Pharmacokinetics of Novel Dopamine Transporter Inhibitor CE-123 and Modafinil with a Focus on Central Nervous System Distribution

S-CE-123, a novel dopamine transporter inhibitor, has emerged as a potential candidate for cognitive enhancement. The objective of this study was to compare the tissue distribution profiles, with a specific focus on central nervous system distribution and metabolism, of S-CE-123 and R-modafinil. To address this objective, a precise liquid chromatography-high resolution mass spectrometry method was developed and partially validated. Neuropharmacokinetic parameters were assessed using the Combinatory Mapping Approach. Our findings reveal distinct differences between the two compounds. Notably, S-CE-123 demonstrates a significantly superior extent of transport across the blood-brain barrier (BBB), with an unbound brain-to-plasma concentration ratio (Kp,uu,brain) of 0.5, compared to R-modafinil's Kp,uu,brain of 0.1. A similar pattern was observed for the transport across the blood-spinal cord barrier. Concerning the drug transport across cellular membranes, we observed that S-CE-123 primarily localizes in the brain interstitial space, whereas R-modafinil distributes more evenly across both sides of the plasma membrane of the brain's parenchymal cells (Kp,uu,cell). Furthermore, our study highlights the substantial differences in hepatic metabolic stability, with S-CE-123 having a 9.3-fold faster metabolism compared to R-modafinil. In summary, the combination of improved BBB transport and higher affinity of S-CE-123 to dopamine transporters in comparison to R-modafinil makes S-CE-123 a promising candidate for further testing for the treatment of cognitive decline.

Unravelling sex-specific BPA toxicokinetics in children using a pediatric PBPK model

Bisphenol A (BPA) is a widely known endocrine disruptor (ED) found in many children's products such as toys, feeding utensils, and teething rings. Recent epidemiology association studies have shown postnatal BPA exposure resulted in developing various diseases such as diabetes, obesity, and neurodegeneration, etc., later in their lives. However, little is known about its sex-specific metabolism and consequently internal exposure. The aim of this study was to develop a sex-specific pediatric physiologically based pharmacokinetic model (PBPK) for BPA to compare their toxicokinetic differences. First, the published adult PBPK model was re-validated, and then this model was extended by interpolation to incorporate pediatric sex specific physiological and biochemical parameters. We used both the classical body weight and ontogeny-based scaling approach to interpolate the metabolic process. Then, the pharmacokinetic attributes of the models using the two-scaling approach mentioned above were compared with adult model. Further, a sex-specific PBPK model with an ontogeny scaling approach was preferred to evaluate the pharmacokinetic differences. Moreover, this model was used to reconstruct the BPA exposure from two cohorts (Helix and PBAT Cohort) from 7 EU countries. The half-life of BPA was found to be almost the same in boys and girls at the same exposure levels. Our model estimated BPA children's exposure to be about 1500 times higher than the tolerable daily intake (TDI) recently set by European Food Safety Authority (EFSA) i.e., 0.04 ng/kg BW/day. The model demonstrated feasibility of extending the adult PBPK to sex-specific pediatric, thus investigate a gender-specific health risk assessment.

Pharmacokinetics, pharmacodynamics and safety evaluation of 5,5'-methylenebis(2-acetoxybenzoic acid) in dogs following intravenous administration

Complement-mediated intravascular hemolysis occurs in canine immune-mediated hemolytic anemia (IMHA). Complement inhibitors might enhance treatment of this disease. Dimers of acetylsalicylic acid such as 5,5'-methylenebis(2-acetoxybenzoic acid) (DAS) have been reported to inhibit complement. This study aimed to characterize the pharmacokinetics and safety profile of a single 3 mg/kg IV dose of DAS in 6 healthy mixed-breed dogs. Serum concentrations of DAS and its primary metabolites were measured by liquid chromatography-tandem mass spectrometry at baseline and at 5, 10 and 30 min, and 1, 2, 4, 6, 8, 12, 18 and 24 h post-administration. Additional blood samples were collected 7 and 14 days after drug administration. Complete blood counts, serum chemistry panels, C-reactive protein measurements, coagulation testing and cytokine analyses were used for safety monitoring. Following IV administration of 3 mg/kg DAS, the estimated mean maximum plasma concentration was 54,709 ng/mL. Pharmacokinetic modeling suggested that DAS was eliminated with a half-life value of 8.1 h, equivalent to a clearance of 6.93 L/hr kg and a volume of distribution of 56 mL/kg. Plasma concentrations of the metabolites were measured rapidly (within 15-60 min for M1 and M2 respectively). Overall, the relative exposure to M1 and M2 suggest significant biotransformation of DAS occurred, but DAS was the most abundant circulating species. No adverse clinical reactions were noted following DAS administration and safety studies suggested DAS caused no inflammatory response or coagulation disturbance. Further clinical evaluation of DAS is warranted.

The Role of Glucagon in the Acute Therapeutic Effects of SGLT2 Inhibition

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) effectively lower plasma glucose (PG) concentration in patients with type 2 diabetes, but studies have suggested that circulating glucagon concentrations and endogenous glucose production (EGP) are increased by SGLT2i, possibly compromising their glucose-lowering ability. To tease out whether and how glucagon may influence the glucose-lowering effect of SGLT2 inhibition, we subjected 12 patients with type 2 diabetes to a randomized, placebo-controlled, double-blinded, crossover, double-dummy study comprising, on 4 separate days, a liquid mixed-meal test preceded by single-dose administration of either 1) placebo, 2) the SGLT2i empagliflozin (25 mg), 3) the glucagon receptor antagonist LY2409021 (300 mg), or 4) the combination empagliflozin + LY2409021. Empagliflozin and LY2409021 individually lowered fasting PG compared with placebo, and the combination further decreased fasting PG. Previous findings of increased glucagon concentrations and EGP during acute administration of SGLT2i were not replicated in this study. Empagliflozin reduced postprandial PG through increased urinary glucose excretion. LY2409021 reduced EGP significantly but gave rise to a paradoxical increase in postprandial PG excursion, which was annulled by empagliflozin during their combination (empagliflozin + LY2409021). In conclusion, our findings do not support that an SGLT2i-induced glucagonotropic effect is of importance for the glucose-lowering property of SGLT2 inhibition.

Effects of Bisphenol A on the microalga Chlamydomonas reinhardtii and the clam Corbicula fluminea

Bisphenol A (BPA) is used throughout the world and it could enter aquatic ecosystems causing harmful effects on humans, animals and plants. The current study relies on the investigation of the toxicity of this emerging pollutant on two freshwater species from different trophic levels: the microalga Chlamydomonas reinhardtii and the clam Corbicula fluminea. After 96 h of exposure to several concentrations of BPA, the growth of C. reinhardtii was affected, being the 96 h-EC₅₀ value for growth 30 mg L^-1. The toxicity and bioaccumulation of 30 mg L^-1 BPA in microalgae after 24 h of exposure were studied. Several cytotoxicity biomarkers such as vitality, oxidative stress and cytoplasmic membrane potential were altered in exposed cells and microalgae accumulated 0.16 pg BPA cell^-1. Regarding C. fluminea, four treatments were established: control without BPA (C); BPA in the food (microalgae pre-exposed for 24 h to 30 mg L^-1) (M); BPA in the water (7.5 mg L^-1) (W); BPA in both food and water (M + W). After one month of exposure, treated bivalves showed a significantly decrease in the filtration rate and increased lipid peroxidation levels, indicating fitness reduction and oxidative damage. Furthermore, the activities of catalase, glutathione reductase, Se-dependent and total glutathione peroxidase enzymes increased significantly in W and M + W treatments with respect to the control. Clams of the M + W treatment were the most affected, indicating that the little amount of BPA bioaccumulated by microalgae could increase the damage. Emerging contaminants may accumulate in several organisms, such as microalgae, and could have negative impacts on ecosystems.

Preliminary toxicokinetic study of BPA in lactating dairy sheep after repeated dietary and subcutaneous administration

Dietary intake is the predominant route of human exposure to bisphenol A and one of the important food commodities is milk. The aim of our study was to preliminarily evaluate the bisphenol A exposure and disposition in sheep milk after repeated dietary and subcutaneous administration of a relatively low dose (100 µg/kg of b. w./day) of bisphenol A to a sheep. On the basis of blood plasma sampling, milk sampling and HPLC analysis, we developed the toxicokinetic model. With the toxicokinetic model we showed that most likely only free bisphenol A passes into the mammary gland and is subsequently conjugated there. The percentage of the dose eliminated with milk was less than 0.1%, regardless of the route of bisphenol A administration. It is proven that the bisphenol A is eliminated through the milk of lactating sheep. However, the amounts excreted in the milk that were detected in this study are minimal.

Development of simultaneous determination of empagliflozin and metformin in human plasma using liquid chromatography-mass spectrometry and application to pharmacokinetics

A rapid and sensitive liquid chromatography-mass spectrometry method was developed, optimized, and validated for simultaneous quantification of empagliflozin and metformin in human plasma using empagliflozin D4and metformin D6 as an internal standard. Analytes and internal standard were extracted from plasma by optimized solid-phase extraction technique using Strata X polymeric reverse phase (30 mg-1cc) solid-phase extraction cartridges. The prepared samples were chromatographed on Orosil C18 column (150 × 4.6 mm, 3 µ). Separation was done by pumping isocratic mobile phase consisting of methanol and 10 mM ammonium trifluoroacetate (90:10, v/v) in positive ion mode at a flow rate of 0.8 mL/min. The API 3200 liquid chromatography-mass spectrometry system having turbo ion spray as an ion source coupled with Shimadzu Prominence ultrafast liquid chromatography system was operated under the selected reaction monitoring mode. Turbo ion spray ionization was used for mass transition of m/z 468.070/355.100 and m/z 130.072/71.200 for empagliflozin and metformin, respectively. A method was successfully validated for concentration range of 10.09-5013.46 ng/mL for both the analytes and according to the United States Food and Drugs Administration guidelines. The linearity was found to be in the range of 10.09-403.46 ng/mL for empagliflozin and 25.44-5013.46 ng/mL for metformin. The limit of quantification was found to be 10.09 ng/mL for empagliflozin and 25.44 ng/mL for metformin. Intra- and inter-day/between batch precision determination for empagliflozin and metformin, expressed as coefficient of variation were within the acceptance limits and ranged below 13.16%. A short run time of 3.3 min allows analysis of more than 400 plasma samples per day. The developed method was successfully applied to fasting pharmacokinetic study in healthy human volunteers. Results of incurred sample re-analysis were within the acceptance range of ±20% of original value, for 97.2% of samples reanalyzed for empagliflozin and 100% of samples reanalyzed for metformin.

