Quantification of fluticasone propionate in human plasma by LC-MS/MS and its application in the pharmacokinetic study of nasal spray at clinical doses.

We developed a method for quantifying fluticasone propionate (FP) using general-purpose liquid chromatography-tandem mass spectrometry equipment to measure the plasma concentration of FP for the pharmacokinetic study of FP following the administration of a prescribed nasal spray dose (100 μg). Using ammonium acetate (0.01 M)-formic acid (pH 2.

Plasma 6β-hydroxycortisol to cortisol ratio as a less invasive cytochrome P450 3A phenotyping method.

Aim: A less invasive evaluation method of cytochrome P450 3A (CYP3A) activity provides an important tool for personalized medicine. We aimed to clarify the usefulness of the plasma 6β-hydroxycortisol to cortisol concentration (6β-OHF/F) ratio as a minimally invasive CYP3A phenotyping method.

Methods: Plasma 6β-OHF and cortisol concentrations were measured via liquid chromatography/tandem mass spectrometry.

Calculation of Human Melatonin Partial Metabolic Clearance in Healthy Adult Volunteers for Investigation of a Novel in Vivo CYP1A2 Phenotyping Method: A Pilot Study.

The method of administering caffeine as a probe to evaluate the phenotypic activity of the CYP1A2, has not yet been applied clinically. In contrast, if endogenous melatonin (MEL) metabolism can be used to assess CYP1A2 activity, it could be a simple method that does not require substance administration. The study aim was to calculate the MEL partial metabolic clearance (CL) from plasma MEL and its urinary metabolites and to test the potential of this approach as a novel CYP1A2 phenotyping method.

Development and Validation of an LC-MS/MS-Based Method for Quantifying Urinary Endogenous 6-Hydroxymelatonin.

Evaluation of endogenous melatonin (MEL) secretion using its urinary metabolites is useful for the treatment of circadian rhythm sleep disorders. The primary melatonin metabolites excreted in the urine are 6-hydroxymelatonin (6-O-MEL) sulfate (S-O-MEL) and 6-O-MEL glucuronate, which result from sequential MEL metabolism by phases I and II drug metabolizing enzymes. To determine the accurate MEL secretion level, these urinary metabolites should be enzymatically deconjugated and converted into MEL.

Dried blood spots analysis of 6β-hydroxycortisol and cortisol using liquid chromatography/tandem mass spectrometry for calculating 6β-hydroxycortisol to cortisol ratio.

Dried blood spot (DBS) sampling is a minimally invasive method used to collect blood samples of any population for personalized medicine. We aimed to develop a sensitive and reliable analytical method for measuring 6β-hydroxycortisol (6β-OHF) and cortisol concentrations in DBS by liquid chromatography/tandem mass spectrometry so as to utilize DBS as a less invasive blood sampling method for calculating the ratio of 6β-OHF/cortisol. The lower limits of quantification obtained using four DBS were 1.

Effect of UGT1A1, CYP3A and CES Activities on the Pharmacokinetics of Irinotecan and its Metabolites in Patients with UGT1A1 Gene Polymorphisms.

Background And Objectives: Irinotecan (CPT-11) is metabolized to an active metabolite 7-ethyl-10-hydroxycamptothecin (SN-38) by carboxylesterase (CES). SN-38 is then converted to the inactive metabolite SN-38 glucuronide (SN-38G) by glucuronosyltransferase 1A1 (UGT1A1). Genetic polymorphisms in UGT1A1 have been associated with altered SN-38 pharmacokinetics, which increase the risk of toxicity in patients.

Midazolam Intoxication in a Premature Neonate.

Purpose: We report the case of a male neonate with a respiratory disorder who developed adverse cardiorespiratory symptoms after the continuous infusion of midazolam.

Methods: To clarify the cause of cardiogenic shock, we performed whole exome sequencing and screened relative single-nucleotide variants of 2 cytochrome P450 (CYP) isoforms, CYP3A4 and CYP3A5, which play a dominant role in the metabolic elimination of midazolam. We measured endogenous cortisol 6β-hydroxylation clearance to phenotypically assess CYP3A activity.

Identification of equol-7-glucuronide-4'-sulfate, monoglucuronides and monosulfates in human plasma of 2 equol producers after administration of by LC-ESI-MS.

Equol is a product formed during the biotransformation of the naturally occurring isoflavone daidzein by intestinal bacteria. The role of equol in the prevention of several hormone-dependent diseases such as prostate cancer and osteoporosis as well as vasomotor symptoms has been extensively investigated. Equol primarily occurs in the form of major metabolites such as glucuronides and sulfates, while intact equol has been detected at only ca.

Sensitive and simultaneous quantitation of 6β-hydroxycortisol and cortisol in human plasma by LC-MS/MS coupled with stable isotope dilution method.

