To determine the pharmacokinetics of gemcitabine (2',2'-difluorodeoxycytidine) in Chinese non-small-cell lung cancer (NSCLC) patients. Six study subjects were administered gemcitabine at a fixed dose rate of 10 mg/m(2) per min (1200 mg/m(2), two hours infusion), and carboplatin and plasma gemcitabine concentrations were measured by ion-pair reversed-phase high-performance liquid chromatography (HPLC). 3P97 Pharmaceutical Kinetics Software was used for the calculation of pharmacokinetic parameters. The obtained mean parameters, elimination half life (t(1/2)) (10.67+/-3.38 min), area under the curve (AUC) (7.55+/-1.53 (microg x h)/ml), and clearance (CL) (3940.05+/-672.08 ml/min), were consistent with those reported in literature. The hematologic toxicology result showed that the regimen was effective on and tolerated by the patients.
Adolescent ; Adult ; Aged ; Carcinoma, Non-Small-Cell Lung ; blood ; China ; Deoxycytidine ; administration & dosage ; analogs & derivatives ; blood ; pharmacokinetics ; Female ; Humans ; Male ; Middle Aged ; Time Factors

This study presents a rapid, specific and sensitive liquid chromatography/tandem mass spectrometry (LC-MS/MS) assay for determination of risperidone (RIS) in human serum using paroxetine as an internal standard (IS). An Alltima-C18 column (2.1 mmx100 mm, 3 microm) and a mobile phase consisting of 0.1% formic acid-acetonitrile (40:60, v/v) were used for separation. The analysis was performed by selected reaction monitoring (SRM) method, and the peak area of the m/z 411.3-->191.1 transition for RIS was measured versus that of the m/z 330.1-->192.1 transition for IS to generate the standard curves. The assay linearity of RIS was confirmed over the range 0.25 approximately 50.00 ng/ml and the limit of quantitation was 0.05 ng/ml. The linear range corresponds well with the serum concentrations of the analytes obtained in clinical pharmacokinetic studies. Intraday and interday relative standard deviations were 1.85% approximately 9.09% and 1.56% approximately 4.38%, respectively. The recovery of RIS from serum was in the range of 70.20% approximately 84.50%. The method was successfully applied to investigate the bioequivalence between two kinds of tablets (test versus reference products) in 18 healthy male Chinese volunteers. The result suggests that two formulations are bioequivalent.
Adolescent ; Adult ; Antipsychotic Agents ; blood ; pharmacokinetics ; Area Under Curve ; China ; Chromatography, High Pressure Liquid ; methods ; Drug Stability ; Humans ; Male ; Mass Spectrometry ; methods ; Reference Standards ; Reproducibility of Results ; Risperidone ; blood ; pharmacokinetics ; Time Factors