The aim of this presentation is to firstly review the development of the powders for inhalation and dry powder inhalers over the past twenty-five years to assess the developments in the formulation science of powders and to examine its translation into pharmaceutical products and, secondly to try to vision the development of the next twenty-five years of respiratory powder drug delivery and consider some of the drivers that will dictate the development of science and products up to 2040.
Introduction
Powders for inhalation were developed about 50 years ago. Two strategies were used. One of these strategies involved the addition of micronized drugs to larger carrier particles, usually lactose, to produce an interactive mixture. In recent years, fine lactose was added to the mixture to improve aerosolisation. The other strategy used only micronized drug powder, sometimes with fine lactose. The powder mixtures were aerosolised using an inhalation device providing the fine drug particles for delivery to the lungs in a somewhat inefficient manner with only a relatively small particle fraction entering the intended target in the deep lung.
The formulation and delivery approaches were somewhat pragmatic and it was not until the early 1990s that these powders received significant attention from the powder scientists…