Searching for diagnostic properties of novel fluorine-18-labeled D-allose.

OBJECTIVE: Two fluorine-18-labeled analogues, 3-deoxy-3-[18F]fluoro-D-allose (3-[18F]FDA) and 6-deoxy-6-[18F]fluoro-D-allose (6-[18F]FDA), were synthesized and their potentials of diagnostic property were characterized. METHODS: In vitro rat red blood cell (RBC) transport and phosphorylation by yeast hexokinase were evaluated in comparison with 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG). The rate of protein binding in pooled human serum was measured by an ultrafiltration method. In vivo metabolite analysis in mice was also performed. Biodistribution, urine excretion, and in vivo renal kinetics in mice were compared with 2-deoxy-2-[18F]fluorosorbitol ([18F]FDS). RESULTS: Rat RBC uptake of 3- and 6-[18F]FDA (7.8 ± 2.5%ID and 10.2 ± 4.8%ID, respectively) was significantly lower than that of [18F]FDG (44.7 ± 8.7%ID). RBC uptake of 3-[18F]FDA was inhibited by D-glucose (30%) and cytochalasin B (40%), indicating the involvement of GLUT1-dependent transport. In contrast, 6-[18F]FDA transport was not inhibited by D-glucose and cytochalasin B. 3- and 6-[18F]FDA were not phosphorylated by yeast hexokinase under the conditions that result in 60% conversion of [18F]FDG into [18F]FDG-6-phosphate within 30 min. Serum protein binding of 3- and 6-[18F]FDA was negligible. Metabolic transformation of both tracers was not detected in plasma and urine at 30 min after injection. The highest tissue uptake of both tracers was observed in kidneys. Heart and brain uptake of both tracers was below blood levels throughout the biodistribution studies (until 120 min after injection). No significant uptake in the bone was observed, indicating the absence of de-fluorination in mice. In vivo PET imaging visualized rapid excretion of the administered 3- and 6-[18F]FDA from the kidneys, with minimal tracer accumulation in other organs. The urine excretion rate of 3-[18F]FDA was much lower than that of 6-[18F]FDA and [18F]FDS. CONCLUSIONS: 3- and 6-[18F]FDA might be unsatisfactory for tumor imaging. In contrast, these tracers demonstrated high levels of kidney uptake and excretion, low serum protein binding, and high metabolic stability as preferable properties for renal imaging. Notably, the urine excretion rate and kidney uptake kinetics of 6-[18F]FDA were comparable with those of the potential renal imaging agent [18F]FDS. Further validation studies in animal models are required to confirm the feasibility of 6-[18F]FDA as a functional renal imaging agent.

Discovery of potent, low-absorbable sodium-dependent glucose cotransporter 1 (SGLT1) inhibitor SGL5213 for type 2 diabetes treatment.

A new series of C-phenyl d-glucitol derivatives was designed and synthesized, and their SGLT1 inhibitory potency and absorbability were evaluated. We also investigated whether kidney drug retention could be avoided by creating molecules with different excretion pathways. To achieve a class of molecules with low absorption and that were excreted in bile, optimized synthesis was performed to bring the ClogP value and the topological polar surface area to within the appropriate ranges. Compounds 34d and 34j were poorly absorbed, but the absorbed compounds were mainly excreted in bile. Thus, smaller amounts of persistent residue in the kidneys were observed. Since 34d exerted a glucose-lowering effect at a dose of 0.3 mg/kg (p.o.) in SD rats, this compound (SGL5213) could be a clinical candidate for the treatment of type 2 diabetes.

Acid-Induced Activated Cell-Penetrating Peptide-Modified Cholesterol-Conjugated Polyoxyethylene Sorbitol Oleate Mixed Micelles for pH-Triggered Drug Release and Efficient Brain Tumor Targeting Based on a Charge Reversal Mechanism.

