Spray Dried Particles for Inhalation

The delivery of active ingredients through inhalation to the lungs has a history dating more than 4000 years, with origins in India and the Middle East. In the late 20th century, significant progress was reported, including the development of inhalation technology. It took 50 years to bring dry powder inhalers into the market. This was due to the limitations of strategies used for formulation of dry powder inhalers, which are key for commercialization of formulations. In that time, though, various technologies were developed. Among the many techniques, spray drying is promising because it is possible to produce the dry powder version of formulations with controlled shapes and sizes, with key properties for inhalation and scalability for commercialization. In this chapter, we discuss spray drying technology, the influence of various parameters on product properties, and applications of spray drying in the formulation and delivery of drugs, genes, and vaccines. We also compare spray drying technology on the scale of the lab versus the industrial scale, advantages and limitations of each, and we also provide insights into possible future directions of this technology. We also discuss various inhalation devices, commercial products, and the market for such technologies and products. Overall, this chapter provides an overview of the present status of spray drying technology for the formulation of dry powder inhalation treatments for lung diseases. Still, there is a prospective for dry powder inhalation technologies and a wide scope for researchers to explore different biomedical applications.