Excipients in DPI Formulations
Understanding how lactose and other excipients can affect formulation performance.
Because most conventional dry powder inhaler (DPI) products contain an extremely small dose of active pharmaceutical ingredient (API) in the form of a very fine, highly cohesive powder, the majority of DPIs rely on excipients, especially lactose, to overcome formulation performance problems. Although a few DPIs, such as AstraZeneca’s Turbohaler Pulmicort budesonide product, include no excipients at all, the majority of dry powder formulations contain inhalation grade lactose. The selection of specific characteristics of the lactose used, as well as the use of ternary excipients, can have a significant impact on handling, dose reproducibility, and respiratory deposition efficiency.