What is the role of particle morphology in pharmaceutical powder aerosols?

Background: The aerosol performance of a powder for inhalation drug delivery is controlled by a number of physicochemical properties of the formulation, including particle size, density and morphology. Objective: The role of particle morphology in powder inhalers will be reviewed. Methods: Original research publications in the literature about the contribution of particle morphology to the aerosol performance of pharmaceutical powders have been selected, including both the lactose carriers and the drugs. Results/conclusion: Existing data showed that morphology of both the lactose carrier and drug particle can affect the aerosol performance of powders significantly, a factor which should be taken into consideration during the development of dry powder inhalation products.