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.

3,3'-Diselenodipropionic acid (DSePA) forms 1:1 complex with Hg (II) and prevents oxidative stress in cultured cells and mice model.

Mercury is one of the most toxic heavy metal for mammals particularly in inorganic form. In present study, 3,3'-diselenodipropionic acid (DSePA), a well-known pharmacological diselenide was evaluated for its interaction with HgCl2 and ability to prevent HgCl2-induced toxicity in experimental cellular and mice models. UV-visible, stopped flow, Fourier-transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy studies confirmed that DSePA sequestered Hg (II) ions with stoichiometry of 1:1 and binding constant of ~104 M-1. X-ray photoelectron spectroscopy and X-ray powder diffraction analysis suggested that diselenide group of DSePA was involved in the complexation with Hg (II) ions. Further, Hg-DSePA complex degraded within 10 days to form excretable HgSe. The binding constant of DSePA and Hg (II) was comparable with that of dihydrolipoic acid, a standard disulfide compound used in heavy metal detoxification. Corroborating these observations, pre-treatment of DSePA (10 µM) significantly prevented the HgCl2 (50 µM)-induced glutathione oxidation (GSH/GSSG), decrease of thioredoxin reductase (TrxR) and glutathione peroxidase (GPx) activities and cell death in Chinese Hamster Ovary (CHO) cells. Similarly, intraperitoneal administration of DSePA at a dosage of 2 mg/kg for 5 consecutive days prior to exposure of HgCl2 (1 mg/kg) significantly suppressed oxidative stress in renal and hepatic tissues of C57BL/6 mice. In conclusion, the protective effect of DSePA against Hg induced oxidative stress is attributed to its ability to rescue the activities of GPx, TrxR and GSH by sequestering Hg (II) ions. DSePA being a relatively safer selenium-compound for in vivo administration can be explored for mercury detoxification.

Discovery of LYC-55716: A Potent, Selective, and Orally Bioavailable Retinoic Acid Receptor-Related Orphan Receptor-γ (RORγ) Agonist for Use in Treating Cancer.

Retinoic acid receptor-related orphan receptor γ (RORc, RORγ, or NR1F3) is the nuclear receptor master transcription factor that drives the function and development of IL-17-producing T helper cells (Th17), cytotoxic T cells (Tc17), and subsets of innate lymphoid cells. Activation of RORγ+ T cells in the tumor microenvironment is hypothesized to render immune infiltrates more effective at countering tumor growth. To test this hypothesis, a family of benzoxazines was optimized to provide LYC-55716 (37c), a potent, selective, and orally bioavailable small-molecule RORγ agonist. LYC-55716 decreases tumor growth and enhances survival in preclinical tumor models and was nominated as a clinical development candidate for evaluation in patients with solid tumors.

Upacicalcet: First Approval.

Upacicalcet (UPASITA®) is an intravenous calcimimetic agent being developed by Sanwa Kagaku Kenkyusho, under license from EA Pharma, for the treatment of secondary hyperparathyroidism (SHPT), a common and early complication of chronic kidney disease, in patients undergoing haemodialysis. By acting directly on parathyroid cell membrane calcium-sensing receptors, upacicalcet suppresses excessive parathyroid hormone (PTH) secretion, thereby lowering blood PTH levels. Upacicalcet received its first approval on 23 June 2021 for the treatment of SHPT in adults undergoing haemodialysis in Japan. It is administered intravenously three times per week into the venous side of the haemodialysis circuit at the time of blood return at the end of the haemodialysis session. The generally recommended starting dose of upacicalcet is 25 µg, with the dose adjusted within a 25-300 µg range based on PTH and serum calcium levels. This article summarizes the milestones in the development of upacicalcet leading to this first approval for the treatment of SHPT in patients undergoing haemodialysis.

GW9508 ameliorates cognitive dysfunction via the external treatment of encephalopathy in Aß1-42 induced mouse model of Alzheimer's disease.

