Pharmacokinetics, pharmacodynamics, and safety of verinurad with and without allopurinol in healthy Asian, Chinese, and non-Asian participants.

Verinurad is a selective inhibitor of uric acid transporter 1 (URAT1). Here, we assessed the safety, pharmacokinetics, and pharmacodynamics of verinurad + allopurinol and verinurad monotherapy in healthy participants. Studies 1 (NCT03836599) and 2 (NCT02608710) were randomized Phase 1 studies. In Study 1, 12 healthy Asian participants received 24 mg verinurad + 300 mg allopurinol or placebo, and 9 healthy Chinese participants received 12 mg verinurad + 300 mg allopurinol. In Study 2, 24 healthy non-Asian male participants received 12 mg verinurad. Safety analyses included assessment of adverse events (AEs). Pharmacokinetic parameters included maximum concentration (Cmax ) and area under plasma concentration-time curve (AUC) over 24 h (AUCτ ). Pharmacodynamic parameters included percentage change from baseline (day -1) in serum uric acid (sUA) and urinary uric acid (uUA). There were no serious AEs or deaths in either study. In Study 1, steady-state geometric mean (gCV%) Cmax and AUCτ values of verinurad after 7 days' dosing were 73.6 (29.0) ng/mL and 478 (18.4) ng·h/mL, respectively, in healthy Asian participants, and 42.0 (40.1) ng/mL and 264 (36.1) ng·h/mL, respectively, in healthy Chinese participants; in Study 2, gCV% values were 36.3 (36.5) ng/mL and 271 (31.0) ng·h/mL, respectively. sUA decreased and uUA excretion increased compared with baseline following verinurad + allopurinol (Study 1) or verinurad (Study 2). When accounting for dose, the steady-state pharmacokinetics of verinurad following multiple dosing were comparable between healthy Asian and Chinese participants and healthy non-Asian participants. Verinurad treatments were well tolerated, including at higher verinurad exposures than previously evaluated after repeated dosing.

Formulation and evaluation of butenafine loaded PLGA-nanoparticulate laden chitosan nano gel.

The present research work is designed to prepare and optimize butenafine (BT) loaded poly lactic co glycolic acid (PLGA) nanoparticles (BT-NPs). BT-NPs were prepared by emulsification probe sonication method using PLGA (A), PVA (B) as polymer and stabilizer, respectively. The optimum composition of BT-NPs was selected based on the point prediction method given by the Box Behnken design software. The optimized composition of BT-NPop showed a particle size of 267.21 ± 3.54 nm with an entrapment efficiency of 72.43 ± 3.11%. The optimum composition of BT-NPop was further converted into gel formulation using chitosan as a natural polymer. The prepared topical gel formulation (BT-NPopG) was further evaluated for gel characterization, drug release, permeation study, irritation, and antifungal studies. The prepared BT-NPopG formulation showed optimum pH, viscosity, spreadability, and drug content. The release and permeation study results revealed slow BT release (42.76 ± 2.87%) with significantly enhanced permeation across the egg membrane. The irritation study data showed negligible irritation with a cumulative score of 0.33. The antifungal study results conclude higher activity than marketed as well as pure BT. The overall conclusion of the results revealed BT-NPopG as an ideal delivery system to treat topical fungal infection.

Characterization of Phase I Hepatic Metabolites of Anti-Premature Ejaculation Drug Dapoxetine by UHPLC-ESI-Q-TOF.

Determination of the metabolism pathway of xenobiotics undergoing the hepatic pass is a crucial aspect in drug development since the presence of toxic biotransformation products may result in significant side effects during the therapy. In this study, the complete hepatic metabolism pathway of dapoxetine established according to the human liver microsome assay with the use of a high-resolution LC-MS system was described. Eleven biotransformation products of dapoxetine, including eight metabolites not reported in the literature so far, were detected and identified. N-dealkylation, hydroxylation, N-oxidation and dearylation were found to be the main metabolic reactions for the investigated xenobiotic. In silico analysis of toxicity revealed that the reaction of didesmethylation may contribute to the increased carcinogenic potential of dapoxetine metabolites. On the other hand, N-oxidation and aromatic hydroxylation biotransformation reactions possibly lead to the formation of mutagenic compounds.

