Manufacturers are expected to begin shipping a new kind of heparin product on Thursday.

Pharmacopeia has adopted new manufacturing controls for the anti-clotting drug. These include a revised reference standard for the drug’s dose unit to guard against potential contamination. The revised standard is about 10% less potent than the former USP unit. The Food and Drug Administration last week notified healthcare providers of the change.

“Although the FDA-approved labeling for heparin has not changed, including the recommended doses, it is essential that health care professionals be aware of the potential difference in potency between the old and new vials of heparin when administering the drug,” said John Jenkins, director of the FDA’s Office of New Drugs.