Toxicokinetics and bioaccumulation characteristics of bisphenol analogues in common carp (Cyprinus carpio)

Toxicokinetics and bioconcentration of eight common bisphenol analogues, including bisphenol A (BPA), -B, -C, -E, -S, -Z, -AF, and -AP in common carp (Cyprinus carpio) were investigated. Both free (BP_free) and total forms (BP_total) of the bisphenols were measured in various fish tissues. The conjugated forms of bisphenols were calculated based on BP_free and BP_total. The calculated bioconcentration factors (BCFs) based on the total bisphenols (BP_total) in the carp whole body were in the range of 0.3-320, agreeing with previous field results from Taihu Lake, China. The elimination rate constant (k_e) positively correlated with the fraction of conjugated form (f_conjugated), which displayed negative correlation with their log K_ow (r = -0.861, p < 0.05), indicating that conjugation facilitated their elimination and those with higher hydrophobicity were more difficult to be eliminated. Except BPA, the concentrations of all bisphenols in the carp tissues were in the order of kidney > liver ≫ muscle. The uptake rate constants (k_u) in kidney (r = 0.836, p < 0.05) and in liver (r = 0.863, p < 0.05) displayed significantly positive correlations with BCFs, and k_u in kidney was greater than in liver except BPA. These results indicated that kidney and liver played important roles in accumulating bisphenols in carp, and kidney made more contribution than liver for most bisphenols. Biliary excretion predominated for elimination of most bisphenols while BPA and BPS were mainly through urinary excretion.

Comparison of pharmacokinetics and the exposure-response relationship of dapagliflozin between adolescent/young adult and adult patients with type 1 diabetes mellitus

AIMS

To quantitatively compare pharmacokinetics (PK) and the exposure-response (ER) relationship of the sodium-glucose cotransporter-2 inhibitor, dapagliflozin, between adolescents/young adults and adults with type 1 diabetes mellitus (T1DM).

METHODS

Data from 2 clinical studies for dapagliflozin were analysed using a non-linear mixed-effects approach. The PK and the relationship between dapagliflozin exposure and response (24-hour urinary glucose excretion) were characterized. PK was evaluated using a 2-compartment model with first-order absorption while the exposure response-relationship was analysed using a sigmoidal maximal-effect model. The 24-hour median blood glucose, estimated glomerular filtration rate (eGFR), sex, age and body weight were evaluated as covariates.

RESULTS

A 2-compartment model with first order absorption provided a reasonable fit to the dapagliflozin PK data. Body weight was found to be a significant covariate on dapagliflozin exposure. The ER relationship was best described by a sigmoidal maximal effect model with 24-hour median blood glucose and eGFR as significant covariates on maximal effect. In accordance with the observed data, model-predicted urinary glucose excretion response following 10 mg dapagliflozin dose was higher in the study in adolescents/young adults (138.0 g/24 h) compared to adults (70.5 g/24 h) with T1DM. This is linked to higher eGFR and 24-hour median blood glucose in this trial.

CONCLUSIONS

Dapagliflozin PK and ER relationship were similar in the 2 analysed studies after accounting for covariate effects. These results suggest that no dose adjustment is required for adolescent patients with T1DM.

Dapagliflozin: A Review in Type 2 Diabetes

Dapagliflozin (Forxiga®) is a highly potent, reversible and selective sodium-glucose cotransporter-2 inhibitor indicated worldwide for the treatment of type 2 diabetes (T2D). In the EU, oral dapagliflozin once daily is approved for use as monotherapy (in patients who are intolerant of metformin) and as add-on combination therapy (with other glucose-lowering agents, including insulin) for T2D when diet and exercise alone do not provide adequate glycaemic control. In numerous well-designed clinical studies and their extensions, dapagliflozin as monotherapy and combination therapy with other antihyperglycaemic agents provided effective glycaemic control and reduced bodyweight and blood pressure (BP) across a broad spectrum of patients. Dapagliflozin reduced the rate of cardiovascular (CV) death or hospitalization for heart failure (HHF), did not adversely affect major adverse CV events (MACE) and possibly reduced progression of renal disease relative to placebo in patients with established atherosclerotic CV disease (CVD) or multiple risk factors for CVD. Dapagliflozin was generally well tolerated, with a low risk of hypoglycaemia; diabetic ketoacidosis (DKA), although rare, and genital infections were more common with dapagliflozin than placebo. Given its antihyperglycaemic, cardioprotective and possibly renoprotective properties and generally favourable tolerability profile, dapagliflozin provides an important option for the management of a broad patient population, regardless of the history of CVD.

Oral Systemic Bioavailability of Bisphenol A and Bisphenol S in Pigs

BACKGROUND

Given its hormonal activity, bisphenol S (BPS) as a substitute for bisphenol A (BPA) could actually increase the risk of endocrine disruption if its toxicokinetic (TK) properties, namely its oral availability and systemic persistency, were higher than those of BPA.

OBJECTIVES

The TK behavior of BPA and BPS was investigated by administering the two compounds by intravenous and oral routes in piglet, a known valid model for investigating oral TK.

METHODS

Experiments were conducted in piglets to evaluate the kinetics of BPA, BPS, and their glucuronoconjugated metabolites in plasma and urine after intravenous administration of BPA, BPS, and BPS glucuronide (BPSG) and gavage administration of BPA and BPS. A population semiphysiologically based TK model describing the disposition of BPA and BPS and their glucuronides was built from these data to estimate the key TK parameters that drive the internal exposure to active compounds.

RESULTS

The data indicated that almost all the BPS oral dose was absorbed and transported into the liver where only 41% of BPS was glucuronidated, leading to a systemic bioavailability of 57.4%. In contrast, only 77% of the oral dose of BPA was absorbed and underwent an extensive first-pass glucuronidation either in the gut (44%) or in the liver (53%), thus accounting for the low systemic bioavailability of BPA (0.50%). Due to the higher systemic availability of BPS, in comparison with BPA, and its lower plasma clearance (3.5 times lower), the oral BPS systemic exposure was on average about 250 times higher than for BPA for an equal oral molar dose of the two compounds.

CONCLUSION

Given the similar digestive tracts of pigs and humans, our results suggest that replacing BPA with BPS will likely lead to increased internal exposure to an endocrine-active compound that would be of concern for human health. https://doi.org/10.1289/EHP4599.

Comparison of Bisphenol A and Bisphenol S Percutaneous Absorption and Biotransformation

BACKGROUND

Bisphenol S (BPS) has been widely substituted for bisphenol A (BPA) on thermal papers, but little is known about its skin absorption.

OBJECTIVES

We compared the percutaneous absorption and biotransformation of BPS and BPA in vitro and in a controlled human trial.

METHODS

Absorption and biotransformation of BPS and BPA were monitored across reconstructed human epidermis at two environmentally relevant doses over 25 h. In the human trial, five male participants handled thermal receipts containing BPS and washed their hands after 2 h. Urine (0-48 h) and serum (0-7.5h) were analyzed for target bisphenols, and one participant repeated the experiment with extended monitoring. BPS data were compared with published data for isotope-labeled BPA ([Formula: see text]) in the same participants.

RESULTS

At doses of 1.5 and [Formula: see text] applied to reconstructed human epidermis, the permeability coefficient of BPS (0.009 and [Formula: see text], respectively) was significantly lower than for BPA (0.036 and [Formula: see text], respectively), and metabolism of both bisphenols was negligible. In participants handling thermal receipts, the quantities of BPS and [Formula: see text] on hands was significantly correlated with maximum urinary event flux ([Formula: see text]), but the slope was lower for BPS than BPA ([Formula: see text] and 1.1, respectively). As a proportion of total urinary bisphenol, free BPS [[Formula: see text]: [Formula: see text]] was higher than for free BPA ([Formula: see text]). Postexposure maximum urinary BPS concentrations (0.93 to [Formula: see text]; [Formula: see text]) were in the 93-98th percentile range of BPS in background Canadians ([Formula: see text]; [Formula: see text]).

CONCLUSION

Both the in vitro and human studies suggested lower percutaneous absorption of BPS compared with BPA, but a lower biotransformation efficiency of BPS should also be considered in its evaluation as a BPA substitute. https://doi.org/10.1289/EHP5044.

