Spectrophotometeric Methods for Determination of Doxycycline in Tablet Formulation

Two simple, economical, precise and reproducible visible spectrophotmetric methods have been developed for the estimation of doxycycline in tablet formulation. The developed methods are based on the formation of chloroform extractable complex of doxycycline with bromo phenol blue and safranine in double distilled water. The complex with bromo phenol blue (method I) shows absorbance maxima at 413 nm and linearity in the concentration range of 5-40 μg/ml. The extracted complex with safranine (Method II) shows absorbance maxima at 525.6 nm and the linearity in the concentration range of 2.5-20 μg/ml. Results of analysis for both the methods were validated statistically and by recovery studies.