Discovery of novel ceramide analogs with favorable pharmacokinetic properties and combination with AKT inhibitor against colon cancer.

Ceramides have emerged as potential therapeutic option with novel mechanism to affect the proliferation, differentiation, senescence, and apoptosis of cancer cells through regulation of multiple signal transduction. Aiming at the improvement of the apoptosis activity and pharmacokinetic profiles of ceramides, a novel series of ceramide analogs were developed through structure simplification and conformation restriction. Among them, compound 12 bearing an alkoxyl naphthyl motif, with favorable rat pharmacokinetic properties, showed better anti-proliferative activity against various colon cancer cells (IC50 ∼20 µM) than other ceramide analogues, as well as the synergistic effect combined with AKT inhibitor MK2206. Additionally, we demonstrated that this combination therapy promoted caspase 3-dependent apoptotic pathway and intensified cell cycle arrest in the G0/G1 phase. Furthermore, the combination of compound 12 and MK2206 displayed synergistic anti-tumor effect in vivo.

Pharmacokinetics and Safety of Dapoxetine Hydrochloride in Healthy Chinese Men: Impact of Dose and High-Fat Meal.

Dapoxetine is the first oral medication specifically developed for the on-demand treatment of premature ejaculation. The pharmacokinetics and safety of 30 mg (n = 40) and 60 mg (n = 38) dapoxetine in healthy Chinese under fasted and fed states were assessed in 2 studies. Both studies are random, single-center, 2-period, open-label, 2-way crossover designs. Plasma concentration of dapoxetine was determined by high-performance liquid chromatography-tandem mass spectrometry, and the pharmacokinetic parameters were calculated using noncompartmental analysis. Dapoxetine was quickly absorbed and reached maximum concentration 1 to 3 hours after oral administration. Elimination was biphasic, and the plasma concentration decreased to 3% to 7% of maximum concentration by 24 hours while half-life was 15 to 18 hours. Meantime, high-fat meals slightly increased its exposure. Both doses of dapoxetine were well tolerated. The adverse events in the high-dose group under fasted and fed states were 37.9% and 19.0%, respectively.

Bioequivalence Analysis of 2 Dapoxetine Hydrochloride Formulations in Healthy Chinese Male Volunteers Under Fed and Fasting Conditions: A Randomized, Open-Label, 2-Sequence, 2-Period, 2-Way Crossover Study.

This study assessed whether the reference and test formulations of dapoxetine hydrochloride were bioequivalent under fed and fasting conditions postadministration of a single dose as well as evaluated the safety profile of these 2 formulations. This study was a randomized, single-center, 2-period, open-label, 2-way crossover design study with a washout period of 7 days between each period. The study included 80 subjects, 40 under fed and 40 under fasting conditions. During each study period, the subjects were administered a single oral dose of either the reference or the test formulation, followed by collection of plasma samples 70 hours postdose. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was performed to determine the concentrations of dapoxetine in plasma samples along with the calculation of Cmax , AUC0-t, and AUC0-inf . In addition, adverse events were monitored to determine the safety of these formulations. The geometric mean ratio (90%CI) for the reference and test formulations was 86% to 100%, 89% to 103%, and 89% to 103% under fasting conditions and 92% to 107%, 91% to 100%, and 92% to 101% under fed conditions for Cmax , AUC0-t , and AUC0-inf , respectively. The 90%CIs for the test/reference ratio for AUC and Cmax were within the acceptable limits of bioequivalence, thus demonstrating bioequivalence for these 2 dapoxetine hydrochloride formulations.

Determination of the Synthetic Cannabinoids JWH-122, JWH-210, UR-144 in Oral Fluid of Consumers by GC-MS and Quantification of Parent Compounds and Metabolites by UHPLC-MS/MS.

