Proteomic Characteristics of the Prefrontal Cortex and Hippocampus in Mice with Chronic Ketamine-Induced Anxiety and Cognitive Impairment.

Schizophrenia, a complex psychiatric disorder with diverse symptoms, has been linked to ketamine, known for its N-methyl-D-aspartate (NMDA) receptor antagonistic properties. Understanding the distinct roles and mechanisms of ketamine is crucial, especially regarding its induction of schizophrenia-like symptoms. Recent research highlights the impact of ketamine on key brain regions associated with schizophrenia, specifically the prefrontal cortex (PFC) and hippocampus (Hip). This study focused on these regions to explore proteomic changes related to anxiety and cognitive impairment in a chronic ketamine-induced mouse model of schizophrenia. After twelve consecutive days of ketamine administration, brain tissues from these regions were dissected and analyzed. Using tandem mass tag (TMT) labeling quantitative proteomics techniques, 34,797 and 46,740 peptides were identified in PFC and Hip, corresponding to 5,668 and 6,463 proteins, respectively. In the PFC, a total of 113 proteins showed differential expression, primarily associated with the immuno-inflammatory process, calmodulin, postsynaptic density protein, and mitochondrial function. In the Hip, 129 differentially expressed proteins were screened, mainly related to synaptic plasticity proteins and mitochondrial respiratory chain complex-associated proteins. Additionally, we investigated key proteins within the glutamatergic synapse pathway and observed decreased expression levels of phosphorylated CaMKII and CREB. Overall, the study unveiled a significant proteomic signature in the chronic ketamine-induced schizophrenia mouse model, characterized by anxiety and cognitive impairment in both the PFC and Hip, and this comprehensive proteomic dataset may not only enhance our understanding of the molecular mechanisms underlying ketamine-related mental disorders but also offer valuable insights for future disease treatments.

Removal of multiple lipids from human plasma using a hydroxyl-functionalized covalent organic framework aerogel as a new sorbent.

A hydroxyl-functionalized covalent organic framework aerogel COFTHB-TAPB-aerogel was designed and prepared as an adsorbent for the removal of multiple lipids from human plasma. The applications of 1,3,5-tris(4'-hydroxy-5'-formylphenyl)benzene (THB) and 1,3,5-tris(4-aminophenyl)benzene (TAPB) as monomers, DMSO/mesitylene (v/v, 4/1) as reaction solvent, and n-propylamine as reaction regulator endow COFTHB-TAPB-aerogel with good adsorption performance for multiple lipids. The morphology, phase purity, specific surface area, pore size, surface charge, and stability of COFTHB-TAPB-aerogel were characterized. Adsorption thermodynamics and adsorption kinetics studies showed that COFTHB-TAPB-aerogel had high equilibrium adsorption capacities (> 15913 mg g-1) and fast adsorption equilibrium (≤ 10 s) for the four model lipids tested. COFTHB-TAPB-aerogel had good reusability with the removal of the model lipids being still more than 91% after 10 use cycles. The sample pretreatment conditions and adsorbent amounts used in lipids removal experiments were optimized. Under the optimized conditions, the method of ultra-high performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) using COFTHB-TAPB-aerogel as solid-phase extraction sorbent was validated with negligible matrix effects (0.4-3.0%) and good accuracy (86.7-110%) and was applied to determine  20 amino acids in human plasma samples from healthy individuals and gastric adenocarcinoma (GA) patients. The established method has been proved to have good application potential for the removal of multiple lipids in human plasma to reduce the matrix effects and improve the accuracy of clinical LC-MS analysis.

Simultaneous quantification of cefuroxime and clindamycin in human lumbar anulus fibrosus, nucleus pulposus and serum via UPLC-MS/MS.

