ABSTRACT
Deoxyglycychloxazol (TY501) is a glycyrrhetinic acid derivative which exhibits high anti-inflammatory activity and reduced pseudoaldosteronism compared to glycyrrhetinic acid. In this study, a sensitive and rapid liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was established for the quantitation of TY501 in rat plasma. Plasma samples were treated by precipitating protein with methanol and supernatants were separated by a Symmetry C8 column with the mobile phase consisting of me-thanol and 10 mM ammonium formate (containing 0.1%of formic acid) (90:10, v/v). The selected reaction monitoring (SRM) transitions were performed at m/z 647.4-191.2 for TY501 and m/z 473.3-143.3 for astragaloside aglycone (IS) in the positive ion mode with atmospheric pressure chemical ionization (APCI) source. Calibration curve was linear over the concentration range of 5–5000 ng/mL. The lower limit of quantification was 5 ng/mL. The mean recovery was over 88%. The intra-and inter-day precisions were lower than 6.0% and 12.8%, respectively, and the accuracy was within 71.3%. TY501 was stable under usual storage conditions and handling procedure. The validated method has been successfully applied to a pharmacokinetic study after oral administration of TY501 to rats at a dosage of 10 mg/kg.
ABSTRACT
Ethanol and dichloromethane extracts of a Brazilian green propolis from Baccharis dracunculifolia were analyzed by HPLC-APCI-MS and GC-MS, respectively. The HPLC-APCI-MS technique, at the positive mode, furnished a complete and unequivocal chemical composition of the green propolis sample. It serves as fingerprint for different propolis samples. The composition of the ethanol extract consisted mainly of cinnamic acid and derivatives, flavonoids, benzoic acid and a few benzoates, non-hydroxylated aromatics, and aliphatic acids and esters, which are normally not reported in the literature because they do not absorb UV light. The main constituents of the dichloromethane extract were prenylated compounds, alkanes and terpenoids.
Os extratos em etanol e diclorometano de uma própolis verde de Baccharis dracunculifolia foram analisados por CLAE-ICPA-EM e CG-EM, respectivamente. A técnica de CLAE-EM-ICPA, no modo positivo, forneceu uma completa e inequívoca composição química da amostra de própolis verde. Ela serve como impressão digital para amostras diferentes de própolis. A composição do extrato em etanol consistiu fundamentalmente de ácido cinâmico e derivados, flavonóides, ácido benzóico e alguns benzoatos, aromáticos não hidroxilados, e ácidos e ésteres alifáticos, os quais são normalmente ignorados na literatura porque não absorvem luz UV. Os constituintes principais do extrato em diclorometano foram compostos prenilados, alcanos e terpenóides.
ABSTRACT
A highly sensitive, rapid and selective liquid chromatography-tandem mass spectrometry(LC-MS/MS) method for the quantitative determination of retinamido-ester in rat plasma was developed and validated. A simplified protein precipitation with acetonitrile was employed for the sample preparation.The separation was carried out on an Agilent TC C18 column ( 150 mm×4. 6 mm ID, 5 μm particle size)with the mobile phase consisted of methanol-water-formic acid (93 : 7 : 0.1). Simvastatin was used as internal standard. The detection was performed on a trap-quadrupele tandem mass spectrometer by selected reaction monitoring (SRM) scan mode via atmospheric pressure chemical ionization (APCI). The range of and inter-day precision values were between 95.97% and 104. 43%, and RSD was between 4. 63% and 10. 69%, respectively. This method was applied to determine the pharmacokinetic parameters. The main pharmacokinetic parameters of retinamido-ester after oral administration via gastric gavage of 2. 5, 5, 10mg·kg-1 were as follows,T1/2;(11.28±7.23),(8.90±3.82),(8.01±5.56)h; AUC0-∞:(103.41±61.46),(190.23±74.99),(421.66±299.20)ng·h·mL-1;MRT:(6.31±0.75),(5.98±0.71), (6.18±0.97) h; CL/F: (30. 10 ± 13.67), (29.58±10.59), (31.18 ±17.51)L·h-1·kg-1;Vd/F:(414.94±159.82),(356.16±139.85),(369.28±322.73)L·kg-1,respectively.
ABSTRACT
AIM: To investigate the pharmacokinetic properties and bioequivalence of nifedipine sustained-release tablets after multiple doses administration in healthy volunteers. METHODS: Twenty two male healthy volunteers were enrolled in a randomized two-way crossover design with multiple doses (20 mg·d-1×7 d) study. Nitrendipine was used as the internal standard and the concentrations of nifedipine in plasma were determined by HPLC-APCI-MS. The pharmacokinetic parameters were calculated and the bioequivalence were compared by DAS (ver 1.0) program. RESULTS: The pharmacokinetic parameters of test and reference preparations were as follows: Cmax (52.5±27.4) and (54.0±31.2) ng·ml-1;Cmin (5.4±4.1) and (6.2±5.9) ng·ml-1;Cav (16.8±9.2) and (19.3±12.4) ng·ml-1;Tmax (3.7±0.9) and (4.1±1.1) h;t1/2 (8.9±4.9) and (8.5±3.1) h;AUC0-τ (403.4±221.0) and (461.9±296.6) μg·h·L-1, AUC0-36h (444.4±256.1) and (503.1±330.9) ng·h·ml-1;AUC0-∞ (482.1±268.9) and (542.3±348.4) ng·h·ml-1;DF (299.8±117.7)% and (279.2±97.5)%, respectively. There were no significant differences (P>0.05) in Tmax, Cmax, Cmin, Cav, DF, AUC0-τ, AUC0-36h, AUC0-∞ and t1/2 between the two preparations. The relative bioavailability of test tablets was (100.6±38.6)%. CONCLUSION:The test and reference preparations were bioequivalence.