(M0930-03-18) Film-Coated Hard Capsules for Dry Powder Inhalers: Improving Inhalation Efficiency and In-Use Stability

Purpose: Capsule-based dry powder inhaler (DPI) formulation is used for pulmonary administration. However, the drug-containing capsule properties change depending on storage condition and affect the inhalation efficiency. film coating can protect internal materials from outer circumstance. The objective of this study is to prepare and evaluate film-coated hard capsules for DPI formulation that can protect inner capsules from external stress.

Methods: HPMC-based capsules containing spray-dried mannitol: L-leucine (95:5, w:w) were film-coated using a pan coater with a PVA-based coating agent. The aerodynamic performance of the coated capsules stored under long-term (25ºC, 65%RH) and accelerated conditions (40ºC, 75%RH) was evaluated by calculating the emitted dose (ED) and fine particle fraction (FPF) with the next-generation impactor.

Results: Under accelerated storage conditions, the capsules coated with 30% PVA showed significant ED and FPF compared to other capsules. PVA-based coating agents showed improvements in inhalation efficiency indicators such as ED and FPF under certain conditions, and it is possible to infer an improvement in stability.

Conclusion: Film-coated hard capsules increased in-use stability in aerodynamic performance. This study has the potential for proposing new methods to improve inhalation efficiency and stability of capsule-based dry powder inhalers.

Acknowledgements:This research was also supported by "Regional Innovation Strategy (RIS)" through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (MOE)(2021RIS-001).