The functions and mechanisms of GPR40 receptor to ameliorating the Alzheimer's disease (AD) by external treatment of encephalopathy remain unknown. In present study, the typical Aß1-42 induced mice model was applied to explore the functions and mechanisms of GPR40 receptor by external treatment of encephalopathy in AD. GPR40 agonist GW9508 and antagonist GW1100 were given by i.g injection to activate/inhibit the GPR40 receptor respectively in the gut of AD mouse which illustrated the function and mechanism of GPR40 receptor in ameliorating AD symptoms by external treatment of encephalopathy. A series of behavioral experiments were used to investigate the cognitive function and memory ability of mice, while molecular biology experiments such as Western blot, ELISA, flow cytometry were used to detect the corresponding changes of signaling pathways. The results revealed that intragastric administrated GW9508 could significantly ameliorate cognitive deficits of AD mouse, up-regulate the expression levels of gut-brain peptides both in blood circulation and hypothalamus thus up-regulate the expression levels of α-MSH in hypothalamus, while the negative autophagy-related proteins and inflammation-related proteins were down-regulated correspondingly. Meanwhile, GW9508 could also inhibit the pathological process of neuroinflammation in microglia. GW1100 reversed the effects of GW9508 significantly. These results suggested that GPR40 was an underlying therapeutic target for the external treatment of encephalopathy related to AD and GPR40 agonist could be explored as the emerging AD therapeutic drug.

Identification of selective ligands targeting two GPCRs by receptor-affinity chromatography coupled with high-throughput sequencing techniques.

The rapid growth of demands for drug discovery has necessitated the ongoing pursuit of new methods for specific ligands screening and identification. This work combined receptor-affinity chromatography (RAC) with high-throughput sequencing techniques to rapidly screen and identify the specific ligands. By this method, immobilized angiotensin II type I receptor (AT1R) and endothelin receptor A (ETAR) based on RAC were utilized for lead screening from a DNA-encoded library. The specific ligands of AT1R (ligand A1, A2) and ETAR (ligand B1, B2) were synthesized after decoding by high-throughput sequencing techniques. The dissociation rate constants (kd) of ligand A1, A2 to AT1R and B1, B2 to ETAR were 9.65 × 10-4, 31.1 × 10-4 and 0.66, 1.22 s-1 by peak profiling assay. The association constant (KA) to the receptors of four ligands was 5.4 × 106, 3.3 × 106 and 1.6 × 106, 2.2 × 105 by injection amount dependent method. The kinetic and thermodynamic parameters of the four specific ligands are similar to those of the positive drugs. This indicates that they are promising to drug candidates. The druggability of the four ligands through pharmacokinetic investigation by HPLC-MS/MS presented desired pharmacokinetic behavior including the fast absorption, the relatively slow elimination. These results, taking together, indicated that the RAC combined with high-throughput sequencing techniques can screen and identify the specific ligands according to various proteins, thus creating a general strategy for rapid discovery of promising drug candidates.

A Phase 1 Study to Investigate the Effects of Cortexolone 17α-Propionate, Also Known as Clascoterone, on the QT Interval Using the Meal Effect to Demonstrate ECG Assay Sensitivity.

Cortexolone 17α-propionate, also known as clascoterone, is a potent androgen receptor inhibitor intended for the topical treatment of skin diseases associated with androgenic pathway alterations. In nonclinical studies, cortexolone 17α-propionate was found to have a weak inhibitory effect on human Ether-à-go-go-Related Gene (hERG) potassium channels, which are vital for normal electrical activity in the heart. When used in a cream formulation, little cortexolone 17α-propionate is absorbed. However, the solution formulation developed for the treatment of androgenetic alopecia leads to a measurable systemic concentration and accumulation of the antiandrogen. This phase 1 study assessed the effect of cortexolone 17α-propionate on the QTc interval using concentration-effect analysis and the effect of a meal on QTc to confirm assay sensitivity. Thirty-two volunteers were randomly assigned to receive the active drug or a matching vehicle as placebo. Participants were dosed twice daily on days 1 to 3 (225 mg applied topically as a 7.5% solution 12 hours apart) and once on day 4. Pharmacokinetic and electrocardiogram assessments were performed after supratherapeutic doses. Assay sensitivity was successfully confirmed by using the food effect on the QTc interval. The results of this concentration-QTc analysis demonstrate that cortexolone 17α-propionate and its metabolite/degradation product had no effect on the QTc interval in the concentration range tested.

