Rudie Damhuis

Dry powder inhalers (DPIs) contain a powder which, when required, is discharged and inhaled. The therapeutic drug is manufactured in powder form as small particles a few micrometres in diameter. In many DPIs, the drug is mixed with much larger sugar crystals, such as lactose, and the smaller drug particles attach to these excipient particles, improving entrainment of the drug upon inhalation. This article examines how the application and combination of versatile processes such as milling, micronizing, sieving and air classification can be used to manufacture dedicated lactose products for practically every possible combination of active and excipient blend in DPIs.