At present, most drug particle production methods involve spraying droplets of a solution into a hot air environment where, after the liquid has dried, solid spheres of active pharmaceutical ingredient (API) are formed.
The problem is that the drying process is hard to control and yields API particles that vary in size and shape. This challenge prompted Dr Meng Wai Woo and his team at Monash University in Melbourne to start looking for alternatives and ultimately develop the new method, which is known as anti-solvent vapour precipitation.
Meng told in-Pharmatechnologist.com the approach "involves spraying the tiny drug droplets into mildly hot ethanol vapour environment [where] the particles are formed not due to drying but due to the solids becoming less soluble in the droplet, as the droplet absorbs the ethanol vapour.”
The scientists claim they can produce drug particles smaller than a micron in diameter, which is much smaller than those made using conventional dehydrating mechanisms that are limited by droplet size.
Manufacturing benefits
While these ultra-small particles could be used to develop for example more effective inhaled drug formulations, there are also potential advantages for manufacturers according to Meng.
“The main economic benefit from this technique is that smaller and more uniform particles can potentially be produced without the need to use smaller atomizers to generate the droplets.
“This will translate to higher production rate and higher financial return from the process. The new technique also negates the need for milling operation for particle size reduction, which is one of the current practices to make such ultrafine particles.”
Demo development
The team has been using the ethanol-based approach to produce API particles in 2011 and first demonstrated the approach to drugmakers at the18th International Drying Symposium in Xiamen, China, last year.
The plan now is to further showcase the technology at industry event according to Meng, who set out the group’s strategy.
“We are now developing a demonstration unit for this new process which is due to complete by the end of the year. Once the demonstration unit is fully running, we will then invite pharmaceutical companies for further discussion on the tech."