Endo International PLC said its lawsuit against the U.S. Food and Drug Administration will remain halted while the ongoing partial shutdown of the government remains in place.

The litigation challenges the FDA's authorization of the bulk compounding of drugs, the process of combining, mixing or altering ingredients by a licensed pharmacist to produce a medication tailored to the specific needs of a patient.

Endo is accusing the regulator of improperly authorizing the bulk compounding of hundreds of drugs, including "essentially a copy" of its blood-pressure drug Vasostrict, according to Reuters.

The FDA was supposed to make a determination by Dec. 31, before the partial government shutdown took place, on the inclusion of vasopressin, the active ingredient in Vasostrict, in the list of medicines that can be bulk compounded.