Optimizing and determining the click chemistry mediated Cu-64 radiolabeling and physiochemical characteristics of trastuzumab conjugates.

Over the last decade, 64Cu-labeling of monoclonal antibody (mAb) via inverse electron demand Diels-Alder click chemistry (IEDDA) have received much attention. Despite the tetrazine-transcyclooctene (Tz-TCO) click chemistry's convenience and efficiency in mAb labeling, there is limited information about the ideal parameters in the development of click chemistry mediated (radio)immunoconjugates. This encourages us to conduct a systematic optimization while concurrently determining the physiochemical characteristics of the model mAb, trastuzumab, and TCO conjugates. To accomplish this, we investigated a few critical parameters, first, we determined the degree of conjugations with varying molar equivalents (eq.) of TCO (3, 5, 10, and 15 eq.). Through analytical techniques like size exclusion chromatography, dynamic light scattering, and zeta potential, qualitative analysis were performed to determine the purity, degree of aggregation and net charge of the conjugates. We found that as the degree of conjugation increased the purity of intact mAb fraction is compromised and net charge of conjugates became less positive. Next, all trastuzumab-PEG4-TCO conjugates with varying molar ratio and quantity (30, 50, 100, 200, 250 µg) were radiolabeled with 64Cu-NOTA-PEG4-Tz via IEDDA click chemistry and radiochemical yields were determined by radio-thin layer chromatography. The radiochemical yields of trastuzumab conjugates improved with increased amount and molar ratio. Next, we investigated the effect of the radioprotectant ascorbic acid (AA) of varied concentrations (0.25, 0.5, 0.75, 1 mM) on radiochemical yields and subsequent pharmacokinetics. A concentration of 0.25 mM of AA was found to be optimal for click reaction and in vivo biodistribution. Finally, we investigated the indirect influence of bioconjugation buffers on radiochemical yields and biodistribution in NIH3T6.7 tumor models that resulted approximately ∼11 %ID/g tumor uptake.

Prothionamide Dose Optimization Using Population Pharmacokinetics for Multidrug-Resistant Tuberculosis Patients.

Prothionamide, a second-line drug for multidrug-resistant tuberculosis (MDR-TB), has been in use for a few decades. However, its pharmacokinetic (PK) profile remains unclear. This study aimed to develop a population PK model for prothionamide and then apply the model to determine the optimal dosing regimen for MDR-TB patients. Multiple plasma samples were collected from 27 MDR-TB patients who had been treated with prothionamide at 2 different study hospitals. Prothionamide was administered according to the weight-band dose regimen (500 mg/day for weight <50 kg and 750 mg/day for weight >50 kg) recommended by the World Health Organization. The population PK model was developed using nonlinear mixed-effects modeling. The probability of target attainment, based on systemic exposure and MIC, was used as a response target. Fixed-dose regimens (500 or 750 mg/day) were simulated to compare the efficacies of various dosing regimens. PK profiles adequately described the two-compartment model with first-order elimination and the transit absorption compartment model with allometric scaling on clearance. All dosing regimens had effectiveness >90% for MIC values <0.4 µg/mL in 1.0-log kill target. However, a fixed dose of 750 mg/day was the only regimen that achieved the target resistance suppression of ≥90% for MIC values of <0.2 µg/mL. In conclusion, fixed-dose prothionamide (750 mg/day), regardless of weight-band, was appropriate for adult MDR-TB patients with weights of 40 to 67 kg.

ICT-based adherence monitoring in kidney transplant recipients: a randomized controlled trial.

