Aim To establish a LC-MS method for determining the concentration of nifedipine in human plasma and to evaluate the pharmacokinetic characteristics of nifedipine sustained-release tablets. Methods A XB-C18 （5 μm, 4....Aim To establish a LC-MS method for determining the concentration of nifedipine in human plasma and to evaluate the pharmacokinetic characteristics of nifedipine sustained-release tablets. Methods A XB-C18 （5 μm, 4.6 mm ×150 mm） column and a mobile phase of methanol： 0.01 mol·L^-1ammonium acetate （60：40, V/V） were used to separate nifedipine, the detections was accuracy under atmosperic pressure electronic spray ionization （AP-ESI） mode and ion mass spectrum （m/z） of 314.9 [M＋H]^＋ for nifedipine, and 320.8 [M＋H]^＋ for lorazepam （Internal Standard, IS）. Results The linear range of nifedipine was 0.3 - 80 ng·mL^-1 （ r = 0.9997）, and the limit of quantitation （LOQ） was 0.3 ng·mL^-1. The nifedipine pharmacokinetic parameters after a single dose of 20 mg nifedipine sustained-release tablets test （T） or reference （R） were as the followings, t1/2 （6.73 ± 2.00） h and （7.04 ± 2.18） h, Tmax （4.28 ± 0.70） h and （4.48 ± 0.70） h, Cmax（39.66 ± 10.58） ng·mL^-1 and （40.19 ± 10.97） ng·mL^-1, AUC0-36 （391.63 ± 108.55） ng·mL^-1·h and （387.57 ± 121.51） ng·mL^-1·h, and AUC0-∞ （408.28 ± 121.16） ng·mL^-1·h and （406.15 ± 133.13） ng·mL^-1·h. The relative bioavailability of nifedipine sustained-release tablets （test） was （103.02 ± 13.93） %. Conclusion LC-MS method for the determination of concentrations of nifedipine in human plasma was sensitive and accurate, and could be used in nifedipine bioavailability and pharmacokinetic studies.展开更多
In the present study,we aimed to determine the pharmacokinetics(PK),pharmacodynamics(PD),adverse events(AEs),and their relationships in Chinese patients with schizophrenia after a single dose of long-acting risperidon...In the present study,we aimed to determine the pharmacokinetics(PK),pharmacodynamics(PD),adverse events(AEs),and their relationships in Chinese patients with schizophrenia after a single dose of long-acting risperidone.Schizophrenic patients(six females and seven males)were enrolled in this study.Serial blood samples were collected after drug administration during 63 d,and the drug concentrations were analyzed by LC-MS/MS.Safety and tolerance were evaluated by monitoring the AEs,changes in clinical laboratory results,12-lead ECG,vital signs,physical examination,and injection-site reactions.The extrapyramidal symptoms were evaluated using the ESRS.Efficacy was evaluated by the PANSS and BPRS.Twelve out of the 13 participants completed the trial.There were few clinically meaningful changes in mean clinical laboratory values,vital signs,or ECG parameters,except for the prolactin level and body weight.There were no serious AEs,and those observed were reversible.Significant clinical improvements in PANSS and PANSS-derived BPRS total scores were observed.The mean(standard deviation,coefficient of variation)values for these PK parameters were as follows:C_(max),8.954(8.059,90.0%)ng/mL;area under the curve AUC_(0-t),2453(1156,47.1%)ng·h/mL;AUC_(0-∞),2472(1160,46.9%)ng·h/mL;t_(max),830.0(min:744.0,max:984.0,11.8%)h;and t_(1/2),68.56(10.77,15.7%)h.The PK characteristics of long-acting risperidone showed a high level of inter-individual variation,while there were no clear correlations between PK,efficacy and AEs among the patients in the present study.展开更多
文摘Aim To establish a LC-MS method for determining the concentration of nifedipine in human plasma and to evaluate the pharmacokinetic characteristics of nifedipine sustained-release tablets. Methods A XB-C18 （5 μm, 4.6 mm ×150 mm） column and a mobile phase of methanol： 0.01 mol·L^-1ammonium acetate （60：40, V/V） were used to separate nifedipine, the detections was accuracy under atmosperic pressure electronic spray ionization （AP-ESI） mode and ion mass spectrum （m/z） of 314.9 [M＋H]^＋ for nifedipine, and 320.8 [M＋H]^＋ for lorazepam （Internal Standard, IS）. Results The linear range of nifedipine was 0.3 - 80 ng·mL^-1 （ r = 0.9997）, and the limit of quantitation （LOQ） was 0.3 ng·mL^-1. The nifedipine pharmacokinetic parameters after a single dose of 20 mg nifedipine sustained-release tablets test （T） or reference （R） were as the followings, t1/2 （6.73 ± 2.00） h and （7.04 ± 2.18） h, Tmax （4.28 ± 0.70） h and （4.48 ± 0.70） h, Cmax（39.66 ± 10.58） ng·mL^-1 and （40.19 ± 10.97） ng·mL^-1, AUC0-36 （391.63 ± 108.55） ng·mL^-1·h and （387.57 ± 121.51） ng·mL^-1·h, and AUC0-∞ （408.28 ± 121.16） ng·mL^-1·h and （406.15 ± 133.13） ng·mL^-1·h. The relative bioavailability of nifedipine sustained-release tablets （test） was （103.02 ± 13.93） %. Conclusion LC-MS method for the determination of concentrations of nifedipine in human plasma was sensitive and accurate, and could be used in nifedipine bioavailability and pharmacokinetic studies.
基金Foundation items:The National Major Scientific and Technological Special Project for"Significant New Drug Development"during the Twelfth Five-year Planning Period of China(Grant No.2014ZX09303303).
文摘In the present study,we aimed to determine the pharmacokinetics(PK),pharmacodynamics(PD),adverse events(AEs),and their relationships in Chinese patients with schizophrenia after a single dose of long-acting risperidone.Schizophrenic patients(six females and seven males)were enrolled in this study.Serial blood samples were collected after drug administration during 63 d,and the drug concentrations were analyzed by LC-MS/MS.Safety and tolerance were evaluated by monitoring the AEs,changes in clinical laboratory results,12-lead ECG,vital signs,physical examination,and injection-site reactions.The extrapyramidal symptoms were evaluated using the ESRS.Efficacy was evaluated by the PANSS and BPRS.Twelve out of the 13 participants completed the trial.There were few clinically meaningful changes in mean clinical laboratory values,vital signs,or ECG parameters,except for the prolactin level and body weight.There were no serious AEs,and those observed were reversible.Significant clinical improvements in PANSS and PANSS-derived BPRS total scores were observed.The mean(standard deviation,coefficient of variation)values for these PK parameters were as follows:C_(max),8.954(8.059,90.0%)ng/mL;area under the curve AUC_(0-t),2453(1156,47.1%)ng·h/mL;AUC_(0-∞),2472(1160,46.9%)ng·h/mL;t_(max),830.0(min:744.0,max:984.0,11.8%)h;and t_(1/2),68.56(10.77,15.7%)h.The PK characteristics of long-acting risperidone showed a high level of inter-individual variation,while there were no clear correlations between PK,efficacy and AEs among the patients in the present study.
