Factors influencing drug deposition in the nasal cavity upon delivery via nasal sprays

Background In nasal drug delivery system, nasal spray seems to be the most promising delivery method for both local and systemic diseases therapy. Nasal deposition behavior is the most basic and important process for nasal sprays, which is related to nasal mucociliary clearance, retention of a formulation in the nose therefore the therapeutic effect. Area covered The present paper systemically summarized and discussed the factors influencing drug deposition in the nasal cavity upon delivery via nasal sprays, including device, formulation and administration techniques. Emitted dose volume of the device, spray pattern and plume geometry, droplet size distribution and velocity of emitted droplets were important device factors influencing nasal deposition. Besides, viscosity, thixotropic property and surface tension were considered to be the formulation factors influencing nasal deposition of spray. In addition, administration technique influencing nasal deposition included head orientation, administration angle, insertion depth of spray nozzle and breathing profile. Meanwhile, the imaging methods used to predict and visualize the deposition of nasal formulation was illustrated. Expert opinion The review provided important theoretical and experimental knowledge to control the deposition pattern of nasal sprays in order to achieve better therapeutic effect in the clinic.