The consumption of synthetic cannabinoids (SCs) has significantly increased in the last decade and the analysis of SCs and their metabolites in human specimens is gaining interest in clinical and forensic toxicology. A pilot study has been carried out using a combination of an initial last generation gas chromatography-mass spectrometry (GC-MS) screening method for the determination of JWH-122, JWH-210, UR-144) in oral fluid (OF) of consumers and an ultra-high performance liquid chromatography high resolution mass spectrometry (UHPLC-HRMS) confirmatory method for the quantification of the parent compounds and their metabolites in the same biological matrix. OF samples were simply liquid-liquid extracted before injecting in both chromatographic systems. The developed methods have been successfully validated and were linear from limit of quantification (LOQ) to 50 ng/mL OF. Recovery of analytes was always higher than 70% and matrix effect always lower than 15% whereas intra-assay and inter-assay precision and accuracy were always better than 16%. After smoking 1 mg JWH-122 or UR-144 and 3 mg JWH-210, maximum concentration of 4.00-3.14 ng/mL JWH-122, 8.10-7.30 ng/mL JWH-210 ng/mL and 7.40 and 6.81 ng/mL UR-144 were measured by GC-MS and UHPLC-HRMS respectively at 20 min after inhalation. Metabolites of JWH 122 and 210 were quantified in OF by UHPLC-HRMS, while that of UR144 was only detectable in traces. Our results provide for the first time information about disposition of these SCs and their metabolites in consumers OF. Last generation GC-MS has proven useful tool to identify and quantify parent SCs whereas UHPLC-HRMS also confirmed the presence of SCs metabolites in the OF of SCs consumers.

Comparative assessment of the effects of bumped kinase inhibitors on early zebrafish embryo development and pregnancy in mice.

Bumped kinase inhibitors (BKIs) are effective against a variety of apicomplexan parasites. Fifteen BKIs with promising in vitro efficacy against Neospora caninum tachyzoites, low cytotoxicity in mammalian cells, and no toxic effects in non-pregnant BALB/c mice were assessed in pregnant mice. Drugs were emulsified in corn oil and were applied by gavage for 5 days. Five BKIs did not affect pregnancy, five BKIs exhibited ~15-35% neonatal mortality and five compounds caused strong effects (infertility, abortion, stillbirth and pup mortality). Additionally, the impact of these compounds on zebrafish (Danio rerio) embryo development was assessed by exposing freshly fertilised eggs to 0.2-50 µM of BKIs and microscopic monitoring of embryo development in a blinded manner for 4 days. We propose an algorithm that includes quantification of malformations and embryo deaths, and established a scoring system that allows the calculation of an impact score (Si) indicating at which concentrations BKIs visibly affect zebrafish embryo development. Comparison of the two models showed that for nine compounds no clear correlation between Si and pregnancy outcome was observed. However, the three BKIs affecting zebrafish embryos only at high concentrations (≥40 µM) did not impair mouse pregnancy at all, and the three compounds that inhibited zebrafish embryo development already at 0.2 µM showed detrimental effects in the pregnancy model. Thus, the zebrafish embryo development test has limited predictive value to foresee pregnancy outcome in BKI-treated mice. We conclude that maternal health-related factors such as cardiovascular, pharmacokinetic and/or bioavailability properties also contribute to BKI-pregnancy effects.

High performance liquid chromatography - Mass spectrometric bioanalytical method for the determination of dapoxetine in human plasma: Application for bioequivalence study.

