Title : Milling to achieve the appropriate particle properties for inhalation, how can we rank or predict?

Authors : Mohammad Hossain Shariare & Frank J. J. Leusen & Marcel de Matas & Peter York & Jamshed Anwar

Abstract : Purpose To explore the use of crystal inter-planar d-spacings and slip-plane interaction energies for predicting and characterising mechanical properties of crystalline solids. Methods Potential relationships were evaluated between mechanical properties and inter-planar d-spacing, interplanar interaction energy, and dispersive surface energy as determined using inverse gas chromatography (IGC) for a set of pharmaceutical materials. Inter-planar interaction energies were determined by molecular modelling. Results General trends were observed between mechanical properties and the largest inter-planar d-spacing, interplanar interaction energies, and IGC dispersive surface energy. A number of materials showed significant deviations from general trends. Weak correlations and outliers were rationalised. Conclusions Results suggest that the highest d-spacing of a material could serve as a first-order indicator for ranking mechanical behaviour of pharmaceutical powders, but with some reservation. Inter-planar interaction energy normalised for surface area shows only a weak link with mechanical properties and does not appear to capture essential physics of deformation. A novel framework linking mechanical properties of crystals to the distinct quantities, slip-plane energy barrier and inter-planar interaction (detachment) energy is proposed.

Journal : Volume : Year : 2011 Issue :
Pages : City : Bath, UK Edition : Editors :
Publisher : Academy of Pharmaceutical Sciences, UK ISBN : Book : Chapter :
Proceeding Title : APS Inhalation’ University of Bath, UK Institution : Issuer : Number :