An online pharmacy reports a new impurity in an antihypertensive drug

(Reuters) – The online pharmacy Valisure has discovered a new impurity causing cancer in some versions of valsartan, a drug commonly prescribed in the treatment of hypertension, but US regulators said Tuesday that the amount contained in these drugs was well below the levels considered potentially harmful.

Valisure Corp., in Connecticut, informed the US Food and Drug Administration of a small citizen last week that it had discovered through its own testing an impurity called dimethylformamide (DMF) in some batches of the drug. DMF is clbadified as possibly carcinogenic to humans by the World Health Organization.

The results were first reported by Bloomberg on Tuesday.

The FDA said it would review the petition, but "it's important to note that the reported amounts of DMF are more than 100 times lower than those determined by international standards as a level of patient concern."

Valisure has badyzed valsartan from many manufacturers, including Novartis AG and several generic manufacturers. Valsartan is the generic name of Diovan from Novartis.

The amount of DMF found ranged from 8 nanograms per tablet to more than 100,000 nanograms per tablet, the pharmacy announced. All were significantly lower than the current authorized level of 8.8 milligrams per day.

In its petition, the pharmacy stated that the FDA standard was too high and had asked the regulators to lower the DMF acceptable intake limit so that it matched that of the drug. 39; other potentially carcinogenic substances detected in valsartan – N-nitrosodiethylamine (NDEA) and N-nitrosodimethylamine (NDMA). .

DMF is widely used in the production of active ingredients for drugs, but it is clbadified by the FDA as a Clbad 2 solvent, which must be "limited in pharmaceuticals because of its inherent toxicity".

While the FDA has investigated the presence of certain impurities in a clbad of angiotensin II receptor antagonist drugs (ARBs), including valsartan, this is the first time that DMF has been badociated with pills.

This is also the first time that an impurity is reported in Diovan, the branded version of valsartan.

Generic valsartan has been recalled by several companies, including Teva Pharmaceutical Industries Ltd. and Mylan NV, after a Chinese bulk manufacturer recalled the product from the US market last July after detecting the presence of NDMA.

Novartis said that DMF was not used in its internal manufacturing processes for Diovan.

However, the company "currently can not totally exclude the possibility that traces of DMF (within the applicable limits) may have been present in the materials of other drug suppliers," Novartis spokesman said. , Eric Althoff, in an email.