Spectrophotometric Assay of Certain Aminoglycosoide Antibiotic Using Chloranil

Abstract

Chloranil (2,3,5,6-teterachloro-p-benzoquinone) reacts with certain aminoglycosoide antibiotics in borate buffer at pH 9.0 to give charge-transfer complexes. The complexes possese an absorption maxmum at about 350 nm with molar absorptivities of 3.78 × 10⁵, 4.69 × 10⁵, 5.0 × 10⁵ and 7.08 × 10⁵ for kanamycin, neomycin B, amikacin and tobramycin reepectively, These high intensity of the chargetransfor band and confirmity to beer's law enabled assay of these antibiotics with appreciable sensitivity and good precision.

Aminoglycosoide antibiotics have a broad spectrum of activity against both gram-negative and gram-positive bacteria.

The official compendia^1,2 recommend the microbiological assay for their evalution. The high experimental errors in microbiological estimation heae been reported³. Numerous spectrophotometric, fluorometric and chromatographic techniques for their quantitation have been thoroughly reviewed^4,5.

Substituted quinones such as 2,5 dichloroquinone⁶, 7,7,8,8-tetracyanoqulnone dimethane⁷, flouranil⁸ are used as TT- acceptors with various electron donors to form charge-transfer(CT) complexes and radical ions^9,10. Some aromatic amines^11,12 and aminoacids have been determined with chloranil^13–15.

The present work describes the utility of chloranil for the spectrophotometric determination of kanamycin sulphate, amikacin sulphate tobramycin aulphate, and neorycin B sulphate (framycetine sulphate) either in bulk or in their reepective doaage forms.