A Data-Mining Approach for the Quantitative Assessment of Physicochemical Properties of Molecular Compounds in the Skin Flux.

This paper aimed to provide an insight into the mechanism of transdermal penetration of drug molecules with respect to their physicochemical properties, such as solubility (S), the presence of enantiomer (ET) and logarithm of octanol-water partition coefficient (log P), molecular weight (MW), and melting point (MP). Propionic acid derivatives were evaluated for their flux through full-thickness skin excised from hairless mice upon being delivered from silicone-based pressure-sensitive adhesive (PSA) matrices in the presence or absence of various enhancers. The skin fluxes of model compounds were calculated based on the data obtained using the method engaged with the diffusion cell system. The statistical design of experiments (DoE) based on the factorial approach was used to find variables that have a significant impact on the outcomes. For the prediction of skin flux, a quantitative equation was derived using the data-mining approach on the relationship between skin permeation of model compounds (~125 mg/ml) and involved physicochemical variables. The most influential variables for the skin flux of propionic acid derivatives were the melting point (0.97) followed by the presence of enantiomer (0.95), molecular mass (0.93), log P values (0.86), and aqueous solubility (0.80). It was concluded that the skin flux of molecular compounds can be predicted based on the relationship between their physicochemical properties and the interaction with cofactors including additives and enhancers in the vehicles.

Structure-Activity Relationship Study and Biological Evaluation of 2-(Disubstituted phenyl)-indole-5-propanoic Acid Derivatives as GPR40 Full Agonists.

G-protein-coupled receptor 40 (GPR40) is considered as an attractive drug target for treating type 2 diabetes, owing to its role in the free fatty acid-mediated increase in glucose-stimulated insulin secretion (GSIS) from pancreatic ß-cells. To identify a new chemotype of GPR40 agonist, a series of 2-aryl-substituted indole-5-propanoic acid derivatives were designed and synthesized. We identified two GPR40 agonist lead compounds-4k (3-[2-(4-fluoro-2-methylphenyl)-1H-indol-5-yl]propanoic acid) and 4o (3-[2-(2,5-dimethylphenyl)-1H-indol-5-yl]propanoic acid), having GSIS and glucagon-like peptide 1 secretory effects. Unlike previously reported GPR40 partial agonists that only activate the Gq pathway, 4k and 4o activated both the Gq and Gs signaling pathways and were characterized as GPR40 full agonists. In in vivo efficacy studies, 4o significantly improved glycemic control in both C57BL/6J and db/db mice and increased plasma-active GLP-1 in C57BL/6J mice. Thus, 4o represents a promising lead for further development as a novel GPR40 full agonist against type 2 diabetes.

One step assembly of ginsenoside Rb1-based nanovehicles with fast cellular transport in photothermal-chemical combined cancer therapy.

Nowadays, the research of photothermal-chemical co-therapy provides new ideas for the treatment of cancer. However, the harsh photothermal temperature hinders the clinical development of photothermal therapy. To ensure low-temperature photothermal-chemical combined therapy, a safe and feasible drug delivery system is highly desirable. Herein, through one step co-precipitation method, ginsenoside Rb1-based nanovehicles composed of the hydrophobic drug doxorubicin, the photochemical reagent Cypate and the heat shock protein inhibitor gambogic acid was prepared, resulting from the amphiphilicity and membrane permeability of Rb1. Encouragingly, this platform exhibited excellent biocompatibility and rapid cellular uptake, both of which led to significant and irreversible death of breast cancer cells under the trigger of short-term near-infrared light.

Pharmacokinetics and Safety of Chiglitazar, a Peroxisome Proliferator-Activated Receptor Pan-Agonist, in Patients < 65 and ≥ 65 Years With Type 2 Diabetes.

