“I’m not sure this is something specific to Indian drug makers.”
****************************************************
I don’t know but last year there was a widespread shortage of the angiotensin receptor blocker (ARB) drugs used for high blood pressure. The shortage was caused by contamination problems in the Indian manufacturing locations to which much production was moved by the pharmaceutical industry. That affected me and my doctor had to move me to a different drug. The common factor to these contamination problems was Indian (and some Chinese) manufacturing facilities.
It is not necessarily contamination that adds NDMA to those drugs, but side reactions in the synthesization process, or by break down by heat in storage. These levels of NDMA may have always been around in some drugs in the past, but were not detectable by the the testing equipment in use at that time.
Heck, even bacon has some NDMA in it.