Dapoxetine is an oral medication used for treatment of premature ejaculation (PE) in men aged (18-64 years). In this study, we present a validated, precise and sensitive method for determination of dapoxetine in human plasma by liquid chromatography/ electrospray ionization-tandem mass spectrometry. Dapoxetine and the internal standard (Dapoxetine- d6) were extracted from plasma via liquid-liquid extraction (LLE). The LC separation was performed utilizing ACE C8 (4.6 X50) mm, 5 µm column. The mobile phase was composed of acetonitrile and buffer (0.01 M Ammonium acetate +0.02% Formic acid solution) (85:15, v/v). The method was linear within the concentration range of 5.0-600 ng/mL for Dapoxetine in human plasma. Short analytical run was achieved with 1.6 min run time. Intra-day and inter-day accuracy was between 97 and 106% with precision (CV, %) of ≤ 5% achieved across all the quality control samples. Dapoxetine was stable in several conditions with recovery rates > 90%. This method was utilized successfully in clinical pharmacokinetic study following oral administration of 60 mg Dapoxetine tablets in 36 healthy male subjects. The result for all 90% confidence intervals were within the preset ranges. The method proved to be highly reproducible and sensitive and thus can be employed in bioequivalence studies and large scale sample analysis of Dapoxetine.

Incorporating ToxCast™ data into naphthalene human health risk assessment.

Chronic inhalation of naphthalene causes nasal olfactory epithelial tumors in rats and benign lung adenomas in mice. The available human data do not establish an association between naphthalene and increased respiratory cancer risk. Therefore, cancer risk assessment of naphthalene in humans depends predominantly on experimental evidence from rodents. The United States Environmental Protection Agency's (US EPA) Toxicity Forecaster (ToxCast™) database contains data from 710 in vitro assays for naphthalene, the majority of which were conducted in human cells. Of these assays, only 18 were active for naphthalene, and all were in human liver cells. No assays were active in human bronchial epithelial cells. In our analysis, all of the active naphthalene ToxCast assay data were reviewed and used to: 1) determine naphthalene human inhalation concentrations corresponding to relevant activity concentrations for all active naphthalene assays, using a physiologically based pharmacokinetic (PBPK) model; and 2) evaluate the transcriptional responses for active assays in the context of consistency with the larger naphthalene data set and proposed modes of action (MoAs) for naphthalene toxicity and carcinogenicity. The transcriptional responses in liver cells largely reflect cellular activities related to oxidative stress and chronic inflammation. Overall, the results from our analysis of the active ToxCast assays for naphthalene are consistent with conclusions from our earlier weight-of-evidence evaluation for naphthalene carcinogenesis.

In vitro and in vivo pharmacological evaluation of the synthetic cannabinoid receptor agonist EG-018.

Synthetic cannabinoid receptor agonists (SCRAs) possess high abuse liability and complex toxicological profiles, making them serious threats to public health. EG-018 is a SCRA that has been detected in both illicit products and human samples, but it has received little attention to date. The current studies investigated EG-018 at human CB1 and CB2 receptors expressed in HEK293 cells in [3H]CP55,940 competition binding, [35S]GTPγS binding and forskolin-stimulated cAMP production. EG-018 was also tested in vivo for its ability to produce cannabimimetic and abuse-related effects in the cannabinoid tetrad and THC drug discrimination, respectively. EG-018 exhibited high affinity at CB1 (21 nM) and at CB2 (7 nM), but in contrast to typical SCRAs, behaved as a weak partial agonist in [35S]GTPγS binding, exhibiting lower efficacy but greater potency, than that of THC at CB1 and similar potency and efficacy at CB2. EG-018 inhibited forskolin-stimulated cAMP with similar efficacy but lower potency, compared to THC, which was likely due to high receptor density facilitating saturation of this signaling pathway. In mice, EG-018 (100 mg/kg, 30 min) administered intraperitoneally (i.p.) did not produce effects in the tetrad or drug discrimination nor did it shift THC's ED50 value in drug discrimination when administered before THC, suggesting EG-018 has negligible occupancy of brain CB1 receptors following i.p. administration. Following intravenous (i.v.) administration, EG-018 (56 mg/kg) produced hypomotility, catalepsy, and hypothermia, but only catalepsy was blocked by the selective CB1 antagonist rimonabant (3 mg/kg, i.v.). Additional studies of EG-018 and its structural analogues could provide further insight into how cannabinoids exert efficacy through the cannabinoid receptors.

Mitigation of Rheumatic Arthritis in a Rat Model via Transdermal Delivery of Dapoxetine HCl Amalgamated as a Nanoplatform: In vitro and in vivo Assessment.