CYP3A phenotyping provides a means for personalized drug therapy. We focused our attention on the plasma 6β-hydroxycortisol (6β-OHF) to cortisol ratio as an index for CYP3A phenotyping. In the present study, we developed a sensitive and reliable method for the simultaneous determination of 6β-OHF and cortisol in human plasma using high-performance liquid chromatography/tandem mass spectrometry together with picolinylester derivatization or nonderivatization methods and 6β-[9,11,12,12- H ]hydroxycortisol and [1,2,4,19- C ]cortisol as internal standards for in vivo CYP3A phenotyping in humans.

Use of endogenous cortisol 6β-hydroxylation clearance for phenotyping in vivo CYP3A activity in women after sequential administration of an oral contraceptive (OC) containing ethinylestradiol and levonorgestrel as weak CYP3A inhibitors.

The present study was undertaken to evaluate the time courses of in vivo cytochrome P450 3A (CYP3A) inhibition in four healthy women after sequential administration of an oral contraceptive (OC) containing ethinylestradiol and levonorgestrel, using 6β-hydroxylation clearance of endogenous cortisol (CLm(6β)) as a new index for CYP3A phenotyping. The 6β-hydroxylation clearance (CLm(6β)) was followed every 2h from 9:00 or 11:00 to 17:00 on days 0 (baseline), 1, 2, 21, and 28 during a single menstrual cycle. The serum concentrations of endogenous estradiol and progesterone were also measured.

Intraindividual and interindividual variabilities in endogenous cortisol 6β-hydroxylation clearance as an index for in vivo CYP3A phenotyping in humans.

This study was designed to evaluate the in vivo activity of cytochrome P450 3A (CYP3A) in 49 healthy Japanese subjects aged 22-58 years using endogenous cortisol 6β-hydroxylation clearance [CLm(6β)], a novel biomarker for CYP3A phenotyping. CLm(6β) in the 49 healthy subjects was 2.40 ± 0.

The effect of water loading on the urinary ratio of cortisone to cortisol in healthy subjects and a new approach to the evaluation of the ratio as an index for in vivo human 11β-hydroxysteroid dehydrogenase 2 activity.

Factors that give rise to a large variation in the urinary ratio of free cortisone to cortisol (UFE/UFF) were investigated to accurately estimate 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2) activity in humans in vivo. A water loading test was first carried out in two healthy subjects to examine the effect of water intake or urine volume on the urinary ratio of free cortisone to cortisol (UFE/UFF). The ratio was found to increase by water loading.

Separation and quantitative determination of 6α-hydroxycortisol and 6β-hydroxycortisol in human urine by high-performance liquid chromatography with ultraviolet absorption detection.

The present study developed an high-performance liquid chromatography (HPLC) method for the simultaneous determination of urinary metabolites of endogenous cortisol, 6α-hydroxycortisol (6α-OHF) and 6β-hydroxycortisol (6β-OHF), in human urine, using 6α-hydroxycorticosterone as internal standard. 6α-OHF and 6β-OHF were extracted from urine with ethyl acetate by using a Sep-Pak C(18) plus cartridge. Separation of the stereoisomers was achieved on a reversed-phase hybrid column by a gradient elution of (A) 0.

Identification and quantification of daidzein-7-glucuronide-4'-sulfate, genistein-7-glucuronide-4'-sulfate and genistein-4',7-diglucuronide as major metabolites in human plasma after administration of kinako.

Much attention has been paid to the metabolism and disposition of isoflavones daidzein (Dein) and genistein (Gein) with regard to the prevention of several hormone-dependent diseases. Recent studies have reported that several conjugates as well as aglycones may be biologically active or may be activated within target cells. However, the disposition of Dein and Gein in plasma is still uncertain.

Simultaneous determination of androstenedione, 11beta-hydroxyandrostenedione, and testosterone in human plasma by stable isotope dilution mass spectrometry.

This study describes a GC-MS method for the simultaneous determination of androstenedione (AD), 11beta-hydroxyandrostenedione (11beta-OHAD), and testosterone (TS) in human plasma. [19,19,19-(2)H(3)]Androstenedione (AD-(2)H(3)), 11beta-hydroxy-[1,2,4,19-(13)C(4)]androstenedione (11beta-OHAD-(13)C(4)), and [1,16,16,17-(2)H(4)]testosterone (TS-(2)H(4)) were used as internal standards. Pentafluoropropionic (PFP) derivatization with good GC behavior was employed for the GC-MS analysis of the three steroids.

Plasma profiling of intact isoflavone metabolites by high-performance liquid chromatography and mass spectrometric identification of flavone glycosides daidzin and genistin in human plasma after administration of kinako.