BACKGROUND: Prior studies have explored the use of regular reminders to improve adherence among kidney transplant recipients (KTRs), but none have included real-time alarms about drug dosage, frequency, and interval. In the present study, we aimed to evaluate the efficacy and stability of an information and communication technology (ICT)-based centralized monitoring system for increasing medication adherence among Korean KTRs. METHODS: In this prospective, multicenter, randomized controlled study, enrolled KTRs were randomized to either the ICT-based centralized monitoring group or control group. The ICT-based centralized monitoring system alerted both patients and medical staff with texts and pill box alarms if there was a missed dose or a dosage/time error. We compared the two groups in terms of medication adherence and transplant outcomes over 6 months, and evaluated patient satisfaction with the ICT-based monitoring system. RESULTS: Among 114 enrolled KTRs, 57 were assigned to the ICT-based centralized monitoring group and 57 to the control group. The two groups did not significantly differ in mean adherence at each follow-up visit. The intrapatient variability of tacrolimus and mycophenolic acid levels, renal function, and adverse transplant outcomes did not differ between the intervention and control groups, or between the intervention group with feedback generation and the intervention group without feedback generation. Patients showed high overall satisfaction with the ICT-based centralized monitoring system, which significantly improved across the study period (p = 0.012). CONCLUSIONS: Due to high baseline adherence, the ICT-based centralized monitoring system did not maximize medication adherence or enhance transplant outcomes among Korean KTRs. However, patients were highly satisfied with the system. Our results suggest that the ICT-based centralized monitoring system could be successfully applied in clinical trials. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03136588. Registered 20 April 2017 - Retrospectively registered.

Estrogen-related receptor γ negatively regulates osteoclastogenesis and protects against inflammatory bone loss.

Estrogen-related receptor γ (ERRγ) is an orphan nuclear receptor that plays an important role in various metabolic processes under physiological and pathophysiological conditions. Here, we report that ERRγ functions as a negative regulator in receptor activator of nuclear factor κΒ ligand (RANKL)-induced osteoclast differentiation. We observed that ERRγ was strongly expressed in osteoclast precursors, bone marrow-derived macrophages (BMMs) while its expression was significantly reduced by RANKL during osteoclastogenesis. Overexpression of ERRγ in BMMs suppressed the formation of multinucleated osteoclasts and attenuated the induction of c-Fos and nuclear factor of activated T cells c1, which are critical modulators in osteoclastogenesis. Similarly, the treatment of ERRγ agonists, N-(4-(diethylaminobenzylidenyl)-N'-(4-hydroxybenzoyl)-hydrazine (DY131) or GSK4716, also inhibited osteoclast generation and the expression of these key modulators. On the other hand, shRNA-mediated knockdown of ERRγ accelerated the formation of bone-resorbing cells and the expression of osteoclastogenic markers. Forced expression of ERRγ blocked RANKL-stimulated phosphorylation of the nuclear factor κB (NF-κB) inhibitor IκBα and suppressed NF-κB transcriptional activity induced by RANKL or the NF-κB subunit p65. Furthermore, by employing a pharmacological approach, we showed that the ERRγ agonist DY131 protected against inflammatory bone loss induced by lipopolysaccharide in vivo. Together, our findings reveal that ERRγ is a pivotal regulator in RANKL-mediated osteoclastogenesis and suggest that ERRγ may have potential as a therapeutic target for pathological bone loss.

Detection of 13 Ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, Rg3, Rh2, F1, Compound K, 20(S)-Protopanaxadiol, and 20(S)-Protopanaxatriol) in Human Plasma and Application of the Analytical Method to Human Pharmacokinetic Studies Following Two Week-Repeated Administration of Red Ginseng Extract.

We aimed to develop a sensitive method for detecting 13 ginsenosides using liquid chromatography-tandem mass spectrometry and to apply this method to pharmacokinetic studies in human following repeated oral administration of red ginseng extract. The chromatograms of Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, Rg3, Rh2, F1, compound K (CK), protopanaxadiol (PPD), and protopanaxatriol (PPT) in human plasma were well separated. The calibration curve range for 13 ginsenosides was 0.5-200 ng/mL and the lower limit of quantitation was 0.5 ng/mL for all ginsenosides. The inter- and intra-day accuracy, precision, and stability were less than 15%. Among the 13 ginsenosides tested, nine ginsenosides (Rb1, Rb2, Rc, Rd, Rg3, CK, Rh2, PPD, and PPT) were detected in the human plasma samples. The plasma concentrations of Rb1, Rb2, Rc, Rd, and Rg3 were correlated with the content in red ginseng extract; however, CK, Rh2, PPD, and PPT were detected although they are not present in red ginseng extract, suggesting the formation of these ginsenosides through the human metabolism. In conclusion, our analytical method could be effectively used to evaluate pharmacokinetic properties of ginsenosides, which would be useful for establishing the pharmacokinetic-pharmacodymic relationship of ginsenosides as well as ginsenoside metabolism in humans.

