A Novel Mathematical Model to Predict The Particle Size Distribution of pMDI Aerosols
H Chizari1, HK Versteeg2, W Malalasekera2 & B Gavtash1,
1Kindeva Drug Delivery, Derby Road, Loughborough, LE11 5SF, UK
2Wolfson School of MEME, Loughborough University, Ashby Road, Loughborough, LE11 3TU, UK
Summary
This paper introduces a fundamental method to estimate droplet size distribution in aerosols from pressurised metered dose inhalers (pMDIs). Accurate droplet size representation is vital for estimating drug deposition. Using the instability equation by Reitz et al., we calculate droplet size based on fast-growing wave modes. The slip velocity, a crucial parameter, is adjustable in our model. Comparing predictions with experimental data shows good agreement for HFA134a and HFA227ea aerosols with minor slip velocity adjustments. This model is essential for predicting droplet distribution and calculating drug deposition in the USP-IP throat.