The effect of age on the pharmacokinetics and safety of chiglitazar was evaluated in patients < 65 and ≥ 65 years with type 2 diabetes mellitus (T2DM). A total of 20 T2DM patients (<65 vs ≥65 years 1:1) completed the study. Patients received multiple doses of 48 mg chiglitazar once daily for 7 days consecutively. After the first dosing, chiglitazar maximum plasma concentration (Cmax ) and area under the plasma concentration-time curve (AUC) in patients ≥ 65 years were similar to those observed in patients < 65 years, with the geometric mean ratio (GMR) for Cmax and AUC being 97.22% and 96.83%, respectively. No significant difference was observed in Cmax (GMR, 97.23%) in the steady state. Compared with the patients < 65 years, a slight increase (8%-13%) of AUC was observed in the patients ≥ 65 years after multiple doses. Chiglitazar was generally well tolerated following multiple doses in both age groups. In conclusion, there were no significant clinical influences on the pharmacokinetic properties and safety profiles of chiglitazar between patients with T2DM < 65 and ≥ 65 years, indicating that in the future it is not required to adjust the dosing regimen by age for T2DM patients ≥ 65 years.

3,3'-Diselenodipropionic acid (DSePA): A redox active multifunctional molecule of biological relevance.

BACKGROUND: Extensive research is being carried out globally to design and develop new selenium compounds for various biological applications such as antioxidants, radio-protectors, anti-carcinogenic agents, biocides, etc. In this pursuit, 3,3'-diselenodipropionic acid (DSePA), a synthetic organoselenium compound, has received considerable attention for its biological activities. SCOPE OF REVIEW: This review intends to give a comprehensive account of research on DSePA so as to facilitate further research activities on this organoselenium compound and to realize its full potential in different areas of biological and pharmacological sciences. MAJOR CONCLUSIONS: It is an interesting diselenide structurally related to selenocystine. It shows moderate glutathione peroxidase (GPx)-like activity and is an excellent scavenger of reactive oxygen species (ROS). Exposure to radiation, as envisaged during radiation therapy, has been associated with normal tissue side effects and also with the decrease in selenium levels in the body. In vitro and in vivo evaluation of DSePA has confirmed its ability to reduce radiation induced side effects into normal tissues. Administration of DSePA through intraperitoneal (IP) or oral route to mice in a dose range of 2 to 2.5 mg/kg body weight has shown survival advantage against whole body irradiation and a significant protection to lung tissue against thoracic irradiation. Pharmacokinetic profiling of DSePA suggests its maximum absorption in the lung. GENERAL SIGNIFICANCE: Research work on DSePA reported in fifteen years or so indicates that it is a promising multifunctional organoselenium compound exhibiting many important activities of biological relevance apart from radioprotection.

Clascoterone: First Approval.

Clascoterone (Winlevi®) is an androgen receptor inhibitor being developed as a topical cream and solution by Cassiopea (a spin-out company of Cosmo Pharmaceuticals) for the treatment of androgen-dependent skin disorders, including androgenetic alopecia and acne vulgaris. Although the exact mechanism of action of clascoterone for the topical treatment of acne vulgaris is unknown, the drug is believed to compete with the androgen dihydrotestosterone for binding to androgen receptors in the sebaceous gland and hair follicles to attenuate signalling necessary for acne pathogenesis. In August 2020, clascoterone cream 1% received its first approval in the USA for the topical treatment of acne vulgaris in patients 12 years of age or older. Clinical studies of a different formulation of clascoterone (a solution containing a higher concentration of the drug) for the treatment of androgenetic alopecia are underway in Germany and the USA. This article summarizes the milestones in the development of clascoterone leading to this first approval for the topical treatment of acne vulgaris.

The modulating effect of lipid bilayer/p-coumaric acid interactions on electrical properties of model lipid membranes and human glioblastoma cells.

