D.c. polarographic determination of certain aminoglycosides

Abstract

A polarographic method for the quantitative determination of kanamycin, gentamicin and amikacin in a pure form or in pharmaceutical dosage forms has been developed. The method is based on the preparation of the polarographically active nitroso detivatives of these compounds and their polarographic behaviour in both alkaline and acidic media has been studied. The nitroso derivative of kanamycin exhibits one cathodic wave at –1.8 V in alkaline medium and one at –0.8 V in acidic medium. The nitroso derivative of gentamicin shows three well defined cathodic waves at –0.4, –0.8 and –1.4 V in basic medium and two waves at –0.8 and 1.4 V in acidic medium. The nitroso derivative of amikacin shows two cathodic waves at –0.8 and –1.4 V in basic medium and at –0.4 and –0.8 V in acidic medium. A rectilinear relationship exists between the diffusion current and concentration in the ranges 10–60, 10–80 and 10–60 mg-% for kanamycin, gentamycin and amikacin with average recoveries of 99.4 ± 1.4, 99.1 ± 0.95 and 99.7 ± 1.1%, respectively.