The Effect of Dissolved Organic Matter (DOM) on the Release and Distribution of Endocrine-Disrupting Chemicals (Edcs) from Sediment under Hydrodynamic Forces, A Case Study of Bisphenol A (BPA) and Nonylphenol (NP)

Endocrine-disrupting chemicals (EDCs) that exist in the aquatic system bring severe environmental risks. In this study, we investigate the dissolved organic matter (DOM) effect on the release and distribution of EDCs under varied hydrodynamic conditions. A water chamber mesocosm was designed to simulate the hydrodynamic forces in a shallow lake. The contents of bisphenol A (BPA) and nonylphenol (NP) in colloid-bound and soluble phases were measured under four increasing hydrodynamic intensities that were 5%, 20%, 50%, and 80% of the critical shear stress. The total BPA and NP contents in overlying water grew linearly with the hydrodynamic intensity (R² = 0.997 and 0.987), from 108.28 to 415.92 ng/L of BPA and 87.73 to 255.52 ng/L of NP. The exponential relationships of EDC content and hydrodynamic intensity in soluble phase (R² = 0.985 of BPA and 0.987 of NP) and colloid phase (R² = 0.992 of BPA and 0.995 of NP) were also detected. The DOM concentrations in colloid-bound phase (cDOM) and in soluble phase (sDOM) were measured and the linear relationships with BPA content (R² = 0.967 of cDOM and 0.989 of sDOM) and NP content (R² = 0.978 of cDOM and 0.965 of sDOM) were detected. We analyzed the ratio (αDOM) of sDOM and cDOM that grew logarithmically with the hydrodynamic intensity (R² = 0.999). Moreover, the ratio (αEDCs) of BPA and NP contents in soluble and colloid-bound phases varied differently with αDOM. The results suggested that BPA tended to be in the soluble phase and NP tended to be in the colloid-bound phase due to the increasing value of αDOM.

Toxicokinetics of bisphenol A, bisphenol S, and bisphenol F in a pregnancy sheep model

Bisphenol A (BPA), S (BPS), and F (BPF) are among the most abundant bisphenols detected in humans, yet pregnancy toxicokinetics for BPS or BPF remain unknown. Because gestational BPS can disrupt placental function and result in reproductive and metabolic disorders in the progeny, the aim of the study was to investigate BPS and BPF toxicokinetics during pregnancy using an in vivo approach. Fetal catheterizations were conducted in pregnant sheep (n = 6) at mid-pregnancy and injected with either a single dose of BPS (n = 3, 0.5 mg/kg, s.c.), or a combination of BPS, BPF, and BPA (n = 3, 0.5 mg/kg for each chemical, s.c.). Maternal and fetal blood and urine and amniotic fluid were collected over 72 h and analyzed for bisphenols by HPLC-MS/MS. We observed significant differences in half-life, maximum concentration, and total body clearance in maternal circulation among bisphenols. Longer half-lives were observed in fetal vs. maternal circulation for all bisphenols. Fetal toxicokinetics differed among bisphenols with BPS having the longest fetal half-life. All bisphenols reached basal levels at 48 h in maternal plasma, but were still detectable in amniotic fluid, fetal urine, and fetal plasma at 72 h. In this first pregnancy toxicokinetic study of BPS and BPF we have demonstrated maternal and fetal toxicokinetic differences among all three bisphenols. Higher BPS persistence in the fetal compartment warrants studies into progeny adverse outcomes following gestational exposure. Additionally, toxicokinetic differences among bisphenols call for a more careful approach when extrapolating kinetic information from one bisphenol chemical to another.

Pharmacokinetics and pharmacodynamics of dapagliflozin in combination with insulin in Japanese patients with type 1 diabetes

AIMS

To assess the pharmacokinetics/pharmacodynamics (PK/PD) of dapagliflozin, a sodium-glucose co-transporter 2 inhibitor that increases urinary glucose excretion (UGE) and its major metabolite, dapagliflozin-3-O-glucuronide (D3OG), in Japanese patients with type 1 diabetes (T1D) and inadequate glycaemic control (HbA1c 7%-10%).

MATERIALS AND METHODS

Japanese patients (18-65 years) with inadequately controlled T1D were randomized 1:1:1 to dapagliflozin 5 mg, 10 mg or placebo (n = 14 each) once daily for 7 days, with adjustable insulin. The PK/PD characteristics of dapagliflozin and D3OG were assessed on Day 7. Patients underwent follow-up evaluation on Days 8 and 14. Adverse events (AEs), hypoglycaemic episodes and events of diabetic ketoacidosis (DKA) were recorded over the treatment and follow-up periods.

RESULTS

A total of 42 randomized patients received dapagliflozin or placebo. PK variables increased in a dose-dependent manner. D3OG was generated rapidly, with a median time to maximum plasma concentration of 2.0 hours (1.0-3.0). The dapagliflozin dose-UGE relationship was attenuated, with larger insulin dose reductions than anticipated. Mean percent (standard error) changes in total daily insulin dose from baseline to Day 7 were - 36.86% (3.32), -39.13% (2.68) and - 4.97% (5.28) for dapagliflozin 5 mg and 10 mg and for placebo, respectively. No DKA was reported. AEs were consistent with the established dapagliflozin safety profile. There was no increase in hypoglycaemia.

CONCLUSIONS

The PK and safety profiles of dapagliflozin in Japanese patients with T1D were consistent with previous studies, but with an unanticipated attenuation of the PD dose-response measured as UGE.

Bisphenol S instead of Bisphenol A: Toxicokinetic investigations in the ovine materno-feto-placental unit

Bisphenol S (BPS) is widely used as a substitute for Bisphenol A in consumer products. Despite its potential endocrine-disrupting effects and widespread exposure, toxicokinetic data, particularly during the critical period of pregnancy, are not available for BPS. The objectives of our study were to evaluate the mechanisms determining fetal exposure to BPS and to BPS glucuronide (BPSG) and to compare them with those prevailing for BPA. The disposition of BPS and BPSG was evaluated in the materno-fetal unit of the catheterized pregnant ewe model, following intravenous administrations of BPS and BPSG to mothers and their fetuses. In a second experiment, the rate of BPS accumulation in the fetal compartment was determined under steady-state conditions after repeated intravenous BPS administrations to the mother. In the maternal compartment, BPS was mainly metabolized into BPSG and totally eliminated in urine. Only 0.40% of the maternal dose was transferred to the fetus. However, once in the fetal compartment, 26% of the fetal dose was rapidly eliminated through placental transfer, while 46% of BPS was metabolized into BPSG which remained trapped in the fetal compartment. Thus, the elimination of BPSG from the fetal compartment required its back-conversion into bioactive BPS, leading to an 87% enhancement of the fetal BPS exposure. Our findings demonstrate that, despite the low materno-fetal placental transfer of BPS, this substitute for BPA is able to accumulate in the fetal compartment after repeated maternal exposure, leading to chronic fetal exposure to BPS in a range of concentrations similar to those of BPA.

Verifying community-wide exposure to endocrine disruptors in personal care products - In quest for metabolic biomarkers of exposure via in vitro studies and wastewater-based epidemiology

This study aimed to identify human specific metabolites of selected known or suspected endocrine disruptors (EDCs), mainly UV filters, used in personal care and consumer products whose metabolism has hardly been explored and to select suitable candidate biomarkers for human exposure studies using wastewater based epidemiology (WBE). The analysis of metabolic biomarkers of target chemicals is crucial in order to distinguish between internal and external exposure, since many sources contribute to chemicals being discharged into wastewater. This was achieved through the employment of a new analytical framework for verification of biomarkers of exposure to chemicals combining human biomonitoring and water fingerprinting. Eight EDCs with unknown metabolic pathways (benzophenone-1 (BP-1); benzophenone-2 (BP-2); 4,4'-dihydroxybenzophenone (4,4'-DHBP); 4-benzylphenol (4-BenzPh); homosalate (HO); octocrylene (OC); 3-benzylidene camphor (3-BC), and two EDCs with known metabolism (bisphenol A (BPA) and benzophenone-3 (BP-3)) were tested. The biotransformation observed consisted mainly of phase I processes such as hydrolysis and hydroxylation together with phase II conjugation reactions such as sulphation and glucuronidation. Only two chemicals (BP-1, BP-3) were identified in urine and three chemicals (BPA, BP-1, BP-3) in wastewater. Five newly discovered metabolites (HO-Met1, OC-Met1, 4-BenzPh-Met4, 4-BenzPh-Met5 and 4-BenzPh-Met6) and one previously known metabolite (BPA-Met3) were detected in tested urine/wastewater samples from five WWTPs serving large communities ranging between 17 and 100 thousand inhabitants. The presence of metabolic biotransformation products of OC, 4-BenzPh, BPA and HO in wastewater provides evidence for internal exposure of studied populations to these chemicals.

Pharmacokinetic and pharmacodynamic profile of the sodium-glucose co-transporter-2 inhibitor empagliflozin in young people with Type 2 diabetes: a randomized trial

AIMS

To assess the pharmacokinetic and pharmacodynamic profile of a single dose of empagliflozin in young people with Type 2 diabetes to identify the appropriate doses for further paediatric development.

METHODS

We conducted a single-dose, open-label, randomized, parallel-group study with empagliflozin 5 mg, 10 mg and 25 mg in young people with Type 2 diabetes aged 10-17 years.

RESULTS

Of 39 participants screened, 27 were randomized and completed the study; their mean (± sd) age was 14.1±2.0 years and body weight was 96.7±23.5 kg. Compared with similar studies in adults with Type 2 diabetes, the maximum observed plasma concentrations were slightly lower with the 10-mg and 25-mg doses, and the area under the plasma concentration-time curve was slightly lower with the 10-mg but slightly higher with the 25-mg dose. The adjusted mean increases in urinary glucose excretion were 53 g/24 h (95% CI 32,74), 73 g/24 h (95% CI 52,94) and 87 g/24 h (95% CI 68,107), and the adjusted mean decreases in fasting plasma glucose were 0.9 mmol/l (95% CI -1.6,-0.1), 0.9 mmol/l (95% CI -1.7,-0.2) and 1.1 mmol/l (95% CI -1.8,-0.5) for the 5- 10- and 25-mg doses, respectively. There were no serious adverse events and one investigator-reported drug-related event (dehydration).

CONCLUSIONS

After a single oral dose of empagliflozin, adults and young people with Type 2 diabetes had similar exposure-response relationships after adjusting for significant covariates. These data support testing 10-mg and/or 25-mg doses of empagliflozin in an upcoming paediatric phase III Type 2 diabetes trial. (ClinicalTrials.gov registration no.: NCT02121483).

