Author(s): C. Rambabu1, CA. Jyothirmayee2 and K. Naga Raju3*
New, simple, selective and accurate spectrophotometric methods are described in the present work for the determination of cabergoline in the pure samples and pharmaceutical formulations. This method I involves quantitative precipitation of drug with PMA (phosphomolybdic acid) (first step) and estimating the PMA released (with acetone from its adduct), by reducing it with (cobalt nitrate) Co(II)-EDTA complex and method II involves quantitative precipitation of CBL(Cabergoline) with tannic acid. (step I). The liberated tannic acid from the precipitate on treatment with acetone was determined with PMAP-Cr (VI) (P-N-methyl amino phenol sulphate- potassium dichromate) at pH 3.0.chromogen with absorption maxima at 840nm and 570nm respectively. Beer's law is obeyed in the concentration ranges of 5-60 µg/ml and 1.6- 12 µg/ml respectively. The results of analysis for the two methods have been validated statistically and by recovery studies. The methods are extended to pharmaceutical formulations.