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To investigate the changes of anesthetic drug concentration in plasma during isolation of autologous blood with acute normovolemic hemodiluti-on and its influence on the depth of anesthesia, muscle relaxant effect and blood drug concentration after reinfusion. METHODS: Forty patients of both sexes, aged 20-60 yr, American Society of Anesthesiologists physical status or Ⅱ, hemoglobin (Hb) >120 g / L, hematocrit (Hct) >35%, undergoing eletive multilevel spinal surgery were included, were divided into 2 groups (n=20 each) using a random number table. ANH group (group A): ANH was performed after stable induction of anesthesia, the target Hct value was 28%-30%, and autologous blood was reinfused after the main operation steps. Control group (group C): routine transfusion and infusion treatment. The bispectral index (BIS) and Train-of-Four stimulation (TOF) were observed and recorded at the stable induction of anesthesia (T1), 30 minutes of stable induction (T2), the end of operation (T3), 30 minutes after the end of the operation (T4), 1 hour after the end of the operation (T5) and 2 hours after the end of the operation (T6). The concentrations of propofol and cisatracurium besylate in plasma at T1-T6, stored blood at 1 h (TS1), 2 h (TS2), and before reinfusion (TS3) were detected by Liquid Chromatography-tandem Mass Spectrometry. The extubation time and recovery score at T4-6 hours were recorded. RESULTS: There was no significant difference in propofol between the two groups at each time point (P > 0.05). The plasma concentration of cisatracurium besylate in group A was higher than that in group C at T3 (P0.05). The BIS value at T4 and TOF value at T3 in group A were significantly lower than those in group C. The recovery score of group A was lower than that of group C at T4 (P0.05). CONCLUSION: The plasma concentrations of propofol and cisatracurium besylate were basically unchanged during the in vitro isolation of ANH autologous blood. The plasma concentrations of cisatracurium besylate were only temporarily affected after the main operation steps, but the postoperative muscle relaxation recovery and recovery quality were not significantly affected.
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AIM: To observe the effect of acute normovolemic hemodilution (ANH) autologous blood transfusion on the EEG bispectral index and muscle relaxation in elderly patients undergoing orthopedic surgery to explore the influence of autologous blood transfusion containing anesthetic components on the quality and safety of postoperative anesthesia recovery. METHODS: Forty patients, aged 65-75, weighing 55-80 kg, ASA grade I-II, with an estimated intraoperative blood loss of more than 600 mL, were selected for elective orthopedic surgery. The patients were randomly divided into two groups (n=20): group A was given acute normovolemic hemodilution (ANH), and the target value of Hct was 28%-30% after induction of anesthesia; group B was the control group which was given routine fluid infusion during operation without ANH. Bispectral index (BIS), TOF values and plasma concentrations of propofol and cisatracurium were measured at the beginning of autotransfusion (T
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Objective: To develop a ultra performance liquid chromatography- tandem mass spectrometry(UPLC- MS/MS) method for the simultaneous determination of rosuvastatin(RT), atorvastatin(AT)and their metabolites, i.e., atorvastatin lactone (ATL), ortho- hydroxy-atorvastatin(O-AT)and para-hydroxy-atorvastatin(P-AT), in human plasma. Methods: Deuterium-labeled compounds, RT-d6, AT-d5 and P-AT-d5 were used as the internal standards(IS). The plasma samples were extracted with ethyl acetate. The chromatographic separation was achieved on a ACQUITY UPLCTM BEH C18 column(50 mm×2.1 mm, 1.7 μm)with the mobile phase of 0.2%(v/v)formic acid aqueous solution and methanol by gradient elution. The flow rate was 0.2 ml/min, and the column temperature was 40℃. Analytes were detected on a tandem mass spectrometer, equipped with an electrospray ionization source that was operated in the positive mode. The selectivity, standard curve, precision and accuracy, extraction recoveries, matrix effect, and stability were investigated. Results: The linear range of RT was 0.1-50 ng/ml with r2 =0.9977. The linear range for AT, ATL, O-AT and P-AT was 0.05-50 ng/ml with r2 =0.9997, 0.9988, 0.9923 and 0.9995, respectively. Conclusion: The established method is rapid, sensitive, accurate, specific and reliable, which is suitable for the simultaneous determination of RT, AT and their metabolites in human plasma.
