A DEVELOPED SPECTROPHOTOMETRIC DETERMINATION OF AMOXICILLIN FORMS VIA CHARGE- TRANSFER REACTION WITH METOL

Abstract

A spectrophotometric method for determination of amoxicillin (AMX) in pure and pharmaceutical formulations is described. The proposed method involves the use of metol (N-methyl-p-hydroxy aniline) as a chromogenic reagent.The drug produce a bluish-green coloured soluble charge- transfer complex with metol in the presence of potassium persulphate in alkaline medium. The coloured product is measured at λmax 620 nm . Under the optimum conditions calibration graph was observed a linear from 5-60 μg ml-1 AMX and with correlation coefficient not less than 0.9994 which was suitable for the quantitative determination of the drug.The molar absorbitivity was 2.726×103 L.mole-1.cm-1,and sandell sensitivity of 0.1538 μg cm-2 . The relative standard deviation of the proposed method was 0.25-2.44% depending on the concentration of AMX. The proposed method was successfully applied to the determination of AMX in injections and capsules.