Spectrophotometric determination of oxytetracycline in pharmaceutical preparations using sodium tungstate as analytical reagent

Abstract

The formation of a complex between oxytetracycline (H₃OTC) and tungstate ion was studied in the pH range 3.0–8.0, in aqueous solution, at room temperature. Using the optimum conditions for complex formation a spectrophotometric method for the assay of H₃OTC in the concentration range 4.9–34.9 µg ml^–1 is proposed. The detection limit of the method is 2.5 µg ml^–1 of H₃OTC. The coefficient of variation is within the range 0.60–1.29%. The proposed method is simple and sensitive and was applied to the determination of H₃OTC in pharmaceutical preparations.