SPECTROPHOTOMETRIC DETERMINATION OF AMOXICILLIN IN PHARMACEUTICAL PREPARATIONS THROUGH DIAZOTIZATION an‎d COUPLING REACTION

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 5g mL^-1 and 0.4 to 14 5g mL^-1 with a limit of detection (LOD) of 0.1877 5g mL^-1 and 0.1916 5g mL^- 1,molar absorbtivity of 1.914×10^4 L mol^-1cm^-1 and 2.544×10^4 L mol-1cm^-1 , Sandell s sensitivity of 21.912×10^-3 5g ml^-1 and 16.486 ×10^-3 5g 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.