ÃÛÌÒÓ°Ïñ

A new study from ÃÛÌÒÓ°Ïñ's Jerome J. Lohr College of Engineering demonstrates a novel approach to target nasal spray deposition for vaccine drug delivery.

Nasal sprays have emerged as a promising way to combat viral infections, like common colds and influenzas, and to deliver intranasal vaccines. Ideally, these devices should be able to deliver and deposit targeted therapeutic agents and antiviral medications directly to the infection-prone sites, eliminating the disease during the early stages of infection.

Respiratory viruses will often first infect the nasopharynx, the region where the nasal cavity and the upper most part of the pharynx meet. The nasopharynx is a critical target area for early treatment and prevention. The problem, however, is that many nasal spray devices are not optimized to deliver drugs specifically to the nasopharynx.

is a global leader in developing and manufacturing drug delivery systems, including nasal spray systems. A few years back, the company began supporting Saikat Basu, associate professor in SDSU's Jerome J. Lohr College of Engineering, who was developing and designing a digital platform to assess the targeted delivery of a wide range of nasal sprays.

In December, were published in the academic journal Frontiers in Drug Delivery.

"The work — resulting from a strong industry-academia collaboration — proposes a novel approach toward improving nasal spray performance and intranasal vaccine delivery, through mechanics-guided parametric mapping of formulation and device properties," Basu said. 

Basu's team on this project, which included one postdoctoral fellow, two doctoral candidates, two master's students and one undergraduate researcher, optimized the nasal spray deposition through computational simulations in realistic human airways and physical experiment tests. The team collected data from CT scans from two adults. The data was used to create realistic upper airway geometries and a 3D-printed replica of an upper airway for validations through physical spray experiments with fluorescent markers in the sprayed solution.

The key to improving targeted drug delivery to the nasopharynx, the team found, was in the droplet size, spray plume angle and the material density of the drug being delivered.

"Multiple generations of graduate students in my team were involved," Basu noted. "They (along with a postdoc) ran the computational simulations of breathing and nasal sprays. They found out the feature values that would enhance targeted drug delivery at the infected tissue sites inside the upper airway."

William O'Connell, the team's undergraduate researcher, had the unique opportunity to run the study's validation experiments.

"Using core engineering skills such as AutoCAD and 3D printing developed here at SDSU really helped kick-start the process. However, it was developing the experimental protocol and writing the image analysis code that highlights distinctive challenges overcome within this project," O'Connell said. "I am grateful for this special opportunity that has helped me grow as a researcher and contribute to drug delivery field."

The team's results provide insight on nasal spray system characteristics needed for intranasal vaccine drug delivery.

Basu's team worked in collaboration with scientists from Aptar Pharma, Cornell University and the Indian Institute of Technology Ropar. Authors on the study include Basu, O'Connell, Md Tariqul Hossain, Abir Malakar, Mohammad Yeasin, Mohammad Mehedi Hasan Akash, Azadeh Borojeni, Devranjan Samanta, Gerallt Williams, Goncalo Farias, Sunghwan Jung and Julie Suman.

Funding for this research was provided by Aptar Pharma, with additional support coming from Basu's National Science Foundation CAREER Award, which aims to decode the flow physics and its impact on local particle transport within the complex space of the human upper airway.