Furthermore, in some instances, research during initial development of the drug relied on test methods individually tailored to the unique characteristics of the device and/or formulation. When the first commercially available inhalers came to market around 50 years ago, the large pharmaceutical companies that led the way, such as 3M, AstraZeneca, GlaxoSmithKline, Novartis and Sanofi (or their predecessors), developed new test methods to verify the performance of their innovative products. In fact, those companies often designed and manufactured their own analytical equipment.
As inhaler technology developed, and the need for pharmacopoeial monographs became more acute, experts from these pioneering companies played an important advisory role in establishing good testing practice. As a result, some proprietary equipment found its way into the pharmacopoeias, but other items did not. Companies were at liberty to validate their own test methods using preferred equipment, and some continue to do so even today.
The inhaler testing apparatuses and methods described in the product-specific phamacopoeial monographs reflect the best approximations for duplicating the historical testing procedures.
It would appear that following the product-specific regulatory guidance and pharmacopoeial monographs remains a matter of choice, and it remains feasible to robustly demonstrate an alternative approach. However, such guidance removes risks associated with a less well-defined approval route, and the net result is to potentially reduce the time taken to achieve a successful ANDA.
Note: The opinions expressed are the author’s own and are not necessarily shared by any regulatory bodies or by the pharmacopoeias. This Q&A has been edited for length. For more in-depth discussion, see www.copleyscientific.com
