UK-based Cambridge Consultants is developing a low-cost, portable instrument that has the potential to revolutionise the way certain drug delivery devices are tested.
The new device measures the droplet size distribution in an airstream, a technique used in testing respiratory drug delivery devices, and claims to be able to mirror the performance and level of data provided by current laboratory laser diffraction measurement machines for an estimated one-hundredth of the cost when integrated into a high volume device.
Airborne drug delivery for deep-lung treatment relies on generating particles of a very specific size. Methods for accurately measuring particle size are very much laboratory-based, such as the Anderson Cascade method, which is laborious and can slow the development of devices, and the current generation of large laser diffraction measurement devices, which have high initial costs and require a lot of space and skill to operate.
By applying its expertise in optical systems, electronic signal processing and advanced capabilities in the Mie scattering mathematical theory - a critical element of this form of droplet analysis - Cambridge Consultants has started developing a test unit that could be manufactured in volume for less than one-hundredth of the cost of a full laboratory laser diffraction installation, the only real solution to such measurements today.
It is also small enough to be highly portable, making it suitable for use in clinical drug delivery trials, where it is critical to establish how much drug reaches the patient's deep lung so that doses can be accurately compared to the patient's response. It would also be useful during end-of-line production testing of drug delivery devices.
The Cambridge Consultants device is based on low-cost LED components, considerably simplified optical configurations and the application of modern signal processing. It is designed to be robust, portable and simple enough to be operated potentially by semi-skilled clinicians, with standard IT equipment to produce highly accurate plots that indicate the number of droplets within a pre-selected range of sizes.
"With this device we can achieve in a very simple configuration the multiple angles of combination, wavelength and polarisation state that you need to get good data from the Mie scatter. The software, developed with this device, is based on Bayesian inference and as a result provides very useful data easily and quickly," said Dr Robert Jones, senior consultant at Cambridge Consultants. "We're now looking for partners with whom to develop this technology further."