PURPOSE: Dapoxetine HCl (DH), a selective serotonin reuptake inhibitor, may be useful for the treatment of rheumatic arthritis (RA). The purpose of this study was to investigate the therapeutic efficacy of transdermal delivery of DH in transethosome nanovesicles (TENVs). This novel delivery of DH may overcome the drawbacks associated with orally administered DH and improve patient compliance. METHODS: DH-TENV formulations were prepared using an injection- sonication method and optimized using a 33 Box-Behnken-design with Design Expert® software. The TENV formulations were assessed for entrapment efficiency (EE-%), vesicle size, zeta potential, in vitro DH release, and skin permeation. The tolerability of the optimized DH-TENV gel was investigated using a rat skin irritation test. A pharmacokinetic analysis of the optimized DH-TENV gel was also conducted in rats. Moreover, the anti-RA activity of the optimized DH-TENV gel was assessed based on the RA-specific marker anti-cyclic cirtullinated peptide antibody (anti-CCP), the cartilage destruction marker cartilage oligomeric matrix protein (COMP) and the inflammatory marker interleukin-6 (IL-6). Level of tissue receptor activator of nuclear factor kappa-Β ligand (RANKL) were also assessed. RESULTS: The optimized DH-TENV formulation involved spherical nanovesicles that had an appropriate EE- % and skin permeation characteristic. The DH-TENV gel was well tolerated by rats. The pharmacokinetics analysis showed that the optimized DH-TENV gel boosted the bioavailability of the DH by 2.42- and 4.16-fold compared to the oral DH solution and the control DH gel, respectively. Moreover, it significantly reduced the serum anti-CCP, COMP and IL-6 levels and decreased the RANKL levels. Furthermore, the DH-TENV gel attenuated histopathological changes by almost normalizing the articular surface and synovial fluid. CONCLUSION: The results indicate that DH-TENVs can improve transdermal delivery of DH and thereby alleviate RA.

Phototoxic risk assessment of dermally-applied chemicals with structural variety based on photoreactivity and skin deposition.

Combined use of photochemical and pharmacokinetic (PK) data for phototoxic risk assessment was previously proposed, and the system provided reliable phototoxic risk predictions of chemicals in same chemical series. This study aimed to verify the feasibility of the screening system for phototoxic risk assessment on dermally-applied chemicals with wide structural diversity, as a first attempt. Photochemical properties of test chemicals, 2-acetonaphthalene, 4'-methylbenzylidene camphor, 6-methylcoumarin, methyl N-methylanthranilate, and sulisobenzone, were evaluated in terms of UV absorption and reactive oxygen species (ROS) generation, and PK profiles of the test chemicals in rat skin were characterized after dermal co-application. All test chemicals showed strong UVA/B absorption with molar extinction coefficients of over 3000 M-1⋅cm-1, and irradiated 2-acetonaphthalene, 6-methylcoumarin, and methyl N-methylanthranilate exhibited significant ROS generation. Dermally-applied 2-acetonaphthalene and 4'-methylbenzylidene camphor indicated high and long-lasting skin deposition compared with the other test chemicals. Based on the photochemical and PK data, 2-acetonaphthalene was predicted to have potent phototoxic risk. The predicted phototoxic risk of the test chemicals by integration of obtained data was mostly consistent with their in vivo phototoxicity observed in rat skin. The screening strategy employing photochemical and PK data would have high prediction capacity and wide applicability for photosafety evaluation of chemicals.

Native and synchronous fluorescence spectroscopy for determination of avanafil in presence of its co-formulated drug (dapoxetine hydrochloride): Application to pharmaceutical product, biological fluid and content uniformity.