Biological membranes are one of the most important elements of living cells determining their permeability to the active compounds. Still, little is known about the drug-membrane interactions in terms of pharmacological properties of potential drugs. Chemoprevention based on natural compounds is becoming a strong trend in modern oncopharmacology, and p-coumaric acid (p-CoA) is one such compound with tentative anticancer activity. The microelectrophoretic mobility measurements and electrochemical impedance spectroscopy were applied to study the effects of p-CoA on electrical properties of liposomes, spherical bilayers, and human glioblastoma cell membranes. Our results demonstrated that after treatment with p-CoA, the surface charge of LBC3, LN-229 and LN-18 cell lines was significantly changed in alkaline pH solutions, but not in acidic pH solutions. In contrast, no changes in surface charge density values were registered for phosphatidylethanolamine liposomal membranes and A172 cell membranes after p-CoA treatment. The impedance data showed an increase in values of both the electrical capacitance and the electrical resistance, indicating that p-CoA can be partially inserted into the phosphatidylcholine bilayers. The MTT assay showed cell line-dependent cytotoxic effect of p-CoA. Further molecular analyses revealed the ATP depletion and gene transcription modulation, which might indicate organelle membrane-crossing potential of p-CoA. These results suggest, that changes in surface charge of membranes of living cells not only might be potential predictor of membrane permeability, but also indicate differential composition of cell membranes in various cell lines. Thus further multidirectional analyses are required to implement electrochemical methods as standard testing procedures during drug development process.

Formulation and Pharmacokinetic Evaluation of Phosal Based Zaltoprofen Solid Self-Nanoemulsifying Drug Delivery System.

BACKGROUND: Phosal based excipients are liquid concentrates containing phospholipids. They are used to solubilize water-insoluble drug and also act as an emulsifier to get the smallest droplet size of the formed emulsion after administration. OBJECTIVE: The aim is to prepare phosal based self nanoemulsifying drug delivery system (SNEDDS) for water insoluble drug zaltoprofen. METHODS: The various parameters like solubility of drug in different vehicles, ternary phase diagram are considered to formulate the stable emulsion which is further characterized by Self emulsification time and globule size analysis to optimize liquid SNEDDS of Zaltoprofen. Optimized L-SNEDDS was converted into free-flowing powder Solid-SNEDDS (S-SNEDDS). S-SNEDDS was evaluated for Globule size analysis after reconstitution, in vitro dissolution study and in vivo pharmacokinetic study in rats. RESULTS: Phosal 53 MCT with highest drug solubility was used as oil along with Tween 80 and PEG 400 as surfactant and cosurfactant respectively to prepare liquid SNEDDS. Neusilin us2 was used as an adsorbent to get free-flowing S-SNEDDS. S-SNEDDS showed improved dissolution profile of the drug as compared to pure drug. In vivo study demonstrated that there is a significant increase in Cmax and AUC of S-SNEDDS compared to zaltoprofen powder. CONCLUSION: Phosal based SNEDDS formation can be successfully used to improve the dissolution and oral bioavailability of poorly soluble drug zaltoprofen.

Pharmacokinetic Profile, Safety, and Tolerability of Clascoterone (Cortexolone 17-alpha propionate, CB-03-01) Topical Cream, 1% in Subjects With Acne Vulgaris: An Open-Label Phase 2a Study

