Korsuva

11 DESCRIPTION KORSUVA (difelikefalin) is a kappa opioid receptor agonist.‍​‍‍‍​‍‍‍‍‍‍‍‍​‍ Difelikefalin is a synthetic peptide with a single stereoisomer and is present as an acetate salt. Difelikefalin acetate is a white to off-white powder with a molecular formula of C 36 H 53 N 7 O 6 ∙xAcOH (1.0≤ × ≤2.0) and a molecular weight of 679.4 g/mol (mono- isotopic; free base). It is soluble in water. The chemical name of difelikefalin acetate is 4-amino-1-(D-phenylalanyl-D-phenylalanyl-D-leucyl-D-lysyl)piperidine-4-carboxylic acid, acetate salt. The chemical structure is: KORSUVA (difelikefalin) injection is supplied in a single-dose vial containing 65 mcg/1.3 mL (50 mcg/mL) of difelikefalin as a sterile, preservative-free, clear and colorless solution for intravenous injection. KORSUVA is formulated as an isotonic 40 mM acetate buffer solution with an osmolality of 250 to 350 mOsm and a pH of 4.5. Each milliliter of KORSUVA injection contains 50 mcg of difelikefalin (equivalent to an average of 58.3 mcg of difelikefalin acetate), 1.3 mg of acetic acid, 2.5 mg of sodium acetate trihydrate, 7.2 mg of sodium chloride (to adjust tonicity), and water for injection. Chemical Structure