Spectrophotometric determination of amoxicillin in pharmaceutical preparations through diazotization and coupling reaction

Abstract EN

Two simple, rapid and sensitive spectrophotometric methods have been developed for the determination of amoxicillin (AMX) in pure form and pharmaceutical preparations.

The proposed methods are based on a coupling reaction between AMX and diazotized p-amino benzoic acid or diazotized procain in alkaline medium to form an intense yellow, water-soluble dyes that are stable and have a maximum absorption at 435 nm using diazotized p- amino benzoic acid and 450 nm on using diazotized procain.

The calibration graphs were linear over the concentration rangs of 0.4 to 10 μg mL-1 and 0.4 to 14 μg mL-1 with a limit of detection (LOD) of 0.1877 μg mL-1 and 0.1916 μg mL-1,molar absorbtivity of 1.914×104 L mol-1cm-1 and 2.544×104 L mol-1cm-1 , Sandells sensitivity of 21.912×10-3 μg ml-1 and 16.486 × 10-3 μg ml-1 for diazotized p-amino benzoic acid and diazotized procain, respectively.

The proposed methods were successfully applied to the determination of AMX in capsules and injections.