Shrewsbury, whose company is developing products for delivery to the upper nasal space, reported that patients seemed to prefer the company’s POD device over traditional nasal pumps, possibly because it results in less product dripping back out of the nose. He added that Impel had worked with the FDA to develop a tool to assess nasal mucosity integrity in the upper nasal space and using that tool and a smell test found very little impact. Moderator Suzanne Craft of VCU noted that safety evaluations would always be compound specific and reported that in her work with an intranasal insulin formulation that contains zinc, the researchers had not identified any olfactory problems. Shrewsbury voiced the opinion that all nasal delivery should go to the olfactory mucosa because the greatly increased absorption in that area allows for a significant reduction of the dose.
On the comparison between powder and liquid formulations for nasal delivery, the panelists agreed that much more research would be necessary to draw any conclusions. Finlay said that his group has not investigated nasal powders using their idealized nasal geometry, and pointed out that a large number of parameters involved and the interactions between them affect where powders will go in the nose. None of the panelists said that they had investigated the dissolution of powders in the nose. Walenga suggested that liquid formulations might be better for some applications and powders for others.
Biorelevant testing
Beyond Finlay’s presentation titled, “Development of an Idealized Nasal Geometry for Estimation of Regional Deposition of Nasal Sprays,” several other presenters discussed the use of realistic nose or mouth-throat models for testing OINDPs. Lonza Small Molecules presented a case study involving jet milled and spray dried mannitol in a workshop on “Biorelevant Aerosol Testing and Modeling for Respiratory Drug Delivery.” Methods for comparing the two mannitol preparations covered in the workshop include the use of the Fast Screening Impactor and the Alberta Idealized Throat, both available from exhibitor Copley Scientific.
And Sneha Dhapare of the FDA compared the Alberta Idealized Throat to a number of other mouth-throat models in her poster, “Factors Influencing Plume Characteristics of Metered Dose Inhalers (MDIs) Following Passage Through Bio-relevant Mouth-Throat Models,” which includes research from Emmace Consulting and was included in the Posters on the Podium session.
Materials still available online
While the live sessions were not recorded, delegates will have access to the presentations, workshops, and posters through June 30, 2021. Additional companies that participated in RDD 2021 and that have materials available on the meeting web site include Intertek, Nanopharm, and Proveris Scientific.
RDD 2022 will take place in Orlando, FL, USA May 1-5, 2022.