G protein-coupled receptor 84 controls osteoclastogenesis through inhibition of NF-κB and MAPK signaling pathways.

GPR84, a member of the G protein-coupled receptor family, is found predominantly in immune cells, such as macrophages, and functions as a pivotal modulator of inflammatory responses. In this study, we investigated the role of GPR84 in receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation. Our microarray data showed that GPR84 was significantly downregulated in osteoclasts compared to in their precursors, macrophages. The overexpression of GPR84 in bone marrow-derived macrophages suppressed the formation of multinucleated osteoclasts without affecting precursor proliferation. In addition, GPR84 overexpression attenuated the induction of c-Fos and nuclear factor of activated T cells, cytoplasmic 1 (NFATc1), which are transcription factors that are critical for osteoclastogenesis. Furthermore, knockdown of GPR84 using a small hairpin RNA promoted RANKL-mediated osteoclast differentiation and gene expression of osteoclastogenic markers. Mechanistically, GPR84 overexpression blocked RANKL-stimulated phosphorylation of IκBα and three MAPKs, JNK, ERK, and p38. GPR84 also suppressed NF-κB transcriptional activity mediated by RANKL. Conversely, GPR84 knockdown enhanced RANKL-induced activation of IκBα and the three MAPKs. Collectively, our results revealed that GPR84 functions as a negative regulator of osteoclastogenesis, suggesting that it may be a potential therapeutic target for osteoclast-mediated bone-destructive diseases.

Neuromedin B and its receptor silencing suppresses osteoclast generation by modulating precursor proliferation via M-CSF/c-Fms/D-type cyclins.

Neuromedin B (NMB), a mammalian bombesin-like peptide, regulates diverse physiological processes, such as energy metabolism, memory and fear behavior, and cellular growth, through its cognate receptor, NMBR. In this study, we report that NMB expression was upregulated during osteoclast development and that silencing NMB or NMBR attenuated osteoclast generation mediated by macrophage colony-stimulating factor (M-CSF) and receptor activator of NF-κB ligand (RANKL). We found that knockdown of NMB or NMBR using a small hairpin RNA suppressed M-CSF-induced proliferation of osteoclast precursor cells without altering osteoclast differentiation. Interestingly, NMB or NMBR knockdown reduced the expression of the M-CSF receptor, c-Fms, which is an important modulator of osteoclast development. Consequently, NMB or NMBR silencing inhibited M-CSF/c-Fms-mediated downstream signaling pathways like activation of ERK and Akt and induction of D-type cyclins, cyclin D1 and D2. Moreover, knockdown of NMB or NMBR accelerated apoptosis in osteoclast lineage cells by inducing caspase-3, caspase-9, and Bim expression. In summary, our study demonstrates that the NMB/NMBR axis plays a pivotal role in osteoclast generation by modulating the proliferation and survival of osteoclast lineage cells.

