Author/Editor     Sher, A; Veber, M; Marolt-Gomišček, M; Gomišček, S
Title     Complexation of copper (II) ions with ampicillin: I. Spectroscopic and electrochemical investigation of interactions under equilibrium conditions
Type     članek
Source     Int J Pharm
Vol. and No.     Letnik 90
Publication year     1993
Volume     str. 181-6
Language     eng
Abstract     The interactions in the copper(II) ion-ampicillin system were studied by the use of electrochemicaf and spectroscopic methods under equilibrium conditions. In the system, two aqueous soluble coordination compounds with molar compositions of 1:1 and 1:3 and a precipitate with molar ratio 1:2 were formed. Copper(II) ions promoted the hydrolysis of the beta-lactam group of ampicillin, therefore the ampicillin ligand in the compounds was transTormed into ampicilloic acid as a result of hydrolysis. The soluble compounds are relatively stable, log Kst being 5.0 and 14.5, respectively. The solubility of the precipitate was constant over a broad pH range (4-10) and the solubility product constant Ksp of the compound was evaluated as 2.7 x 10-11 under equilibrium conditions.
Descriptors     AMPICILLIN
COPPER
DRUG INTERACTIONS
SPECTRUM ANALYSIS
POLAROGRAPHY
POTENTIOMETRY