AstraZeneca installs new nitrogen purged milling system

AstraZeneca has installed a new nitrogen purged milling system

Runcorn, UK - AstraZeneca has installed a new nitrogen purged milling system from Hosokawa Micron Ltd for delumping an active pharmaceutical ingredient (API) prior to packaging. The unit was designed in conjunction with AstraZeneca engineers to provide integrated and additional safety features and best operating practices for handling potentially explosive fine powder ingredient.

The milling process has been introduced to the production line to deliver a homogenous free flowing, lump free product of consistent particle size.  To facilitate the homogenisation of this API, the system has been designed incorporating a Bepex Bexmill homogenisation mill. With its low energy, gentle action the mill is suitable for handling sensitive products such as pharmaceuticals where a significant temperature rise would be detrimental.

The mill has a single vertical rotor which rotates close to a conical screen mesh and by careful selection of screen mesh size and adjustment of rotor speed lumpy materials can be rendered free flowing and of a consistent particle size. Air flow through the unit is minimal and the product temperature rise insignificant ensuring very gentle size reduction with minimum fines.

The Astra Zeneca material is transferred from a pressure filter dryer into a receiving vessel and then metered into a Hosokawa pharmaceutical design of easy clean Bexmill via a rotary valve. The mill is a slow speed comminution device which is very effective in delumping without product damage.

After milling the product falls into a receiving hopper and is then transferred to the packaging drums using a pharmaceutical design of inclined screw conveyor.

The whole system is operated under a positive pressure of nitrogen and has an integrated self leak test facility. The system is pressurised to 0.1 bar and until the leak integrity test has proved that no leak has been detected and a green light been activated the system cannot start. Once the system has passed the leak test then the milling sequence can commence.

Designed to be easy clean by hand the whole system can be readily stripped down before a final sterilisation in place with compressed air and peracetic acid at 0.1 bar takes place.

‘We are always looking at the opportunities for product, process and environmental improvement with our personnel a key factor in the determination of technology both in terms of technical input and health and safety," said John Sherwood, associate principal scientist, product development  PR&D at AstraZeneca Macclesfield.

"AstraZeneca has total commitment to meet or exceed legal requirements and international agreements in respect of Heath and Safety and Environment and to provide a safe and healthy work environment for all our employees," added Sherwood.