Final Amended Safety Assessment of Sodium Sulfate as Used in Cosmetics.

The Expert Panel for Cosmetic Ingredient Safety (Panel) reopened the safety assessment of Sodium Sulfate, a cosmetic ingredient that is an inorganic salt reported to function in cosmetics as a viscosity increasing agent-aqueous. The Panel reviewed the relevant new data for the ingredient, including frequency of use and concentration of use, and considered data from the previous Panel assessment. The Panel concluded that Sodium Sulfate is safe in cosmetics in the present practices of use and concentrations described in this safety assessment when formulated to be nonirritating.

A positive-negative switching LC-MS/MS method for quantification of fenoldopam and its phase II metabolites: Applications to a pharmacokinetic study in rats.

Fenoldopam is an approved drug used to treat hypotension. The purpose of this study is to develop and validate an LC-MS method to quantify fenoldopam and its major metabolites fenoldopam-glucuronide and fenoldopam-sulfate in plasma and apply the method to a pharmacokinetic study in rats. A Waters C18 column was used with 0.1% formic acid in acetonitrile and 0.1% formic acid in water as the mobile phases to elute the analytes. A positive-negative switching method was performed in a triple quadrupole mass spectrometer using Multiple Reaction Monitoring (MRM) mode. A one-step protein precipitation using methanol and ethyl acetate was successfully applied for plasma sample preparation. The method was validated following the FDA guidance. The results show that the LLOQ of fenoldopam, fenoldopam-glucuronide and fenoldopam-sulfate is 0.98, 9.75 and 0.98 nM, respectively. The intraday and interday variance is less than 8.4% and the accuracy is between 82.5 and 116.0 %. The extraction recovery for these three analytes ranged from 81.3 ± 4.1% to 113.9 ± 13.2%. There was no significant matrix effect and no significant degradation under the experimental conditions. PK studies showed that fenoldopam was rapidly eliminated (t1/2 = 0.63 ± 0.24 h) from the plasma and glucuronide is the major metabolite. This method was suitably selective and sensitive for pharmacokinetic and phase II metabolism studies.

The Potency of Seaweed Sulfated Polysaccharides for the Correction of Hemostasis Disorders in COVID-19.

Hemostasis disorders play an important role in the pathogenesis, clinical manifestations, and outcome of COVID-19. First of all, the hemostasis system suffers due to a complicated and severe course of COVID-19. A significant number of COVID-19 patients develop signs of hypercoagulability, thrombocytopenia, and hyperfibrinolysis. Patients with severe COVID-19 have a tendency toward thrombotic complications in the venous and arterial systems, which is the leading cause of death in this disease. Despite the success achieved in the treatment of SARS-CoV-2, the search for new effective anticoagulants, thrombolytics, and fibrinolytics, as well as their optimal dose strategies, continues to be relevant. The wide therapeutic potential of seaweed sulfated polysaccharides (PSs), including anticoagulant, thrombolytic, and fibrinolytic activities, opens up new possibilities for their study in experimental and clinical trials. These natural compounds can be important complementary drugs for the recovery from hemostasis disorders due to their natural origin, safety, and low cost compared to synthetic drugs. In this review, the authors analyze possible pathophysiological mechanisms involved in the hemostasis disorders observed in the pathological progression of COVID-19, and also focus the attention of researchers on seaweed PSs as potential drugs aimed to correction these disorders in COVID-19 patients. Modern literature data on the anticoagulant, antithrombotic, and fibrinolytic activities of seaweed PSs are presented, depending on their structural features (content and position of sulfate groups on the main chain of PSs, molecular weight, monosaccharide composition and type of glycosidic bonds, the degree of PS chain branching, etc.). The mechanisms of PS action on the hemostasis system and the issues of oral bioavailability of PSs, important for their clinical use as oral anticoagulant and antithrombotic agents, are considered. The combination of the anticoagulant, thrombolytic, and fibrinolytic properties, along with low toxicity and relative cheapness of production, open up prospects for the clinical use of PSs as alternative sources of new anticoagulant and antithrombotic compounds. However, further investigation and clinical trials are needed to confirm their efficacy.

