Ultrasound technology is not widely used in the pharmaceutical industry; there is a need for further evaluation before it finds a use as a commonplace technology.
But the technology has potential in that it provides non-destructive testing, real time data acquisition and potentially enabling on-line use. These concepts have a big advantage in Process Analytical Tool (PAT) applications, where the results will be used to increase efficiency as the process progresses. In addition, ultrasound technology is also complementary to other approaches currently in use by the industry, such as dynamic light scattering (DLS) and size exclusion chromatography (SEC).
LGC, an international science service company, has through its designated role as the National Measurement Institute (NMI) for chemical and biochemical analysis taken the lead on a measurement ultrasound research project, which is supported by the Department of Trade and Industry (DTI) as part of the National Measurement System (NMS) Measurements for Biotechnology (MfB) programme.
The British government has shown its support for the programme, across four measurement themes - genes, proteins, cells and bioproduct characterisation (ultrasound technology) - with £9 million over three years (2004-2007).
"In active ultrasound spectroscopy, measurements of the velocity and absorption of ultrasound signals of known frequency, strength and timing are made within or after transmission through a test material. Both methods tell you information about the sample composition and same physical parameters about solutes present in the sample (e.g. particle size, density, viscosity etc)," Julian Braybrook, LGC's MfB programme manager, told In-PharmaTechnologist.com.
The main interest for the industry is in identifying the presence of protein aggregates, which may cause adverse immune reactions, and protein folding. In comparison to other methods, ultrasound technology offers advantages in determination of aggregates but it also has disadvantages, which are now under evaluation. The main disadvantage relates to standardisation across the range of ultrasound instruments present on the market, hence data interpretation issues become complex. Also, the technique seems to be at optimum capacity with high concentrations of analytes limiting its applicability in specific fields, explains Braybrook.
The (bio)pharmaceutical industry has shown an interest in using ultrasound technology as a tool in PAT, where quality assessment is incorporated throughout the process rather than as end-product quality control.
A manufacturer of ultrasound spectroscopy, Process Analysis and Automation (PAA) Ltd, confirms that the market for ultrasound technology is small and that it awaits its "killer application".
"It is difficult to speculate about a "killer application" but potentially it could be conformational studies of proteins," said Mike Collins of PAA.