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Objective@#To investigate the effect of omeprazole on plasma concentration, efficacy and adverse reactions of capecitabine in patients with colon cancer.@*Methods@#Seventy-two patients with colon cancer treated with capecitabine were analysed retrospective. The patients treated with capecitabine combined with omeprazole were identified as experimental group and the capecitabine treatment alone as control group.The differences of blood concentration and the side effects of capecitabine between these two groups were compared.@*Results@#The plasma concentration of 5-Fluorouracilum in experimental group was (126.25±50.59) μg/ml, without significant difference of (123.09±56.70) μg/ml in control group (P=0.121). The incidence of Ⅲ to Ⅳ degree bone marrow suppression, nausea, vomiting, diarrhea and hand-foot syndrome in experimental group were 13.8%, 0%, 0% and 19.4%, respectively. In control group, the incidence of Ⅲ to Ⅳ degree bone marrow suppression, nausea, vomiting, diarrhea and the hand-foot syndrome were 11.1%, 0%, 0% and 19.4%, respectively, without significant difference of experimental group (P>0.05). The incidence of acid reflux and heartburn in the control group was 72.2%, significantly higher than 44.4% of the experimental group (P<0.05). The objective response rate (ORR) and progression-free survival time (PFS) in these two groups were 30.6% and 33.3%, and 8.0 month and 8.5 month, respectively, without significant difference (P>0.05).@*Conclusion@#The intravenous omeprazole attenuates reflux and heartburn of colon cancer patients treated with capecitabine, without affecting its plasma concentration and side effects and has no impact on the PFS of these patients.
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Objective:To assess the influence of glimepiride on the plasma concentrations and antihypertensive effects of losartan and its active metabolite losartan carboxylic acid(E-3174) in the patients with type 2 diabetes mellitus and hypertension. Methods:Pragmatic randomized controlled trial was used in the clinical study. Forty-five patients were enrolled and randomized into glimepiride group and the control group. Losartan was used as the antihypertensive drug in the two groups. After two-week interference,the plasma concentrations of losartan and its active metabolite E-3174 were determined using an LC-MS/MS method and the reduction of hyperten-sion was measured. Results:The plasma trough concentrations of losartan in glimepiride group was not higher than those in the control group,and those of E-3174 in glimepiride group was not lower than those in the control group. Additionally,the reduction of hyperten-sion was similar in the two groups. Conclusion: Glimepiride does not influence the plasma concentrations and the antihypertensive effects of losartan and its active metabolite E-3174 in the patients with type 2 diabetes mellitus and hypertension, suggesting no drug-drug interactions between them. Owing to the small sample,large clinical trial should be performed to confirm the above conclusion.
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Objective:To establish a liquid chromatography tandem mass spectrometry ( LC-MS/MS) method for the determination of 5-fluorouracil (5-Fu) in patient’s plasma and apply it in clinics patients validation. Methods:5-Fu was analyzed on an Agela Inno-val NH2 (2. 1 mm × 50 mm, 5 μm) column. Methanol:ultra pure water (2 ∶98) was used as the mobile phase with isocratic elution. The flow rate was 0. 3 ml ·min-1 and the column temperature was set at 40℃. The ion transitions with electrospray ionization negative model were m/z 128. 8→42. 1 and m/z 188. 6→42. 1 for 5-Fu and 5-bromouracil (the internal standard), respectively. The LC-MS/MS method was verified according to the guideline of quantitative analysis validation of biological samples ( Chinese Pharmacopoeia, 2015 edition, the fourth part) . Results:The calibration curve of 5-Fu was linear within the range of 10-1 000 ng · ml-1 . The lower limit of quantification was 10 ng · ml-1 . The precision, accuracy, matrix effect and stability within the linear range were all in line with the requirements of method validation. Conclusion:The LC-MS/MS method developed in the study for the determination of 5-Fu is simple, rapid, accurate and reproducible, which can be used for the plasma concentration detection of 5-Fu in patients.