Physiologically Based Pharmacokinetic (PBPK) Modeling of the Bisphenols BPA, BPS, BPF, and BPAF with New Experimental Metabolic Parameters: Comparing the Pharmacokinetic Behavior of BPA with Its Substitutes

BACKGROUND

The endocrine disrupting chemical bisphenol A (BPA) has been facing stricter regulations in recent years. BPA analogs, such as the bisphenols S, F, and AF (BPS, BPF, and BPAF) are increasingly used as replacement chemicals, although they were found to exert estrogenic effects similar to those of BPA. Research has shown that only the parent compounds have affinity to the estrogen receptors, suggesting that the pharmacokinetic behavior of bisphenols (BPs) can influence their potency.

OBJECTIVES

Our goal was to compare the pharmacokinetic behaviors of BPA, BPS, BPF, and BPAF for different age groups after environmentally relevant external exposures by taking into account substance-specific metabolism kinetics and partitioning behavior. This comparison allowed us to investigate the consequences of replacing BPA with other BPs.

METHODS

We readjusted a physiologically based pharmacokinetic (PBPK) model for peroral exposure to BPA and extended it to include dermal exposure. We experimentally assessed hepatic and intestinal glucuronidation kinetics of BPS, BPF, and BPAF to parametrize the model for these BPs and calibrated the BPS model with a biomonitoring study. We used the PBPK models to compare resulting internal exposures and focused on females of childbearing age in a two-dimensional Monte Carlo uncertainty analysis.

RESULTS

Within environmentally relevant concentration ranges, BPAF and BPS were glucuronized at highest and lowest rates, respectively, in the intestine and the liver. The predominant routes of BPS and BPAF exposure were peroral and dermal exposure, respectively. The calibration of the BPS model with measured concentrations showed that enterohepatic recirculation may be important. Assuming equal external exposures, BPS exposure led to the highest internal concentrations of unconjugated BPs.

CONCLUSIONS

Our data suggest that the replacement of BPA with structural analogs may not lower the risk for endocrine disruption. Exposure to both BPS and BPAF might be more critical than BPA exposure, if their respective estrogenic potencies are taken into account. https://doi.org/10.1289/EHP2739.

The design and rationale for the Dapagliflozin Effect on Cardiovascular Events (DECLARE)-TIMI 58 Trial

BACKGROUND

Dapagliflozin is a sodium-glucose co-transporter-2 (SGLT-2) inhibitor that reduces blood glucose in patients with type 2 diabetes mellitus (T2DM) by promoting glycosuria via inhibiting urinary glucose reabsorption. In addition to improving blood glucose control, treatment with dapagliflozin results in glucose-induced osmotic diuresis, weight loss, and blood pressure lowering. Previous trials of SGLT-2 inhibitors showed reductions in cardiovascular (CV) events, including CV death and hospitalization for heart failure, and ischemic events in patients with atherosclerotic cardiovascular disease (ASCVD).

RESEARCH DESIGN AND METHODS

DECLARE-TIMI 58 (NCT01730534) is a phase 3b randomized, double-blind, placebo-controlled trial designed to evaluate the CV safety and efficacy of dapagliflozin that has completed randomization of 17,160 patients with T2DM and a history of either established ASCVD (n=6,971) or multiple risk factors for ASCVD (n=10,189). Patients were randomized in a 1:1 fashion to dapagliflozin 10 mg or matching placebo. The primary safety outcome is the time to the first event of the composite of CV death, myocardial infarction, or ischemic stroke (major adverse cardiovascular events; MACEs). The co-primary efficacy outcomes are the composite of CV death, myocardial infarction, or ischemic stroke and the composite of CV death or hospitalization for heart failure. This event-driven trial will continue until at least 1,390 subjects have a MACE outcome, thereby providing >99% power to test for the primary outcome of safety of dapagliflozin measured by rejecting the hypothesis that the upper bound of the CI >1.3 for the primary outcome of MACE, as well as 85% power to detect a 15% relative risk reduction in MACE and an estimated 87% power to detect a 20% reduction in the composite of CV death or hospitalization for heart failure at a 1-sided α level of .0231.

CONCLUSION

The DECLARE-TIMI 58 trial is testing the hypotheses that dapagliflozin is safe (does not increase) and may reduce the occurrence of major CV events. DECLARE-TIMI 58 is the largest study to address this question with an SGLT-2 inhibitor in patients with T2DM and with established CV disease and without CV disease but with multiple risk factors.

The development of a pregnancy PBPK Model for Bisphenol A and its evaluation with the available biomonitoring data

Recent studies suggest universal fetal exposure to Bisphenol A (BPA) and its association with the adverse birth outcomes. Estimation of the fetal plasma BPA concentration from the maternal plasma BPA would be highly useful to predict its associated risk to this specific population. The objective of current work is to develop a pregnancy-physiologically based pharmacokinetic (P-PBPK) model to predict the toxicokinetic profile of BPA in the fetus during gestational growth, and to evaluate the developed model using biomonitoring data obtained from different pregnancy cohort studies. To achieve this objective, first, the adult PBPK model was developed and validated with the human BPA toxicokinetic data. This validated human PBPK model was extended to develop a P-PBPK model, which included the physiological changes during pregnancy and the fetus sub-model. The developed model would be able to predict the BPA pharmacokinetics (PKs) in both mother and fetus. Transplacental BPA kinetics parameters for this study were taken from the previous pregnant mice study. Both oral and dermal exposure routes were included into the model to simulate total BPA internal exposure. The impact of conjugation and deconjugation of the BPA and its metabolites on fetal PKs was investigated. The developed P-PBPK model was evaluated against the observed BPA concentrations in cord blood, fetus liver and amniotic fluid considering maternal blood concentration as an exposure source. A range of maternal exposure dose for the oral and dermal routes was estimated, so that simulation concentration matched the observed highest and lowest mother plasma concentration in different cohorts' studies. The developed model could be used to address the concerns regarding possible adverse health effects in the fetus being exposed to BPA and might be useful in identifying critical windows of exposure during pregnancy.

In silico binding of 4,4'-bisphenols predicts in vitro estrogenic and antiandrogenic activity

Bisphenols, anthropogenic pollutants, leach from consumer products and have potential to be ingested and are excreted in waste. The endocrine disrupting effects of highly manufactured bisphenols (BPA, BPS, and BPF) are known, however the activities of others are not. Here, the estrogenic and androgenic activities of a series of 4,4'-bisphenols that vary at the inter-connecting bisphenol bridge were determined (BPA, BPB, BPBP, BPC2, BPE, BPF, BPS, and BPZ) and compared to in silico binding to estrogen receptor-alpha and the androgen receptor. Bioassay results showed the order of estrogenicity (BPC2 (strongest) > BPBP > BPB > BPZ > BPE > BPF > BPA > BPS, r²  = 0.995) and anti-androgenicity (BPC2 (strongest) > BPE, BPB, BPA, BPF, and BPS, r²  = 0.996) correlated to nuclear receptor binding affinities. Like testosterone and the anti-androgen hydroxyflutamide, bisphenol fit in the ligand-binding domain through hydrogen-bonding at residues Thr877 and Asn705, but also interacted at either Cys784/Ser778 or Gln711 through the other phenol ring. This suggests the 4,4'-bisphenols, like hydroxyflutamide, are androgen receptor antagonists. Hydrogen-bond trends between ERα and the 4,4'-bisphenols were limited to residue Glu353, which interacted with the -OH of one phenol and the -OH of the A ring of 17β-estradiol; hydrogen-bonding varied at the -OH of ring D of 17β-estradiol and the second phenol -OH group. While both estrogen and androgen bioassays correlated to in silico results, conservation of hydrogen-bonding residues in the androgen receptor provides a convincing picture of direct antagonist binding by 4,4'-bisphenols.

Exposure to bisphenols and parabens during pregnancy and relations to steroid changes

BACKGROUND

The harmful effects of endocrine disrupting compounds (EDCs) on human health are generally well-known, and exposure during fetal development may have lasting effects. Fetal exposure to bisphenol A (BPA) has been recently relatively well-studied; however, less is known about alternatives such as bisphenol S (BPS), bisphenol F (BPF) and bisphenol AF (BPAF), which have started to appear in consumer products. Parabens are another widespread group of EDCs, with confirmed transplacental passage. The usage of many cosmetic, pharmaceutical and consumer products during the pregnancy that may contain parabens and bisphenols has led to the need for investigation.

OBJECTIVES

To shed more light into the transplacental transport of BPA, its alternatives, and parabens, and to study their relation to fetal steroidogenesis.

METHODS

BPA, BPS, BPF, BPAF, methylparaben, ethylparaben, propylparaben, butylparaben, benzylparaben and 15 steroids including estrogens, corticoids, androgens and immunomodulatory ones were determined in 27 maternal (37th week of pregnancy) and cord plasma samples using liquid chromatography - tandem mass spectrometry methods.

RESULTS

In cord blood, significantly higher BPA levels (p=0.0455) were observed compared to maternal plasma. The results from multiple regression models showed that in cord blood, methylparaben (β=-0.027, p=0.027), propylparaben (β=-0.025, p=0.03) and the sum of all measured parabens (β=-0.037, p=0.015) were inversely associated with testosterone levels.

CONCLUSION

To the best of our knowledge, this is the first study reporting the simultaneous detection of BPA, alternative bisphenols, parabens and steroids in maternal and cord plasma. Our study confirmed the transplacental transport of BPA, with likely accumulation in the fetal compartment. The negative association of cord blood parabens and testosterone levels points to possible risks with respect to importance of testosterone for prenatal male development.

