate forces under the influence of the environmental conditions with a DEM based model for the blending and aerosolization processes. The modeling approach is further adapted for use in a multi-experiment optimization in order to estimate several inter-particulate force parameters based on several available experimental data sets. I'll also present some of the simulation results showing how they can be used for designing stable dry powder inhaler formulations. I'll conclude with some of the key challenges in modeling pharmaceutical powders.