BACKGROUND: This study aimed to develop a sensitive, accurate method for simultaneously quantifying cefuroxime and clindamycin in human serum, lumbar anulus fibrosus and nucleus pulposus. METHODS: Cefuroxime and clindamycin were quantified using ultra high-performance liquid chromatography-electrospray ionization tandem mass spectrometry in multiple-reaction-monitoring mode on a triple-quadrupole AB Qtrap 5500 system in positive ion mode. Internal standards were D3-cefuroxime and D3,13C-clindamycin. Samples were pretreated by precipitating total protein. RESULTS: The method showed high sensitivity and good linearity over broad calibration ranges from 100 to 100 000 ng/mL for cefuroxime and 10 to 10 000 ng/mL for clindamycin in serum, and from 10 to 10 000 ng/mL for cefuroxime and 1 to 1 000 ng/mL for clindamycin in lumbar nucleus pulposus. In all sample types, correlation coefficients were greater than 0.99, intra- and inter-day precision (relative standard deviation) was less than 15%, and accuracy (relative error) was within 14% for both analytes. This method was effective at quantifying penetration of cefuroxime and clindamycin in patients undergoing oblique lumbar interbody fusion surgery. CONCLUSIONS: A very sensitive, specific method for simultaneous detection of cefuroxime and clindamycin has been developed for human lumbar anulus fibrosus, nucleus pulposus and serum samples.

Development and validation of a UPLC-MS/MS method for quantification of C-005, a novel third-generation EGFR TKI, and its major metabolite in plasma: Application to its first-in-patient study.

C-005 is a novel third-generation EGFR tyrosine kinase inhibitor for the treatment of non-small cell lung cancer (NSCLC). To support its clinical trial, we developed a rapid and sensitive bioanalytical method based on ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) technique for the quantification of C-005 and its major metabolite in NSCLC patients following international bioanalytical guidelines. After a simple and quick protein precipitation step, the supernatant was injected to a Waters Acquity BEH C18 column (2.1 × 50 mm i.d., 1.7 mm), and the column was eluted with a gradient of buffer A (5 mM ammonium acetate and 0.1% formic acid in water) and buffer B (formic acid-acetonitrile (1:1000, v/v)). The eluates were subsequently detected by an AB QTRAP 5500 mass spectrometer with electrospray ionization using multiple-reaction monitoring mode. The method showed good linearity from 2.00 to 1000 ng/mL for C-005 and 1.00 to 500 ng/mL for M1. In conclusion, the validation results demonstrated the robustness of the method and its well-poised to support the first-in-patient study of C-005 in NSCLC patients.

Pharmacokinetics of Ginsenoside Rh2, the Major Anticancer Ingredient of Ginsenoside H Dripping Pills, in Healthy Subjects.

Ginsenoside H dripping pill (GH) is a novel clinical-stage adjuvant for the treatment of non-small cell lung cancer. In this study, the pharmacokinetics of ginsenoside Rh2, the major anticancer ingredient of GH, was investigated in healthy volunteers. Enrolled volunteers were assigned to 3 cohorts-7.8, 15.6, and 31.2 mg-and received single and/or multiple GH orally. Blood samples were assayed by a validated bioanalytical method, and drug concentrations were analyzed using a noncompartmental methodology. The results showed that ginsenoside Rh2 was absorbed with medium speed and reached Cmax a median of 3 hours after administration. The exposure of ginsenoside Rh2 was approximately dose-dependent in terms of AUC and Cmax . The plasma concentration of ginsenoside Rh2 reached steady state after oral administration of GH twice daily for 5 days. There was no obvious accumulation in exposure parameters in the multiple-dose study.

Detoxification of aflatoxin B1 in corn by chlorine dioxide gas.

Chlorine dioxide (ClO2) gas was utilized for detoxifying aflatoxin B1 (AFB1) in corn for the first time. Four degradation compounds were identified by LC-MS as C17H13O8, C17H15O10, C16H15O10, and C15H11O8. Structurally, the biological activity of ClO2-treated AFB1 was removed due to the disappearance of C8-C9 double bond in the furan ring and the modification of cyclopentanone and methoxy after ClO2 treatment. The cell viability assay on human embryo hepatocytes confirmed little toxicity of the degradation products. The degradation efficiency of AFB1 on corn peaked near 90.0% under the optimized conditions and reached 79.6% for low initial contamination of AFB1 at 5-20 µg/kg. Accordingly, ClO2 has the potential to be developed into an effective, efficient, and economic approach to detoxify AFB1 in grains.

High-sensitivity detection of therapeutic drugs in complex biofluids using a packed ballpoint-electrospray ionization technique.

