Background: Nowadays, inhaled corticosteroids have become the core of therapy for patients with asthma and chronic obstructive pulmonary disease (COPD). Fluticasone propionate (FP) is among the most lipophilic steroids (water solubility ~ 0.1 mg/ml) and its clinical efficacy has been confirmed in many studies. The inclusion of different carrier materials in a dry powder inhaler (DPI) system can alter formulation performance, which might be attributable to variation in the adhesion between drug and carrier particles.

Materials and methods: To this aim, we used two different carriers to be mixed in different times with drug on the one hand to facilitate the powder flow during manufacturing, and on the other hand to help fluidization upon patient inhalation. The prepared DPI formulations were examined in terms of drug content uniformity upon the physical blending, particle shape, and in vitro pulmonary deposition. The latter was determined using an Andersen cascade impactor and Cyclohaler® as a single-dose DPI.

Results: Our results revealed that the highest fine particle fraction (FPF) and fine particle dose (FPD) value belonged to the formulation contained FP: mannitol, mixed in 30 minutes.

Conclusion: It can be concluded that using mannitol as the coarse carrier can improve the physical properties as well as the aerosolization behavior of the resultant DPI formulations.

Keywords: Dry powder inhaler (DPI), Fluticasone propionate, Lactose, Mannitol.