Development and application of analytical procedures for the GC-MS/MS analysis of the sulfates metabolites of anabolic androgenic steroids: The pivotal role of chemical hydrolysis.

In this work, we present a gas-chromatography tandem mass spectrometry (GC-MS/MS) method for the identification of the sulfo-conjugate metabolites of pseudo-endogenous steroids (endogenous steroids when administered exogenously). We have preliminarily evaluated the performances of different preparations of sulfatases from Pseudomonas aeruginosa and Helix pomatia, characterized by various origins and catalytic activities, and compared the efficacy of the enzymatic hydrolysis with chemical hydrolysis, performed with a mixture of ethyl acetate, methanol, and sulphuric acid. A procedure for the selective isolation of steroid conjugates from the urine matrix has been designed and optimized, based on the "sequential" extraction of the glucuro-conjugated and of the sulfo-conjugated fractions, performed by two different direct methods, i.e. by ion paired extraction or solid-phase extraction. More specifically, the former method is based on the use of N,N-dimethylephedrinium bromide as the ion paired extraction reagent, while the latter on the use of WAX® (weak anion exchange) cartridges. The performance of the newly developed procedure has been assessed by the analysis of real urine excretion samples collected after the oral intake of a single dose of dehydroepiandrosterone (DHEA) or androstenedione (AED), measuring the concentration of epiandrosterone (EpiA) sulfate. Our results have shown the following: (i) although the yields of chemical hydrolysis and enzymatic hydrolysis are in some cases quite similar, the former is generally preferable since it results in the quantitative cleavage of sulfate moiety; (ii) ion paired extraction has been selected as the most reliable method for direct isolation of sulfate steroids from urine matrices; (iii) EpiA sulfate allows to prolong the detectability of DHEA and AED when compared to routinely used steroidal target compounds.

Experimental and theoretical insights into kinetics and mechanisms of hydroxyl and sulfate radicals-mediated degradation of sulfamethoxazole: Similarities and differences.

Hydroxyl radical (•OH)- and sulfate radical ()-based advanced oxidation technologies (AOTs) have been proven an effective method to remove antibiotics in wastewater treatment plants (WWTPs). This study aims to gain insights into kinetics and mechanisms of neutral sulfamethoxazole (SMX) degradation, a representative antibiotic, by •OH and using an experimental and theoretical approach. First, the second-order rate constants (k) of SMX with •OH and were determined to be (7.27 ± 0.43) × 109 and (2.98 ± 0.32) × 109 M-1 s-1 in UV/H2O2 and UV/persulfate (UV/PS) systems, respectively. The following theoretical calculations at the M06-2X level of theory revealed that addition of radicals to the benzene ring is the most favorable first-step reaction for both •OH and , but that exhibits higher energy barriers and selectivity than •OH due to steric hindrance. We further analyzed subsequent reactions and, interestingly, our findings closely corroborated HOMO/LUMO distributions of SMX to the oxidation pathways. Finally, the estimation of energy consumption for UV alone, •OH-, and -mediated oxidation processes was compared. These comparative results, for the first time, provide insights into the similarities and differences of degradation of SMX by •OH/ at the molecular level and can help improve antibiotics removal using radical based AOTs in WWTPs.

Metabolite profiling of guanfacine in plasma and urine of healthy Japanese subjects after oral administration of guanfacine extended-release tablets.

Guanfacine is used for the treatment of attention-deficit/hyperactivity disorder (ADHD). Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), metabolite profiling of guanfacine was performed in plasma and urine collected from healthy Japanese adults following repeated oral administration of guanfacine extended-release formulation. Unchanged guanfacine was the most abundant component in both plasma and urine (from the MS signal intensity). In plasma, the M3 metabolite (a sulfate of hydroxy-guanfacine) was the prominent metabolite; the M2 metabolite (a glucuronide of a metabolite formed by monooxidation of guanfacine), 3-hydroxyguanfacine and several types of glucuronide at different positions on guanfacine were also detected. In urine, the M2 metabolite and 3-hydroxyguanfacine were the principal metabolites. From metabolite analysis, the proposed main metabolic pathway of guanfacine is monooxidation on the dichlorobenzyl moiety, followed by glucuronidation or sulfation. A minor pathway is glucuronidation at different positions on guanfacine. As the prominent metabolites in plasma were glucuronide and sulfate of hydroxyguanfacine, which have no associated toxicity concerns, further toxicity studies of the metabolites, for example in animals, were not deemed necessary.

