Half a Century of Technological Advances in Pulmonary Drug Delivery: A Personal Perspective
The last half century of pulmonary product development is reviewed in the context of the main drivers of innovation, technology development, and the advancement of science. A perspective on development timeframes, patent lifetimes, and the odds of success of developing of new inhaler technologies is presented.
Inhalation therapy has been documented in various forms for over 2000 years and has likely been practiced in some form for much longer than that (Stein and Theil, 2017). However, the modern era of inhalation therapy corresponds, not surprisingly, with the rise of modern pharmacology, a deeper understanding of the biology underlying respiratory diseases, and an elucidation of airway structure, aerosol transport, and deposition (Clark, 1995).
During the early part of the 19th century significant advances in the discovery of drugs to treat asthma (Andersen et al., 2022) (beta agonists, corticosteroids, and anticholinergics) were setting the stage for a transition from early nebulizer devices to more advanced delivery systems. In 1956, 3M invented the now ubiquitous pressurized metered dose inhaler (pMDI) (Thiel, 1996); and in the late 1960s, Fisons Pharmaceuticals invented lactose carrier blends and the Spinhaler (Bell et al., 1971), which became the precursor to the modern dry powder inhaler (DPI). The basic delivery technologies that have evolved over the past half century can best be described as small personal portable aerosol generators, and they can be divided into four major classes utilizing three physical “forms” of drugs. The various technologies have different operating characteristics, patient interface/user requirements, and dose limitations.
Clark AR (2022) Half a Century of Technological Advances in Pulmonary Drug Delivery: A Personal Perspective. Front. Drug. Deliv. 2:871147. doi: 10.3389/fddev.2022.871147