Modulating the Fine Particle Fraction, Surface Area and Surface Energy of a High Dose Fluticasone Propionate Formulation Using Isothermal Dry Particle Coating (iDPC) Technology

Rhys Jones1, Jasdip S Koner1, Shital Lungare1, Amandip Gill1, Isobel Clark1,2, David Wyatt1,2 & Afzal Mohammed2

1Aston Particle Technologies, Aston Triangle, Birmingham, B4 7ET, United Kingdom

2Aston University, School of Life & Health Sciences, Birmingham, B4 7ET, United Kingdom


Isothermal Dry Particle Coating (DPC) technology is a proprietary powder blending/coating technology that can be utilised to manufacture a range of DPI formulations due to its controlled and predictable formulation pathway. This study reported here was conducted to assess how iDPC can modify fine particle fraction (FPF) performance, surface area and total surface energy of a high dose fluticasone propionate (FP) (50%w/w) formulation by simply adjusting Critical Process Parameters (CPPs). A single FP formulation was processed in a series of experiments in which the rotation speed of the chamber (centrifugal force), gas flow rate in the fluidising air blade and the process time was varied. Twenty-three formulations were manufactured and analysed for aerodynamic particle size distribution. Five formulations across the range of FPF were selected for surface area and total surface energy analysis using an inverse gas chromatography–surface energy analyser. The surface area of these formulations ranged from 4.58–7.33m2/g and the total surface energy range heterogeneity analysis varied from 17.01–22.14mJ/m2. The ability to modify these values show that it may be possible to prepare high dose formulations with a targeted FPF performance through control of the iDPC process parameters. This level of control in dry powder inhaler (DPI) formulation manufacturing would circumvent trial-and-error practices used with existing technologies and improve the efficiency of DPI formulation development. Further research is ongoing to fully understand the effects of each of the three critical process parameters on the surface area and surface energy of DPI formulations and their FPF performance.

Key Message

High dose DPI formulation manufactured by iDPC enables the systematic manipulation of FPF performance, surface area and surface energy of the formulation.