Pharmaceutical companies are looking to offer improved versions of drugs and new forms of delivery as a method of 'life-cycle management'; inhaled formulations and devices can offer advantages
With inhaled insulin recently gaining FDA approval and predicted to earn $1.5bn (euro1.2bn) a year, pulmonary drug delivery is winning the race to be accepted as a viable alternative for the delivery of systemic drugs, and this is one of the factors that has increased the demand for newer forms of particle size testing according to Melbourn Scientific.
As patents expire, many pharmaceutical companies are looking to offer improved versions of drugs and new forms of drug delivery as a method of 'life-cycle management'; inhaled formulations and devices can offer significant advantages in this.
According to Mark Hammond, business development manager at Melbourn Scientific the contract analytical services company, demand for NGI (new generation impactors) testing is now challenging that of the more traditional Andersen Cascade Impactor (ACI).
The company is one of the few UK based contract laboratories to offer method development, validation and routine testing using the NGI.
Hammond comments: "We are seeing increased demand for NGI, which shows industry and regulatory acceptance for this improved technology".
"Due to the user friendly design we have found that our staff have adopted new ways of working leading to higher productivity rates.
"The need to generate analytical data over long periods of time means that pharmaceutical companies are often reluctant to change to newer and improved test equipment during on-going development projects.
"This is due to the need for additional correlation studies and the wealth of data already generated.
"However an increasing number of our clients are choosing to start using the NGI for new development projects".
The company has worked closely with Copley Scientific in order to expand its capacity for NGI testing.
Mark Copley, sales manager at Copley Scientific, welcomes Melbourn's observations and comments that published studies between the ACI and NGI generally show good correlation between particle size distributions.
"I think that the feedback from Melbourn is very encouraging and shows that a significant number of companies are now opting for the NGI as the impactor of choice for new product development programmes.
"Melbourn is one of the few contract research companies currently able to offer this service".
"Melbourn's investment in NGI technology combined with their breadth of experience makes them a leader in this field".
In addition to its range of traditional pharmaceutical testing capabilities, Melbourn provides delivered dose and particle size distribution testing for a range of inhalation devices including metered-dose inhalers (MDI), dry powder inhalers (DPI), nasal sprays as well as nebulisers and novel delivery systems.
Impactors test the 'fine particle' dose based on the mass of the active component capable of reaching the lung and indicate where inhaled particles would be deposited within the lungs.
The NGI was developed by a large consortium of pharmaceutical companies to improve on the design of the Andersen Cascade Impactor, which was originally devised as a bacteriological air sampler.
It has been specifically designed to operate at flow rates between 15 and 100l/min to facilitate testing of inhalers and nebulisers.
The aerodynamics of the impactor follow established scientific principles, giving confident particle size fractionation behaviour over the entire flow range.
The advantages offered by NGI have prompted many development projects to adopt the new technology.
As Mark Hammond explains: "Inhaled product testing requires specialist skills, and specialist equipment".
"Testing is needed at all stages of the development of new devices or formulations and stability trials are also required on the products themselves.
"The NGI has several features that increase throughput, for example particles are deposited on a series of collection cups held in a tray".
"This tray can be removed as a single unit complete with the cups, facilitating quick sample turn-around times if multiple trays are used ".
"These user-friendly features provide an impactor well suited to the needs of a contract analysis laboratory where fast response is essential." Melbourn has been an early adopter of the NGI for testing inhaled products, and has gained significant experience, both internally and from the industry.
This has enabled it to adopt best practices and to provide guidance as well as a service.
Evidence suggests that demand will continue to increase for NGI testing as companies continue to embrace the technology for their new development programmes.
