Abstract

Two simple and sensitive visible spectrophotometric methods for the analysis of some anesthetic drugs in pure and available pharmaceutical preparations have been developed. The first method is based on the formation of colored ion-pair complexes by the drugs, ketamine hydrochloride, lignocaine hydrochloride, bupivacaine hydrochloride and tetracaine hydrochloride with bromothymol blue. The ion-pair complexes formed are quantitatively extracted into dichloromethane and absorbance is measured at 420 nm. The second method is based on the coupling of the diazotized drugs benzocaine and procaine hydrochloride with a new and highly sensitive coupling agent, monosodium salt of 4-amino-5 hydroxynaphthalene-2,7-disulfonc acid. The absorbance of the red azo-dye is measured at 530 nm. These methods are quantitatively evaluated and found to be precise and accurate. Beer's law is obeyed in the concentration range 1-1 5 μg/ml and 0.1-7μg/ml for first and second methods, respectively.