A simple and sensitive C18 packed ballpoint-electrospray ionization (PBP-ESI) technique was developed for biofluid analysis. In this technique, the configuration of a commercial ballpoint consisting of a hollow chamber, an intermediate socket, and a metal ball was fully exploited. The rear-end hollow chamber was used for loading C18 adsorbent and sample, and the front metal ball served as a spray emitter for online ionization. The good electrical conductivity of the metal body allowed high voltage to be conveniently applied to the ballpoint without inserting the electrode into the solution for electrical connection. Urine sample was directly analyzed with the C18 packed ballpoint; plasma and whole blood samples were premixed with C18 adsorbent before being packed into the ballpoint for detection. As a result of the sample cleanup by C18 adsorbent, the salt matrix in the urine sample as well as the phospholipid and protein matrices in plasma and whole blood samples was significantly reduced. The lower limits of quantitation (LLOQs) for urine, plasma, and whole blood samples reached the subnanogram-per-milliliter level. Graphical abstract.

A rapid method for simultaneous quantification of berberine, berbamine, magnoflorine and berberrubine in mouse serum using UPLC-MS/MS.

Berberidis cortex, the dry bark of Berberis L., is used to treat diabetes and contains at least three bioactive components: berberine (BBR), berbamine (BBM) and magnoflorine (MGF). BBR in turn is metabolized into berberrubine (BRB). Although it is possible to quantify each of these components individually in serum, there are currently no methods for simultaneously quantifying all four. Here, we developed a specific and rapid method for simultaneously quantifying BBR, BBM, MGF and BRB in mouse serum using ultra high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Samples were pretreated by protein precipitation, separated using an ACQUITY UPLC® BEH C18 column and detected by a triple quadrupole mass spectrometer with electrospray ionization. The compound [9,10-(OC2H3)2]-BBR (d6-BBR) was used as internal standard for BBR and BRB, boldine (BOL) for MGF and tetrandrine (TET) for BBM. The m/z transitions for precursor/product ion pairs were 336.1/320.2 for BBR, 305.2/566.3 for BBM, 342.0/297.1 for MGF, 322.1/307.2 for BRB, 342.2/294.3 for d6-BBR, 312.2/580.3 for TET and 328.1/265.2 for BOL. We validated our method in terms of selectivity, linearity and lower limit of quantification, accuracy, precision, matrix effect and recovery, dilution integrity and stability. This method showed good linearity from 0.1 to 40 ng/mL for BBR, 8 to 3200 ng/mL for BBM, 5 to 2000 ng/mL for MGF and 0.2 to 80 ng/mL for BRB. The chromatographic run time was 3.9 min, and sample preparation took approximately 15 min per batch. Finally, we used our method to measure BBR, BBM, MGF and BRB in serum from diabetic mice after gavage administration of BBR hydrochloride, BBM hydrochloride, and MGF. This method is precise, accurate and suitable for high-throughput sample analysis.

[Determination of 5-hydroxytryptamine,Adrenalin and Noradrenalin in Human Plasma by Pre-column Derivatization HPLC-MS/MS].

OBJECTIVE: To establish a method for the determination of 5-hydroxy tryptamine (5-HT),adrenalin (AD) and noradrenalin (NA) in human plasma using pre-column derivatization HPLC-MS/MS. Methods Derivatives of the plasma samples were produced with dansyl chloride under pH 10.5,and then extracted and enriched with ethyl acetate. The detected chemicals were separated using Ultimate C18 (50 mm×4.6 mm,5 µm) with acetonitrile-water-formic acid=95∶5∶0.05 (V∶V∶V) at 0.2 mL/min. The HPLC-MS//MS system was operated under a multiple reaction monitoring mode (MRM) using the electrospray ionization technique in positive mode. RESULTS: Linear range of the calibration curve appeared in 250-2.5 ng/mL. The method had a less than 9% intra- and inter-assay relative standard deviation (RSD),95.44%-109.71% recoveries,and 4.86%-12.81% matrix effects. CONCLUSION: This method is simple,accurate,and suitable for detection of 5-HT,AD and NA in human plasma.

[Determination of Voriconazole in Human Plasma and Its Bioequivalence by HPLC-MS/MS].