Clascoterone (cortexolone 17α-propionate, CB-03-01) 1% cream, a topical, androgen receptor (AR) inhibitor under investigation for the treatment of acne vulgaris, is rapidly metabolized to cortexolone in human plasma. The primary objectives of this study were to determine the pharmacokinetic (PK) properties and adrenal suppression potential of clascoterone topical cream, 1% in subjects with acne vulgaris. Study Design: This study was an open-label, multicenter study in 42 subjects ≥12 years of age with moderate-to-severe acne (Grade 3-4 on the Investigator's Global Assessment [IGA]), on the face, chest and/or back. Cohort 1(>18 years of age) and Cohort 2 (12-18 years of age) applied clascoterone topical cream, 1% twice daily (BID) for 14 days. Primary safety endpoints included hypothalamic-pituitary-adrenal (HPA) axis response to cosyntropin via a Cosyntropin Stimulation Test (CST) upon screening (day 1) and at day 14 (HPA axis suppression was defined as a post-stimulation serum cortisol level <18 µg/dL at day 14); and PK evaluation including concentration-time profiles of clascoterone and cortexolone in plasma­PK parameters were determined using "non-compartmental" analysis. Secondary safety endpoints included clinical laboratory testing, local and systemic adverse events (AEs), physical examination/vital signs, and electrocardiogram (ECG). Results: 42 subjects (Cohort 1=20, Cohort 2= 22) enrolled. Cohort 1 was comprised of 15 females (15/20, 75%) and 5 males (5/20, 25%), non-Hispanic/Latino (20/20, 100%), mean age is 24.4 years. Cohort 2 was comprised of 12 females (12/22, 54.5%) and 10 males (10/22, 45.5%), non-Hispanic/Latino (21/22, 95.5%), and mean age is 15.6 years. Three subjects (3/42,7%), 1 adult and 2 adolescents, demonstrated an abnormal HPA axis response with post-stimulation serum cortisol levels ranging from 14.9 to 17.7 µg/dL at day 14. All returned to normal HPA axis function, four weeks after day 14. None showed clinical evidence of adrenal suppression. Clascoterone plasma concentrations achieved PK steady-state by day 5. Clascoterone systemic exposure was similar between both cohorts. At steady-state, plasma concentrations increased ~1.8 to 2.1 fold versus first dose with mean (coefficient of variation [CV] %) maximum plasma concentrations of 4.4 ng/mL (67%) and 4.6 ng/mL (103%) in Cohort 1 and Cohort 2, respectively. Cortexolone plasma concentrations trended below the lower limit of quantitation (0.5 ng/mL) in both cohorts. Local skin reactions (LSRs) were mostly mild, with only one moderate case of pruritus. There were nine AEs categorized as follows: definitely related (N=2), probably related (N=4), unlikely/not related (N=3), to clascoterone. Conclusion: This study demonstrates the safety and tolerability of clascoterone topical cream, 1% in adolescents and adults with acne vulgaris treated BID for 14 consecutive days. J Drugs Dermatol. 2019;18(6):563-568.

Pharmacokinetics, Safety and Tolerability of Chiglitazar, A Novel Peroxisome Proliferator-Activated Receptor (PPAR) Pan-Agonist, in Healthy Chinese Volunteers: A Phase I Study.

BACKGROUND AND OBJECTIVES: Chiglitazar is a novel configuration-restricted non-thiazolidinedione peroxisome proliferator-activated receptor pan-agonist currently in the Phase III clinical development stage for type 2 diabetes mellitus patients. The objective of this Phase I study was to evaluate the pharmacokinetics, safety and tolerability of single and multiple doses of chiglitazar tablets taken orally and the effect of food on its pharmacokinetics in healthy Chinese subjects. METHODS: A single-centre, open-label, randomised, two-stage Phase I study was carried out. In the first-stage study, we evaluated a single dose of 8, 16, or 32 mg, and multiple doses of 16 mg, taken once daily for 9 days. The effect of food consumption was also studied in this stage. In the second-stage study, a greater range of single doses (24, 48 or 72 mg) were further evaluated. Pharmacokinetics, safety and tolerability profiles were assessed at each study stage. RESULTS: After a single oral dose of chiglitazar, at doses ranging from 8 to 72 mg, the maximum plasma concentration (Cmax) and area under the concentration-time curve (AUC) were proportionally increased (165-1599 ng/mL for the mean Cmax and 1356-12,584 ng·h/mL for the mean AUC0-t), with low inter-subject variability. There were no significant changes in the mean terminal phase half-life (t1/2), which ranged from 9.0 to 11.9 h, and the clearance and volume of distribution were similar for all evaluated doses. The results from the examination of multiple dose of 16 mg once daily for nine consecutive days showed that a steady-state condition was achieved by Day 6. There was no apparent accumulation of chiglitazar observed at Day 9, as compared with the first administration. While food increased the AUC0-t of chiglitazar by about 13%, there were no effects on other parameters, including Cmax, Tmax and t1/2. There were no serious or severe adverse events observed in the single- or multiple-dose studies. CONCLUSIONS: Chiglitazar tablets showed a good dose-dependent linear pharmacokinetic profile in the dose range of 8-72 mg. There was no accumulation after multiple daily administration of chiglitazar at a dose of 16 mg.  High-fat/calorie food increased the absorption of the drug, but there were no significant changes in exposure and other pharmacokinetic parameters. Chiglitazar was safe and well tolerated in healthy Chinese subjects at the dose levels and administration regimens evaluated.

Pharmacokinetics and metabolism of GW9508 in rat by liquid chromatography/electrospray ionization tandem mass spectrometry.

