Background: Recently, nasal drug delivery has emerged as a convenient modality for the treatment of multiple, allergic, infectious, and inflammatory sinonasal conditions. Some patients report discomfort and irritation associated with the pressure and flow generated by using typical atomizers which may lead to decrease patient compliance and lower satisfaction. We sought to develop a rather gentle atomizer for nasal irrigation that would ameliorate the discomfort associated with nasal drug delivery. Herein, we report the development of an atomizer via fluid dynamics modeling and evaluating the patient experience.
Methods: Using computational flow dynamics modeling, we assessed the distribution of atomized droplets to compare the conventional narrow-angle (NA) Vs a new open-angle swirling effect (OSE) atomizer. The goal for the new atomizer was to generate a swirling effect by opening a spray cone from a tapered nozzle bottle at different head tilted positions to determine the most efficient one that would enhance drug delivery and aid in patient comfort. Once the best computational model was generated and the atomizer developed, a group of 13 healthy volunteers consented to participate in the performance evaluation of the two atomizers (NA and OSE). Participants gauged both atomizers for ergonomics, pressure, and comfort for drug delivery (saline). The participants' feedback was collected using the nozzle tip sensory attributes questionnaire.
Results: Atomizer Fluid Dynamics: The comparison was made between NA and OSE using the latest recommendation on the intranasal delivery angle of 45º with the nozzle 1.5 cm into the nose bypassing the nasal valve. The NA went 7cm into the nose, and hence generated high frictional pressure in the nasal mucosa. On the other hand, the OSE deliverd doses between 3 - 7 cm, thus generating less pressure. Patient Experience: 60% of the participants encountered irritation with the NA atomizer such as pain and a burning sensation. About 20% felt the OSE to be soft and pleasant, while 90% reported a misting sensation.
Conclusion: The results of the present study suggest that OSE is a viable and more comfortable system to deliver intranasal therapies. These findings shed light on our understanding of the fluid flow dynamics to design extra efficient and comfortable atomizers to maximize drug delivery in the nasal cavity and potentially increase patient satisfaction as well as compliance.