OBJECTIVE: To develop a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for the determination of voriconazole in human plasma and its bioequivalence. METHODS: 48 healthy male volunteers received a single dose of 200 mg voriconazole tablets in a two period (with two preparations) and randomized crossover bioequivalence study. Their plasma voriconazole was determined using HPLC-MS/MS. The pharmacokinetic parameters and bioequivalence of the two preparations were calculated with WinNonlin®6.1. RESULTS: The calibration curve of voriconazole ranged from 1 to 5 000 ng/mL. The HPLC-MS/MS method had less than 11% intra- and inter-day relative standard deviation (RSD),with 100.00% to 109.73% accuracies. The RSD of the matrix effect of voriconazole adjusted with internal standard was less than 15%. The extract recoveries exceeded 50% with good stability. The 90% confidence intervals for the peak concentration (Cmax) and the area under the curve (AUC0-t and AUC0-∞)of voriconazole fell into the bioequivalence range of 80.00%-125.00%. There was no significant difference in peak time (Tmax) between the two preparations. CONCLUSION: HPLC-MS/MS can be used for determination of voriconazole in human plasma. The two tested preparations of voriconazole are bioequivalent.

[Pharmacokinetics Study of Phentolamine Mesylate Injection in Healthy Volunteers].

OBJECTIVE: To study the pharmacokinetic profile of phentolamine mesylate injection in healthy Chinese volunteers. METHODS: A total of 16 healthy volunteers were randomly divided into two groups, each receiving anterior teeth submucosal infiltration anesthesia and inferior alveolar nerve block anesthesia, respectively. The participants were injected with 0.9 mL, 1.8 mL, and 3.6 mL of 2% lidocaine HCl with 1∶100 000 epinephrine over three periods sequentially, followed by corresponding sequential injection of 0.2 mg, 0.4 mg, 0.8 mg of phentolamine mesylate at the same sites 30 min later.Blood samples were drawn from 5 min before injection to 15 h post the injection of phentolamine mesylate (16 time points). Adverse events were closely observed all the time. Plasma phentolamine mesylate was detected using UPLC-MS/MS with isotope as internal standard. WinNolin 6.1 software was used to calculate the pharmacokinetic parameters. RESULTS: Time to peak concerntration (Tmax) ranged from 12 to 13 min. Half-time of elimination (t1/2) ranged from 3.84 to 4.07 h, with a clearance (CL) of 190 L/h. Peak concentration (Cmax), area under concentration-time curves from 0 to t hour and from 0 to infinite time (AUC0-t and AUC0-∞) increased proportionally in the dose range of 0.2 mg to 0.8 mg. The results of confidence interval analysis showed nearly linear dynamic characteristics for the injection of phentolamine mesylate. All participants experienced mild adverse events, including pain at the injection point, dizziness, and palpitations. These adverse events disappeared without treatments. CONCLUSIONS: Phentolamine mesylate injection is effective for reversing oral local anesthetic effects.

[Bioequivalence of Ubenimex Capsules in Healthy Volunteers].

OBJECTIVE: To evaluate bioequivalence of two specifications of ubenimex capsules in comparison with the Japanese branded product (R). METHODS: The study adopted a 3-way crossover design in twenty-four healthy male volunteers, whose plasma concentrations of ubenimex were determined by UPLC-MS/MS after administration a single oral dose of 30 mg of domestic ubenimex T1 (10 mg/capsule), T2 (30 mg/capsule) and branded ubenimex R (30 mg/capsule) sequentially. The bioequivalence was evaluated using WinNonlin6. 1 statistical analysis software. RESULTS: One volunteer was excluded because of failure to follow medication instructions. The main pharmacokinetic parameters of ubenimex of T1, T2 and R were as follows: C(max) (2 646.73 ± 454.09) ng/mL, (2 675.91 ± 474.32) ng/mL and (2 432.79 ± 544.32) ng/mL, respectively; T(max) (0.68 ± 0.23) h, (0.76 ± 0.19) h and (0.77 ± 0.26) h, respectively; AUC(0-t) (3 925.23 ± 478.34)(ng x h)/mL, (3 804.62 ± 448.84)(ng x h)/mL and (3 789.30 ± 443.15)(ng x h)/mL, respectively; AUC(0-∞)(3 938.31 ± 479.54)(ng x h)/mL, (3 817.26 ± 450.90) (ng x h)/mL and (3 800.90 ± 444.77) (ng x h)/mL, respectively; CL/F (7.72 ± 0.92) L/h, (7.97 ± 0.98) L/h and (7.99 ± 0.90) L/h, respectively; Vd (26.08 ± 9.20 )L, (25.65 ± 10.22) L and (26.03 ± 10.05) L, respectively. The relative bioavailability F(0-t) and F(0-∞) of T1 and T2 against the branded preparation R were (103.90 ± 9.19)% and (100.77± 9.36)%, and (103.93 ± 9.20)% and (100.79 ± 9.33)%, respectively. CONCLUSION: Both ubenimex capsules T1 and T2 are bioequivalent to the Japanese branded products.