Population Pharmacokinetic- Pharmacodynamic Analysis to Characterize the Effect of Empagliflozin on Renal Glucose Threshold in Patients With Type 1 Diabetes Mellitus

Sodium glucose cotransporter 2 inhibitors increase urinary glucose excretion (UGE) by lowering the renal threshold for glucose (RT_G ). We aimed to quantify the effect of the sodium glucose cotransporter inhibitor empagliflozin on renal glucose reabsorption in patients with type 1 diabetes mellitus (T1DM) using a mechanistic population pharmacokinetic-pharmacodynamic (PK-PD) model and to compare results with analyses in patients with type 2 diabetes mellitus (T2DM). The PK-PD model was developed using data from a randomized phase 2 study in which patients with T1DM received oral once-daily empagliflozin 2.5 mg, empagliflozin 10 mg, empagliflozin 25 mg, or placebo as an adjunct to insulin. The model assumed that UGE was dependent on plasma glucose and renal function and that empagliflozin lowered RT_G . The final model was evaluated using visual predictive checks and found to be consistent with observed data. Calculated RT_G with placebo was 181 mg/dL, and with empagliflozin (steady state) 1 mg and 2.5 mg was 53.4 mg/dL and 12.5 mg/dL, respectively. Empagliflozin 10 mg and 25 mg yielded negative RT_G values, implying RT_G was reduced to a negligible value. Although estimated PK-PD parameters were generally comparable between patients with T1DM and patients with T2DM, slight differences were evident, leading to lower RT_G and higher UGE in patients with T1DM compared with patients with T2DM. In conclusion, the model provided a reasonable description of UGE in response to administration of empagliflozin and placebo in patients with T1DM.

Bioaccumulation and biomagnification of emerging bisphenol analogues in aquatic organisms from Taihu Lake, China

Due to regulations on bisphenol A (BPA) in many countries, a variety of bisphenol analogues are being widely manufactured and applied. However, there is a big knowledge gap on bioaccumulation and biomagnification of these emerging bisphenols in aquatic organisms. The bioaccumulation and magnification of nine bisphenol analogues in aquatic organisms at different trophic levels collected from Taihu Lake, China, were evaluated. The total concentrations of the nine bisphenols in the lake waters were in the range of 49.7-3480ng/L (mean, 389ng/L). BPA, bisphenol AF (BPAF) and bisphenol S (BPS) were the most predominant analogues in the water. The mean natural logarithm bioaccumulation factor (log BAFs) of BPAF, bisphenol C (BPC), bisphenol Z (BPZ) and bisphenol E (BPE) were greater than BPA, and there was a significantly positive correlation between log BAFs of the biphenols and their octanol-water partition coefficients (log K_ow). The trophic magnification factors of BPAF, BPC and BPZ were 2.52, 2.69 and 1.71, respectively, suggesting that they had the potential to biomagnify in the food web. The results of this study call for further investigations on risk assessment of these emerging pollutants in the environment.

Effects of dapagliflozin on insulin-requirement, glucose excretion and ß-hydroxybutyrate levels are not related to baseline HbA1c in youth with type 1 diabetes

Youth with type 1 diabetes (T1D) infrequently achieve HbA1c targets. Therefore, this placebo-controlled, randomized, crossover study was set up to assess the safety, effect and pharmacokinetics of a single dose of 10 mg dapagliflozin (DAPA) as add-on to insulin in relationship to HbA1c in youth. A total of 33 youths (14 males, median age 16 years, diabetes duration 8 years) were included and stratified into 3 baseline HbA1c categories (<7.5%, 7.5%-9.0% or >9.0; n = 11 each). During the study period of 24 hours, intravenous insulin administration and glucose-infusion kept blood glucose levels at 160 to 220 mg/dL. DAPA reduced mean insulin dose by 13.6% ( P  < .0001 by ANOVA) and increased urinary glucose excretion by 610% (143.4 vs 22.4 g/24 h; P  < .0001), both irrespective of baseline HbA1c. Six independent episodes in 6 patients with plasma ß-hydroxybutyrate levels between ≥0.6 and <1.0 mmol/L were observed after liquid meal challenges, 5 episodes in the DAPA group and 1 in the placebo group. This study provides a proof-of-concept, irrespective of preexisting HbA1c levels, for adjunct SGLT2-inhibitor therapy in the paediatric age group by lowering insulin dose and increasing glucose excretion.

Prenatal exposure estimation of BPA and DEHP using integrated external and internal dosimetry: A case study

Prenatal exposure to Endocrine disruptors (EDs), such as Bisphenol A (BPA) and di (2-ethylhexyl) phthalate (DEHP), has been associated with obesity and diabetes diseases in childhood, as well as reproductive, behavioral and neurodevelopment problems. The aim of this study was to estimate the prenatal exposure to BPA and DEHP through food consumption for pregnant women living in Tarragona County (Spain). Probabilistic calculations of prenatal exposure were estimated by integrated external and internal dosimetry modelling, physiologically based pharmacokinetic (PBPK) model, using a Monte-Carlo simulation. Physical characteristic data from the cohort, along with food intake information from the questionnaires (concentrations of BPA and DEHP in different food categories and the range of the different food ratios), were used to estimate the value of the total dietary intake for the Tarragona pregnancy cohort. The major contributors to the total dietary intake of BPA were canned fruits and vegetables, followed by canned meat and meat products. In turn, milk and dairy products, followed by ready to eat food (including canned dinners), were the most important contributors to the total dietary intake of DEHP. Despite the dietary variations among the participants, the intakes of both chemicals were considerably lower than their respective current tolerable daily intake (TDI) values established by the European Food Safety Authority (EFSA). Internal dosimetry estimates suggest that the plasma concentrations of free BPA and the most important DEHP metabolite, mono (2-ethylhexyl) phthalate (MEHP), in pregnant women were characterized by transient peaks (associated with meals) and short half-lives (< 2h). In contrast, fetal exposure was characterized by a low and sustained basal BPA and MEHP concentration due to a lack of metabolic activity in the fetus. Therefore, EDs may have a greater effect on developing organs in young children or in the unborn child.

Prolonged Exposure to Bisphenol A from Single Dermal Contact Events

Bisphenol A (BPA) is an endocrine disruptor frequently detected in human biofluids. Dermal absorption of BPA from thermal paper receipts occurs but BPA pharmacokinetics following dermal exposure is not understood. To compare the pharmacokinetics of dermal and dietary BPA exposure, six male participants handled simulated receipts containing relevant levels of BPA (isotope-labeled BPA-d₁₆) for 5 min, followed by hand-washing 2 h later. Urine (0-48 h) and serum (0-7.5 h) were monitored for free and total BPA-d₁₆. One week later, participants returned for a dietary administration with monitoring as above. One participant repeated the dermal administration with extended monitoring of urine (9 days) and serum (2 days). After dietary exposure, urine total BPA-d₁₆ peaked within 5 h and quickly cleared within 24 h. After dermal exposure, cumulative excretion increased linearly for 2 days, and half the participants still had detectable urinary total BPA-d₁₆ after 1 week. The participant repeating the dermal exposure had detectable BPA-d₁₆ in urine for 9 days, showed linear cumulative excretion over 5 days, and had detectable free BPA-d₁₆ in serum. Proportions of free BPA-d₁₆ in urine following dermal exposure (0.71%-8.3% of total BPA-d₁₆) were generally higher than following the dietary exposure (0.29%-1.4%). Compared to dietary BPA exposure, dermal absorption of BPA leads to prolonged exposure and may lead to higher proportions of unconjugated BPA in systemic circulation.

Human exposure to endocrine disrupting chemicals: effects on the male and female reproductive systems

Endocrine disrupting chemicals (EDCs) comprise a group of chemical compounds that have been examined extensively due to the potential harmful effects in the health of human populations. During the past decades, particular focus has been given to the harmful effects of EDCs to the reproductive system. The estimation of human exposure to EDCs can be broadly categorized into occupational and environmental exposure, and has been a major challenge due to the structural diversity of the chemicals that are derived by many different sources at doses below the limit of detection used by conventional methodologies. Animal and in vitro studies have supported the conclusion that endocrine disrupting chemicals affect the hormone dependent pathways responsible for male and female gonadal development, either through direct interaction with hormone receptors or via epigenetic and cell-cycle regulatory modes of action. In human populations, the majority of the studies point towards an association between exposure to EDCs and male and/or female reproduction system disorders, such as infertility, endometriosis, breast cancer, testicular cancer, poor sperm quality and/or function. Despite promising discoveries, a causal relationship between the reproductive disorders and exposure to specific toxicants is yet to be established, due to the complexity of the clinical protocols used, the degree of occupational or environmental exposure, the determination of the variables measured and the sample size of the subjects examined. Future studies should focus on a uniform system of examining human populations with regard to the exposure to specific EDCs and the direct effect on the reproductive system.

Empagliflozin for Type 2 Diabetes Mellitus: An Overview of Phase 3 Clinical Trials

INTRODUCTION

Sodium glucose cotransporter 2 (SGLT2) inhibitors have a unique mechanism of action leading to excretion of glucose in the urine and subsequent lowering of plasma glucose. This mechanism is independent of β-cell function; thus, these agents are effective treatment for type 2 diabetes mellitus (T2DM) at theoretically any disease stage. This class should not confer an additional risk of hypoglycemia (unless combined with insulin or an insulin secretagogue) and has the potential to be combined with other classes of glucose-lowering agents. Empagliflozin is one of three currently approved SGLT2 inhibitors in the United States, and has shown a favorable benefit-risk ratio in phase 3 clinical trials as monotherapy and as add-on to other glucose-lowering therapy in broad patient populations. In addition to its glucose-lowering effects, empagliflozin has been shown to reduce body weight and blood pressure without a compensatory increase in heart rate. Moreover, on top of standard of care, empagliflozin is the first glucoselowering agent to demonstrate cardiovascular risk reduction in patients at high risk of cardiovascular disease in a prospective outcomes trial: a 14% reduction in risk of the 3-point composite endpoint of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. Like other SGLT2 inhibitors, empagliflozin is associated with a higher rate of genital mycotic infections than placebo and has the potential for volume depletion-associated events.