The native and synchronous fluorescence spectroscopy procedures have been established and validated for the simultaneous determination of a binary mixture of dapoxetine hydrochloride (DAP) and avanafil (AVA). The first procedure is based on measurement of native fluorescence intensity of both drugs at λEm 337 nm and 370 nm using λEx 290 nm and 314 nm for DAP and AVA in methanol respectively. The second procedure describes a measurement of synchronous fluorescence intensity of these drugs at 232 nm for DAP, and 267 nm for AVA, using Δλ of 90nm. In the first procedure the fluorescence concentration were 0.1-4.0 µg/mL for DAP and 0.5-16 µg/mL for AVA. For the second procedure fluorescence concentrations were 0.025-1.0 µg/mL and 0.5-16 µg/mL for DAP and AVA respectively, with lower detection limit and quantification limits. The processes were successfully used for the limitation of DAP and AVA in their drug product without pre-separation. Then, the techniques were utilized for the determination of DAP and AVA in biological fluids. There is a good agreement between these results and the results obtained using a reference method.

Zein-alpha lipoic acid-loaded nanoparticles to enhance the oral bioavailability of dapoxetine: optimization and clinical pharmacokinetic evaluation.

BACKGROUND: Premature ejaculation (PE) is the most common type of male sexual disorder with important psychological consequences. Dapoxetine (DPX), a recently approved drug for the treatment of PE, suffers from low bioavailability with large variability that ranges from 15-76% (mean 42%) after oral administration. The objective of this study is to optimize the parameters for the preparation of DPX-Zein-alpha lipoic acid (ALA) nanoparticles (NPs) to improve the bioavailability of DPX and consequently decrease therapeutic dose and adverse effect, leading to patient satisfaction and compliance. METHODS: We investigated the effect of ALA concentration, PVA concentration and stirring rate on nanoparticle size (Y1), zeta potential (Y2), initial DPX release (Y3) and cumulative DPX release (Y4). In addition, in vivo pharmacokinetic study was performed for the optimized DPX formulation on human healthy volunteers compared with marketed DPX tablet. RESULTS: The optimized DPX-loaded NPs showed Y1, Y2, Y3, and Y4 of 159.24 nm, 19.14 mV, 25.31% and 95.9 %, respectively. A single oral dose of 30 mg of optimized DPX-loaded NPs to human volunteers resulted in 2-fold improvement of AUC (1376.145±339.592 vs 709.178±146.307 in DPX), 4-fold increase in tmax (2.5±0.314 vs 0.583±0.144), prolongation of MRT (7.637±1.373 compared to 6.031±1.826 h), but with reduction in t1/2 (5.283±1.077 vs 8.452±2.813). CONCLUSION: The clinical findings suggest 194% enhancement of relative bioavailability of the optimized DPX-loaded NPs, potentially leading to a decrease in therapeutic dose and associated side effects in the treatment of PE.

Toxicokinetic Interaction between Hepatic Disposition and Pulmonary Bioactivation of Inhaled Naphthalene Studied Using Cyp2abfgs-Null and CYP2A13/2F1-Humanized Mice with Deficient Hepatic Cytochrome P450 Activity.

