TY - JOUR T1 - The Formation of an Aluminum-Epinephrine Complex and Its Effect on the Addition of Bisulfite to Epinephrine JF - PDA Journal of Pharmaceutical Science and Technology JO - PDA J Pharm Sci Technol SP - 165 LP - 169 VL - 37 IS - 5 AU - E. A. Milano AU - D. A. Williams Y1 - 1983/09/01 UR - http://journal.pda.org/content/37/5/165.abstract N2 - Aluminum(IH) has been shown to catalyze epinephrine degradation in lidocaine HCl with epinephrine solutions by increasing the rate of bisulfite addition. The rate accelerating effect of aluminum-(III) is attributed principally to its capacity to form a complex with epinephrine. The interaction of aluminum with epinephrine was investigated by spectrophotometric means and the results compared with those for other ligands; catechol and phenylephrine, and other metal ions; zinc(II) and copper(II). In acidic solutions, pH 4, there is evidence that aluminum chelates epinephrine through its catecholate structure in a 1:1 ratio. The logarithm of the formation constant (K1) for this complex was found to be 16.26 ± 0.02 by a spectrophotometric procedure and 16.12 ± 0.08 by an alternative potentiometricprocedure. ER -