Pharmacokinetics and bioequivalence of a rosuvastatin/ezetimibe fixed-dose combination tablet versus single agents in healthy male subjects
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OBJECTIVE: The pharmacokinetic profiles and bioequivalence of a new rosuvastatin/ezetimibe fixed-dose combination (FDC; NVP-1205) vs. rosuvastatin and ezetimibe concomitantly administered as single agents were evaluated. MATERIALS AND METHODS: In this open-label, single-dose, crossover study (NCT02029625), eligible subjects were randomly assigned in a 1 : 1 ratio to receive a single dose of rosuvastatin (10 mg) with ezetimibe (10 mg) as either a FDC or as single agents concomitantly administered under fasted conditions, followed by a 2-week washout period and administration of the alternate formulation. Serial blood samples were collected predose and up to 96 hours postdose in each period for determination of plasma rosuvastatin and ezetimibe concentrations by liquid-chromatography tandem mass spectroscopy and calculation of pharmacokinetic parameters. RESULTS: The mean Cmax and AUC0-t values of rosuvastatin were 12.5 ng/mL and 115.6 ng×h/mL for the FDC, and 12.2 ng/mL and 115.1 ng×h/mL for the single agents concomitantly administered, respectively. The mean Cmax and AUC0-t values of ezetimibe were 4.7 ng/mL and 67.3 ng×h/mL for the FDC, and 4.5 ng/mL and 68.2 ng×h/mL for the single agents concomitantly administered, respectively. The geometric mean ratio (GMR) and 90% confidence interval (CI) for the rosuvastatin Cmax and AUC0-t were 106.20 (96.62 - 116.74) and 102.88 (96.32 - 109.90), respectively. The GMR and 90% CI for the ezetimibe Cmax and AUC0-t were 108.96 (98.56 - 120.51) and 98.13 (92.01 - 104.66), respectively. All treatments were well tolerated during this study, with no serious adverse events reported. CONCLUSION: The rosuvastatin/ezetimibe (10/10 mg) FDC was bioequivalent to single agents concomitantly administered. A single dose of rosuvastatin/ezetimibe as the FDC or as single agents was well tolerated.
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A Pharmacometabolomic Approach to Predict Response to Metformin in Early-Phase Type 2 Diabetes Mellitus Patients.

Metformin is a first-line medication for type 2 diabetes mellitus (T2DM). Based on its universal use, the consideration of inter-individual variability and development of predictive biomarkers are clinically significant. We aimed to identify endogenous markers of metformin responses using a pharmacometabolomic approach. Twenty-nine patients with early-phase T2DM were enrolled and orally administered metformin daily for 6 months. A total of 22 subjects were included in the final analysis. Patients were defined as responders or non-responders based on changes in their glycated haemoglobin A1c (HbA1c) from baseline, over 3 months. Urine metabolites at baseline, as well as at the 3 and 6 month follow-ups after the start of treatment were analysed using gas chromatography-mass spectrometry and evaluated with multivariate analyses. Metabolites distinguishable between the two response groups were obtained at baseline, as well as at the 3 and 6 month follow-ups, and significantly different metabolites were listed as markers of metformin response. Among the identified metabolites, citric acid, myoinositol, and hippuric acid levels showed particularly significant differences between the non-responder and responder groups. We thus identified different metabolite profiles in the two groups of T2DM patients after metformin administration, using pharmacometabolomics. These results might facilitate a better understanding and prediction of metformin response and its variability in individual patients.

G Protein-Coupled Receptor 120 Signaling Negatively Regulates Osteoclast Differentiation, Survival, and Function.

G protein-coupled receptor 120 (GPR120) plays an important role in the regulation of inflammation and lipid metabolism. In this study, we investigated the role of GPR120 in osteoclast development and found that GPR120 regulates osteoclast differentiation, survival and function. We observed that GPR120 was highly expressed in osteoclasts compared to their precursors, bone marrow-derived macrophages (BMMs). Activation of GPR120 by its ligand GW9508 suppressed receptor activator of NF- κB ligand (RANKL)-induced osteoclast differentiation and the expression of nuclear factor of activated T cells c1 (NFATc1), a key modulator of osteoclastogenesis. GPR120 activation further inhibited the RANKL-stimulated phosphorylation of IκBα and JNK. In addition to osteoclast differentiation, GPR120 activation increased the apoptosis of mature osteoclasts by inducing caspase-3 and Bim expression. Activation of GPR120 also interfered with cell spreading and actin cytoskeletal organization mediated by M-CSF but not by RANKL. Coincident with the impaired cytoskeletal organization, GPR120 activation blocked osteoclast bone resorbing activity. Furthermore, knockdown of GPR120 using small hairpin RNA abrogated all these inhibitory effects on osteoclast differentiation, survival, and function. Together, our findings identify GPR120 as a negative modulator of osteoclast development that may be an attractive therapeutic target for bone-destructive diseases. J. Cell. Physiol. 231: 844-851, 2016. © 2015 Wiley Periodicals, Inc.

