Chapter 7: Inhalation Devices and Formulations

As therapeutic products that combine drug(s) and device, orally inhaled drug products are classed as combination drug products, with both the drug formulation and delivery device (and its interface to the patient) influencing delivery of a reproducible dose and its particle size distribution. Maintaining these product quality attributes through shelf life and assuring equivalence of product performance pre-/post-implementation of changes during the product lifecycle (e.g., input materials, manufacturing site, test methodologies, etc.) present a not insignificant challenge to the product manufacturer. Most currently marketed inhaled products employ local delivery of small molecule therapeutics to treat respiratory diseases (e.g., asthma, COPD, cystic fibrosis), delivered at low dose (<10 mg)and with an immediate release profile governed by deposition site within the lung and biopharmaceutical properties of component API(s). Delivery of novel modalities demands innovative solutions for delivery of large molecules (e.g., peptides and proteins, siRNA, vaccines), higher doses and products with a modulated release profile. Covering aspects of drug formulation, device design, product manufacture, analytical testing and materials characterisation, the aim of this chapter is to review how recent advances in the scientific understanding of inhaled products can improve control and prediction of product quality/process performance for marketed products and enable development of innovative products.