A diabetes drug has been recalled because it contains high levels of cancer-causing agent

An Indian pharmaceutical company is recalling some metformin tablets because they may contain higher-than-normal levels of a carcinogen.

(CNN)A widely-used diabetes drug has been recalled after manufacturers found it contained unacceptably high levels of a cancer-causing contaminant.

Indian pharmaceutical company Marksans Pharma Limited is recalling metformin hydrochloride extended-release tablets because their levels of NDMA, a "probable human carcinogen," were higher than the acceptable daily intake limit of 96 nanograms per day, according to a recall published this week by the US Food and Drug Administration (FDA).
Metformin tablets are used to treat type 2 diabetes and are designed to lower glucose levels.
    The recall applies to metformin tablets between 500 mg and 750 mg, sold under the brand name Time-Cap Labs, Inc.
    The recall expands an earlier recall of the same product from this summer. But it's just one of several metformin products that have been found to contain NDMA in the last year. Seven other pharmaceutical companies have issued recalls for metformin hydrochloride extended-release tablets due to their carcinogenic contents.
    The FDA is still investigating where NDMA comes from and how it ends up in metformin products. Most levels found in medications are generally low and fall within the FDA's accepted daily intake, but recently recalled medications exceed that. Marksans Pharma Limited, India, however, did not reveal how much NDMA its recalled products contained.
    The recall applies to the following products, which can be identified by their