Glioblastoma multiforme is the most devastating malignant brain tumor in adults. Even with the standard care of therapy, the prognosis remains dismal due to tumor heterogeneity, tumor infiltration, and, more importantly, the restrictive nature of the blood-brain barrier (BBB). To overcome the challenge of effectively delivering therapeutic cargo into the brain, herein a "smart", multifunctional polymeric micelle was developed using a cholesterol-conjugated polyoxyethylene sorbitol oleate. A cell-penetrating peptide, arginine-glycine repeats (RG)5, was incorporated into the micelles to improve cellular uptake, while a pH-sensitive masking sequence, histidine-glutamic acid repeats (HE)5, was introduced for charge shielding to minimize nonspecific binding and uptake at physiological pH. Results demonstrated that (RG)5- and (HE)5-modified mixed micelles were optimized using this strategy to effectively mask the cationic charges of the activated cell-penetrating peptide (RG)5 at physiological pH, i.e., limiting internalization, and were selectively triggered in response to a mildly acidic microenvironment in vitro based on a charge reversal mechanism. In vivo results further confirmed that such micelles preferentially accumulated in both brain and tumor tissues in both xenograft and orthotropic glioma mouse models. Furthermore, micelles significantly inhibited tumor growth with limited toxicity to peripheral tissues. The combination of BBB penetration, tumor targeting, potent efficacy, and high tolerance of these micelles strongly suggests that they could be a promising candidate for safe and effective drug delivery to the brain.

Pharmacokinetics and Pharmacodynamics of Luseogliflozin, a Selective SGLT2 Inhibitor, in Japanese Patients With Type 2 Diabetes With Mild to Severe Renal Impairment.

This open-label, parallel-group, multicenter study aimed to assess the effects of renal impairment on the pharmacokinetics, pharmacodynamics, and safety of luseogliflozin. A single 5-mg dose of luseogliflozin was administered to Japanese patients with type 2 diabetes mellitus in the following groups: G1, normal renal function; G2, mild renal impairment; G3a, mild to moderate impairment; G3b, moderate to severe impairment; G4, severe impairment, based on estimated glomerular filtration rate (eGFR; ≥90, 60-89, 45-59, 30-44, 15-29 mL/min/1.73 m2 , respectively). While luseogliflozin pharmacokinetics were similar for patients across all renal function groups, the increase in plasma concentration was slightly slower and maximum concentration was slightly reduced in the lower eGFR groups compared with the other groups. However, luseogliflozin pharmacodynamics were affected by the severity of renal impairment. Urinary glucose excretion (UGE) increased in all groups relative to baseline levels, but the degree of UGE increase was smaller in the lower eGFR groups. Moreover, plasma glucose AUC changes from baseline tended to be smaller in the lower eGFR groups. No clear trends were observed between eGFR and incidence, type, or severity of adverse events. Thus, luseogliflozin administration should be carefully considered, as patients with renal impairment may show an insufficient response to treatment.

Luseogliflozin, an SGLT2 Inhibitor, in Japanese Patients With Mild/Moderate Hepatic Impairment: A Pharmacokinetic Study.

This open-label, parallel-group study evaluated the effect of mild and moderate hepatic impairment on the pharmacokinetics of a single dose of luseogliflozin in Japanese subjects. Thirteen subjects with hepatic impairment (mild, n = 8; moderate, n = 5) and 6 healthy subjects received a single 5-mg dose of luseogliflozin. Serial blood sampling over 72 hours and 24-hour urine collection were done for pharmacokinetic analysis of luseogliflozin and its metabolites and to measure pharmacokinetic and pharmacodynamic parameters, respectively. Demographic characteristics were similar at baseline for both groups. Geometric mean ratios of maximum plasma concentration (Cmax ) and area under the plasma concentration-time curve from time zero to infinity (AUCinf [90%CI]) of unchanged luseogliflozin were 1.02 (0.790-1.32) and 0.774 (0.580-1.03), respectively, on comparing patients with hepatic impairment with healthy subjects, and 0.939 (0.752-1.17) and 1.00 (0.780-1.28), respectively, in subjects with mild and moderate hepatic impairment. Although mean plasma concentrations of metabolites were slightly higher in patients with hepatic impairment versus healthy subjects, their time-course plasma concentrations were very low compared with those of unchanged luseogliflozin. Single-dose luseogliflozin 5 mg was well tolerated by study participants, indicating luseogliflozin dose adjustment is not necessary in patients with mild and moderate hepatic impairment.

