In today's pharmaceutical development environment, scientists are looking
to new analytical test methods for help in determining the sources of variability
in all aspects of drug development and production. For example, it is necessary
for the pharmaceutical scientist to identify and quantify batch-to-batch variation
in the processing of powders. The BET surface area technique can help provide
accurate answers to these questions.

It is common knowledge that different batches of the same APIs can exhibit
different physical and mechanical properties. The source of batch-to-batch variability
of these APIs can be difficult to ascertain. According to an article by Novartis
Pharmaceutical Corporation (1), East Hanover, NJ, their researchers have
discovered that BET surface area can help them determine batch-to-batch variability.
Novartis scientists used a Micromeritics
ASAP 2020 Accelerated Surface Area and Porosity analyzer to characterize
different batches of API that exhibited different flow properties. They found
that the amorphous content of the batches varied. From this information, they
were able to conclude that the varying amorphous content of the batches was
the source of the variability in flow behavior. These Novartis findings strongly
support the BET surface area test method as an important tool in the investigation
of batch-to-batch variation and their overall development and production process.
The Pharmaceuticals division of Novartis is recognized worldwide for its innovative
medicines provided to patients, physicians, and healthcare organizations. This
growing business develops and markets patent-protected prescription drugs in
major therapeutic areas that include cardiovascular and metabolism, oncology,
neuroscience and ophthalmics, respiratory, immunology and infectious diseases.
Their current product portfolio includes more than 50 key marketed products,
many which are leaders in their respective therapeutic areas.
Micromeritics manufactures a broad line of automated analytical laboratory
instruments that measure the physical characteristics of powders and solids
for fundamental research, product development, quality assurance and control,
production, and process control applications, including nanoscience. Physical
characteristics determined include: Particle Size, Surface Area, Pore Volume,
Pore Size and Pore Size Distribution, Absolute Density, Envelope Density, Bulk
Density, Catalytic Activity, and Active Surface Area. Micromeritics Pharmaceutical
Services (MPS) is a DEA-licensed, FDA-registered, cGMP/GLP-compliant contract
analytical laboratory.
(1) "Application of surface area measurement for identifying the source
of batch-to-batch variation in processability"
Radha R. Vippagunta, Changkang Pan, Ronak Vakil, Vindhya Meda, Richard Vivilecchia,
and Michael Motto; Pharmaceutical Development and Technology, 1097-9867, first
published on 25 February 2009.