[Determination of Warfarin Enantiomers in Human Plasma with HPLC-MS/MS].

OBJECTIVE: To establish a high performance liquid chromatography-mass spectrometry/mass spectrometry (HPLC-MS/MS) method for determination of warfarin enantiomers in human plasma. METHODS: Warfarin enantiomers were extracted with ethyl acetate. The HPLC-MS/MS method used naproxen as internal standard, with methanol : water : formic acid = 85 : 15 : 0.05 as mobile phase, at a flow rate of 0.18 mL/min. R-warfain, S-warfarin and internal standard (IS) were separated on column MS Chiral MS-OD (50 x 2.1 mm, 3 µm). Warfarin enantiomers were protonated with electroapry ionization (ESI) in negative electron ionization mode. The ion pairs being detected were (m/z) 307.2-160.9 (R-warfain and S-warafrin) and (m/z) 228.9 --> 185.1 (IS). RESULTS: The within-run precision relative standard deviations (RSD) and between-run precision RSD of R-warfarin were 3.2%-5.8% and 2.5%-5.1%, respectively. The method recoveries and extraction recoveries of R-warfarin were (96.1 ± 5. 6)%-(105.4 ± 4.7)% and 80.7%-84.4%, respectively. The matrix effect RSD was less than 10%. The within-run precision RSD and between-run precision RSD of S-warfarin were 3.7%-5.2% and 3.2%-4.8%, respectively. The method recoveries and extraction recoveries of 5-warfarin were (98.3 ± 5.1)%-(103.7 ± 3.8)% and 81.3%-84.6%, respectively. The limit of quantification was 0.1 µg/mL for both analytes. CONCLUSION: This new method is fully validated with satisfactory accuracy and adequate reproducibility. Therefore, it can be applied for separating and detecting plasma warfarin enantiomers.

Using Monte Carlo simulation to determine optimal dosing regimen for cefetamet sodium for injection.

The objective of the study was to use Monte Carlo simulation to determine the optimal treatment dosing regimen of the cefetamet sodium for injection by analysing the pharmacokinetics (PK) parameters in healthy Chinese volunteers, and antibacterial activity in vitro was also examined. A three-cross Latin square single-dose PK study was designed. Twelve healthy volunteers were randomized to receive 500, 1000, and 2000 mg of cefetamet sodium for IV infusion over 30 minutes in three periods sequentially; and the washout time in between periods was 3 days. The drug concentrations in plasma were analysed by high-performance liquid chromatography, and the PK parameters were calculated using DAS2.0 PK software. The peak concentrations (Cmax) at 0.5 hours were 37.78±7.29, 76.18±12.81, and 149.32±29.94 mg/l, the areas under concentration-time curve (AUC0-t) were 69.75±14.44, 139.06±22.62, and 278.54±53.12 mg h/l, and the elimination half-life (t1/2) were 1.69±0.19, 1.69±0.27, and 1.81±0.23 hours for 500, 1000, and 2000 mg of cefetamet sodium for injection, respectively. The disposition of cefetamet was appear to fit a two-compartment model with linear kinetics. Antibacterial activity in vitro showed that most Gram-negative bacteria, including non-extended-spectrum beta-lactamases (ESBL)-producing Enterobacter, Haemophilus influenzae, Moraxella catarrhalis, and Neisseria gonorrhoeae, were sensitive to cefetamet. The result of Monte Carlo simulation showed that the probability of target attainment for bactericidal response (%fT>MIC≧50%) for susceptible bacteria was reached at all three dosing regimens of 500 mg, q6h, 1000 and 2000 mg, q8h and q6h. Considering the efficacy, safety, and pharmacoeconomy comprehensively, we recommended the dosing regimen of 500 mg, q6h for further clinical treatment based on the principle of minimum daily dosage.