Evaluation of the influence of mirabilite on the absorption and pharmacokinetics of the ingredients in Dahuang-mudan decoction by a validated UPLC/QTOF-MS/MS method.

Dahuang-mudan decoction (DMD) has been widely used for disease treatment in China for 1700 years. The formula consists of Rhubarb, moutan bark, Prunus persica, wax gourd kernel and mirabilite, which have been well studied by multidisciplinary approaches. However, the role of the mineral mirabilite in DMD is unclear. The objective of this study was to investigate the effects of mirabilite on the absorption and pharmacokinetics of the ingredients in DMD. The constituents were identified in DMD extract and the plasma of mirabilite-DMD (MDMD, 50 g kg-1 ) treated rats and nonmirabilite-DMD (NMDMD, 50 g kg-1 ) treated rats. The plasma was also used to investigate the effects of mirabilite on the pharmacokinetics of active ingredients in DMD using a new validated UPLC-MS/MS method. The results showed that 63 compounds were identified in the extract of DMD, 27 and 22 of which were found in the plasmas of MDMD- and NMDMD-treated rats, respectively. Furthermore, the results of a pharmacokinetic study suggested that mirabilite influenced the absorption of the five constituents by decreasing the absorption of emodin and rhein while increasing the absorption of aloe-emodin, paeoniflorin and amygdalin; the pharmacokinetic parameters, including the Tmax , Cmax , AUC0-t , MRT0-t , CLz and t1/2 of five constituents, significantly changed in MDMD-treated rats compared with the NMDMD. The method validation for selectivity, precision, accuracy, matrix effect, recovery and stability met the acceptance criteria. These findings uncover the roles of mirabilite in DMD and demonstrate the application of scientific principles to the study of DMD in human health care.

Preparation of phenylephrine 3-O-sulfate as the major in vivo metabolite of phenylephrine to facilitate its pharmacokinetic and metabolism studies.

INTRODUCTION: The in vivo disposition and metabolism of phenylephrine have not been establishedby previous analytical methods and there is a lack of available standards for quantitating the metabolites. METHODS: We pursued and compared the preparation of sulfation metabolites of phenylephrine and its ethyl analog etilefrine via chemical and bio-synthesis. RESULTS: Both sulfates were obtained in higher yield and purity through chemical syntheses compared to biosynthesis. DISCUSSION: A facile method for the production of phenylephrine 3-O-sulfate and etilefrine 3-O-sulfate was established. These compounds will be useful in the development of analytical assays for studying the pharmacokinetics of phenylephrine and its main route of metabolism in the presence of formulation changes and pharmacogenetic variation.

Pharmacokinetics and Biliary Excretion of Fisetin in Rats.

The hypothesis of this study is that fisetin and phase II conjugated forms of fisetin may partly undergo biliary excretion. To investigate this hypothesis, male Sprague-Dawley rats were used for the experiment, and their bile ducts were cannulated with polyethylene tubes for bile sampling. The pharmacokinetic results demonstrated that the average area-under-the-curve (AUC) ratios ( k (%) = AUCconjugate/AUCfree-form) of fisetin, its glucuronides, and its sulfates were 1:6:21 in plasma and 1:4:75 in bile, respectively. Particularly, the sulfated metabolites were the main forms that underwent biliary excretion. The biliary excretion rate ( kBE (%) = AUCbile/AUCplasma) indicates the amount of fisetin eliminated by biliary excretion. The biliary excretion rates of fisetin, its glucuronide conjugates, and its sulfate conjugates were approximately 144, 109, and 823%, respectively, after fisetin administration (30 mg/kg, iv). Furthermore, biliary excretion of fisetin is mediated by P-glycoprotein.

