Development of In Vitro Nasal Cast Imaging Techniques to Predict In Vivo Nasal Deposition

Nasal casts have considerable potential as in vitro tools for the prediction of in vivo nasal deposition, to support nasal drug product development. This article describes an experimental assessment of two alternative nasal cast techniques for assessing nasal deposition, for powder and liquid nasal formulations. With the in-situ assay method nasal deposition was determined via the assay of solutions produced by dissolving radioactive-labelled material from the nasal cast plates. With the imaging method, a gamma camera was used to determine distribution directly. Though certain differences were observed between the two data sets the results confirm the feasibility of using imaging in combination with a nasal cast (use courtesy of Aptar Pharma/DTF/Univ. of Tours) to investigate nasal deposition. Improved delivery to the olfactory region was observed with the nasal powder relative to the nasal spray.