Mechanism-Based Pharmacokinetic-Pharmacodynamic Modeling of Luseogliflozin, a Sodium Glucose Co-transporter 2 Inhibitor, in Japanese Patients with Type 2 Diabetes Mellitus.

Luseogliflozin is a selective sodium glucose co-transporter 2 (SGLT2) inhibitor that reduces hyperglycemia in type 2 diabetes mellitus (T2DM) by promoting urinary glucose excretion (UGE). A clinical pharmacology study conducted in Japanese patients with T2DM confirmed dose-dependency of UGE with once-daily administration of luseogliflozin; however, the reason for sustained UGE after plasma luseogliflozin decreased was unclear. To elucidate the effect of inhibition rate constants, Kon and Koff, and to explain the sustained UGE, a pharmacokinetic-pharmacodynamic (PK-PD) model was built based on the mechanisms of glucose filtration in the glomerulus and reabsorption in the renal proximal tubule of kidney as well as the kinetics of competitive inhibition of SGLT1/2 and inhibition rate constants of SGLT2, by using UGE and plasma glucose levels and luseogliflozin concentrations. This acquired population PK-PD model adequately described the sustained UGE and the estimated population means of the inhibition constant for SGLT2 (Ki2) and inhibition-rate constants for SGLT2 (Kon and Koff) were 0.31- and 3.6-fold lower or higher than the in vitro values. Because the dissociation half-time of luseogliflozin from SGLT2 calculated from Koff, 6.81 h, was consistent with the value in vitro, we considered that the sustained UGE could be explained by the long dissociation half-time. Moreover, by calculating the SGLT2 inhibition ratio using the model, we discuss other properties of the UGE time course after luseogliflozin administration.

Torsemide Fast Dissolving Tablets: Development, Optimization Using Box-Bhenken Design and Response Surface Methodology, In Vitro Characterization, and Pharmacokinetic Assessment.

The present study planed to develop new fast dissolving tablets (FDTs) of torsemide. Solid dispersions (SDs) of torsemide and sorbitol (3:1) or polyvinylpyrrolidone (PVP) k25 were prepared. The prepared SDs were evaluated for in-vitro dissolution. Fourier transform infrared spectroscopy and differential scanning calorimetry for SDs revealed no drug/excipient interactions and transformation of torsemide to the amorphous form. Torsemide/sorbitol SD was selected for formulation of torsemide FDTs by direct compression method. Box-Bhenken factorial design was employed to design 15 formulations using croscarmellose sodium and crospovidone at different concentrations. The response surface methodology was used to analyze the effect of changing these concentrations (independent variables) on disintegration time (Y1), percentage friability (Y2), and amount torsemide released at 10 min. The physical mixtures of torsemide and the used excipients were evaluated for angle of repose, Hausner's ratio, and Carr's index. The prepared FDTs tablets were evaluated for wetting and disintegration time, weight variation, drug content, percentage friability, thickness, hardness, and in vitro release. Based on the in-vitro results and factorial design characterization, F10 and F7 were selected for bioavailability studies following administration to Albino New Zealand rabbits. They showed significantly higher C max and (AUC0-12) and shorter T max than those obtained after administration of the corresponding ordinary commercial Torseretic ® tablets. Stability study was conducted for F10 that showed good stability upon storage at 30°C/75% RH and 40°C/75% RH for 3 months.

A simple and rapid LC-MS/MS method for quantitation of luseogliflozin in rat plasma and its application to a PK study.