Pharmacokinetic and Tissue Distribution of Fucoidan from Fucus vesiculosus after Oral Administration to Rats.

Fucus vesiculosus L., known as bladderwrack, belongs to the brown seaweeds, which are widely distributed throughout northern Russia, Atlantic shores of Europe, the Baltic Sea, Greenland, the Azores, the Canary Islands, and shores of the Pacific Ocean. Fucoidan is a major fucose-rich sulfated polysaccharide found in Fucus (F.) vesiculosus. The pharmacokinetic profiling of active compounds is essential for drug development and approval. The aim of the study was to evaluate the pharmacokinetics and tissue distribution of fucoidan in rats after a single-dose oral administration. Fucoidan was isolated from F. vesiculosus. The method of measuring anti-activated factor X (anti-Xa) activity by amidolytic assay was used to analyze the plasma and tissue concentrations of fucoidan. The tissue distribution of fucoidan after intragastric administration to the rats was characterized, and it exhibited considerable heterogeneity. Fucoidan preferentially accumulates in the kidneys (AUC0–t = 10.74 µg·h/g; Cmax = 1.23 µg/g after 5 h), spleen (AUC0–t = 6.89 µg·h/g; Cmax = 0.78 µg/g after 3 h), and liver (AUC0–t = 3.26 µg·h/g; Cmax = 0.53 µg/g after 2 h) and shows a relatively long absorption time and extended circulation in the blood, with a mean residence time (MRT) = 6.79 h. The outcome of this study provides additional scientific data for traditional use of fucoidan-containing plants and offers tangible support for the continued development of new effective pharmaceuticals using fucoidan.

Detection and characterization of the metabolites of rutaecarpine in rats based on ultra-high-performance liquid chromatography with linear ion trap-Orbitrap mass spectrometer.

CONTEXT: Rutaecarpine is an active indoloquinazoline alkaloid ingredient originating from Evodia rutaecarpa (Wu-zhu-yu in Chinese), which possesses a variety of effects. However, its metabolism has not been investigated thoroughly yet. OBJECTIVE: This study develops a highly sensitive and effective method for detection and characterization of the metabolites of rutaecarpine in Sprague-Dawley (SD) rats. MATERIALS AND METHODS: In this study, an efficient method was developed using ultra-high-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometer (UHPLC-LTQ-Orbitrap MS) to detect the metabolism profile of rutaecarpine in rat plasma. First, a blood sample (1 mL) was withdrawn 2 h after oral administration of rutaecarpine in SD rats (50 mg/kg). Second, the blood was centrifuged at 4000 rpm for 10 min and pretreated by solid-phase extraction method. Third, 2 µL of the plasma was injected into UHPLC-LTQ-Orbitrap MS for analysis. Finally, the metabolites of rutaecarpine were tentatively identified based on accurate mass measurements, fragmentation patterns and chromatographic retention times. RESULTS: A total of 16 metabolites (four new metabolites, viz., dihydroxylation and sulphate conjugation products of rutaecarpine (M8-M11)) as well as parent drug itself, including three phase I and 12 phase II metabolites were detected and identified in rat plasma. Hydroxylation, sulphate conjugation and glucuronidation were confirmed as the primary metabolic pathways for rutaecarpine in rat plasma. DISCUSSION AND CONCLUSION: These results provide an insight into the metabolism of rutaecarpine and also can give strong indications on the effective forms of rutaecarpine in vivo.

Direct detection of phenylephrine 3-O-sulfate in LS180 human intestinal cells using a novel hydrophilic interaction liquid chromatography (HILIC) assay.

The efficacy of phenylephrine (PE) is controversial due to its extensive pre-systemic metabolism through sulfation to form phenylephrine-3-O-sulfate (PES). Hence quantitation of PES is important in order to study the metabolism of PE. There are no published methods available for direction detection of PES. We have developed and validated a hydrophilic interaction liquid chromatography (HILIC) method for the direct detection of PES and simultaneous detection of PE to study the enzyme kinetics and metabolism of PE to enable approaches to reduce the presystemic metabolism of PE. This is the first method which facilitates direct detection of PES and simultaneous detection of PE using a zwitterionic HILIC column with improved sensitivity in a single short run. The observed quantitative ranges of our method for PE and PES were 0.39-200µM and 0.0625-32µM (respectively) with a run time of 6.0min. The method was applied to the determination of PE and PES in LS180 human intestinal cell line, recombinant enzymes and human intestinal cytosol (HIC).

