So far US FDA inspectors believe contaminated compounds were unintentionally created through a chemical reaction.
A probable carcinogenic impurity found in the pill Valsartan, commonly prescribed medication to treat hypertension, is giving generic drug makers high blood pressure.
Earlier this week, Aurobindo Pharma recalled 80 lots of medicines containing blood pressure drug Valsartan from the shelves in the US, after they were tested positive for NDEA, a probable cancer-causing impurity.
Aurobindo pulled off the drugs voluntarily on USFDA's advice.
NDEA is a substance that occurs naturally in certain foods, drinking water, air pollution, and industrial processes, and has been classified as a probable human carcinogen, according to the International Agency for Research on Cancer (IARC).
So far the USFDA inspectors believed contaminated compounds were unintentionally created through a chemical reaction.
"The agency continues to investigate and test all angiotensin II receptor blockers (ARBs) for the presence of NDEA and N-Nitrosodimethylamine (NDMA) and is taking swift action when it identifies these impurities that are above interim acceptable daily intake levels," USFDA said in a statement
The latest recall is the third by Aurobindo in the US in last three months.
To be sure, Aurobindo isn't the only company that's making recalls, Torrent Pharma, Hetero, Mylan, Teva and Sandoz had multiple recalls of medications containing Valsartan.
Aurobindo manufactures Valsartan API and formulations in-house and maintained its route of synthesis is different, with chances of impurity almost nil.
Along with US, drug regulators in Europe, Japan and Canada have increased scrutiny.
"Companies marketing sartan medicines in the EU have been asked to test their products for these impurities. Additional testing is being carried out by EU laboratories," the European Medicines Agency (EMA) said recently.
The matter isn't ending at recalls, several class action lawsuits were filed against distributors and manufacturers of the drug in the US. In December last year, there were media reports of a class action lawsuit initiated against Aurobindo Pharma for selling contaminated Ibersartan.
Aurobindo said it hasn't received notices of any class action lawsuit yet.
The global recall of valsartan medications began in summer last year when the USFDA and EU learned that the Valsartan API made by China’s Zhejiang Huahai Pharmaceuticals contained probable carcinogenic impurities NDEA and NDMA, in more than permissible limits.
The detection of probable carcinogenic impurities in Valsartan APIs supplied by Zhejiang Huahai has now led to a widening of the net to include all other API makers making sartan APIs.
Among the pharma players in India, Torrent was a customer of the Chinese company. Not anymore. Aurobindo, Hetero Labs and Mylan manufacture sartans. All of them are under scrutiny now.Analysts' take
Analysts said the recalls may not have much monetary impact on the companies, as Valsartan drugs are low margin generics and their contribution for sales isn't that meaningful.
"It's a short-term opportunity for Indian companies due to the shortage created by the recalls, we have seen Aurobindo Pharma in the second quarter made decent sales on the sartans," Amey Chalke, Pharma Analyst at HDFC Securities said.
Chalke said that class action lawsuit may not be a huge threat, as these companies have been manufacturing the drug whose process has been approved by USFDA and this impurity is the outcome of the unintentional chemical reaction.
Another analyst who tracks pharma on anonymity said companies will have to review their manufacturing process to ensure the impurity doesn't occur. Then they have to seek fresh approval from USFDA."That's going to take some time. Meanwhile, this creates shortages. More than the carcinogen, the patient will be at immediate risk if he doesn't take the blood pressure pill," the above analyst said.