AIM: Luseogliflozin is a novel sodium-dependent glucose cotransporter-2 inhibitor for the treatment of Type 2 diabetes mellitus. To assist pharmacokinetic and toxicodynamic studies, a rapid LC-MS/MS method were developed and validated for the quantitation of luseogliflozin in rat plasma. RESULTS: Sample preparation was carried out using simplified protein precipitation and liquid-liquid extraction procedures, and the run time was only 4 min. Extraction recovery was 92.9 to 95.3%, and the method was validated over the range 0.5 to 500 ng/ml for luseogliflozin with acceptable specificity, accuracy and precision. CONCLUSION: The validated method is considered suitable to quantify luseogliflozin in pharmacokinetic and pharmacodynamic/toxicodynamic studies in rats.

A Systematic Approach for Developing Bacteria-Specific Imaging Tracers.

The modern patient is increasingly susceptible to bacterial infections including those due to multidrug-resistant organisms (MDROs). Noninvasive whole-body analysis with pathogen-specific imaging technologies can significantly improve patient outcomes by rapidly identifying a source of infection and monitoring the response to treatment, but no such technology exists clinically. METHODS: We systematically screened 961 random radiolabeled molecules in silico as substrates for essential metabolic pathways in bacteria, followed by in vitro uptake in representative bacteria-Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and mycobacteria. Fluorine-labeled analogs, that could be developed as PET-based imaging tracers, were evaluated in a murine myositis model. RESULTS: We identified 3 novel, nontoxic molecules demonstrating selective bacterial uptake: para-aminobenzoic acid (PABA), with uptake in all representative bacteria including Mycobacterium tuberculosis; mannitol, with selective uptake in S. aureus and E. coli; and sorbitol, accumulating only in E. coli None accumulated in mammalian cells or heat-killed bacteria, suggesting metabolism-derived specificity. In addition to an extended bacterial panel of laboratory strains, all 3 molecules rapidly accumulated in respective clinical isolates of interest including MDROs such as methicillin-resistant S. aureus, extended-spectrum ß-lactamase-producing, and carbapenem-resistant Enterobacteriaceae. In a murine myositis model, fluorine-labeled analogs of all 3 molecules could rapidly detect and differentiate infection sites from sterile inflammation in mice (P = 0.03). Finally, 2-deoxy-2-[F-18]fluoro-d-sorbitol (18F-FDS) can be easily synthesized from 18F-FDG. PET, with 18F-FDS synthesized using current good manufacturing practice, could rapidly differentiate true infection from sterile inflammation to selectively localize E. coli infection in mice. CONCLUSION: We have developed a systematic approach that exploits unique biochemical pathways in bacteria to develop novel pathogen-specific imaging tracers. These tracers have significant potential for clinical translation to specifically detect and localize a broad range of bacteria, including MDROs.

Lactase Non-Persistence Genotyping: Comparison of Two Real-Time PCR Assays and Assessment of Concomitant Fructose/Sorbitol Malabsorption Rates.