Metabolism and Disposition of Hepatitis C Polymerase Inhibitor Dasabuvir in Humans.

Dasabuvir [also known as ABT-333 or N-(6-(3-(tert-butyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2-methoxyphenyl)naphthalen-2-yl)methanesulfonamide] is a potent non-nucleoside NS protein 5B polymerase inhibitor of the hepatitis C virus (HCV) and is being developed in combination with paritaprevir/ritonavir and ombitasvir in an oral regimen with three direct-acting antivirals for the treatment of patients infected with HCV genotype 1. This article describes the mass balance, metabolism, and disposition of dasabuvir in humans. After administration of a single oral dose of 400-mg [(14)C]dasabuvir (without coadministration of paritaprevir/ritonavir and ombitasvir) to four healthy male volunteers, the mean total percentage of the administered radioactive dose recovered was 96.6%. The recovery from the individual subjects ranged from 90.8% to 103%. Dasabuvir and corresponding metabolites were predominantly eliminated in feces (94.4% of the dose) and minimally through renal excretion (2.2% of the dose). The biotransformation of dasabuvir primarily involves hydroxylation of the tert-butyl group to form active metabolite M1 [N-(6-(5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-3-(1-hydroxy-2-methylpropan-2-yl)-2-methoxyphenyl)naphthalen-2-yl)methanesulfonamide], followed by glucuronidation and sulfation of M1 and subsequent secondary oxidation. Dasabuvir was the major circulating component (58% of total radioactivity) in plasma, followed by metabolite M1 (21%). Other minor metabolites represented < 10% each of total circulating radioactivity. Dasabuvir was cleared mainly through cytochrome P450-mediated oxidation metabolism to M1. M1 and its glucuronide and sulfate conjugates were primarily eliminated in feces. Subsequent oxidation of M1 to the tert-butyl acid, followed by formation of the corresponding glucuronide conjugate, plays a secondary role in elimination. Cytochrome P450 profiling indicated that dasabuvir was mainly metabolized by CYP2C8, followed by CYP3A4. In summary, the biotransformation pathway and clearance routes of dasabuvir were characterized, and the structures of metabolites in circulation and excreta were elucidated.

Pharmacokinetic study of harmane and its 10 metabolites in rat after intravenous and oral administration by UPLC-ESI-MS/MS.

Context The ß-carboline alkaloid harmane is widely distributed in common foods, beverages and hallucinogenic plants. Harmane exerts potential in therapies for Alzheimer's and depression diseases. However, little information on its dynamic metabolic profiles and pharmacokinetics in vivo is currently available. Objective This study investigates the dynamic metabolic profiles and pharmacokinetic properties of harmane and its metabolites in rats in vivo. Materials and methods A highly selective, sensitive and rapid ultra-performance liquid chromatography combined with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) method was developed and well-validated for simultaneous quantitative determination of harmane and its uncertain endogenous metabolite harmine, as well as for semiquantitative determination of 10 harmane metabolites in rats after intravenous injection and oral administration of harmane at 1.0 and 30.0 mg/kg, respectively. Results The calibration curves of harmane and harmine showed excellent linearity within the concentration range of 1-2000 ng/mL with acceptable accuracy, precision, selectivity, recovery, matrix effect and stability. Ten metabolites, including harmane but not harmine, were detected and identified after intravenous and oral administration of harmane. The absolute bioavailability of harmane following an oral dose was 19.41 ± 3.97%. According to the AUC0-t values of all the metabolites, the metabolic levels of phase II metabolites were higher than those of phase I metabolites, and the sulphation pathways were the dominant metabolic routes for harmane in both routes of administration. Discussion and conclusion The pharmacokinetic properties of harmane and its 10 metabolites in rats were determined. Sulphate conjugation was the predominant metabolic process of harmane in rats.

