SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF DEMECLOCYCLINE USING SODIUM MOLYBDATE AS ANALYTICAL REAGENT

By means of spectroscopic methods it has been found that demeclocycline reacts with molybdate ions forming a complex compound [MoO3HDMTC]2-. The relative stability constant of this compound has been determined by applying spectrophotometric methods. Under optimum conditions for complex formation a very senstivie spectrophotometric method for the estimation of demeclocycline in the concentration range 5.0-35.1-mu-g/ml is proposed. The detection limit of the method is 2.5-mu-g/ml of demeclocycline. The relative standard deviation (n = 10) varies between 0.76% and 1.46%. The method proved to be accurate and sensitive for the analysis of the demeclocycline content in tablets.