Determination of monohydroxyethylrutoside in heart tissue by high-performance liquid chromatography with electrochemical detection

7-Monohydroxyethylrutoside (monoHER) is one of the components of the regist ered drug Venoruton. It showed a good protection against the cardiotoxic ef fects of doxorubicin. The analysis of monoHER was developed to study the ph armacokinetic profile of the drug in heart tissue. MonoHER was extracted fr om heart tissue homogenate with methanol. The supernatant was diluted 1:1 ( v/v) with 25 mM phosphate buffer and injected onto a reversed-phase ODS col umn. The mobile phase consisted of 49% methanol and 51% of an aqueous solut ion containing 10 mM sodium dihydrogenphosphate (pH 3.4), 10 mM acetic acid and 36 muM EDTA. The retention time of monoHER was about 5.2 min and no en dogenous peaks were interfering. The lower limit of quantification was 0.07 2 nmol g(-1) wet heart tissue. The calibration line was linear up to 24 nmo l g(-1). The within-day accuracy and precision of the quality controls (0.1 2, 1.2 and 12.0 nmol g(-1)) were smaller than 17 and 19%, respectively. The between-day accuracy and precision were better than 6 and 11%, respectivel y. The recovery of monoHER from heart tissue ranged from 104.1 to 114.3% an d was concentration independent. MonoHER was stable in heart tissue when st ored at -80 degreesC for 6 months. Repeated injection of monoHER from aliqu ots of 7.2 nmol g(-1) placed on the sample tray at 4 degreesC for 24 h show ed a decrease in the concentration of 30.3%. Analyzing sample duplicates in a mirror image sequence could compensate for the influence of this gradual decrease. The small sample volume allowed one to measure monoHER in the he arts of mice. (C) 2001 Elsevier Science B.V. All rights reserved.