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Objective To explore the effect of CYP2C19 polymorphism on plasma minimum concentration of Voriconazole in children with hematological malignancies complicated with invasive fungal infection.Methods Twenty children with hematological malignancies complicated with invasive fungal infection were selected from the Department of Pediatrics,the First Affiliated Hospital of Zhengzhou University were selected,and 5 mL venous blood for each was extracted.CYP2C19 genotypes of the whole blood of all patients were detected by using the method of polymerase chain-reaction restriction -fragment length polymorphism(PCR -RFLP).All the patients were treated with Voriconazole at the same time and by the same way.Plasma concentration of Voriconazole was measured by the method of fluo rescence polarization immunoassay.The impact of CYP2C19 genotypes on plasma minimum concentration of voriconazole was analyzed by using the rank sum test.Results Typing results showed that the incidence of iuhomozygous extensive me-tabolizers (EM)genotype (CYP2C19* 1 /*1 )was 30%(6 /20 cases);the incidence of mixed sub extensive metaboli-zers (IM)genotype (CYP2C19*1 /*2 or CYP2C19*1 /*3)was 45%(9/20 cases),among which ,CYP2C19*1 /*2 was in 4 cases,CYP2C1 9*1 /*3 was in 5 cases;and that of poor metabolizer (PM)genotype (CYP2C1 9*2 /*2 or CYP2C1 9*2 /*3 or CYP2C1 9*3 /*3)was 25%(5 /20 cases),among which,CYP2C1 9*2 /*2 was in 3 cases, CYP2C1 9*2 /*3 was in 1 case,and CYP2C1 9*3 /*3 was in 1 case.The serum trough concentration of Voriconazole in EMgroup,IMgroup and PMgroup was(2.30 ±0.50)mg/L,(3.23 ±0.71 )mg/L,(4.84 ±0.29)mg/L,respec-tively.There was a statistically significant relationship between CYP2C19 genotype and plasma minimum concentration of Voriconazole (F =26.99,P =0.032).Conclusions CYP2C19 polymorphism has a significant effect on the mini-mum concentration of Voriconazole in children with hematological malignancies complicated with invasive fungal infec-tion,which indicates that administration of Voriconazole for clinical treatment should be based on individual CYP2C19 genotype.
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ObjectiveTo investigate the extracorporeal clearance rate of imipenem in severe infection patients in the mode of continuous vena-venous hemofiltration (CVVH) during continuous renal replacement therapy (CRRT), in order to approach if the concentration of imipenem in plasma could achieve effective levels of anti-infection, and to explore the effect of time and anticoagulation measure on imipenem clearance during CRRT treatment.Methods A prospective observational study was conducted. All adult severe infection patients complicating acute kidney injury (AKI) in the Department of Critical Care Medicine of the Fourth Hospital of Hebei Medical University from March 2013 to September 2014, who were prescribed imipenem as part of their required medical care, and CRRT for treatment of AKI were enrolled. 0.5 g doses of imipenem was administered intravenously every 6 hours or 8 hours according to random number table, and infused over 0.5 hour. The unfractionated heparin was used for anticoagulation in the patients without contraindications, and no anticoagulation strategy was used in the patients with high risk of bleeding. At 24 hours after first time of administration, postfilter venous blood and ultrafiltrate samples were collected at 0, 0.25, 0.5, 0.75, 1, 2, 5, 6, and 8 hours after imipenem administration. The concentration of imipenem in above samples was determined with liquid chromatography-mass spectrometer/mass spectrometer (LC-MS/MS).Results A total of 25 patients were enrolled. Thirteen patients received imipenem intravenously every 6 hours, and 12 patients, every 8 hours. The anticoagulation was conducted with heparin in 13 cases, and 12 cases without anticoagulation. The intra-day precision, inter-day precision, matrix effect, and recovery rate in low, medium, and high concentration of plasma and ultrafiltrate, and the stability of samples under different conditions showed a good result, the error of accuracy was controlled in the range of±15%. With the application of Prismaflex blood filtration system and AN69-M100 filter, under the mode with CVVH, the total clearance rate of imipenem was (8.874±2.828) L/h when the actual dose of replacement fluid was (31.63±1.48) mL·kg-1·h-1, the total CRRT clearance rate of imipenem in vitro was (2.211±0.539) L/h, which accounting for (30.1±15.7)% of the total drug clearance. In 6 hours interval dosage regimen, the percentages of the time> 4×minimum inhibitory concentration (MIC) at specific 4×MIC of 2, 4, 6, and 8μg/mL of imipenem were more than 40% of the dosing interval. But in the 8 hours interval dosage regimen, when the level was above