Determination of oxytetracycline and doxycycline in pharmaceutical compounds, urine and honey by derivative spectrophotometry.

Derivative spectrophotometric methods have been developed for determining oxytetracycline and doxycycline and for resolving their binary mixtures. Oxytetracycline and doxycycline were determined in pharmaceutical samples, urine and honey without any pre-treatment of the samples. In all instances, first-derivative spectra were used.