Pharmacokinetics and bioequivalence evaluation of acamprosate calcium tablets in healthy Chinese volunteers.

BACKGROUND: Few pharmacokinetic data of acamprosate were available in Chinese population and no medication is approved for alcohol dependence in China. PURPOSE: 1. Investigate the pharmacokinetic properties of acamprosate calcium in healthy Chinese male volunteers on single- and multiple-dose administration. 2. Compare the bioequivalence of two formulations of acamprosate calcium tablets both under fasting and fed conditions. METHODS: This open-label, randomized study included 3 stages. In each stage, a 2-way crossover bioequivalence study was conducted to study the pharmacokinetic properties and bioequivalence of acamprosate calcium tablets on multiple dosing after standardized meals, single dosing under fasting conditions and fed conditions, respectively. The washout period between each treatment in a stage and between each stage was 1week. Plasma acamprosate calcium was quantified by a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Tolerability was evaluated by monitoring adverse events, physical examinations, 12-lead ECG, and laboratory tests. RESULTS: Totally, 36 male subjects were enrolled in the study and all of them completed the whole 3 study stages. Main pharmacokinetic parameters of test and reference formulations were as follows: multiple dosing, Tmax 9.94±6.59 and 9.47±5.47h, Cmax 435.74±348.10 and 346.54±155.66ng·mL(-1), AUC0-t 8600.52±5264.77 and 9315.10±6820.03ng·mL(-1)·h, AUC0-∞ 8845.38±5838.18 and 9669.24±7326.53ng·mL(-1)·h, t1/2 10.06±8.83 and 9.87±10.35h; single dosing under fasting conditions, Tmax 7.29±4.87 and 6.57±1.85h, Cmax 247.85±110.05 and 244.64±132.43ng·mL(-1), AUC0-t 3385.41±1418.92 and 3496.24±1767.29ng·mL(-1)·h, AUC0-∞ 3781.53±1556.96 and 3829.56±1981.25ng·mL(-1)·h, t1/2 13.07±17.24 and 10.26±7.78h; single dosing under fed conditions, Tmax 17.72±9.42 and 19.50±9.84h, Cmax 183.90±74.52 and 168.14±60.67ng·mL(-1), AUC0-t 3181.71±1368.24 and 3575.11±1416.39ng·mL(-1)·h, AUC0-∞3442.39±2002.53 and 3624.44±1418.12ng·mL(-1)·h, t1/2 8.76±12.28 and 6.67±4.84h, respectively. In all three stages, 90% CIs for the test/reference ratio of AUC0-t and AUC0-∞ were located within 80%-125%, 90% CI for Cmax was within 70%-143%. CONCLUSIONS: Similar pharmacokinetic results of acamprosate calcium tablets in healthy Chinese volunteers were found as those in Caucasic population. In all three stages, the two formulations met the regulatory criteria for bioequivalence. Chictr.org identifier: ChiCTR-TTRCC-14004853.

[Pharmacokinetics study of injected doripenemin healthy volunteers].

OBJECTIVE: To study the pharmacokinetics of injected doripenem in Chinese healthy volunteers, in order to optimize dosages for patients. METHODS: Twelve healthy volunteers were recruited in the threecross Latin square designed study. Participants received intravenous infusions of 0.25, 0.5 and 1.0 g doripenem sequentially in three periods at a random order. Plasma and urine doripenem were measured by HPLC-UV, using an internal standard method with meropenem for plasma samples and an external standard method for urine samples, respectively. Phoenix WinNonlin 6.1 pharmacokinetic software was used to calculate non-compartment pharmacokinetics parameters. SPSS 19.0 software was used for statistical analysis. RESULTS: A single dose infusion of 0.25, 0.5 and 1.0 g doripenemin 60 min produced the following respective parameters: Cmax (11.81 +/- 1.52), (22.80 +/- 3.80) and (47.26 +/- 8.38) microg/mL, Tmax (60.42 +/- 1.44), (58.33 +/- 5.77) and (60.00 +/- 0) min, t(1/2) (63.48 +/- 10.51), (69.12 +/- 16.72) and (69.30 +/- 11.71) min, AUC(0-1), (1100.86 +/- 150.04), (2111.50 +/- 359.58) and (4359.50 +/- 789.38) microg/(mL x min). Linear Regression and Confidence Interval analyses suggested a linear kinetic characteristic. Doripenem was mainly excreted through kidneys, with 24 h cumulative urine excretion rates ranging from 70% to 75% for the three doses of infusions. It was safe to administer doripenem through infusion in healthy volunteers. Adverse reactions occurred in 19.44% cases of infusions, although all were mild reactions. Tinnitus happened in two cases (8.33%) of infusions, which required close observations. CONCLUSION: Doripenem infusion possesses a linear kinetics. There is no need to adjust the regimenpatients.

