| Abstrakt: |
The direct current polarographic behaviour of dipyridamole, a coronary vasodilator, in the supporting electrolyte consisting of 0.2 M KCl, 20 % (v/v) ethanol and buffer solutions is described in this study. Morphologically well-defined DC polarographic curves have appeared within the pH range of 7–8 and the optimum polarographic conditions found were, a potential rate of 4 m V.s-1, drop time of 1 s and a pressure of 1000 dyne.cm-2. The factor effecting the polarographic current was diffusion-controlled and the reduction reaction was highly reversible. The effect of concentration on the limiting current was examined using DC, SCAP, SIAP and DP polarographic modes at pH 7.8 and optimum conditions. Linear calibration equations with good correlations were obtained for all techniques. DP polarography was used among the modes for the determination of dipyridamole in the tablets. The results obtained were compared with the results of the UV-spectrophotometric method. Using the Mann-Whitney U-test, it was concluded that there is an insignificant variance between the two methods. The relative standard deviations are 75±1% and 75.3±0.7% for DP polarographic and UV-spectrophotometric methods, respectively. The determination method proposed in this study seems to be accurate, rapid and practical. Therefore, it may be suitable for the content uniformity test (USP XXI). |
