Determination of doxycycline in its pure form and in its pharmaceutical formulation by charge transfer complex method

Abstract

Asimple, rapid and accurate spectrophotometric method was developed for the determination of Schiff base for doxycycline (Dxoy) in its pure form and in its pharmaceutical preparation (Doxycline Capsule 100 mg). at a wavelength of 344 nm. The optimal conditions for complex formation (time, temperature, type and size of the best reagent, addition sequence) were studied.The linearity of the method for the compound ranged from (0.25-5) µg/mL, Sandel's significance was 0.008038 µg/cm², the molar absorption coefficient was 5.982396×10⁴ L/mol.cm, the detection limit was 0.000873 µg/mL, the quantitative limit was 0.002643 µg/mL, and the recovery percentage was Rec%. Between (95.640-98.037)% and the relative standard deviation rate RSD% does not exceed ≤ 0.1864. The method was successfully applied to estimate (Doxy) in its pharmaceutical formulation by the direct method and the method of standard additives.