Lipocalin-2 inhibits osteoclast formation by suppressing the proliferation and differentiation of osteoclast lineage cells.

Lipocalin-2 (LCN2) is a member of the lipocalin superfamily and plays a critical role in the regulation of various physiological processes, such as inflammation and obesity. In this study, we report that LCN2 negatively modulates the proliferation and differentiation of osteoclast precursors, resulting in impaired osteoclast formation. The overexpression of LCN2 in bone marrow-derived macrophages or the addition of recombinant LCN2 protein inhibits the formation of multinuclear osteoclasts. LCN2 suppresses macrophage colony-stimulating factor (M-CSF)-induced proliferation of osteoclast precursor cells without affecting their apoptotic cell death. Interestingly, LCN2 decreases the expression of the M-CSF receptor, c-Fms, and subsequently blocks its downstream signaling cascades. In addition, LCN2 inhibits RANKL-induced osteoclast differentiation and attenuates the expression of c-Fos and nuclear factor of activated T cells c1 (NFATc1), which are important modulators in osteoclastogenesis. Mechanistically, LCN2 inhibits NF-κB signaling pathways, as demonstrated by the suppression of IκBα phosphorylation, nuclear translocation of p65, and NF-κB transcriptional activity. Thus, LCN2 is an anti-osteoclastogenic molecule that exerts its effects by retarding the proliferation and differentiation of osteoclast lineage cells.

Characterization of fimasartan metabolites in human liver microsomes and human plasma.

1. The metabolites of fimasartan (FMS), a new angiotensin II receptor antagonist, were characterized in human liver microsomes (HLM) and human subjects. 2. We developed a method for a simultaneous quantitative and qualitative analysis using predictive multiple reaction monitoring information-dependent acquisition-enhanced product ion scanning. To characterize metabolic reactions, FMS metabolites were analyzed using quadrupole-time of flight mass spectrometer in full-scan mode. 3. The structures of metabolites were confirmed by comparison of chromatographic retention times and mass spectra with those of authentic metabolite standards. 4. In the cofactor-dependent microsomal metabolism study, the half-lives of FMS were 56.7, 247.9 and 53.3 min in the presence of NADPH, UDPGA and NADPH + UDPGA, respectively. 5. The main metabolic routes in HLM were S-oxidation, oxidative desulfuration, n-butyl hydroxylation and N-glucuronidation. 6. In humans orally administered with 120 mg FMS daily for 7 days, the prominent metabolites were FMS S-oxide and FMS N-glucuronide in the 0-8-h pooled plasma sample of each subject. 7. This study characterizes, for the first time, the metabolites of FMS in humans to provide information for its safe use in clinical medicine.

Pharmacokinetic drug interaction study using fimasartan and rosuvastatin in healthy volunteers.

