DETERMINATION OF DOXORUBICIN HYDROCHLORIDE BY VISIBLE SPECTROPHOTOMETRY

Four simple and sensitive visible spectrophotometric methods (A-D) hav e been described for the assay of doxorubicin hydrochloride either in pure form or in pharmaceutical formulations. Method A was developed ba sed on oxidation of the drug with Fe(III) to produce Fe(II), which sub sequently reacts with 1,10-ortho-phenanthroline to form a red colored complex (lambda(max): 510 nm) at pH 4.6. Method B involves the reducti on of Folin-Ciocalteu (F-C) reagent by the drug and the reduced specie s formed possesses a characteristic intense blue color (lambda(max): 7 70 nm). In methods C and D, oxidation of the drug with periodate at sp ecified experimental conditions yields formaldehyde and dialdehyde, wh ich in turn react either with 3-methyl-2-benzothiazolinone hydrazone h ydrochloride to form an intensely brilliant blue cationic dye (lambda( max): 620-670 nm, method C) or by condensation with phenylhydrazine hy drochloride (PHH) to form orange-red colored product (lambda(max): 510 nm, method D) in the presence of potassium ferricyanide. All of the v ariables have been optimized and the reaction mechanisms presented. Th e concentration measurements are reproducible within a relative standa rd deviation of 1.0%.