BACKGROUND: Genetic testing is a standard technique for the diagnosis of primary adult-type hypolactasia, also referred to as lactase non-persistence. The aim of this study was to compare the lactase gene (LCT) C/T-13910 polymorphism genotyping results of two commercially available real-time (RT)-PCR assays in patients referred to our outpatient clinic for primary lactose malabsorption testing. Furthermore, concomitant conditions of fructose/sorbitol malabsorption were assessed. METHODS: Samples obtained from 100 patients were tested in parallel using the LCT T-13910C ToolSet for Light Cycler (Roche, Rotkreuz, Switzerland) and the LCT-13910C>T RealFast Assay (ViennaLab Diagnostics GmbH, Vienna, Austria). Additionally, patients were also screened for the presence of fructose/sorbitol malabsorption by functional hydrogen (H2)/methane (CH4) breath testing (HMBT). Cohen's Kappa (κ) was used to calculate the agreement between the two genotyping methods. The exact Chi-Square test was performed to compare fructose/sorbitol HMBT with LCT genotyping results. RESULTS: Twenty-one (21.0%) patients had a LCT C/C-13910 genotype suggestive of lactase non-persistence, and 79 (79.0%) patients were identified with either a LCT T/C-13910 or T/T-13910 genotype (i.e., lactase persistence). In all genotype groups, concordance between the two RT-PCR assays was 100%. Cohen's κ demonstrated perfect observed agreement (p < 0.001, κ = 1). Fructose and sorbitol malabsorption was observed in 13/100 (13.0%) and 25/100 (25.0%) individuals, respectively. CONCLUSIONS: Both RT-PCR assays are robust and reliable LCT genotyping tools in a routine clinical setting. Concomitant fructose and/or sorbitol malabsorption should be considered in individuals with suspected lactase-non-persistence. However, standardization of clinical interpretation of laboratory HMBT results is required.

Infection Imaging With (18)F-FDS and First-in-Human Evaluation.

PURPOSE: The noninvasive imaging of bacterial infections is critical in order to reduce mortality and morbidity caused by these diseases. The recently reported (18)F-FDS ((18)F-2-fluorodeoxy sorbitol) as a PET (positron emission tomography) tracer can be used to image Enterobacteriaceae-specific infections and provides a potential alternative to this problem compared with other probes for imaging infections. In this study, automatic synthesis, validation of (18)F-FDS and a first-in-human study were performed and discussed. METHODS: A multifunctional synthesis module was employed for the radiosynthesis of (18)F-FDG ((18)F-2-fluorodeoxy glucose) and (18)F-FDS starting from (18)F ion using two-pot three-step fully automated reactions. The behavior of (18)F-FDS as an in vivo imaging probe for infections was evaluated in an Escherichia coli mouse infection model. The first detailed pharmacokinetic and biodistribution parameters were obtained from healthy human volunteers. RESULTS: The uptake of (18)F-FDS in an E. coli mouse-myositis infection model was easily differentiated from other organs and normal muscle. Intensive lesion uptake declined after antibiotic treatment. In the pilot human study, no adverse effects due to (18)F-FDS were observed up to 24 h post-injection. The radiotracer was rapidly cleared from the circulation and excreted mainly through the urinary system. CONCLUSION: We conclude that (18)F-FDS PET holds great potential for appropriate and effective for the imaging of bacterial infections in vivo. These preliminary results indicate that further clinical studies are warranted.

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.

Initial Preclinical Evaluation of 18F-Fluorodeoxysorbitol PET as a Novel Functional Renal Imaging Agent.

Accurate assessment of kidney function plays an essential role for optimal clinical decision making in a variety of diseases. The major intrinsic advantages of PET are superior spatial and temporal resolutions for quantitative tomographic renal imaging. 2-deoxy-2-18F-fluorodeoxysorbitol (18F-FDS) is an analog of sorbitol that is reported to be freely filtered at the renal glomerulus without reabsorption at the tubule. Furthermore, it can be synthesized via simple reduction of widely available 18F-FDG. We tested the feasibility of 18F-FDS renal PET imaging in rats. METHODS: The systemic and renal distribution of 18F-FDS were determined by dynamic 35-min PET imaging (15 frames × 8 s, 26 frames × 30 s, 20 frames × 60 s) with a dedicated small-animal PET system and postmortem tissue counting in healthy rats. Distribution of coinjected 99mTc-diethylenetriaminepentaacetic acid (DTPA) was also estimated as a reference. Plasma binding and in vivo stability of 18F-FDS were determined. RESULTS: In vivo PET imaging visualized rapid excretion of the administrated 18F-FDS from both kidneys, with minimal tracer accumulation in other organs. Initial cortical tracer uptake followed by visualization of the collecting system could be observed with high contrast. Split-function renography curves were successfully obtained in healthy rats (the time of maximal concentration [Tmax] right [R] = 2.8 ± 1.2 min, Tmax left [L] = 2.9 ± 1.5 min, the time of half maximal concentration [T1/2max] R = 8.8 ± 3.7 min, T1/2max L = 11.1 ± 4.9 min). Postmortem tissue counting of 18F-FDS confirmed the high kidney extraction (kidney activities at 10, 30, and 60 min after tracer injection [percentage injected dose per gram]: 1.8 ± 0.7, 1.2 ± 0.1, and 0.5 ± 0.2, respectively) in a degree comparable to 99mTc-DTPA (2.5 ± 1.0, 1.5 ± 0.2, and 0.8 ± 0.3, respectively). Plasma protein binding of 18F-FDS was low (<0.1%), and metabolic transformation was not detected in serum and urine. CONCLUSION: In rat experiments, 18F-FDS demonstrated high kidney extraction and excretion, low plasma protein binding, and high metabolic stability as preferable properties for renal imaging. These preliminary results warrant further confirmatory studies in large animal models and clinical studies as a novel functional renal imaging agent, given the advantages of PET technology and broad tracer availability.

