Abstract

Technology for inhalation drug delivery has been continually evolving over the past two decades. The current situation is that while nebulizers remain as a niche market for preferred users, major development has occurred in the propellant-driven metered-dose inhalers (MDIs) and particularly the dry powder inhalers (DPIs). For MDI, Stein and Fradley (2010) believed that “future MDIs will not be radically different from existing MDIs.” They predicted the future trend will be on the dose counters, canisters with internal coating to reduce drug adhesion, valves with fast fill and empty designs to minimize the need for priming, actuators with special mechanism to slow down the aerosol plume (thus reducing oropharyngeal deposition), novel elastomers to reduce leachables, new suspending agents, and engineered particles to improve formulation quality (1). In contrast, DPI technology is still undergoing a changing phase, and disruptive innovation is yet to appear in the scene. Development of DPI is particularly challenging involving production of fine drug particles, formulation approaches, inhaler device design, and interface with the patient usage. All of these areas are progressing with sustaining technologies toward personalized treatment in the future (2,3). This chapter will focus on some key aspects of the emerging technologies for the DPIs.