From in vitro studies to product information useful for patients: Evaluation of physical properties and the stability of nasal spray devices containing hydroxypropyl methylcellulose-based liquid and powder formulations.

Hydroxypropyl methylcellulose (HPMC)-based formulations are commonly used in nasal sprays due to their gelling and viscosity-enhancing properties. However, data on in vitro studies that mimic patient use remain limited. This study investigated two commercial HPMC-based aqueous formulations and HPMC-based powder formulations to provide an understanding of the relationship between the physical properties, their performance, and the stability of nasal products. Physical properties, quality tests focused on shot mass and shot volume were assessed. The coverage area within the nasal cavity was examined at various angles of actuation (15°, 30°, 45°, and 80°) using a simulated inhalation model. The 45° spray angle exhibited the highest coverage area (%) within the nasal cavity. Devices containing liquid formulations demonstrated more reproducible shot mass and shot volume compared to dry powder preparations. These findings provide valuable insights for patients and manufacturers, leading to a better understanding of optimal usage and formulation effectiveness.