the 4×MIC of 4μg/mL, maintaining time would drop below 40% of the dosing interval, with significant differences compared with that in 6 hours interval dosage regimen [4×MIC = 2μg/mL: (60.84±20.25)%vs. (94.01±12.46)%,t = 4.977,P = 0.001; 4×MIC = 4μg/mL: (39.85±15.88)% vs. (68.74±9.57)%,t = 5.562, P = 0.000; 4×MIC = 6μg/mL: (27.58±13.70)% vs. (53.97±8.36)%,t = 5.867,P = 0.000; 4×MIC = 8μg/mL:(18.87±12.43)% vs. (43.48±7.83)%,t = 5.976,P = 0.000]. No significant change in sieving coefficient of imipenem was found within a short time (6 hours), which indicated that there was no effect of anticoagulation on clearance of imipenem by AN69-M100 filter, and no statistical significance was found with repeated measure analysis (F = 0.186, P> 0.05).ConclusionsThe clearance rate of imipenem is increased significantly in vitro under the mode of CVVH with the actual dose of replacement fluid was (31.63±1.48) mL·kg-1·h-1 in severe infective patients with severe sepsis complicating AKI, affecting the level of plasma drug concentration, need to adjust the dosage regimen. When the time of the dosing interval was shortened, the concentration of imipenem in patients' plasma could be increased significantly. In a short period of time, the sieving coefficient of imipenem through AN69 filter is not affected by anticoagulation measures and time cleaning efficiency will not decline.
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OBJECTIVE: To develop a sensitive and rapid HPLC-MS/MS method for the determination of febuxostat in human plasma. METHODS: The plasma samples were extracted with ethyl acetate after addition of internal standard and 0.1% formic acid solution, the extract was evaporated and the dry residue was reconstituted with 1 mL of methanol and 5 μL was injected to the API3000 HPLC-MS/MS system for analysis. The analytical column was SHISEIDO, CAPCELLPAK C18(2.0 mm × 50 mm, 5 μm). The mobile phase was composed of 0.1% formic acid in water-0.1% formic acid in acetonitrile (15: 85) and the flow rate was 0. 25 mL · min-1. Detection was performed with multiple reactions monitoring (MRM) using positive electrospray ionization (ESI). The pharmacokinetic characteristics of the febuxostat tablet(febuxostat 40 mg) was investigated in 12 healthy volunteers after single oral dose administration of 40 or 80 mg febuxostat and multiple oral dose administration of 40 mg febuxostat. The serial blood samples were collected and after centrifugation, the plasma was separated and analysed by HPLC-MS/MS established. RESULTS: The calibration curves were linear over the concentration ranges of 10.02-8020 ng · mL-1. The lower limit of quantifications was 10.02 ng · mL-1. Inter- and intra-day precisions were less than 12.40% and accuracy was within 85.75%-105.91%. Extraction recoveries were around 87% and the ana-lytes were proved to be stable under all the required conditions. Total runtime of an analyte was only 2.0 min. Results of the statistical analysis indicated that febuxostat followed linear kinetics in healthy Chinese volunteers at the investigated dose range of 40 to 80 mg. No significant drug accumulation was found after multiple dose administration of 40 mg febuxostat tablets. Furthermore, there was no significant difference of pharmacokinetics between males and females in Chinese population. CONCLUSION: This method is rapid, sensitive, specific and applicable to the pharmacokinetic study in human of febuxostat.
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OBJECTIVE: To develop an LC-MS/MS method for simultaneous determination of clevidipine and its major metabolite H152/81 concentration in rat plasma. METHODS: The plasma samples were processed with liquid-liquid extraction, with nimo-dipin as an internal standard. The separation was achieved on ZORBAX SB C18 column (2.1 mm×100 mm, 3.5 μm) and eluted with linear gradient using acetonitrile and 0.1% formic acid at the flow rate of 0.3 mL·min-1, the injection volume was 10 μL and the column temperature was maitained at 30℃. The total time of the analysis was 3.5 min. Detection of the analytes were achieved using positive ion electrospray ionization (ESI) in the multiple reaction monitoring (MRM) mode. RESULTS: The linear calibration curve of clevidipine and its major metabolite H152/81 were obtained concentration range of 1.0-200 μg·L-1 (r>0.99), with the lower limit of quantitation (LLOQ) of 1.0 μg·L-1. The average recovery was between 92.5%-109.8%, Intra-day and inter-day relative standard deviations were both below 15%. The recoveries of low, middle and high concentrations were 71.3%-82.6%, respectively. CONCLUSION: The established method is rapid, sensitive, accurate, specific and reliable, and suitable for simultaneous determination of clevidipine and its major metabolite H152/81 in rat plasma.
