Powder performance

Abstract

Ternary blends for pulmonary drug delivery are increasingly important, as the success of the combination product Advair/Seretide shows. Model formulations of albuterol in two lactose grades of differing dispersity and fine lactose fraction are decribed here. After actuation into the Electrical Low Pressure Impactor (ELPI) using a Rotahaler DPI device, the mass of drug and lactose found on each ELPI stage was assayed. The deposition profile did not reflect the primary particle size distribution and varied across the stages. Charges on particles of different size for a given formulation and between formulations varied significantly, which may have implications for product performance.