Previous studies using Cyp2abfgs-null (lacking all genes of the Cyp2a, 2b, 2f, 2g, and 2s subfamilies), CYP2A13/2F1-humanized, and liver-Cpr-null (LCN) mice showed that although hepatic cytochrome P450 (P450) enzymes are essential for systemic clearance of inhaled naphthalene (a possible human carcinogen), both hepatic and extrahepatic P450 enzymes may contribute to naphthalene-induced lung toxicity via bioactivation. Herein, we aimed to further understand the toxicokinetics of inhaled naphthalene in order to provide a basis for predicting the effects of variations in rates of xenobiotic disposition on the extent of target tissue bioactivation. We assessed the impact of a hepatic deficit in naphthalene metabolism on the toxicokinetics of inhaled naphthalene using newly generated Cyp2abfgs-null-and-LCN and CYP2A13/2F1-humanized-and-LCN mice. We determined plasma, lung, and liver levels of naphthalene and naphthalene-glutathione conjugate, a biomarker of naphthalene bioactivation, over time after naphthalene inhalation. We found that the loss of hepatic naphthalene metabolism severely decreased naphthalene systemic clearance and caused naphthalene to accumulate in the liver and other tissues. Naphthalene release from tissue, as evidenced by the continued increase in plasma naphthalene levels after termination of active inhalation exposure, was accompanied by prolonged bioactivation of naphthalene in the lung. In addition, transgenic expression of human CYP2A13/2F1 in the respiratory tract caused a reduction in plasma naphthalene levels (by 40%, relative to Cyp2abfgs-null-and-LCN mice) and corresponding decreases in naphthalene-glutathione levels in the lung in mice with hepatic P450 deficiency, despite the increase in local naphthalene-bioactivating P450 activity. Thus, the bioavailability of naphthalene in the target tissue has a significant effect on the extent of naphthalene bioactivation in the lung. SIGNIFICANCE STATEMENT: In this study, we report several novel findings related to the toxicokinetics of inhaled naphthalene, the ability of which to cause lung carcinogenesis in humans is a current topic for risk assessment. We show the accumulation of naphthalene in the liver and lung in mice with compromised hepatic cytochrome P450 (P450) activity; the ability of tissue-stored naphthalene to redistribute to the circulation after termination of active inhalation exposure, prolonging exposure of target tissues to naphthalene; and the ability of non-CYP2ABFGS enzymes of the lung to bioactivate naphthalene. These results suggest potentially large effects of deficiencies in hepatic P450 activity on naphthalene tissue burden and bioactivation in human lungs.

A Randomized, Placebo-Controlled, Double-Blind, Dose Escalation, Single Dose, and Steady-State Pharmacokinetic Study of 9cUAB30 in Healthy Volunteers.

9cUAB30 is a synthetic analogue of 9-cis retinoic acid with chemoprevention activity in cell lines and animal models. The purpose of this phase I placebo-controlled, double-blinded, dose escalation study of 9cUAB30 was to evaluate its safety, pharmacokinetics, and determine a dose for future phase II studies. Participants received a single dose of study drug (placebo or 9cUAB30) on day 1 followed by a 6-day drug-free period and then 28 days of continuous daily dosing starting on day 8. Fifty-three healthy volunteers were enrolled into five dose cohorts (20, 40, 80, 160, and 240 mg). Participants were randomized within each dose level to receive either 9cUAB30 (n = 8) or placebo (n = 2). 9cUAB30 was well tolerated, with no dose limiting toxicities reported and no evidence of persistent elevations in serum triglycerides or cholesterol. Treatment-emergent grade 3 hypertension occurred in 1 of 8 participants at the 20 mg dose level and in 2 of 8 at the 240 mg dose level, all considered unlikely related to study agent; no other grade 3 adverse events were observed. The AUC increased, as expected, between day 1 (single dose) and day 36 (steady state). Pharmacokinetics were linear in dose escalation through 160 mg. 9cUAB30 administered by daily oral dosing has a favorable safety and pharmacokinetic profile. On the basis of the observed safety profile and lack of linearity in pharmacokinetics at doses greater than 160 mg, the recommended phase II dose with the current formulation is 160 mg once daily.

15N-labelled nitrite/nitrate tracer analysis by LC-MS/MS: Urinary and fecal excretion of nitrite/nitrate following oral administration to mice.

Determination of the modulation of nitrite and nitrate levels in biological samples usually poses a major challenge, owing to their high background concentrations. To effectively investigate the variation of nitrite/nitrate in vivo, in this study, we developed a15N-labelled nitrite/nitrate tracer analysis using LC-MS/MS following the derivatization with 2,3-diaminonaphthalene. This method allows for the determination of 15N-labelled nitrite/nitrate as 15N-2,3-naphthotriazole (15N-NAT) that can efficiently differentiate newly introduced nitrite/nitrate from the background nitrite/nitrate in biological matrices. We also investigated the contribution of background 14N-NAT isotopomers to 15N-NAT, which has long been overlooked in the literature. Our results indicated that the contribution of background 14N-NAT isotopomers to 15N-NAT is significant. Such contribution is constant (~2.2% under positive ion mode and 1.1% under negative ion mode), and does not depend upon the concentration of 14N-NAT or the sample matrix measured. An equation has been therefore developed, for the first time, to correct the contribution of background 14N-NAT isotopomers to 15N-NAT. With the proposed 15N-labelled nitrite/nitrate tracer analysis, the amount and percentage distribution of 15NO2- and 15NO3-, both in urine and feces, after oral administration of 15N-labelled nitrite/nitrate are clearly demonstrated. The excretions of 15NO2- and 15NO3- were significantly increased with the increasing dose implying that the dietary nitrite/nitrate intake is an important source in urine/feces. The present method allows for the simple, reliable and accurate quantification of 15NO2- and 15NO3-, and it should also be useful to trace the biotransformation of nitrite and nitrate in vivo.