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OBJECTIVE: To establish an UPLC-MS/MS method for the determination of linezolid in human plasma. METHODS: The analytical column was packed with Acquity BEH C18(2.1 mm × 50 mm, 1.7 μm, Waters). The mobile phase A consisted of water(containing 0.1% formic acid), the mobile phase B consisted of acetonitrile. The analytes were eluted from the column with a linear gradient. The flow rate was 0.4 mL · min-1. A tandem mass spectrometer equipped with electrospray ionization source was used as detector multiple reaction monitoring(MRM) using the precursor to production pairs of m/z 338.2→296.2 (for linezolid) and m/2: 237.1→-194.2(for carbamazepin) were used to quantification. RESULTS: The liner range of linezolid in human plasma was 20-20 000 μg · L (r=0.9979). The limit of detection was 20 μg · L-1. Intra-day and inter-day RSD for assaying the plasma sample of linezolid were both lower than 6.26%, absolute recovery were more than 80%. CONCLUSION: The method is proved to be highly sensitive, selective, and suitable for pharmacokinetic investigations of linezolid.
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Objective: To assess the value of plasma concentration of 5-FU (5-fluorouracil) predicting the efficacy and safety in patients with advanced gastric cancer receiving capecitabine plus cisplatin as first-line chemotherapy. Methods: The clinical data from 113 advanced gastric cancer patients receiving capecitabine plus cisplatin in Shanghai First People's Hospital from July 2007 to December 2010 were retrospectively collected. The plasma concentration of 5-FU was examined at each cycle of chemotherapy. The relationships between plasma concentration of 5-FU and the OS (overall survival), PFS (progression-free survival) and RR (response rate) were determined by statistical analysis. Results: The mean plasma concentration of 5-FU was 25.8 μg/L. The patients were divided into group A (plasma concentration of 5-FU > 25 μg/L, n = 59) and group B (plasma concentration of 5-FU < 25 μg/L, n = 54). The median OS time of group A and group B were 14.4 and 9.6 months, respectively (hazard ratio = 0.36, P = 0.000). The median PFS time of group A and group B were 8.0 and 4.9 months, respectively (hazard ratio = 0.37, P = 0.000). The RR of group A and group B were 55.9% and 33.3%, respectively (P = 0.023). All toxicities occurred more frequently in group A than in group B. The grade III/IV mocositis and hand-foot syndrome were significantly increased in group A as compared with group B. Conclusion: For advanced gastric cancer, high plasma concentration of 5-FU might predict efficacy and toxicities of capecitabine plus cisplatin. Copyright © 2013 by TUMOR.
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OBJECTIVE: To develop a sensitive and specific LC-MS/MS method for the determination of pilsicainide in human plasma and urine. METHODS: The samples were processed by LLE(liquid-liquid extraction), acetonitrile-ammonium acetate(0.1‰ formic acid)-water was used as the mobile phase with isocratic elution(25:37.5:37.5 in plasma, 35:6:59 in u-rine), and separation was carried out on Welch Material Ultimate AQ-C18 column(2.100 × 100 mm, 3.5 μm), setting the flow rate as 0.35 mL · min-1, the column temperature at 25°C. The injection volume was 5 μL. ESI under positive ion mode and multiple reaction monitoring scan(MRM) were used for quantitative analysis with m/z 213.4 → 110.2 for pilsicainide and m/z 287.4 → 110.2 for internal standard, methyl-pilsicainide. RESULTS: The linear ranges of the calibration curves for pilsicainide were 1-1200 μg · L-1 for plasma and 1-150 mg · L-1 for urine. The limitation of detection were 1 μg · L-1 for plasma and 1 mg · L-1 for urine. The correlation coefficient was between 0.9962 and 0.9991. The extraction recoveries, matrix effects, and intra-/inter-assay precisions all met the requirements of pharmacokinetic studies. This approach was applied to determine pilsicainide concentrations in human plasma and urine in a clinical pharmacokinetic research. CONCLUSION: This approach possesses convenience, accuracy, high sensitivity and good reproducibility, which can meet the requirements of pharmacokinetic studies.