Preclinical metabolism and disposition of luseogliflozin, a novel antihyperglycemic agent.

1. We investigated the metabolism and disposition of luseogliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, in rats and dogs, as well as in vitro metabolism in rats, dogs and humans. In addition, we studied its localization in the rat kidney. 2. [14C]Luseogliflozin was rapidly and well absorbed (>86% of the dose) after oral administration to rats and dogs. The drug-derived radioactivity was mainly excreted via the feces in both species. 3. The predominant radioactivity component in the excreta was associated with the metabolites, with only a minor fraction of unchanged luseogliflozin. The major metabolites were two glucuronides (M8 and M16) in the rats, and the O-deethylated form (M2) and other oxidative metabolites (M3 and M17) in the dogs. 4. The in vitro metabolism in dog and human hepatocytes was significantly slower than that in the rat hepatocytes. The biotransformation in animal hepatocytes was similar to that observed in vivo. Incubation with human hepatocytes resulted in the formation of metabolites, including M2, M3, M8 and M17, via multiple metabolic pathways. 5. [14C]Luseogliflozin was well-distributed to its target organ, the kidney, and was found to be localized in the renal cortex, which shows SGLT2 expression. This characteristic distribution was inhibited by preinjection of phlorizin, an SGLT inhibitor, suggesting that the renal radioactivity was associated with SGLT2.

Randomized, Controlled, Thorough QT/QTc Study Shows Absence of QT Prolongation with Luseogliflozin in Healthy Japanese Subjects.

Luseogliflozin is a selective sodium glucose co-transporter 2 (SGLT2) inhibitor. To evaluate the cardiac safety of luseogliflozin, a thorough QT/QTc study was conducted in healthy Japanese subjects. The effects of moxifloxacin on QT prolongation in Japanese subjects were also evaluated. In this double-blind, placebo- and open-label positive-controlled, 4-way crossover study, 28 male and 28 female subjects received a single dose of luseogliflozin 5 mg (therapeutic dose), luseogliflozin 20 mg (supratherapeutic dose), placebo, and moxifloxacin 400 mg. Serial triplicate digital 12-lead electrocardiograms (ECGs) were recorded before and after dosing, and results were analyzed using the Fridericia correction (QTcF) method. Serial blood sampling was performed for pharmacokinetic analyses of luseogliflozin and moxifloxacin to analyze the relationship between QTcF interval and plasma concentration. The upper limits of the two-sided 90% confidence intervals (CIs) for baseline and placebo-adjusted QTcF intervals (ΔΔQTcF) in the 5 mg and 20 mg luseogliflozin groups were less than 10 ms at all time points. No correlation between plasma luseogliflozin concentrations and ΔΔQTcF was observed. In the moxifloxacin group, the lower limits of the two-sided 90% CIs for ΔΔQTcF were greater than 5 ms at all time points. A positive relationship was observed between plasma moxifloxacin concentration and change in ΔΔQTcF. Luseogliflozin was well tolerated at both dose levels. The majority of adverse events were mild in severity, and no serious or life-threatening adverse events occurred. Neither therapeutic (5 mg) nor supratherapeutic (20 mg) doses of luseogliflozin affected QT prolongation in healthy Japanese subjects.