In this study, a simple, fast and sensitive LC/MS/MS method was developed and validated for the determination of GW9508 in rat plasma. The sample was precipitated with acetonitrile and subsequently separated on ZORBAX Eclipse XDB C18 column (50 mm × 2.1 mm, 5 µm). Mobile phase was composed of 0.1% formic acid in water and acetonitrile with gradient elution, at a flow rate of 0.4 mL/min. The analyte and internal standard were quantitatively monitored with precursor-to-product transitions of m/z 348.2→183.1 and m/z 397.2→260.2, respectively. The linearity of the assay was evident in the range of 1-1000 ng/mL with correlation coefficient more than 0.998. The validation parameters were all within the acceptable limits. The validated method has been successfully applied to the pharmacokinetics study of GW9508 in rat plasma, and our results demonstrated that GW9508 showed low clearance, moderate half-life and ideal bioavailability (54.88%). Furthermore, metabolites stemmed from rat plasma, rat hepatocytes and human hepatocytes were analyzed by an LC-Q-Exactive-Orbitrap-MS assay, resulting in the identification of seven metabolites based on the accurate mass and fragment ions. Acylglucuronide conjugate (M6) was found as the most abundant metabolite in all tested matrices. The metabolic pathways were proposed as hydroxylation and glucuronidation. This study provided an overview of disposition of GW9508, which is highly instructive for better understanding the effectiveness and toxicity of this drug.

Thromboxane-prostaglandin receptor antagonist, terutroban, prevents neurovascular events after subarachnoid haemorrhage: a nanoSPECT study in rats.

BACKGROUND: Several lipid metabolites in cerebrospinal fluid are correlated with poor outcomes in aneurysmal subarachnoid haemorrhage. Most of these metabolites bind to ubiquitous thromboxane-prostaglandin (TP) receptors, causing vasoconstriction and inflammation. Here, we evaluated terutroban (TBN), a specific TP receptor antagonist, for the prevention of post-haemorrhage blood-brain barrier disruption, neuronal apoptosis and delayed cerebral hypoperfusion. METHODS: The rat double subarachnoid haemorrhage model was produced by twice injecting (days 1 and 2) autologous blood into the cisterna magna. Seventy-eight male Sprague-Dawley rats were assigned to experimental groups. Rats exposed to subarachnoid haemorrhage were allocated to no treatment (SAH group) or TBN treatment by gastric gavage during the first 5 days after haemorrhage (SAH+TBN group). Control rats received artificial cerebrospinal fluid injections (CSF group). Sham-operated rats with or without TBN administration were also studied. Body weight and Garcia neurological scores were assessed on day 2 and day 5. We used nanoscale single-photon emission computed tomography (nanoSPECT) to measure brain uptake of three radiolabelled agents: 99mTechnetium-diethylenetriaminepentacetate (99mTc-DTPA), which indicated blood-brain barrier permeability on day 3, 99mTechnetium-annexin V-128 (99mTc-Anx-V128), which indicated apoptosis on day 4, and 99mTechnetium-hexamethylpropyleneamineoxime (99mTc-HMPAO), which indicated cerebral perfusion on day 5. Basilar artery narrowing was verified histologically, and cerebral TP receptor agonists were quantified. RESULTS: 99mTc-DTPA uptake unveiled blood-brain barrier disruption in the SAH group. TBN mitigated this disruption in the brainstem area. 99mTc-Anx-V128 uptake was increased in the SAH group and TBN diminished this effect in the cerebellum. 99mTc-HMPAO uptake revealed a global decreased perfusion on day 5 in the SAH group that was significantly counteracted by TBN. TBN also mitigated basilar artery vasoconstriction, neurological deficits (on day 2), body weight loss (on day 5) and cerebral production of vasoconstrictors such as Thromboxane B2 and Prostaglandin F2α. CONCLUSIONS: Based on in vivo nanoscale imaging, we demonstrated that TBN protected against blood-brain barrier disruption, exerted an anti-apoptotic effect and improved cerebral perfusion. Thus, TP receptor antagonists showed promising results in treating post-haemorrhage neurovascular events.