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A fast,simple and sensitive high performance liquid chromatographic (HPLC) method has been developed for determination of 10α-methoxy-6-methyl ergoline-8β-methanol (MDL,a main metabolite of nicergoline) in human plasma.One-step liquid-liquid extraction (LLE) with diethyl ether was employed as the sample preparation method.Tizanidine hydrochloride was selected as the internal standard (IS).Analysis was carried out on a Diamonsil ODS column (150 mm × 4.6 mm,5 μm) using acetonitrile-ammonium acetate (0.1 mol/L) (15/85,v/v) as mobile phase at detection wavelength of 224 nm.The calibration curves were linear over the range of 2.288-73.2 ng/mL with a lower limit of quantitation (LLOQ) of 2.288 ng/mL.The intra- and inter-day precision values were below 13％ and the recoveries were from 74.47％ to 83.20％ at three qtality control levels.The method herein described was successfully applied in a randomized crossover bioequivalence study of two different nicergoline preparations after administration of 30 mg in 20 healthy volunteers.
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OBJECTIVE:To establish a rapid and sensitive HPLC method for simultaneous determination of plasma concentrations of 6 antidepressants.METHODS:With diprozin as internal standard,the alkalized samples were extracted by liquid-liquid extraction and separated on a Phenomenex-C18 column using acetonitrile-0.05 mol?L-1 sodium dihydrogen phosphate(pH was adjusted to 2.5 by phosphoric acid) as mobile phase at a flow rate of 1.2 mL?min-1 by a gradient elution.The column temperature was set at 40℃.Venlafaxine was detected by fluorescence detection at an Ex wavelength of 276 nm and Em wavelength of 598 nm;doxepin,paroxetine,sertraline,fluoxetine and amitriptyline were detected at an UV detection wavelength of 200 nm.RESULTS:The linear ranges of venlafaxine,doxepin,paroxetine,sertraline,fluoxetine and amitriptyline were 5～1 000 ?g?L-1,40 ～200 ?g?L-1,20～800 ?g?L-1,40～1 000 ?g?L-1 and 10～400 ?g?L-1,respectively,with correlation coefficients ≥0.990 for all.Both the intra-day RSD and inter-day RSD were less than 15%;the extraction recovery rates were greater than 60% and methodological recovery were greater than 90% for all the samples.CONCLUSION:The method is simple,economical,rapid,accurate and sensitive,and it is applicable for the clinical monitoring of plasma drug concentrations as well as the analysis and pharmacokinetic study of toxic drugs.
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OBJECTIVE:To determine the concentration of dehydroisoandrosterone sulfate (DHEAS) in human plasma by LC-MS.METHODS:With estrogen sulfate (ES) served as an internal standard,the plasma samples were deproteinized with acetonitrile,extracted by solid phase,hydrolyzed and derivatized.Then the concentration of DHEAS was determined by HPLC-MSD on Agilent SB C18 with column temperature kept at 40℃.The mobile phase consisted of acetonitrile-water (in gradient elution).Atmosphere pressure chemical ion source in negative ion detection model was employed.The ions selected for SIM (selected ion monitoring) quantitative analysis included m/z 490.0 (DHEAS ) and m/z 472.1(ES)[M-H]-.RESULTS:The linear range of DHEAS was 250.0～320.0 ng?mL-1(r=0.999 4).The extraction recovery of the simulated human albumin samples ranged from 71.1%～78.9% and its relative recovery ranged from 98.3%～101.4%.Both the intra-day RSD and inter-day RSD were less than 10%.The mean concentration of DHEAS in 15 health aged male volunteers was (981.6?353.4) ng?mL-1.CONCLUSION:The method is simple,practical,accurate and sensitive,and it is applicable for the determination of plasma concentration of DHEAS.
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OBJECTIVE:To determine the concentration of ozagrel in human plasma by RP-HPLC.METHODS:The sample separation was performed on a SinoChrom OPS-AP column.The mobile phase consisted of 0.025 mol?L-1 potassium dihydrogen phosphate buffer solution-acetonitrile(85∶15) with a flow rate of 0.8 mL?min-1 and a detection wavelength of 274 nm.The internal standard was levodropropizine.RESULTS:The linear range of ozagrel was 0.7～21.3 ?g?mL-1,(r=0.999 6).The extraction recovery of ozagrel was 83.78%～89.14% and the methodological recovery of it was 101.95%～106.68%.The intra-day RSD and inter-day RSD were 1.33%～3.27% and 2.72%～5.97%,respectively.CONCLUSION:This method is simple,rapid,accurate and reproducible,and it is applicable for the pharmacokinetic study of ozagrel in human plasma.
