Spectrophotometric Determination of Demeclocycline and Minocycline using Molybdenum (VI)

The author has developed simple, new, convenient, rapid and selective methods for determination of Demeclocycline (DMC) and Minocycline (MNC). The procedure based on the observation that, DMC or MNC forms colored complexes with molybdenum (VI), the absorbance of which is proportional to the amount of tetracycline present. The variable effecting development of the color has been investigated and the conditions are optimized. Beer's law is obeyed in the range 0.962 to 7.36 μg/ml DMC and for 0.96 to 7.68μg/ml MNC. The proposed methods can be employed for the analytical determination of molybdenum (VI). The corresponding Beer's law ranges are 0.005 to 0.040 mg/ml with DMC and 0.004 to 0.040 mg/ml with MNC. These methods are successful applied for the determination of DMC and MNC in pharmaceutical formulations. These methods are applied where ever possible for the analysis of real samples in pharmaceutical industries.