OBJECTIVE: This study evaluated the possible pharmacokinetic interactions between rosuvastatin and fimasartan, an angiotensin II type 1 (AT1) receptor blocker (ARB), approved in Korea for the treatment of mild to moderate hypertension. METHODS: In this open-label, multiple-dose, two-period, single-sequence study, the enrolled subjects were randomized into two separate parts (A and B). In part A, subjects received 120 mg of fimasartan alone for 7 days during period I, and 120 mg fimasartan with 20 mg rosuvastatin for 7 days during period II. In Part B, subjects received rosuvastatin alone, followed by concomitant administration of fimasartan, with the same doses used as in Part A. There was a 7-day washout between periods I and II. Serial blood samples were collected for up to 48 hours for fimasartan and for up to 72 hours for rosuvastatin after the last dose of each period to determine the steady-state pharmacokinetics of both drugs. RESULTS: The mean Cmax,ss and AUCτ,ss values of fimasartan were 258.03 ± 176.75 ng/mL and 746.52 ± 273.49 ng×h/mL for fimasartan alone, and 289.40 ± 231.44 ng/mL and 848.43 ± 267.45 ng×h/mL for fimasartan and rosuvastatin coadministration, respectively (p-values for Cmax,ss and AUCτ,ss, 0. 513 and 0.006, respectively). The mean Cmax,ss and AUCτ,ss values of rosuvastatin were 9.94 ± 4.48 ng/mL and 85.29 ± 36.25 ng×h/mL for rosuvastatin alone and 11.94 ± 8.47 ng/mL and 77.33 ± 38.71 ng×h/mL for fimasartan and rosuvastatin coadministration, respectively (p-values for Cmax,ss and AUCτ,ss, 0.066 and 0.009, respectively). The geometric mean ratio (GMR) and 90% confidence intervals (CI) for the Cmax,ss and AUCτ,ss of fimasartan (with/without rosuvastatin) were 1.109 (0.813 - 1.511) and 1.159 (1.061 - 1.265), respectively. The GMR and 90% CI for the Cmax,ss and AUCτ,ss of rosuvastatin (with/without fimasartan) were 1.090 (0.979 - 1.213) and 0.870 (0.804 - 0.940), respectively. CONCLUSIONS: These results suggest that fimasartan and rosuvastatin have no relevant pharmacokinetic drug-drug interactions. All treatments were well tolerated during this study, with no serious adverse effects.
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Synthesis and Evaluation of New Generation Cross-Bridged Bifunctional Chelator for (64)Cu Radiotracers.

Bifunctional chelators have been successfully used to construct (64)Cu-labeled radiopharmaceuticals. Previously reported chelators with cross-bridged cyclam backbones have various essential features such as high stability of the copper(II) complex, high efficiency of radiolabeling at room temperature, and good biological inertness of the radiolabeled complex, along with rapid body clearance. Here, we report a new generation propylene-cross-bridged chelator with hybrid acetate/phosphonate pendant groups (PCB-TE1A1P) developed with the aim of combining these key properties in a single chelator. The PCB-TE1A1P was synthesized from cyclam with good overall yield. The Cu(II) complex of our chelator showed good robustness in kinetic stability evaluation experiments, such as acidic decomplexation and cyclic voltammetry studies. The Cu(II) complex of PCB-TE1A1P remained intact under highly acidic conditions (12 M HCl, 90 °C) for 8 d and showed quasi-reversible reduction/oxidation peaks at -0.77 V in electrochemical studies. PCB-TE1A1P was successfully radiolabeled with (64)Cu ions in an acetate buffer at 60 °C within 60 min. The electrophoresis study revealed that the (64)Cu-PCB-TE1A1P complex has net negative charge in aqueous solution. The biodistribution and in vivo stability study profiles of (64)Cu-PCB-TE1A1P indicated that the radioactive complex was stable under physiological conditions and cleared rapidly from the body. A whole body positron emission tomography (PET) imaging study further confirmed high in vivo stability and fast clearance of the complex in mouse models. In conclusion, PCB-TE1A1P has good potential as a bifunctional chelator for (64)Cu-based radiopharmaceuticals, especially those involving peptides.

Bioequivalence of a single 400-mg dose of imatinib 100-mg oral tablets and a 400-mg tablet in healthy adult Korean volunteers.