[Phase I clinical trial on the safety of injectable cefetamet sodium with a single dose in healthy volunteers].

OBJECTIVE: To investigate the safety and maximum tolerable dosage of injectable cefetamet sodium Sixty healthy volunteers were enrolled in this study. with a single infusion in Chinese healthy volunteers. METHODS: A double-blinded, randomized, placebo-controlled design was adopted. Eight dosages ranging from 100 mg to 5 000 mg were tested. The pharmacokinetics of the drug was analyzed using a Latin square three-cross self-controlled design, with 12 healthy volunteers receiving 500 mg, 1 000 mg and 2 000 mg of injectable cefetamet sodium in a randomized sequence. Blood and urine samples were collected and analyzed using high performance liquid chromatography with UV detection. The main pharmacokinetics parameters were calculated with DAS2.0 software. RESULTS: 59 healthy volunteers completed the tolerance tests. Clinical adverse reactions occurred in 22.73% of participants in the test group and 6.67% of participants in the placebo group; but the difference was not statistically significant. Common adverse events included infusion pain and dizziness. Rare adverse events such as palpitations, diarrhea and rash occurred in participants in the test group. All of the adverse reactions were mild. Abnormal laboratory test results occurred in 43.18% participants in the test group and 53.33% participants in the placebo group; again the difference was not statistically significant. Common abnormal laboratory test results included abnormal bowel flora, stool abnormalities, abnormal urine and elevated serum potassium. After a single infusion of 500 mg, 1 000 mg and 2 000 mg of injectable cefetamet sodium, peak concentration of the drug at 0.5 h reached (37.92 +/- 7.43), (74.90 +/- 10.67) and (148.54 +/- 31.63) mg/L, with areas under concentration-time curve of (72.08 +/- 14.98), (144.28 +/- 24.57) and (286.66 +/- 54.25) (mg x h)/L, respectively. Their elimination half-life was (2.03 +/- 0.38), (2.04 +/- 0.26), and (2.12 +/- 0.26) h, respectively. The disposition of cefetamet was presented as a two-compartment model with linear kinetics. The 24-hour urinary accumulation excretion was 76.6%-67.5%. CONCLUSION: The maximum single tolerated dose of injectable cefetamet sodium is 5 000 mg. The pharmacokinetics is a two-compartment model with linear kinetics within a dose range 500-2 000 mg.

[Determination of dimemorfan in human plasma and urine with HPLC-MS/MS].

OBJECTIVE: To develop a sensitive and reproducible HPLC-MS/MS method for analyzing dimemorfan in human plasma and urine. METHODS: Dimemorfan was extracted from plasma and urine by redistilled ether, with lidocaine serving as the internal standard (IS). The analysis was performed on a column of ultimate C18 (50 mm x 4.6 mm, 5 microm) with the mobile phase consisting of methyl alcohol-water-formic acid = 75:25 : 0.05 at a flow rate of 0. 2 mL/min. Dimemorfan was detected by API 3000 mass spectrometer, with multiple reaction monitoring after protonated with ESI in positive electron ionization mode. The ion pairs being detected were (m/z) 256.4-->155. 3 (dimemorfan) and 235.4-->86.1 (lidocaine), respectively. RESULTS: The regression equation for dimemorfan showed excellent linearity (r = 0.995 7) from 0. 025 to 5.0 ng/mL of plasma with detecting limitation of 0.025 ng/mL and perfect linearity (r = 0.9983) from 0.1 to 20.0 ng/mL of urine with detecting limitation of 0.1 ng/mL. The method recoveries of dimemorfan in plasma and urine were ranging from 103.38% to 106.88% and 90.05% to 101.40%, respectively. The maximum intra-day and inter-day relative standard deviations (RSD) of concentration of dimemorfan were 5.92% and 5. 70% (for plasma), 10.35% and 8.80% (for urine), respectively. CONCLUSION: This new method was validated to be accurate and sensitive to determinate the concentration of dimemorfan in plasma and urine samples, and can be applied for pharmacokinetic studies of dimemorfan.

