Speaking at CPhI 2009 Mark Hammond, CEO of Melbourn Scientific, explained that traditional film thickness evaluation technology looks at weight gain but this is imperfect.
This is because the weight gain technique is unable to tell if the film is thicker on different areas of the tablet. In contrast terahertz pulsed imaging (TPI) provides an image of film thickness, allowing the user to see what areas are only covered by a thin layer.
By viewing this companies can correlate film thickness to dissolution to see what is affecting results. Furthermore, the user can "identify and quantify key attributes such as coating, uniformity, thickness and porosity", allowing physical features to be related to the product's performance.
Hammond believes the addition of the technology improves Melbourn's offering, adding that few companies in Europe offer the service.
Melbourn has access to the technology following the signing of an agreement with TeraView. Both UK-based companies will now offer the service but Hammond believes their other capabilities differentiate them.
TeraView has its own clients but lacks good manufacturing and laboratory practice (GMP and GLP) facilities, according to Hammond, and consequently some projects will be better suited to Melbourn.
Furthermore, Melbourn believes that it can combine the technology with its wider analytical capabilities and experience, enabling "for the first time the full power" of TPI.
Further benefits
Melbourn believes TPI will be particularly useful for modified and controlled release products, which it claims now account for about 25 per cent of all launched products.
TPI can view the thickness of each layer and check for delamination, providing manufacturers of these products with useful information.
In addition TPI can see though elements, such as titanium dioxde. Speaking about TPI the US Food and Drug Administration (FDA) said it may be "an attractive replacement for wet dissolution testing both in product development and eventually for process analysis".