In Vitro Anatomical Models for Nasal Drug Delivery

COVID-19 has stimulated interest in the use of nasal drug delivery for vaccines and anti-viral prophylactics, but the route also holds promise for treating disorders of the CNS.

This paper discusses the use of nasal casts, replicas of the human nasal cavity, for in vitro testing to improve our understanding of nasal drug delivery and more specifically to target deposition for optimal pharmacokinetic effect. The anatomy of the nose is discussed with reference to its impact on drug delivery and the evolution of nasal casts is reviewed. The application of nasal casts in vitro is examined along with strategies for validating performance against in vivo behavior. It is concluded that although nasal casts have certain well-recognized shortcomings, they are a useful tool for nasal drug delivery studies, for formulation and device optimization, targeted drug delivery and generic product development.