In vitro characterization of luseogliflozin, a potent and competitive sodium glucose co-transporter 2 inhibitor: Inhibition kinetics and binding studies.

In this study, we evaluated an inhibition model of luseogliflozin on sodium glucose co-transporter 2 (SGLT2). We also analyzed the binding kinetics of the drug to SGLT2 protein using [(3)H]-luseogliflozin. Luseogliflozin competitively inhibited human SGLT2 (hSGLT2)-mediated glucose uptake with a Ki value of 1.10 nM. In the absence of glucose, [(3)H]-luseogliflozin exhibited a high affinity for hSGLT2 with a Kd value of 1.3 nM. The dissociation half-time was 7 h, suggesting that luseogliflozin dissociates rather slowly from hSGLT2. These profiles of luseogliflozin might contribute to the long duration of action of this drug.

Pharmacokinetics, Pharmacodynamics, and Safety of Luseogliflozin in Japanese Patients with Type 2 Diabetes Mellitus: A Randomized, Single-blind, Placebo-controlled Trial.

INTRODUCTION: Luseogliflozin, a potent, selective sodium glucose cotransporter 2 inhibitor, promotes urinary glucose excretion (UGE) and reduces plasma glucose concentrations. Luseogliflozin was approved for use in Japan after favorable pharmacokinetic, pharmacodynamic, and safety profiles were reported in healthy Japanese subjects and patients with type 2 diabetes mellitus (T2DM) in clinical development studies. We aimed to investigate the pharmacokinetics, pharmacodynamics, and safety of multiple doses of luseogliflozin administered once daily for 7 days in Japanese patients with T2DM. METHODS: We conducted a randomized, placebo-controlled, single-blind, parallel-group, clinical pharmacology study at the P-One Clinic, Keikokai Medical Corporation (Tokyo, Japan) between August 2009 and November 2009. Forty Japanese patients with T2DM were randomly assigned to receive once-daily 0.5, 1, 2.5 or 5 mg luseogliflozin or placebo for 7 days. We assessed the pharmacokinetics, pharmacodynamics (including changes in UGE and plasma glucose concentrations), and safety of luseogliflozin. RESULTS: The plasma concentrations of luseogliflozin and its active metabolite, M2, were dose proportional, without accumulation. 24-h UGE was greater in all luseogliflozin groups versus placebo. Least-squares mean differences in 24-h UGE on Day 7 increased dose dependently in the luseogliflozin groups, with values of 49.2, 66.5, 89.4, and 101 g/day at 0.5, 1, 2.5, and 5 mg, respectively. On Day 7, the areas under the concentration-time curves for post-meal plasma glucose and the mean plasma glucose for 0-16 h were significantly lower in all luseogliflozin groups versus placebo. Seven patients had mild adverse events (AEs); all were resolved. No AEs led to study discontinuation. CONCLUSION: Once-daily administration of luseogliflozin for 7 days increased 24-h UGE in a dose-dependent manner, reduced plasma glucose concentrations, and was well tolerated in Japanese patients with T2DM. The pharmacokinetic and pharmacodynamic profile of luseogliflozin observed in this study supports its once-daily dosing regimen. FUNDING: Taisho Pharmaceutical Co., Ltd.

Luseogliflozin for the treatment of type 2 diabetes.