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OBJECTIVE:To develop an HPLC-fluorescence method for simultaneous determination of losartan and its major metabolite(E-3174) in human plasma.METHODS:Plasma sample was pretreated by liquid-liquid extraction with aether then determined with valsartan served as internal standard.The determination was performed on Diamonsil C18 with column temperature set at room temperature.The mobile phase consisted of 0.02 mol?L-1 sodium dihydrogen phosphate buffer (adjusted to pH=2.35 with phosphoric acid)-acetonitrile (57∶43) at a flowrate of 0.5 mL?min-1.The excitation wavelength was set at 250 nm and the emission wavelength was set at 370 nm.RESULTS:The linear range of losartan was 10～1 000 ng?mL-1(r=0.999 0) with a lowest limiest of quantification(LLOQ) of 10 ng?mL-1;the linear range of E-3174 was 5～1 000 ng?mL-1(r=0.999 0) with a LLOQ of 5 ng?mL-1.The methodological recoveries of losartan and E-3174 were 94.05%～110.09% and 107.7%～110.94%,respectively,with both intra-day RSD and inter-day RSD at less than 10.0%;the extraction recoveries of losartan and E-3174 were 69.16%～70.85% and 67.50%～70.77%,respectively.CONCLUSION:The developed method is simple,accurate and reproducible,and it is applicable for the concentration determination and pharmacokinetic studies of losartan and its major metabolite (E-3174) in human plasma.
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OBJECTIVE:To develop a simple micellar electrokinetic capillary chromatography for determination of theophylline concentration in human plasma. METHODS: The determination of plasma sample(without any pretreatment) was performed on un-coated fused-silica capillaries (at an effective length of 21 cm) in which the cathodic buffer solution (solution A) was 15 mmol?L-1 borax(pH=10) and the running buffer solution(solution B) was sodium dodecyl sufate (SDS)(200 mmol?L-1) -contained solution A. The sample was injected into capillary by pressure with separation voltage of 12 kV;the UV detection wavelength was set at 280 nm;quantitation was performed by external standard peak area method. RESULTS: The average determination time of each sample was 11 min;the linear range of theophylline was 1.25～40 ?g?mL-1 with its lowest detectable limit at 0.5 ?g?mL-1;the average methodological recovery was 90.33%(RSD=2.51%);the intra-day RSD was 2.34%～3.36% and the inter-day RSD was 2.03%～6.51%,respectively. CONCLUSION: The developed method is simple,rapid and sensitive and it is applicable for the therapeutic drug monitoring of theophylline.
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OBJECTIVE:To develop a high performance liquid chromatography-mass spectrography method (LC-MS/MS) for determination of huperzine A in human serum. METHODS:The clonidine was used as the internal standard,and the test serum samples after being liquid-liquid extracted by ethyl acetate,dried in organic phase and reconstituted in mobile phase were analyzed on a Phenomenex Luna CN column interfaced with LC-MS with Methanol-0.08% formic acid (46∶54 containing 0.2% ammonium acetate). Positive ion SRM detection was performed for ESI iron source. Target ions were at m/z 243. 2→210. 9 for Huperzine A with an impact energy of 30V and m/z 229. 9→212. 9 for the internal standard with an impact energy of 32V during 0.5 s (scan time). RESULTS:The assay was proved to be free from the interference from endogenous substance,and the linear concentration range of Huperzine A was 0.08～8 ng?mL-1(r=0.993 0～0.996 0). The intra-and inter-day precision over the entire concentration range were less than 15%. At low,middle and high concentrations,the mean extraction recoveries of Huperzine A were 69.9%,63.7% and 63.7%,respectively. CONCLUSION:The LC-MS/MS method is rapid,sensitive,simple,accurate and in which little amount of mediator is needed,thus meeting the requirement for the detection of biological specimen and applicable for the treatment of large batch of serum samples in clinical pharmacokinetic study.