CONCLUSION

This review summarizes the empagliflozin phase 3 clinical trials program and its potential significance in the treatment of patients with T2DM. Evidence from these clinical trials show reductions in glycated hemoglobin (-0.59 to -0.82%) with a low risk of hypoglycemia except when used with insulin or insulin secretagogues, and moderate reductions in body weight (-2.1 to - 2.5 kg) and systolic blood pressure (-2.9 to -5.2 mm Hg), thus supporting the use of empagliflozin as monotherapy or in addition to other glucose-lowering agents. In addition, evidence from the recent EMPA-REG OUTCOME study, which demonstrated relative risk reductions in major adverse cardiac events (14%), cardiovascular mortality (38%) and all-cause mortality (32%), as well as hospitalization for heart failure (36%), supports use of empagliflozin in patients with T2DM and increased cardiovascular risk.

Maternal and Fetal Pharmacokinetics of Oral Radiolabeled and Authentic Bisphenol A in the Rhesus Monkey

The present study was conducted in pregnant rhesus monkeys to determine the rapidity and extent to which BPA reaches the fetal compartment following oral ingestion, and the 24-hr fate of BPA. To assess metabolism changes during the course of pregnancy, we compared BPA biotransformation during the second and third trimesters in the same animals, measuring the levels of sulfated, gluronidated, and free BPA in maternal serum, amniotic fluid, and fetal serum. All animals showed measurable unconjugated and conjugated BPA in the fetal compartment and slow clearance compared to maternal serum. There were higher levels of BPA-G in amniotic fluid at 150 days gestation compared to 100 days gestation, as well as higher levels of BPA-G than BPA-S. We also monitored ³H-BPA (and metabolites) in key tissues and excreta from a mother and fetus and from a non-pregnant female. The elimination of radioactivity was rapid, but residues were still detectable 24 hr after dosing in all tissues analyzed. These data suggest that, in primates, rapid maternal processing of BPA does not alleviate the risk of exposure to the developing fetus. This study elevates concerns about levels of current BPA human exposure from potentially a large number of unknown sources and the risks posed to developing fetuses.

Bisphenol A alters gut microbiome: Comparative metagenomics analysis

Mounting evidence has shown that an alteration of the gut microbiota is associated with diet, and plays an important role in animal health and metabolic diseases. However, little is known about the influence of environmental contaminants on the gut microbial community. Bisphenol A (BPA), which is widely used for manufacturing plastic products, has recently been classified as an environmental obesogen. Although many studies have demonstrated the metabolic-disrupting effects of BPA on liver and pancreatic functions, the possible effects of this synthetic compound on the metabolic diversity of the intestinal microbiota is unknown. Using 16S rRNA gene sequencing analysis on caecum samples of CD-1 mice, the present study aimed to test the hypothesis that dietary BPA intake may influence the gut microbiota composition and functions, an important attributing factor to development of the metabolic syndrome. A high-fat diet (HFD) and high-sucrose diet (HSD) were included as the positive controls for comparing the changes in the intestinal microbial profiles. Our results demonstrated a significant reduction of species diversity in the gut microbiota of BPA-fed mice. Alpha and beta diversity analyses showed that dietary BPA intake led to a similar gut microbial community structure as that induced by HFD and HSD in mice. In addition, comparative analysis of the microbial communities revealed that both BPA and a HFD favored the growth of Proteobacteria, a microbial marker of dysbiosis. Consistently, growth induction of the family Helicobacteraceae and reduction of the Firmicutes and Clostridia populations were observed in the mice fed BPA or a HFD. Collectively, our study highlighted that the effects of dietary BPA intake on the shift of microbial community structure were similar to those of a HFD and HSD, and revealed microbial markers for the development of diseases associated with an unstable microbiota.

[Dapagliflozin (forxiga®) : SGLT 2 cotransporter inhibitor as glucose-lowering agent in type 2 diabetes]

Dapagliflozin, a specific inhibitor of sodium-glu¬cose cotransporters type 2 (SGLT2, inhibits glucose reabsorp¬tion in renal tubules and thus promotes glucosuria. This effect results in a reduction in fasting and postprandial glycaemia and a decrease of glycated haemoglobin (HbA1c), with a minor risk of hypoglycaemia, a weight reduction and a reduction in arterial blood pressure. The efficacy of empagliflozin on HbA1c reduction increases according to the level of hyper¬glycaemia but decreases in patients with renal insufficiency. Mycotic genital infections occur more frequently, especially in women, while a negligible increase in mild urinary tract infections may be observed. Dapagliflozin (Forxiga®), 10 mg once daily, is indicated for the treatment of T2DM and reim¬bursed in Belgium with conditions as add-on to a background glucose-lowering therapy (either metformin or sulfonylurea/ repaglinide or metformin plus sulfonylurea/repaglinide or basal insulin plus at least one of these oral glucose-lowering agents). Preliminary results suggest some cardiovascular and renal protection. These results should be confirmed in an ongoing large prospective controlled trial (DECLARE) in type 2 diabetic patients at high cardiovascular risk.

Pharmacokinetic drug interaction study between overactive bladder drugs mirabegron and tolterodine in Japanese healthy postmenopausal females

Mirabegron, the first selective β₃-adrenoceptor agonist for the treatment of overactive bladder (OAB), inhibits cytochrome P450 isozyme CYP2D6. This study was performed in Japanese healthy postmenopausal female volunteers to assess any pharmacokinetic drug interaction between mirabegron and tolterodine, another OAB drug and a sensitive substrate of CYP2D6. Tolterodine 4 mg was orally administered from Days 1-7 and co-administered with mirabegron 50 mg from Days 8-14. Mirabegron 50 mg increased maximum concentration (C_max) and area under the concentration-time curve from zero to 24 h after dosing (AUC_24h) of tolterodine by 2.06-fold (90% confidence interval [CI] 1.81, 2.34) and 1.86-fold (90% CI 1.60, 2.16), respectively, and increased C_max and AUC_24h of the metabolite 5-hydroxymethyl tolterodine by 1.36-fold (90% CI 1.26, 1.47) and 1.25-fold (90% CI 1.15, 1.37), respectively. This suggested a weak pharmacokinetic drug interaction between mirabegron and tolterodine. Mean change from baseline of Fridericia's QT correction formula (ΔQTcF) was slightly higher on Day 14 than on Day 7. No subject had QTcF >480 msec or ΔQTcF >60 msec. All the treatment-emergent adverse events were mild. Mirabegron 50 mg was considered to be safe and well tolerated when coadministered with tolterodine 4 mg in healthy postmenopausal female volunteers.

Pharmacokinetics and pharmacodynamics of dapagliflozin in children and adolescents with type 2 diabetes mellitus

AIMS

To evaluate the pharmacokinetic (PK)/pharmacodynamic (PD) and safety profile of dapagliflozin in paediatric patients aged 10-17 years with type 2 diabetes mellitus (T2DM).

METHODS

Patients were randomized to a single oral dose of dapagliflozin 2.5, 5 or 10 mg. The PK characteristics for individual patients were derived by non-compartmental methods. Urinary glucose excretion (UGE), fasting plasma glucose (FPG) and ease of swallowing were also evaluated.

RESULTS

A total of 24 patients with a mean (range) body weight of 99.7 (61.5-169.5) kg received dapagliflozin. Dapagliflozin was rapidly absorbed after oral administration (median time to maximum plasma concentration ∼1.5 h) and systemic exposures to dapagliflozin and its 3-O-glucuronide metabolite appeared dose-proportional. The mean 24-h UGE increased in a dose-related manner (52.8, 62.4 and 89.0 g for the 2.5, 5 and 10 mg groups, respectively). Mean FPG concentrations were lower for all dose groups on day 2 (6.9, 6.2 and 6.8 mmol/l for 2.5, 5 and 10 mg groups, respectively) than they were predose on day 1 (9.5, 8.5 and 8.2 mmol/l for 2.5, 5 and 10 mg groups, respectively). Six patients (25%) experienced ≥1 adverse event (AE), however, there was no dose-related pattern. All AEs occurred only once and most were mild in intensity. Nearly all patients (n = 23; 95.8%) reported easy swallowing of the dapagliflozin tablets.

CONCLUSIONS

Dapagliflozin was well tolerated in this paediatric population, with no significant safety findings. PK/PD characteristics were similar to those observed in adults with T2DM, thereby supporting the hypothesis that the same dapagliflozin dosage as that used in adults can be evaluated in future phase III paediatric studies.

Comparison of the exposure-response relationship of dapagliflozin in adult and paediatric patients with type 2 diabetes mellitus

AIMS

To quantitatively compare the exposure-response relationship of dapagliflozin in adult and paediatric patients with type 2 diabetes mellitus (T2DM) and to assess the potential impact of covariate effects.

METHODS

Data from three clinical studies of single-dose (2.5, 5 and 10 mg), orally administered dapagliflozin in adult (NCT00162305, NCT00538174) and paediatric (NCT01525238) patients with T2DM were analysed to examine the relationship between dapagliflozin exposure (area under concentration-time curve) and response [24-h urinary glucose excretion (UGE)] using a sigmoidal maximum effect model. Baseline fasting plasma glucose (FPG), estimated glomerular filtration rate (eGFR), baseline 24-h UGE, sex and race were evaluated as covariates.

