Junyu Xu

Peking University, Peping, Beijing, China

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Publications (2)4.56 Total impact

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    ABSTRACT: The objectives of the present study were to investigate the pharmacokinetics (PK) of tacrine analogue octahydrogenacridine (OHA) succinate tablets in healthy Chinese subjects. A single-center, randomized, open-label, dose-escalation study was conducted in 42 healthy Chinese subjects. Part I of the study (n=30, 16 male and 14 female) evaluated the PK profiles of OHA in healthy Chinese subjects (aged 18-45 years) after single and multiple doses of 2 mg, 4 mg and 8 mg. Part II (n=10) assessed food effect on PK characteristics of OHA. The 10 participants of 4 mg dose group in part I were given another single dose of 4 mg OHA under fed condition. Part III (n=12, 7 male and 5 female) investigate PK behavior of OHA in elderly (aged 65-75 years) Chinese healthy subjects. In Part I, following a single- and multiple-dose, octahydrogenacridine succinate was rapidly absorbed with a median t(max) of 0.67 to 1.00 h, and was eliminated with a mean t(1/2) of 2.27 to 2.98 h in all dose groups and did not appear to be dose dependent. In Part II, there were no significant differences in C(max), AUC(0-tn) or t(max) between 4 mg single dose fasting group and fed group (p=0.257, 0.153, 0.098, respectively). In Part III, both in single-dose and multiple-dose treatment, the main PK parameters of OHA in the elderly healthy Chinese subjects showed no statistical difference with those of non-elderly group. All these results indicated that OHA might be a promising drug under development for Alzheimer's disease (AD) therapy.
    Preview · Article · Sep 2012 · Biological & Pharmaceutical Bulletin
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    ABSTRACT: A rapid, sensitive and specific liquid chromatography-tandem mass spectrometric (LC-MS/MS) method has been developed and validated for the determination of silodosin in human plasma. Silodosin and internal standard (IS) were extracted from human plasma by liquid-liquid extraction using methyl t-butyl ether and analyzed on an Agilent C(8) column with the mobile phase of acetonitrile-10 mM ammonium acetate (40:60, v/v) adjusted to pH 4.5 with acetic acid. Detection was carried out by MS/MS using TurboIonSpray (TIS) ionization and multiple reaction monitoring (MRM) in the positive-ion mode. The mass transitions monitored were m/z 496.3-->261.4 and m/z 440.4-->259.3 for silodosin and IS, respectively. The standard curve was linear in the range of 0.50-50.0 ng/ml with intra- and inter-day precision of 3.2-7.2% and 2.0-7.5%, respectively. The lower limit of quantification (LLOQ) for silodosin was 0.50 ng/ml using 500 microl plasma sample. This method was successfully applied to the pharmacokinetic study in healthy volunteers.
    No preview · Article · Aug 2009 · Journal of chromatography. B, Analytical technologies in the biomedical and life sciences