An impurity of Eptifibatide. Eptifibatide, is an antiplatelet drug of the glycoprotein IIb/IIIa inhibitor class. Eptifibatide is a cyclic heptapeptide derived from a protein found in the venom of the southeastern pygmy rattlesnake (Sistrurus miliarius barbouri). It belongs to the class of the so-called RGD (arginine-glycine-aspartate)-mimetics and reversibly binds to platelets.