A long nozzle for intra-nasal drug delivery by pMDI: prediction of spray velocity and droplet size

Intra-nasal drug delivery via nasal pressurized metered-dose inhalers (nasal-pMDI) is very successful in delivering treatment of conditions of the anterior regions of the human nasal cavity, such as rhinitis and sinusitis [1]. Intranasal drug delivery has also been postulated as a potential technique to treat central nervous system (CNS) diseases by delivering CNS-active drugs to the olfactory region – positioned at the upper region of the nasal cavity [1]. Our in-house in-vitro data suggest that the olfactory region can be targeted more accurately by extending the nasal pMDI nozzle length. Such nozzle length extension can potentially impact spray characteristics such as velocity, which directly determines the deposition efficiency [2]. In this work we report the development of a modeling tool validated by particle image velocimetry (PIV) and laser diffraction (LD) measurements, to predict the velocity and droplet size delivered from a long nozzle solution pMDI.