A Hypersil ODS C-18 column (250 × 4.6 mm, packed with 5 microns) is used as stationary phase. An isocratic mode with mobile phase consisting of acetonitrile, methanol and 1% phosphate buffer (pH-3) in ratio of 18:58:24 (v/v/v) at a flow rate of 1 ml/min and effluent was monitored at 232 nm. Chromatogram showed a peak of DZP at retention time of 6.23 ± 0.002 min. The linearity range was found to be 2–20 μg/ml.