Malvern's Spraytec is a laser diffraction system that delivers automated in situ analysis of high concentration aerosols and sprays.
Valois, the world's leader in spray pump design and manufacturing and one of only five companies that can perform the task, has been relying on this technology to provide a routine method of verifying the batch-to-batch consistency of its nasal pump delivery systems, particularly in the development and performance testing of its a new nasal spray pump Equadel.
Equadel is designed to generate user-independent performance, meaning that no matter how much force is used by a patient to spray the drug, the particle size will remain consistent, unlike currently available spray pumps where the particle sizes can change according to force.
Particle size in sprays and aerosols is important in defining product delivery and performance in an increasing range of pharmaceutical applications and spray characterisation, such as spray droplet size measurement, has become routine in the testing of nasal spray products and devices.
Within the draft guidance for the characterisation of nasal sprays, for example, the US Food and Drug Administration (FDA) has recommended the use of laser diffraction to determine the droplet size produced for a given device and formulation and also recommends that a certain number of devices from each batch are tested prior to despatch.
"There is evidence linking particle size to the site of deposition in the nasal mucosa - if the particles are too fine, they risk going into the lungs, which the FDA is keen to avoid as many nasal sprays have excipients that are not licensed for the lung," Malvern spokesperson Paul Kippax told In-PharmaTechnologist.com.
"Similarly, if the particles too large, they don't reach the nasal cavity at all as the nose is designed to strip out large particles."
Kippax said that the ideal particle size for nasal sprays varies between 10-150 microns, depending on the type of drug and patient group.
"Once you have decided the right particle size you want to keep consistency otherwise the efficacy of the drug delivery changes," said Kippax.
"As far as I know, the Equadel pump is unique in being able to achieve this."