2.5.3. Ex Vivo Mucoadhesion

The texture analyzer TA-XT2 (MicroSystems) was used in the adhesion test mode. The nasal mucosa used in the mucoadhesion and permeation assay was obtained from pigs from a local slaughterhouse (Araraquara, São Paulo, Brazil). The mucosa was removed from the nasal cavity with the aid of surgical scissors and scalpel. The nasal mucosa was fixed in the cylindrical probe of the equipment (10 mm diameter). The formulations (8 g) were placed in tubes below the analytical probe and maintained at 32 °C. The probe went down at constant speed (1 mm s⁻¹) until the mucosa encountered the formulation’s surface, keeping in contact for 60 s without force under samples. After that time, the nasal mucosa was separated from the hydrogels and detachment force was registered, indicating the bioadhesion strength (N). The analyses were performed in five replicates, at 32 ± 0.5 °C.