RESULTS

Data from 63 predominantly white or Asian (92.4%) adult and 20 paediatric (45.8% white; 45.8% black) patients were included. The model appeared robust, with predictions fitting well with observed data. Baseline eGFR, FPG and sex were significant covariates in both populations; race was a significant covariate in the paediatric population only. Model-predicted UGE response was higher in paediatric (47.4, 67.5 and 85.9 g/24 h for 2.5, 5 and 10 mg) than in adult (31.2, 43.5 and 54.3 g/24 h for 2.5, 5 and 10 mg) patients, which may be associated with the higher eGFR values in paediatric patients.

CONCLUSIONS

After a single oral dose of dapagliflozin, adult and paediatric patients with T2DM had similar exposure-response relationships after accounting for significant covariates. These results support the planned dosage strategy for a phase III dapagliflozin safety and efficacy study in paediatric patients with T2DM, for whom treatment options are currently limited.

Mixed-effects modelling to quantify the effect of empagliflozin on renal glucose reabsorption in patients with type 2 diabetes

AIMS

To quantify the effect of the sodium-glucose co-transporter 2 inhibitor, empagliflozin, on renal glucose reabsorption in patients with type 2 diabetes, and to evaluate covariate effects, using a mechanistic population pharmacokinetic-pharmacodynamic (PK-PD) model.

METHODS

Four phase I/II trials were used for model development. Empagliflozin's PK characteristics were characterized by a two-compartmental model with sequential zero- and first-order absorption. Urinary glucose excretion (UGE) was described as dependent on renal glucose filtration and reabsorption; splay of the glucose reabsorption/excretion curves was considered. The modelling assumed that empagliflozin lowers the maximum renal glucose reabsorption capacity and, thereby, the renal threshold for glucose (RTg). Covariate effects were investigated using a full covariate modelling approach, emphasizing parameter estimation.

RESULTS

The PK-PD model provided a reasonable description of the PK characteristics of empagliflozin and its effects on UGE across a range of renal function levels. Its parameters are consistent with reported values for renal physiology. Using this model, the effect of empagliflozin on renal glucose reabsorption was quantified. Steady-state empagliflozin doses (1, 5, 10 and 25 mg) reduced RTg from 12.5 mmol/L [95% confidence interval (CI) 12.0, 13.1] to 5.66 (95% CI 4.62, 6.72), 3.01 (95% CI 2.33, 3.69), 2.53 (95% CI 1.83, 3.14) and 2.21 (95% CI 1.47, 2.84) mg/dl, respectively. Covariate analysis showed the effect of empagliflozin on UGE was not influenced, to a clinically relevant extent, by sex, age or race.

CONCLUSIONS

A method for characterizing renal glucose reabsorption was developed that does not require complex glucose clamp experiments. These analyses indicate that empagliflozin provided concentration-dependent RTg reductions, with 10 and 25 mg providing near-maximum RTg-lowering.

Comparison of the pharmacokinetics and pharmacodynamics of dapagliflozin in patients with type 1 versus type 2 diabetes mellitus

AIMS

To compare the pharmacokinetics and pharmacodynamics of dapagliflozin in patients with type 1 diabetes mellitus (T1DM) versus type 2 diabetes mellitus (T2DM) in order to explore the potential of dapagliflozin as add-on therapy to insulin in patients with T1DM.

METHODS

Steady-state pharmacokinetics and pharmacodynamics of dapagliflozin (1-100 mg) were evaluated in a meta-analysis of patients with T1DM or T2DM. A model was constructed of the relationship between dapagliflozin systemic exposure and urinary glucose excretion (UGE) in patients with T1DM versus those with T2DM.

RESULTS

Data were analysed from 160 patients (T1DM, n = 70; T2DM, n = 90). Dapagliflozin systemic exposure (maximum concentration and area under the curve) increased similarly in a dose-related manner in both patient populations. Dose-dependent increases in 24-h UGE were observed with dapagliflozin in both populations. Unadjusted results showed that with regard to UGE response, dapagliflozin was more potent in patients with T1DM {mean half-maximum effective concentration [EC50 ] = 2.72 ng/ml [95% confidence interval (CI) 1.14, 5.08]} than in patients with T2DM [EC50  = 12.2 ng/ml (95% CI 4.91, 21.1)]. After normalization for baseline fasting plasma glucose, estimated glomerular filtration rate and UGE, however, the UGE potency of dapagliflozin was similar between the two populations [T1DM: mean EC50 , 8.12 ng/ml (95% CI 2.95, 14.6); T2DM: mean EC50 , 7.75 ng/ml (95% CI 1.35, 18.1)].

CONCLUSIONS

Dapagliflozin pharmacokinetics and the predicted UGE dose exposure response to dapagliflozin were similar in patients with T1DM and those with T2DM and suggest that the dapagliflozin dosages currently used for the treatment of T2DM may provide benefit as add-on therapy to insulin in patients with T1DM.

Characterization and comparison of sodium-glucose cotransporter 2 inhibitors in pharmacokinetics, pharmacodynamics, and pharmacologic effects

The sodium-glucose cotransporter (SGLT) 2 offer a novel approach to treating type 2 diabetes by reducing hyperglycaemia via increased urinary glucose excretion. In the present study, the pharmacokinetic, pharmacodynamic, and pharmacologic properties of all six SGLT2 inhibitors commercially available in Japan were investigated and compared. Based on findings in normal and diabetic mice, the six drugs were classified into two categories, long-acting: ipragliflozin and dapagliflozin, and intermediate-acting: tofogliflozin, canagliflozin, empagliflozin, and luseogliflozin. Long-acting SGLT2 inhibitors exerted an antihyperglycemic effect with lower variability of blood glucose level via a long-lasting increase in urinary glucose excretion. In addition, ipragliflozin and luseogliflozin exhibited superiority over the others with respect to fast onset of pharmacological effect. Duration and onset of the pharmacologic effects seemed to be closely correlated with the pharmacokinetic properties of each SGLT2 inhibitor, particularly with respect to high distribution and long retention in the target organ, the kidney. While all six SGLT2 inhibitors were significantly effective in increasing urinary glucose excretion and reducing hyperglycemia, our findings suggest that variation in the quality of daily blood glucose control associated with duration and onset of pharmacologic effects of each SGLT2 inhibitor might cause slight differences in rates of improvement in type 2 diabetes.

Enhanced Bioconcentration of Bisphenol A in the Presence of Nano-TiO2 Can Lead to Adverse Reproductive Outcomes in Zebrafish

Titanium dioxide nanoparticles (n-TiO2) and bisphenol A (BPA) are widespread environmental contaminants in the aquatic environment. We hypothesized that n-TiO2 may adsorb BPA, and thus modify its bioavailability and toxicity to aquatic organisms. In this study, the bioavailability and toxicity of BPA (0, 2, 20, 200 μg/L) was investigated in the presence of n-TiO2 (100 μg/L). The n-TiO2 sorbed BPA and the resulting nanoparticles were taken up by zebrafish, where they translocated to the liver, brain, and gonad tissues. Increased tissue burdens of both BPA and n-TiO2 were observed following coexposure, and they also caused a reduction in plasma concentrations of estradiol (E2), testosterone (T), follicle-stimulating hormone (FSH), and luteinizing hormone (LH). Plasma vitellogenin (VTG) concentrations were significantly increased in males and females upon exposure to BPA. Histological examination of the ovary and testes did not show obvious morphological alterations; however, inhibition of egg production was noted in the presence of n-TiO2. The results indicated that n-TiO2 acts as a carrier of BPA and enhances its bioconcentration in zebrafish, leading to endocrine disruption and impairment of reproduction.

Biomonitoring of human exposures to chlorinated derivatives and structural analogs of bisphenol A

The high reactivity of bisphenol A (BPA) with disinfectant chlorine is evident in the instantaneous formation of chlorinated BPA derivatives (ClxBPA) in various environmental media that show increased estrogen-activity when compared with that of BPA. The documented health risks associated with BPA exposures have led to the gradual market entry of BPA structural analogs, such as bisphenol S (BPS), bisphenol F (BPF), bisphenol B (BPB), etc. A suite of exposure sources to ClxBPA and BPA analogs in the domestic environment is anticipated to drive the nature and range of halogenated BPA derivatives that can form when residual BPA comes in contact with disinfectant in tap water and/or consumer products. The primary objective of this review was to survey all available studies reporting biomonitoring protocols of ClxBPA and structural BPA analogs (BPS, BPF, BPB, etc.) in human matrices. Focus was paid on describing the analytical methodologies practiced for the analysis of ClxBPA and BPA analogs using hyphenated chromatography and mass spectrometry techniques, because current methodologies for human matrices are complex. During the last decade, an increasing number of ecotoxicological, cell-culture and animal-based and human studies dealing with ClxBPA exposure sources and routes of exposure, metabolism and toxicity have been published. Up to date findings indicated the association of ClxBPA with metabolic conditions, such as obesity, lipid accumulation, and type 2 diabetes mellitus, particularly in in-vitro and in-vivo studies. We critically discuss the limitations, research needs and future opportunities linked with the inclusion of ClxBPA and BPA analogs into exposure assessment protocols of relevant epidemiological studies.

Pharmacokinetics of bisphenol A in humans following a single oral administration

BACKGROUND

Human exposures to bisphenol A (BPA) are widespread. The current study addresses uncertainties regarding human pharmacokinetics of BPA.

OBJECTIVE

To reduce uncertainties about the metabolism and excretion of BPA in humans following oral administration.

METHODS

We exposed six men and eight women to 100 μg/kg bw of deuterated BPA (d6-BPA) by oral administration and conducted blood and urine analysis over a three day period. The use of d6-BPA allowed administered d6-BPA to be distinguished from background native (unlabeled) BPA. We calculated the rate of oral absorption, serum elimination, half-life, area under the curve (AUC), urinary excretion, and metabolism to glucuronide and sulfate conjugates.

