Melbourn Offers Testing For New Era Of Nasal Inhalers - Laser Particle Sizing Ensures Accurate Delivery To Target

Main Category: Medical Devices
Also Included In: Immune System / Vaccines
Article Date: 02 May 2008 - 1:00 PDT

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Performance testing for nasal delivery devices is one of the new services being offered by Melbourn Scientific. Although traditionally used for the local administration of decongestants and anti-histamines, the potential of a nasal route is now being investigated for a wide range of treatments from the instant relief of panic attacks through to needle-free vaccinations. This creates new challenges for devices and requires new testing regimes.

Mark Hammond, Business Development Director of Melbourn Scientific explains:

"The nasal route has advantages for delivery of drugs for migraine and pain relief, as the tissue has a large surface area and high permeability. The location of lymphoid tissue at the back of the nasal cavity offers rapid transport into the systemic circulation, and the olfactory region at the top of the nasal cavity is of interest for the treatment for ageing diseases such as Alzheimer's, as it allows rapid absorption into the central nervous system.

"The challenge of a nasal delivery device is to get the particle size right in order to ensure that drug is deposited within the nasal passages and not the lungs or gastro-intestinal tract. Research has shown that a particle size of greater than 10 to 20 microns is required in order to optimise this."

Melbourn Scientific uses a range of techniques to determine particle size and behaviour and can provide advice on the comparative benefits of the different techniques. It can also offer method development and validation.

In particular, it is the first UK contract laboratory to offer GLP and GMP compliant laser particle sizing for nasal sprays using the Malvern Spraytec.

The Spraytec system allows for the complete characterisation of the aerosol produced by nasal spray devices. It achieves this by measuring droplet size distributions using laser diffraction. The spray is passed through a laser beam and the angular intensity of the scattered light is measured. This scattering pattern is then analysed using an appropriate optical model to yield a size distribution.

Laser screening of particles gives immediate results. It provides a measurement of the size and distribution of the particles but does not identify them. However, the speed, accuracy and consistency of laser particle analysis is making this technique popular, especially in the development of new devices.

Melbourn Scientific has been involved in a number of device developments for companies taking a lead in this field, providing a wealth of experience in this new area. For nasal devices the company is able to offer a portfolio of tests to characterise and measure particles and their distribution.

Melbourn Scientific Ltd. http://www.melbournscientific.com