Sulphate absorption across biological membranes.

1. Sulphonation is unusual amongst the common Phase II (condensation; synthetic) reactions experienced by xenobiotics, in that the availability of the conjugating agent, sulphate, may become a rate-limiting factor. This sulphate is derived within the body via the oxygenation of sulphur moieties liberated from numerous ingested compounds including the sulphur-containing amino acids. Preformed inorganic sulphate also makes a considerable contribution to this pool. 2. There has been a divergence of opinion as to whether or not inorganic sulphate may be readily absorbed from the gastrointestinal tract and this controversy still continues in some quarters. Even more so, is the vexing question of potential absorption of inorganic sulphate via the lungs and through the skin. 3. This review examines the relevant diverse literature and concludes that sulphate ions may move across biological membranes by means of specific transporters and, although the gastrointestinal tract is by far the major portal of entry, some absorption across the lungs and the skin may take place under appropriate circumstances.

Metabolites identification of bioactive licorice compounds in rats.

Licorice (Glycyrrhiza uralensis Fisch.) is one of the most popular herbal medicines worldwide. This study aims to identify the metabolites of seven representative bioactive licorice compounds in rats. These compounds include 22ß-acetoxyl glycyrrhizin (1), licoflavonol (2), licoricidin (3), licoisoflavanone (4), isoglycycoumarin (5), semilicoisoflavone B (6), and 3-methoxy-9-hydroxy-pterocarpan (7). After oral administration of 250mg/kg of 1 or 40mg/kg of 2-7 to rats, a total of 16, 43 and 31 metabolites were detected in the plasma, urine and fecal samples, respectively. The metabolites were characterized by HPLC/DAD/ESI-MS(n) and LC/IT-TOF-MS analyses. Particularly, two metabolites of 1 were unambiguously identified by comparing with reference standards, and 22ß-acetoxyl glycyrrhizin-6″-methyl ester (1-M2) is a new compound. Compound 1 could be readily hydrolyzed to eliminate the glucuronic acid residue. The phenolic compounds (4-7) mainly undertook phase II metabolism (glucuronidation or sulfation). Most phenolic compounds with an isoprenyl group (chain or cyclized, 2-5) could also undertake hydroxylation reaction. This is the first study on in vivo metabolism of these licorice compounds.

Extensive metabolism and route-dependent pharmacokinetics of bisphenol A (BPA) in neonatal mice following oral or subcutaneous administration.

Orally administered bisphenol A (BPA) undergoes efficient first-pass metabolism to produce the inactive conjugates BPA-glucuronide (BPA-G) and BPA-sulfate (BPA-S). This study was conducted to evaluate the pharmacokinetics of BPA, BPA-G and BPA-S in neonatal mice following the administration of a single oral or subcutaneous (SC) dose. This study consisted of 3 phases: (1) mass-balance phase in which effective dose delivery procedures for oral or SC administration of (3)H-BPA to postnatal day three (PND3) mice were developed; (2) pharmacokinetic phase during which systemic exposure to total (3)H-BPA-derived radioactivity in female PND3 mice was established; and (3) metabolite profiling phase in which 50 female PND3 pups received either a single oral or SC dose of (3)H-BPA. Blood was collected from 5 pups/route/time-point at various times post-dosing, the blood plasma samples were pooled by group, and time-point and samples were profiled by HPLC with fraction collection. Fractions were analyzed for total radioactivity and data used to reconstruct radiochromatograms and to integrate individual peaks. The identity of the BPA, BPA-G, and BPA-S peaks was confirmed using authentic standards and LC-MS/MS analysis. The result of this study revealed that female PND3 mice have the capacity to metabolize BPA to BPA-G, BPA-S and other metabolites after both routes of administration. Systemic exposure to free BPA is route-dependent as the plasma concentrations were lower following oral administration compared to SC injection.

Impact on abiraterone pharmacokinetics and safety: Open-label drug-drug interaction studies with ketoconazole and rifampicin.

