Federal Register Notice: FDA has withdrawn approval of two NADAs for a suspension implant of estradiol benzoate microspheres, Duralease (estradiol benzoate), used in steers and heifers fed in confinement for slaughter for increased rate of weight gain and improved feed efficiency, and Celerin-C (estradiol benzoate), used in suckling beef calves for increased rate of weight gain. The products are no longer manufactured or marketed. In a separate Federal Register final rule FDA is amending the animal drug regulations to remove the portion that reflected the approval of the two NADAs. To view this notice, click here.