Electrochemistry of Redox Active Drugs&its Application to Hplc Determination in Pharmaceutical Analysis

Quantitative study of these compounds was performed by HPLC technique using electrochemical detector in alkaline mobil phase ( pH 11.8 ) on alumina column . The chromatographic conditions were optimized for each compound . Photostability of these compounds, in acetonitrile to fluoresecent and room light, sun light and UV light at 365 nm was estimated by HPIC method and it was found that all compounds are approximatly stable to fluorescent and room light up to 5h. while sun and UV lights cause their rapid dagradation . Isradipine, due to its unique structure, was. found to be the most stable one . Effect of heat on the stability of these drugs in acetonitrile was studied at three temperatura levels ( 40,60 and 80ºC ) and it was found that all compounds are stable temperature levvels.The proposed HPLC/ ECD method was applid for pharmacokinetic studt of barnidipine HCI after its oral adminstration to dogs. Pharmacokinetic data were obtained by analysis using a one compartment model with a first order elimination rate constant.these data demonstrate that this compound is rapidy absorbed and eliminated by the dog . By this method, barnidipine can be accurately determined for bioavilability studies.