A population pharmacokinetic analysis of the oral CYP17 lyase and androgen receptor inhibitor seviteronel in patients with advanced/metastatic castration-resistant prostate cancer or breast cancer.

PURPOSE: Seviteronel is an orally-administered selective cytochrome P450c17a 17,20-lyase and androgen receptor inhibitor with anti-tumor activity in vitro and in vivo, and clinical activity in men with advanced castration-resistant prostate cancer (CRPC) and men and women with advanced breast cancer. The purpose of this study was to assess the pharmacokinetics (PK) of seviteronel across the aforementioned populations. METHODS: This report describes the PK of seviteronel (50-750 mg, QD or BID) using noncompartmental and population approaches from 243 patients with advanced breast or prostate cancer pooled across 4 clinical studies. First dose and steady-state PK were examined, as well as covariates including prandial status, sex and concomitant dexamethasone. RESULTS: Seviteronel PK can be characterized by transit absorption and a bi-phasic first-order elimination while accounting for covariance between random effects. Prandial status did not significantly affect any parameters to a clinically-relevant extent. Both sex and body weight were significant covariates on clearance, explaining 37% of the interindividual variability on that parameter. There were no significant effects from the race or the presence of a corticosteroid (either dexamethasone or prednisone). CONCLUSIONS: Seviteronel demonstrates linear PK over the dose range of 50-750 mg given either BID or QD in men with advanced CRPC or men and women with breast cancer. The disposition of seviteronel following oral administration is well described by this population PK model and can be used for accurate simulations for future studies with body weight and sex affecting clearance, but not to a clinically-meaningful degree requiring a change in the current dosing scheme.

Distribution of the (synthetic) cannabinoids JWH-210, RCS-4, as well as ∆9-tetrahydrocannabinol following pulmonary administration to pigs.

New psychoactive substances, especially synthetic cannabinoids (SC), are gaining increasing relevance in postmortem forensic toxicology. Particularly, the interpretation of analytical results is challenging, as usually, no toxicokinetic (TK) data concerning distribution in organs and tissues are available. Thus, a controlled pig TK study allowing for examination of organ and tissue distribution of SC was performed. For this purpose, 12 pigs received a single pulmonary dose of 200 µg/kg body weight each of 4-ethylnaphthalene-1-yl-(1-pentylindole-3-yl)methanone (JWH-210), 2-(4-methoxyphenyl)-1-(1-pentylindole-3-yl)methanone (RCS-4), and Δ9-tetrahydrocannabinol (THC) via an ultrasonic nebulizer. Eight hours after administration, the animals were put to death by the administration of T61. Thereupon, relevant organs, important body fluids such as bile and colon content, and tissues such as muscle tissue were collected. After enzymatic hydrolysis and solid-phase extraction, analysis was performed by liquid chromatography-tandem mass spectrometry. For quantification, a standard addition method was applied. The parent compounds could be detected in every analyzed specimen with the exception of colon content. Regarding JWH-210, the kidneys and lungs are viable matrices for postmortem analysis. In terms of RCS-4, the lungs were found to be an appropriate matrix. Concerning THC, the liver, bile fluid as well as duodenum content were suitable matrices for detection. Metabolites were only detected in tissues/body fluids involved in metabolism and/or elimination. Bile fluid and duodenum content were shown, as the most appropriate specimens for quantification of metabolites.