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The Hammer Mill for Sizing Active Pharmaceutical Ingredients (API)

The FitzMillTM Hammer Mill has become a popular choice within the API manufacturing industry due to its flexibility in being able to produce different target particle sizes.

The challenge of milling and sizing APIs 

Commonly manufacturers of APIs deploy a variety of different mills to achieve their desired range of particle size distributions. This can become costly to not only purchase all of these mills but also complex to maintain them in terms of keeping spares and also the servicing required.

The reason they have so many is that the manufacture of APIs is complex. Particle sizes of the materials need to be regularly ‘tweaked’ because manufacturers are trying to get the API powders to have a particle size distribution that is complementary to the other OSD powders involved in the formulation so that the materials mix well and can be successfully compounded into the final dosage form.

What does the FitzmillTM Hammer Mill offer?

Over the decades, users of the Fitzpatrick Powder Milling Equipment have found that it is a mill that offers flexibility. There are various parameters that can easily be adjusted to produce different ranges of particle sizes. This versatility comes from the ability to adjust:

  • Rotor speed – this shifts the PSD from coarse to fine
  • Rotor blade style - a knife edge rotor blade will create coarser milling results, whilst the blunt impact edge will produce finer powder distributions.
blade images
  • Feed rate or feeding method – decreasing feed rates will increase attrition and create finer results.
  • Screen aperture size and open area – this controls the residence time of material inside the milling chamber, which affects the capacity, temperature and particle size creation.

Over the years we have responded to increased regulatory requirements and have developed improved designs and features. These have conferred a number of benefits to our customers:

  • Heat-sensitive materials can be delicately handled by adding on water jackets and/or throats that change the feed entry points and reduce the milling heat
  • High containment levels can be achieved with the addition of patented Powder Containment Systems (PCS)
  • Cleaning is straightforward as the unique segmented milling chamber can be disassembled for 100% cleaning access.
  • A one-piece sanitary rotor design ensures no metal-to-metal blade assemblies in the powder contact zone, where powders could be trapped and/or make it very difficult to clean and sanitize. In other words, it is overall a better GMP design.
  • Where needed, explosion protection can be offered via nitrogen inerting & monitoring systems.
  • With the ability to use the lab-scale model for trials and then directly transfer these results to the production model, it is ideal to enable particle size matching from API to OSD processing.

A Fitzpatrick represents a solid investment that offers versatility and flexibility in the manufacturing of Pharmaceutical APIs.  It is not a surprise that it has earned the reputation as the ‘work-horse’ of the industry.

Contact our team experts to find out if this is the right mill for your process.

Download the Whitepaper  FitzMill and its role in sizing Active Pharmaceutical Ingredients
Posted by Wilf Sanguesa


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