Safety cabinet for droplet size measurement by laser diffraction
Aurélie Doméné1, Maria Cabrera1, Michael Pasteur2, Marguerite Tulli3 & Laurent Vecellio 1
1 CEPR, INSERM U1100, University of Tours, 10 boulevard Tonnellé, Tours, 37032, France
2Pharmacie Centrale des Armées, TSA 30004, Fleury-les-Aubrais cedex, 45404, France
3Stratégie Santé, 19 rue Georges Clémenceau, Versailles, 78000, France
Laser diffraction is the recommended method to measure the droplet size distribution from aqueous nasal spray products. There is a risk in terms of Spraytec instrument contamination (lens and body) and air contamination by the sprayed drug product with the standard experimental set up. The use of drug products may require protective equipment such as fume cupboards or chemical hoods. Unfortunately, the measure of the droplet size distribution using the Spraytec cannot be carried out in such devices. In addition, the Malvern inhalation cell is not suitable for aqueous nasal spray due to the risk of lens contamination and spray impaction in the inhalation cell.
In this context, we developed a safety cabinet allowing the measurement of the droplet size distribution of a new drug (aqueous nasal spray) using the Spraytec. To validate the cabinet, the first step was the particle size measurement with and without the safety cabinet. The second step was the evaluation of ambient air contamination using a chemical tracer (fluorescein) in a form of spray and aerosol.
Results have showed that droplet size distributions were similar in terms Dv10, Dv50, Dv90, Span and percentage of particle smaller than 10 µm with and without safety cabinet. No contamination was detected in the ambient air.
The safety cabinet is an efficient protection system allowing droplet size measurement by laser diffraction for aqueous nasal spray products.