BACKGROUND: Imatinib mesylate (IM) is a selective tyrosine kinase inhibitor for the treatment of chronic myeloid leukemia and gastrointestinal stromal tumors. A new once-daily 400-mg film-coated tablet of imatinib has been developed by a pharmaceutical company in Korea. OBJECTIVE: The present study was designed to assess and compare the PK parameters, bioavailability, and bioequivalence of the new imatinib 400-mg formulation (test) versus the conventional 100-mg formulation (reference) administered as a single 400-mg dose in healthy adult male volunteers. METHODS: This randomized, open-label, single-dose, two-way crossover study was conducted in healthy Korean male volunteers. Eligible subjects were randomly assigned in a 1 : 1 ratio to receive 400 mg of the test (one 400-mg tablet) or reference (four 100-mg tablets) formulation, followed by a 2-week washout period and administration of the alternate formulation. Serial blood samples were collected at 0 (predose), 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 24, 48, and 72 hours after administration. Plasma imatinib concentrations were determined using liquid chromatography coupled with tandem mass spectrometry. The formulations were to be considered bioequivalent if the 90% confidence intervals (CIs) of the adjusted geometric mean ratios for Cmax, AUC(0-t), and AUC(0-∞)ž were within the predetermined range of 0.80 - 1.25. RESULTS: In total, 35 subjects completed the study. No serious adverse event was reported during the study. The 90% CIs of the adjusted geometric mean ratios of the test formulation to the reference formulation for C(max), AUC(0-t) and AUC(0-∞)ž of imatinib were all within the bioequivalence criteria range of 0.8 - 1.25. CONCLUSIONS: The test formulation of imatinib met the Korean regulatory requirements for bioequivalence. Both imatinib formulations were well-tolerated in all subjects.

Comparative evaluation of extraction methods for simultaneous mass-spectrometric analysis of complex lipids and primary metabolites from human blood plasma.

Metabolomic results on human blood plasma largely depend on the sample preparation protocols employed for protein precipitation and metabolite extraction. Five different extraction methods were examined, which can be grouped into two categories, liquid-liquid extraction and protein precipitation methods, including long-standing protocols such as the Folch extraction and Bligh-Dyer extraction in comparison to modern methods such as the Matyash protocol and two global metabolite extraction methods. Extracts were subjected to analysis of blood plasma lipids and primary metabolites by using chip-based direct infusion nanoelectrospray tandem mass spectrometry and gas chromatography coupled to time-of-flight mass spectrometry, respectively. Optimal extraction schemes were evaluated based on the number of identified metabolites, extraction efficiency, compound diversity, reproducibility, and convenience for high-throughput sample preparations. Results showed that Folch and Matyash methods were equally valid and robust for lipidomic assessments while primary metabolites were better assessed by the protein precipitation methods with organic solvent mixtures.

Alterations in Plasma Lipid Profile before and after Surgical Removal of Soft Tissue Sarcoma.

Soft tissue sarcoma (STS) is a relatively rare malignancy, accounting for about 1% of all adult cancers. It is known to have more than 70 subtypes. Its rarity, coupled with its various subtypes, makes early diagnosis challenging. The current standard treatment for STS is surgical removal. To identify the prognosis and pathophysiology of STS, we conducted untargeted metabolic profiling on pre-operative and post-operative plasma samples from 24 STS patients who underwent surgical tumor removal. Profiling was conducted using ultra-high-performance liquid chromatography-quadrupole time-of-flight/mass spectrometry. Thirty-nine putative metabolites, including phospholipids and acyl-carnitines were identified, indicating changes in lipid metabolism. Phospholipids exhibited an increase in the post-operative samples, while acyl-carnitines showed a decrease. Notably, the levels of pre-operative lysophosphatidylcholine (LPC) O-18:0 and LPC O-16:2 were significantly lower in patients who experienced recurrence after surgery compared to those who did not. Metabolic profiling may identify aggressive tumors that are susceptible to lipid synthase inhibitors. We believe that these findings could contribute to the elucidation of the pathophysiology of STS and the development of further metabolic studies in this rare malignancy.

Pattern recognition analysis for hepatotoxicity induced by acetaminophen using plasma and urinary 1H NMR-based metabolomics in humans.