RESULTS

Mean serum total (unconjugated and conjugated) d6-BPA Cmax of 1711 nM (390 ng/ml) was observed at Tmax of 1.1 ± 0.50h. Unconjugated d6-BPA appeared in serum within 5-20 min of dosing with a mean Cmax of 6.5 nM (1.5 ng/ml) observed at Tmax of 1.3 ± 0.52 h. Detectable blood levels of unconjugated or total d6-BPA were observed at 48 h in some subjects at concentrations near the LOD (0.001-0.002 ng/ml). The half-times for terminal elimination of total d6-BPA and unconjugated d6-BPA were 6.4 ± 2.0 h and 6.2 ± 2.6h, respectively. Recovery of total administered d6-BPA in urine was 84-109%. Most subjects (10 of 14) excreted >90% as metabolites within 24h.

CONCLUSIONS

Using more sensitive methods, our study expands the findings of other human oral pharmacokinetic studies. Conjugation reactions are rapid and nearly complete with unconjugated BPA comprising less than 1% of the total d6-BPA in blood at all times. Elimination of conjugates into urine largely occurs within 24h.

Pharmacokinetics of bisphenol A in humans following a single oral administration

BACKGROUND

Human exposures to bisphenol A (BPA) are widespread. The current study addresses uncertainties regarding human pharmacokinetics of BPA.

OBJECTIVE

To reduce uncertainties about the metabolism and excretion of BPA in humans following oral administration.

METHODS

We exposed six men and eight women to 100 μg/kg bw of deuterated BPA (d6-BPA) by oral administration and conducted blood and urine analysis over a three day period. The use of d6-BPA allowed administered d6-BPA to be distinguished from background native (unlabeled) BPA. We calculated the rate of oral absorption, serum elimination, half-life, area under the curve (AUC), urinary excretion, and metabolism to glucuronide and sulfate conjugates.

RESULTS

Mean serum total (unconjugated and conjugated) d6-BPA Cmax of 1711 nM (390 ng/ml) was observed at Tmax of 1.1 ± 0.50h. Unconjugated d6-BPA appeared in serum within 5-20 min of dosing with a mean Cmax of 6.5 nM (1.5 ng/ml) observed at Tmax of 1.3 ± 0.52 h. Detectable blood levels of unconjugated or total d6-BPA were observed at 48 h in some subjects at concentrations near the LOD (0.001-0.002 ng/ml). The half-times for terminal elimination of total d6-BPA and unconjugated d6-BPA were 6.4 ± 2.0 h and 6.2 ± 2.6h, respectively. Recovery of total administered d6-BPA in urine was 84-109%. Most subjects (10 of 14) excreted >90% as metabolites within 24h.

CONCLUSIONS

Using more sensitive methods, our study expands the findings of other human oral pharmacokinetic studies. Conjugation reactions are rapid and nearly complete with unconjugated BPA comprising less than 1% of the total d6-BPA in blood at all times. Elimination of conjugates into urine largely occurs within 24h.

Lessons learned from the application of BEES-C: Systematic assessment of study quality of epidemiologic research on BPA, neurodevelopment, and respiratory health

Epidemiologic studies evaluating associations between biomarkers of exposure to short-lived chemicals and health endpoints in humans face special challenges. Perhaps the most critical challenges are the need to determine the type and optimal number of samples, and the proper timing of specimen collection. Further, as many short-lived chemicals are ubiquitous in the environment, utmost care is required to avoid sample contamination. A separate set of challenges is associated with appropriate interpretation and reporting of results from multiple simultaneous analyses, which are becoming increasingly feasible. The Biomonitoring, Environmental Epidemiology, and Short-Lived Chemicals (BEES-C) instrument is specifically designed to evaluate the quality of epidemiologic studies that measure biomarkers of chemicals with short physiologic half-lives. The instrument provides systematic guidance for evaluating 14 different aspects of study quality divided into three broad categories: 1) biomarker selection and measurement, 2) strategy and execution of exposure assessment, and 3) general considerations of study design and reporting. We evaluated the utility of the BEES-C instrument using epidemiologic studies of exposure to bisphenol A and its association with neurodevelopmental and respiratory health indicators. Each BEES-C element was assessed with respect to needed modifications and concordance among reviewers using professional, scientific judgment. Based on this first use of the BEES-C instrument, we found that most of its elements were effective in comparing the quality of available studies, with reviews generally concordant and justifications consistent. However, we note that certain elements would be improved with slight adjustments and that one of the elements appeared redundant and should be removed.

Reconstruction of bisphenol A intake using a simple pharmacokinetic model

Bisphenol A (BPA) is used in the manufacture of a range of consumer products, and human biomonitoring studies suggest that exposure to BPA is nearly ubiquitous. We constructed and calibrated a simple pharmacokinetic model to predict urinary concentrations of BPA based on a known initial dose. This descriptive (rather than physiologically based) model has three compartments: "stomach/liver," "blood," and "bladder." We calibrated and validated the model parameters using blood and urine measurements from nine volunteers who consumed 5 mg of d₁₆-BPA. We then applied the model to a second group of eight persons, who supplied full volumes of urine over 7 consecutive days and a diary identifying times and types of food and beverage consumed, to "reconstruct" the time and mass of BPA intakes. These reconstructed daily intakes ranged on average from 60 to 100 ng/kg-day, within the range of, but slightly higher than, those surmised from other studies. About two-thirds of intakes occurred within an hour of reported food or drink consumption, supporting the hypothesis that diet is the main pathway of exposure to BPA. However, one-third of all reconstructed intakes took place outside this time window, suggesting that other sources of BPA exposure may also be relevant.

Dapagliflozin twice daily or once daily: effect on pharmacokinetics and urinary glucose excretion in healthy subjects

The primary objective of this single-centre, open-label crossover study (NCT01072578) was to assess the effect of dapagliflozin on the amount of glucose in the blood and urine in healthy volunteers when dapagliflozin was administered once a day (10 mg) versus twice a day (5 mg every 12 h) after 5 days of dosing. At steady state, the AUC(ss)₀₋₂₄ (area under the dapagliflozin curve (0-24 hours) at steady state), C(ss,av) (average concentration at steady state) between dapagliflozin 5 mg twice daily and 10 mg once daily were similar AUC(ss)₀₋₂₄ [5 mg bid, (458.0 (28.7)) and 10 mg qd, (470.0 (28.5))] and C(ss,av) [5 mg bid 18.8 (28.9)) and 10 mg qd, (19.6(28.5))], but minimum and maximum plasma levels of dapagliflozin differed significantly. Percent inhibition of renal glucose reabsorption (%IRGRA) and total urinary glucose excretion over 24 h were similar for both doses. The relationship between the mean dapagliflozin concentration and %IRGRA and the total urinary glucose excreted was well described by a maximum effect model. The results indicate that dapagliflozin may be used for either once daily or twice daily administration.

Widespread occurrence and accumulation of bisphenol A diglycidyl ether (BADGE), bisphenol F diglycidyl ether (BFDGE) and their derivatives in human blood and adipose fat

Despite the widespread use of bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE) in various consumer products, studies on human exposure to these compounds are scarce. In this study, BADGE, BFDGE, and seven of their derivatives were determined in human adipose fat and blood plasma samples collected from New York City, NY. Bisphenol A bis (2,3-dihydroxypropyl) ether [BADGE·2H2O] was the major BADGE derivative found in 60% of the adipose samples and 70% of the plasma samples analyzed. High concentrations and detection frequencies of BFDGE were found in both adipose and plasma samples. BFDGE concentrations in adipose fat ranged from 19.1 to 4500 ng/g wet weight. A significant correlation between BADGE or BFDGE and their derivatives in adipose and plasma samples suggested hydration of these reactive compounds in humans. A significant positive correlation existed between BADGEs (i.e., the sum of BADGE and its five derivatives) and BFDGEs in adipose samples, which suggested similar exposure sources and pathways for these compounds in humans. Bisphenol A (BPA) also was analyzed in adipose fat and plasma, and its concentrations were positively correlated with those of BADGEs, which confirmed coexposure of BADGEs and BPA in humans.

Pharmacodynamic differences between canagliflozin and dapagliflozin: results of a randomized, double-blind, crossover study

AIMS

To compare the pharmacodynamic effects of the highest approved doses of the sodium glucose co-transporter 2 (SGLT2) inhibitors canagliflozin and dapagliflozin on urinary glucose excretion (UGE), renal threshold for glucose excretion (RTG ) and postprandial plasma glucose (PPG) excursion in healthy participants in a randomized, double-blind, two-period crossover study.

METHODS

In each treatment period, participants (n = 54) received canagliflozin 300 mg or dapagliflozin 10 mg for 4 days (20 min before breakfast). A mixed-meal tolerance test (600 kcal; 75 g glucose) was performed at baseline and on day 4 of each treatment period to assess changes in incremental PPG (PPGΔAUC0-2 h ). We measured 24-h UGE and plasma glucose on day 4 to determine 24-h mean RTG .

RESULTS

Canagliflozin 300 mg and dapagliflozin 10 mg had similar effects on UGE and RTG for 4 h after dosing, but canagliflozin was associated with higher UGE and greater RTG reductions for the remainder of the day. Mean 24-h UGE was ∼25% higher with canagliflozin than with dapagliflozin (51.4 vs. 40.8 g), and 24-h mean RTG was ∼0.4 mmol/l (7 mg/dl) lower with canagliflozin than with dapagliflozin (3.79 vs. 4.17 mmol/l; p < 0.0001). Dapagliflozin had no effect on PPG excursion; canagliflozin delayed and reduced PPG excursion (between-treatment difference in PPGΔAUC0-2 h from baseline expressed as a percentage of baseline mean, -10.2%; p = 0.0122). Canagliflozin and dapagliflozin were generally well tolerated.

CONCLUSIONS

In healthy participants, canagliflozin 300 mg provided greater 24-h UGE, a lower RTG and smaller PPG excursions than dapagliflozin 10 mg.