New Portable Instrument Tests Inhalable Drug-Delivery Devices

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ePT--the Electronic Newsletter of Pharmaceutical Technology

Cambridge Consultants is developing a low-cost portable instrument to test respiratory drug-delivery devices.

Cambridge, UK (May 2)-Cambridge Consultants is developing a low-cost portable instrument to test respiratory drug-delivery devices. The new device achieves performance similar to that of laboratory laser-diffraction measurement and captures a comparable level of data. The unit measures the droplet-size distribution in an airstream.

The instrument is based on light-emitting diodes, simplified optical configurations, and modern signal processing. When used with standard equipment, the instrument produces highly accurate plots that indicate the number of droplets within a preselected size range. The machine thus allows drugs to be tested at the point of delivery to ensure that doses are delivered as the drug developer intends.

The unit is designed to be robust and simple enough to be operated by semiskilled clinicians. According to the company, the device would be suitable for testing how much drug reaches the patient’s deep lung during clinical trials. The machine could also be used during end-of-line production testing.


In a company press release, Dr. Robert Jones, senior consultant at Cambridge Consultants, said, “With this device we can achieve in a very simple configuration the multiple angles of combination, wavelength, and polarization 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.”

Airborne drug delivery for deep-lung treatment requires particles of a specific size. Methods for accurately measuring particle size are generally laboratory-based. The Anderson Cascade method, for example, is labor-intensive. The current generation of large laser-diffraction measurement devices impose high initial costs and require much space and skill to operate. Cambridge Consultants is developing a test unit that it says could be manufactured in volume for less than one-hundredth the cost of a full laboratory laser-diffraction installation.