The roles of isoflavones in the prevention of several hormone-dependent cancers and osteoporosis are of great interest. Despite many pharmacokinetics studies of the isoflavones, the actual types of conjugates circulating in the body and the position(s) of conjugation sites on the flavone skeleton are still uncertain because, in general, conjugated compounds in biological fluids have been evaluated by measuring the free aglycones obtained after selective enzymatic hydrolysis. Using an high-performance (HPLC)-UV-diode-array detector (DAD) method combined with solid-phase extraction, we have obtained HPLC profiles of isoflavone glycosides [daidzin (Din) and genistin (Gin)] and of intact isoflavone metabolites in human plasma: daidzein, genistein, daizein-7-glucuronide, daidzein-4'-glucuronide, genistein-7-glucuronide, genistein-4'-glucuronide, daidzein-7-sulfate, daidzein-4'-sulfate, genistein-7-sulfate, and genistein-4'-sulfate.

Use of 11alpha-deuterium labeled cortisol as a tracer for assessing reduced 11beta-HSD2 activity in vivo following glycyrrhetinic acid ingestion in a human subject.

This study describes an oral administration of 5 mg of [1,2,4,19-13C4,11alpha-2H]cortisol (cortisol-13C4,2H1) to a human subject performed on two separate occasions, one with cortisol-13C4,2H1 alone and the other with cortisol-13C4,2H1 plus 130 mg per day of glycyrrhetinic acid for 6 days. The stable isotope methodology employed allowed for the evaluation of the individual in vivo activities of the two isozymes of 11beta-hydroxysteroid dehydrogenase (11beta-HSD), 11beta-HSD1 and 11beta-HSD2, and to demonstrate the sensitivity of changes in cortisol elimination half-life for detecting inhibition of 11beta-HSD2 activity induced with glycyrrhetinic acid. The kinetic analysis associated with the loss of 11alpha-2H during the conversion of cortisol-13C4,2H1 to cortisone-13C4 by 11beta-HSD2 clearly indicated reduced 11beta-HSD2 activity with glycyrrhetinic acid ingestion, as observed by an increase in the elimination half-life of cortisol-13C4,2H1.

Simultaneous determination of 6beta-hydroxycortisol and cortisol in human urine by liquid chromatography with ultraviolet absorbance detection for phenotyping the CYP3A activity determined by the cortisol 6beta-hydroxylation clearance.

This study describes a high-performance liquid chromatographic (HPLC) method for the simultaneous determination of 6beta-hydroxycortisol (6beta-OHF) and cortisol in human urine using either methylprednisolone or beclomethasone as internal standard. Separation was achieved on a reversed-phase phenyl column by a gradient elution of 0.05 M KH(2)PO(4)-0.

Evidence for the validity of cortisol 6 beta-hydroxylation clearance as a new index for in vivo cytochrome P450 3A phenotyping in humans.

This study uses stable isotope methodology to evaluate the validity of 6beta-hydroxylation clearance of endogenous cortisol as a new index for in vivo CYP3A phenotyping in humans. Important factors contradictory to the use of a conventional index of urinary ratio of 6beta-hydroxycortisol to cortisol (6beta-OHF/F) to evaluate in vivo CYP3A activity are also discussed. Stable isotopically labeled cortisol (3-5 mg) was orally administered to three healthy adult subjects to accurately determine the fractional metabolic clearance specific for the 6beta-hydroxylation of cortisol.

Evaluation of 11beta-HSD activities in vivo following oral administration of cortisol-13C4,2H1 to a human subject.

This study is concerned with an oral administration of 5mg of [1,2,4,19-13C(4),11alpha-2H]cortisol (cortisol-13C(4),2H(1)) to a human subject to reliably evaluate the individual activities of two isozymes of 11beta-HSD. The use of a GC-MS method allowed the simultaneous measurement of the plasma concentrations of cortisol-13C(4),2H(1), cortisone-13C(4), and cortisol-13C(4) together with endogenous cortisol and cortisone. The loss of 11alpha-2H during the conversion of cortisol-13C(4),2H(1) to cortisone-13C(4) by 11beta-HSD2 and the regenerated cortisol-13C(4) from cortisone-13C(4) by 11beta-HSD1 provided a direct and accurate means of distinguishing the activities of the two isozymes.

Measurement of cortisol secretion rate by stable isotope methodology following oral administration of 13C-labeled cortisol to a human subject.

Plasma concentration measurements of 13C-labeled cortisol ([1,2,4,19-13C(4)]cortisol, cortisol-13C(4)) and its metabolite cortisone-13C(4) were made simultaneously with measurements of endogenous cortisol and cortisone by gas chromatography-mass spectrometry (GC-MS). After administering a small amount (3mg) of cortisol-13C(4) to a human subject, changes in cortisol secretion rates were estimated by deconvolution techniques from the measured plasma cortisol and cortisone levels and the rates of elimination and interconversion of cortisol and cortisone were obtained from the plasma concentration-time data of cortisol-13C(4) and cortisone-13C(4). The objective of this study was to look for a novel approach to quantitate rates of minute-to-minute cortisol secretion in man by taking into account the interconversion of cortisol and cortisone by 11beta-hydroxysteroid dehydrogenase (11beta-HSD).