U.S. flag An official website of the United States government

On Oct. 1, 2024, the FDA began implementing a reorganization impacting many parts of the agency. We are in the process of updating FDA.gov content to reflect these changes.

U.S. Food and Drug Administration
  1. Home
  2. Drugs
  3. Drug Safety and Availability
  4. Laboratory analysis of rifampin/rifapentine products
  1. Drug Safety and Availability

Laboratory analysis of rifampin/rifapentine products

FDA continues to investigate the presence of 1-methyl-4-nitrosopiperazine (MNP) in rifampin or 1-cyclopentyl-4-nitrosopiperazine (CPNP) in rifapentine approved for sale in the U.S. These antibacterial drugs are used to treat tuberculosis; rifampin is also used to treat or prevent other serious infections.

The acceptable intake limits are 0.16 parts per million (ppm) for MNP in rifampin and 0.1 ppm for CPNP in rifapentine. These acceptable intake limits were calculated based on methods described in the 2018 ICH Guidance M7(R1) Assessment and Control of DNA Reactive (Mutagenic) Impurities in Pharmaceuticals to Limit Potential Carcinogenic Risk. To maintain the supply of these lifesaving medicines to patients, as a temporary measure the agency will not object to manufacturers distributing rifampin containing MNP below 5 parts per million (ppm). The agency also will not object to manufacturers temporarily distributing rifapentine containing CPNP below 20 ppm.

FDA is posting its laboratory results in the table below showing MNP in rifampin or CPNP in rifapentine products it tested. FDA is also collaborating with international regulators to share testing results for these products.

Company (Manufacturer)

Product

Lots Tested

MNP* level (micrograms-mcg/tablet or injection)

MNP* level (ppm)

Akorn

Rx Rifampin 300 mg

3185938, 3185931, 3184496, 3174136, 3191250

0.45-0.96

1.49-3.20

Akorn

Rx Rifampin 150 mg

3178340, 3174138, 3186047

0.44-0.52

2.95-3.47

Fresenius Kabi

Rx Rifampin Injection 600 mg

6123714

0.56

0.94

Lannett

Rx Rifampin 300 mg

26702.011A, 26702.001E, 18233439C

0.56-0.76

1.88-2.52

Lannett

Rx Rifampin 150 mg

26701.001D, 26701.002B

0.33-0.36

2.22-2.43

Lupin Pharmaceuticals Inc.

Rx Rifampin 300mg

A904639, A906770, A002982, A002983, A904704, A808691

0.39-0.63

1.31-2.08

Lupin Pharmaceuticals Inc.

Rx Rifampin 150mg

A000882, A808686, A904725, A002791

0.23-0.34

1.52-2.26

Mylan

Rx Rifampin Injection 600 mg

7008768, 7008694, 7008769

0.60-1.51

0.99-2.51

Sandoz/Epic

Rx Rifampin 300 mg

ME171080, ME190353, ME200197

0.56-0.80

1.86-2.66

Sandoz/Epic

Rx Rifampin 150 mg

ME190788, ME180471, ME190156, ME190470, ME190660

0.36-0.41

2.39-2.76

Sanofi Pharmaceuticals

Rx Rifampin Injection 600 mg

9J126, A9042, A8039, 9J1261

0.48-0.67

0.80-1.11

*1-Methyl-4-Nitrosopiperazine (MNP)

Company (Manufacturer)

Product/API

Lots Tested

CPNP level (microgram-mcg/tablet)

CPNP** level (ppm)

Sanofi

Rx Rifapentine 150 mg

9J2361, 0J0191, 0J1981

1.22-2.13

8.10-14.18

** 1-Cyclopentyl-4-Nitrosopiperazine

Back to Top