DESCRIPTORS OF IRREGULAR PARTICLE MORPHOLOGY AND POWDER PROPERTIES

The description of irregular particle morphology and powder properties may offer unique insights into the performance of materials intended for use in dry powder inhalers. A number of mathematically similar app roaches have been used to study these phenomena, all based on evaluati ng data in terms of irregular oscillations around a mean value. The sp ecific methods described are Fourier, fractal and chaos analysis, stoc hastic and percolation models. Data describing the morphology of disod ium cromoglycate particles, the behaviour of lactose and sodium chlori de powders and dispersion of Intal(R) (disodium cromoglycate/lactose b lend) utilizing a Spinhaler(R) is presented to demonstrate the applica tion of these approaches to dry powder inhaler systems. It is envisage d that these techniques may be used to characterize powders with a vie w to guiding formulation and that ultimately this may lead to a greate r understanding of the nature and magnitude of performance variables. (C) 1997 Elsevier Science B.V.