INTRODUCTION: Sodium glucose cotransporter 2 (SGLT2) inhibitors are expected to provide adequate glycemic control, and be safe and well tolerated, for treating type 2 diabetes mellitus (T2DM). Luseogliflozin is a highly selective SGLT2 inhibitor that was recently approved for marketing and launched in Japan to treat T2DM. AREAS COVERED: This review summarizes the published data regarding the mechanism of action, clinical efficacy, and safety of luseogliflozin for treating T2DM. Other potential benefits of luseogliflozin, including lowering body weight and blood pressure, beyond its glucose-lowering effects are also discussed. EXPERT OPINION: Luseogliflozin lowers plasma glucose concentration and body weight, and has beneficial effects on other clinically relevant parameters, including blood pressure and uric acid, in patients with T2DM. Although it had a good safety profile in clinical trials, there may be some safety concerns, including a possible decrease in muscle mass and an increase in ketone bodies. Therefore, careful administration and consideration of its benefit-risk balance are necessary. When using luseogliflozin, it is important to select appropriate patients and to adhere to its guidelines for use. If used correctly, luseogliflozin is expected to be positioned as a new type of oral hypoglycemic drug for treating T2DM.

Safety, pharmacokinetics, and pharmacodynamics of single and multiple luseogliflozin dosing in healthy Japanese males: a randomized, single-blind, placebo-controlled trial.

INTRODUCTION: Luseogliflozin, a sodium glucose cotransporter 2 inhibitor, inhibits reabsorption of glucose in the proximal renal tubule. It was developed for the treatment of type 2 diabetes mellitus. METHODS: For this first human study of luseogliflozin, randomized, single-blind, placebo-controlled, single ascending dose (1-25 mg) and multiple ascending dose (5 or 10 mg/day, 7 days) trials were conducted in healthy male Japanese subjects to investigate safety, pharmacokinetics, and pharmacodynamics. RESULTS: There were no serious adverse events, adverse events leading to discontinuation, or episodes of hypoglycemia. After administration of a single oral dose of luseogliflozin, its maximum plasma level (C max) and area under the concentration-time curve increased in a dose-dependent manner, and no food effects were observed on pharmacokinetics. The mean time taken to reach C max (T max) ranged from 0.667 to 2.25 h. The mean plasma half-life of luseogliflozin (T 1/2) after multiple dosing for 7 days ranged from 9.14 to 10.7 h, and no detectable accumulation of luseogliflozin was observed. Urinary glucose excretion increased in a dose-dependent manner, ranging from 18.9 to 70.9 g (single-dose study). CONCLUSION: Luseogliflozin was well tolerated and showed favorable pharmacokinetic and pharmacodynamic profiles in healthy male Japanese subjects.

A novel zwitterionic inhibitor of aldose reductase interferes with polyol pathway in ex vivo and in vivo models of diabetic complications.

Recently a zwitterionic principle has been suggested as an alternative to bioisosteric replacement for increasing low bioavailability of aldose reductase inhibitors bearing an acidic function. In the present work we studied the effect of a novel zwitterionic inhibitor of aldose reductase [(2-benzyl-2,3,4,5-tetrahydro-1 H-pyrido[4,3-b]indole-8-yl)-acetic acid, compound 1] on sorbitol accumulation in ex vivo and in vivo models of diabetic complications. The effect of 1 on sorbitol accumulation in isolated rat eye lenses incubated with high glucose and in selected organs of streptozotocin-induced diabetic rats was evaluated. Significantly increased sorbitol levels were recorded in the lenses incubated with 50 mM glucose in comparison with controls. Sorbitol production was inhibited by 1 at concentrations of 25 and 100 µM. Under in vivo conditions in diabetic rats, significant elevation of sorbitol levels in selected organs was recorded. Compound 1 administered i.g. for five consecutive days (twice a day 25 mg/kg) inhibited sorbitol accumulation in erythrocytes and the sciatic nerve, yet it was without effect in eye lenses. A similar picture of inhibition was observed after i.p. administration of 1. To conclude, the results suggest that the zwitterionic principle may represent a practicable way of improving bioavailability of aldose reductase inhibitors bearing an acidic function.