Drug-induced liver injury (DILI) is currently an increasingly relevant health issue. However, available biomarkers do not reliably detect or quantify DILI risk. Therefore, the purpose of this study was to comparatively evaluate plasma and urinary biomarkers obtained from humans treated with acetaminophen (APAP) using a metabolomics approach and a proton nuclear magnetic resonance (NMR) platform. APAP (3 g/day, two 500 mg tablets every 8 h) was administered to 20 healthy Korean males (age, 20-29 years) for 7 days. Urine was collected daily before and during dosing and 6 days after the final dose. NMR spectra of these urine samples were analyzed using principal component analysis (PCA) and partial least-squares-discrimination analysis. Although the activities of aspartate aminotransferase and lactate dehydrogenase were significantly increased 7 days post-APAP treatment, serum biochemical parameters of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total bilirubin, γ-glutamyl transpeptidase, and lactate dehydrogenase were within normal range of hepatic function. However, urine and plasma (1)H NMR spectroscopy revealed different clustering between predosing and after APAP treatment for global metabolomic profiling through PCA. Urinary endogenous metabolites of trimethylamine-N-oxide, citrate, 3-chlorotyrosine, phenylalanine, glycine, hippurate, and glutarate as well as plasma endogenous metabolites such as lactate, glucose, 3-hydroxyisovalerate, isoleucine, acetylglycine, acetone, acetate, glutamine, ethanol, and isobutyrate responded significantly to APAP dosing in humans. Urinary and plasma endogenous metabolites were more sensitive than serum biochemical parameters. These results might be applied to predict or screen potential hepatotoxicity caused by other drugs using urinary and plasma (1)H NMR analyses.

Influence of hepatic dysfunction on the pharmacokinetics and safety of fimasartan.

This study was designed to assess the pharmacokinetics (PK) and safety of fimasartan, an angiotensin II type 1 receptor blocker, in hepatic impairment patients as compared with healthy subjects. An open-label, single-dose, parallel study was conducted in 6 healthy male volunteers and 12 subjects with hepatic impairment. Healthy subjects were matched with hepatic dysfunction patients on the basis of age, gender, and body weight. After a single 120-mg oral administration of fimasartan, PK parameters and safety were analyzed between the hepatic dysfunction groups and healthy group. Compared with the healthy subjects, the geometric mean ratio and 90% confidence intervals for the maximum plasma concentration and the mean area under the plasma concentration-time curve from 0 to infinity (AUC)inf were 0.77 (0.24-2.47) and 1.11 (0.50-2.46), respectively, for the mild hepatic impairment and 6.55 (3.56-12.03) and 5.17 (4.19-6.37), respectively, for moderate hepatic impairment. However, there was no significant difference in time to peak plasma concentration (t(max)) and elimination half-life, and there were no serious or severe adverse events in all subjects. Subjects with mild hepatic impairment exhibited similar bioavailability compared with healthy subjects, whereas subjects with moderate hepatic impairment seemed to exhibit a higher level of systemic exposure to fimasartan than healthy subjects. In addition, all subjects were tolerable with fimasartan.

Comparative Pharmacokinetic Profiles of a Novel Low-Dose Micronized Formulation of Raloxifene 45 mg (AD-101) and the Conventional Raloxifene 60 mg in Healthy Subjects.

Raloxifene hydrochloride shows poor bioavailability (only 2%) when orally administered because of its poor aqueous solubility and its extensive first-pass metabolism. A new micronized formulation of raloxifene was developed to improve bioavailability via enhanced gastrointestinal absorption. The primary objective of this study was to evaluate the pharmacokinetic characteristics of a new micronized raloxifene formulation (AD-101) in comparison with the conventional raloxifene formulation. This study was designed as an open-label, randomized, 2-treatment-period, crossover study with a 2-week washout period. Two treatments consisted of micronized raloxifene 45 mg daily; and conventional raloxifene 60 mg daily administered in fasting conditions. Plasma raloxifene concentrations were determined by a validated method using ultra-fast liquid chromatography-tandem mass spectrometry, and pharmacokinetic parameters were calculated using a noncompartmental model. In total, 49 subjects completed the study. The geometric mean ratio (micronized/conventional) of the maximum concentration and the area under the plasma concentration-time curve from time zero to the last concentration values were 1.08 (90% CI, 0.95-1.24) and 0.97 (90% CI, 0.89-1.05), respectively. The adverse event profile did not differ between the 2 formulations. The results demonstrate that micronized formulation of raloxifene 45 mg is equivalent to conventional formulation of raloxifene 60 mg when administered at the single dose in the fasted state. After single oral dosing of AD-101, there were no serious or unexpected adverse events.