[Pharmacokinetics study of amoxicillin sodium clavulanate potassium (10:1) injection in healthy volunteers].

OBJECTIVE: To study the pharmacokinetics of amoxicillin sodium clavulanate potassium (10:1) injection with different single doses intravenous infusion and one dose repeated intravenous injection in healthy volunteers for guiding the rational clinical regimen. METHODS: Using infusion pump constantly intravenous dripping in 30 min, 4 mL blood samples were collected before and after the administration at 10 min, 20 min, 30 min, 45 min, and 1, 1.25, 1.5, 2, 2.5, 3, 4, 6, 8, 10 h. The plasma concentrations of amoxicillin and clavulanate were detected by high performance liquid chromatography- mass spectrometry/mass spectrometry method. The pharmacokinetic parameters were calculated by DAS2.0.1 software. RESULTS: The dispositions of amoxicillin and clavulanate matched three or two compartment model with the weight coefficient 1/cc. To avoid the biases caused by compartment model fitting, the pharmacokinetic parameters were statistical moment parameters of non-compartment model. The peak concentrations, the areas under curve, the half-lifes and the clearances after single injections of 0. 55 g, 1.1 g and 2.2 g indicated that both amoxillin and clavulanate had linear dynamics characteristics. After 1.1 g single dose and multiple doses infusion, the pharmacokinetic parameters of amoxicillin and clavulanate were close respectively, and the trough concentrations before the 7th to 13th administration were lower than the detection limitation, which implied that the previous administration had cleared out before the next administration, and no accumulation happened after multiple doses. CONCLUSIONS: The amoxicillin sodium clavulanate potassium (10:1) injection possesses the linear kinetics. The dosage regimen of 1.1 g Q8h intravenous infusion could meet the needs of clinical therapy.

[Pharmacokinetics of injected cefozopran hydrochloride in healthy volunteers].

OBJECTIVE: To study the pharmacokinetics of injected cefozopran hydrochloride in healthy volunteers. METHODS: 24 healthy volunteers were enrolled to receive low (0.5 g), middle (1.0 g), high (2.0 g) doses of single injection and multiple doses (1.0 g) injection of cefozopran hydrochloride in an open randomized study. The plasma concentrations of cefozopran were determined by RP-HPLC. The DAS2.0 was used to fit the concentration-time data and to calculate the pharmacokinetic parameters. RESULTS: The main pharmaeokinetic parameters for a single injection of low, middle and high doses of cefozopran were as follows: Cmax (48.27 +/- 9.84), (77.99 +/- 15.08) and (171.59 +/- 18.27) mg/L; Tmax (0.50 +/- 0.00), (0.51 +/- 0.02) and (0.51 + 0.02) h; AUCo-t (92.43 +/- 24.02), (152.45 +/- 16.26) and (341.03 +/- 44.16) mg x h/L; t1/2beta (1.97 +/- 0.19), (2.44 +/- 0.24) and (2.18 +/- 0.31) h, respectively. The main pharmacokinetic parameters for a multiple doses injection of cefozopran were as follows: Cmax (80.39 +/- 11.86) mg/L; Tmax (0.51 +/- 0.02) h; AUCo-t (159.74 +/- 15.06) mg x h/L; t1/2beta (2.55 +/- 0.55) h. The accumulative rate of cefozopran through urine pathway within 24 h was (89.4 +/- 15.5)%. The statistical analysis showed that Cmax, AUCo-t, and AUCo-infinity increased significantly with increased doses of injection (P < 0.05). Those parameters were linearly correlated with the doses of injection (r = 0.9950, 0.9960, 0.9963). However, dosage did not have an impact on other pharmacokinetic parameters (P > 0.05). No gender differences in the parameters were found (P > 0.05). CONCLUSION: Cefozopran hydrochloride performs a linear kinetics in healthy volunteers. The main pharmacokinetic parameters have no significant gender differences, and there is no drug accumulated with multiple doses of injection.