Summary

A particle profile of the active pharmaceutical ingredient (API) fluticasone propionate (FP) was produced using previously validated molecular modelling techniques. The Tripos 5.2 ^[1] and Dreiding II ^[2] molecular mechanics potentials were used to calculate crystalline FP’s lattice energy, attachment energy, morphology and surface chemistry. Predicted morphologies partially resemble previous experimental examples and both force fields predict the {001} form is prominent. Also, it is predicted that post micronisation the {10-1} and {11-1} forms would be prominent. This would increase particle cohesivity as surfaces in {11-1} directions are prone to forming hydrogen bonds. Performing an in-silico study is important as it can form the basis of predicting particle interactions at the molecular scale. Improving the understanding of how particles interact with each other and with other materials in the canister of the delivery device will aid the process of material selection in formulation development.

Key Message

Molecular modelling techniques have identified prominent faces of crystalline FP particles. Additionally, the surfaces most likely to appear after micronisation were predicted. This work can be utilised further to study particle interactions between materials of interest within pressurised metered dose inhalers (pMDIs).