| Autor: |
Borges NC; Synchrophar Assessoria e Desenvolvimento de Projetos Clínicos S/S Ltda, 24, Cesar Bierrenbach St., Campinas, SP 13015-025, Brazil. carsver@synchrophar.com, Astigarraga RB, Sverdloff CE, Galvinas PR, da Silva WM, Rezende VM, Moreno RA |
| Jazyk: |
angličtina |
| Zdroj: |
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences [J Chromatogr B Analyt Technol Biomed Life Sci] 2009 Nov 01; Vol. 877 (29), pp. 3601-9. Date of Electronic Publication: 2009 Sep 04. |
| DOI: |
10.1016/j.jchromb.2009.08.048 |
| Abstrakt: |
In the present study, a novel, fast, sensitive and robust method to quantify ethinylestradiol in human plasma using 17alpha-ethinylestradiol-d4 as the internal standard (IS) is described. The analyte and the IS were extracted from acidified plasma by liquid-liquid extraction (LLE) using diethyl ether-hexane followed by online solid phase extraction (SPE) using online C18 cartridges. Extracted samples were analyzed by high-performance liquid chromatography coupled to atmospheric pressure photoionization tandem mass spectrometry (HPLC-APPI-MS/MS). Chromatography was performed isocratically on a C18, 5 microm analytical column. The method had a chromatographic run time of 2.50 min and a linear calibration curve over the range 5-500 pg ml(-1) (r(2)>0.9992). The lowest concentration quantified was 5 pg ml(-1), demonstrating acceptable accuracy and precision. The intra-assay precisions ranged from 2.1 to 14.6%, while inter-assay precisions ranged from 4.4 to 11.4%. The intra-assay accuracies ranged from 94.6 to 103.8%, while the inter-assay accuracies ranged from 98.9 to 101.6%. The recovery of ethinylestradiol was determined as part of the assay validation process and was 73.1 and 79.0% for the concentrations 15 and 375 pg ml(-1), respectively. Short-term stability showed that ethinylestradiol was stable in plasma for at least 19 h at room temperature or for at least 385 days when stored at -20 degrees C. In the study of bioequivalence conducted in Brazil, healthy volunteers received two ethinylestradiol 0.035 mg tablet formulations using an open, randomized, two-period crossover design with a 2-week washout interval. Since the 90% confidence interval for C(max) and area under the curve ratios were all inside the 80-125% interval proposed by the US Food and Drug Administration, it was concluded that the two ethinylestradiol formulations are bioequivalent with respect to both the rate and the extent of absorption. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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