We evaluated the impact of a strong CYP3A4 inhibitor, ketoconazole, and a strong inducer, rifampicin, on the pharmacokinetic (PK) exposure of abiraterone in two studies in healthy men. All subjects received 1,000 mg of abiraterone acetate on Days 1 and 14. Study A subjects (n = 20) received 400 mg ketoconazole on Days 11-16. Study B subjects (n = 19) received 600 mg rifampicin on Days 8-13. Serial PK sampling was done on Days 1 and 14. Study A: When given with ketoconazole, abiraterone exposure increased by 9% for maximum plasma concentration (Cmax ) and 15% for area under the plasma concentration-time curve from 0 to time of the last quantifiable concentration (AUClast ) and AUC from time 0 to infinity (AUC∞ ) compared to abiraterone acetate alone. Study B: When given with rifampicin, abiraterone exposure was reduced to 45% for Cmax and AUC∞ and to 42% for AUClast compared to abiraterone acetate alone. Ketoconazole had no clinically meaningful impact on abiraterone exposure. Rifampicin decreased abiraterone exposure by half. Hence, strong CYP3A4 inducers should be avoided or used with careful evaluation of clinical efficacy when administered with abiraterone acetate.

Simultaneous determination of a novel oral Janus kinase inhibitor ASP015K and its sulfated metabolite in rat plasma using LC-MS/MS.

A sensitive and selective liquid chromatography with tandem mass spectrometry (LC-MS/MS) was developed for determining the concentrations of novel Janus kinase inhibitor ASP015K and its sulfated metabolite M2 in rat plasma. This method involves solid-phase extraction (SPE) from 25 µL of rat plasma. LC separation was performed on an Inertsil PH-3 column (100 mm L ×4.6 mm I.D., 5 µm) with a mobile phase consisting of 10 mM ammonium acetate and methanol under linear gradient conditions. Analytes were introduced to the LC-MS/MS through an electrospray ionization source and detected in positive-ion mode using selected reaction monitoring. Standard curves were linear from 0.25 to 500 ng/mL (r ≥0.9964). This assay enabled quantification of ASP015K and M2 at a concentration as low as 0.25 ng/mL in rat plasma. Validation data demonstrated that the method is selective, sensitive and accurate. Further, we also successfully applied this method to a preclinical pharmacokinetic study in rats.

Relative bioavailability of iron proteinate for broilers fed a casein-dextrose diet.

An experiment was carried out to determine the bioavailability of organic Fe as Fe proteinate (Alltech, Nicholasville, KY) relative to inorganic Fe source (FeSO4•7H2O) for broiler chicks fed a casein-dextrose diet. A total of 448 1-d-old Arbor Acres commercial male broiler chicks were randomly allotted to 1 of 8 replicate cages (8 chicks per cage) for each of 7 treatments in a completely randomized design involving a 2 × 3 factorial arrangement of treatments with 2 Fe sources (Fe proteinate and Fe sulfate) and 3 levels of added Fe (10, 20, or 40 mg of Fe/kg) plus a Fe-unsupplemented control diet containing 4.56 mg of Fe/kg by analysis. Feed and distilled-deionized water were available ad libitum for an experimental phase of 14 d. At 14 d of age, blood samples were collected for testing hemoglobin (Hb) and hematocrit, and calculating total body Hb Fe, whereas liver and kidney samples were excised for Fe analyses. The results showed that ADG, ADFI, blood Hb, hematocrit, and total body Hb Fe and Fe concentrations in liver and kidney increased linearly (P < 0.0001), whereas mortality decreased linearly (P < 0.0001) as dietary Fe level increased. However, only blood Hb concentration and total body Hb Fe differed (P < 0.004) between the 2 Fe sources. Based on slope ratios from the multiple linear regression of Hb concentration and total body Hb Fe on daily intake of analyzed dietary Fe, the bioavailability of Fe proteinate relative to FeSO4•7H2O (100%) was 117 and 114%, respectively (P < 0.009). The results indicated that blood Hb concentration and total body Hb Fe were sensitive indices in reflecting differences in bioavailability among different Fe sources, and Fe proteinate was significantly more available to broilers than inorganic Fe sulfate in enhancing Hb concentration and total body Hb Fe.