Two open-label, randomized, two-period crossover studies were conducted to investigate the pharmacokinetic (PK) properties, safety, and bioequivalence of the test formulation (KD4004), a new fixed-dose combination (FDC) formulation of dapagliflozin and metformin extended release (XR) tablets, relative to the reference formulation (10 mg dapagliflozin/1,000 mg metformin XR FDC tablet) in healthy subjects under fasting (Part A) and fed (Part B) conditions. After giving the dose, serial blood samples were collected for a period of 48 hours. Primary PK parameters (AUC 0-t and C max ) were used to assess bioequivalence between two dapagliflozin/metformin XR (10/1,000 mg) FDC formulations under fed and fasting conditions. Safety and tolerability were also evaluated. Part A and Part B were completed by 32 and 37 subjects, respectively. Bioequivalence of the two FDC formulations of dapagliflozin and metformin XR tablets was established in both the fasted and the fed conditions as the 90% confidence interval of the ratios of adjusted geometric means for AUC 0-t and C max were contained within the predefined range of 0.800–1.250 bioequivalence criteria. Single-dose administration of dapagliflozin and metformin XR was safe and well tolerated as the two FDC formulations. In conclusion, both FDC formulations of dapagliflozin and metformin XR tablets were bioequivalent in fed and fasted subjects. All treatments were well tolerated.

A new fixed-dose combination (FDC) formulation of raloxifene 60 mg and cholecalciferol 800 IU was developed to improve the medication compliance and overall efficacy of raloxifene treatment in postmenopausal osteoporosis patients. The aim of this study was to compare the pharmacokinetics between two tablets of FDC formulation of raloxifene/cholecalciferol and the two products administered concomitantly at respective doses. This randomized, open-label, single-dose, two-treatment, two-way crossover study included 46 volunteers. During each treatment period, subjects received the test formulation (FDC formulation containing raloxifene and cholecalciferol) or the reference formulation (co-administration of raloxifene and cholecalciferol), with a 14-d washout period. Serial blood samples were collected periodically over 96 hours after drug intake. In total, 46 subjects completed the study. The geometric mean ratios and its 90% confidence intervals of the FDC to the single agents for the area under the concentration-time curve from zero to the last quantifiable time point and the maximum plasma concentration met the regulatory criteria for bioequivalence: 1.1364 (1.0584–1.2201) and 1.1010 (0.9945–1.2188) for raloxifene and 1.0266 (0.9591–1.0989) and 1.0354 (0.9816–1.0921) for baseline-corrected cholecalciferol, respectively. Both formulations were well tolerated. No significant differences was observed in the incidence of adverse events between the two treatments. It was concluded that two tablets of the newly developed FDC formulation of raloxifene and cholecalciferol and the corresponding two agents administered concomitantly at respective doses were bioequivalent.

β-Lapachone has been reported to have anticancer and various other therapeutic effects, but is limited in clinical applications by its low bioavailability. pH-Dependent isomerization can be suggested as one plausible factor influencing its low bioavailability. Since it is known that β-lapachone is converted to its isomer, α-lapachone in hydrochloric acid (HCl) solution, isomerization in the human body may be driven by HCl in the gastric fluid. The purpose of this study was to evaluate the possibility of isomerization of β-lapachone in the human body. Chemical reactions were conducted using simulated gastric fluid (SGF, pH 1.2) and simulated intestinal fluid (SIF, pH 7.5) at 37°C. β-Lapachone was observed in SGF at 37°C for 1 hour and SIF for 3 hours. In addition, biofluid analysis was performed on plasma samples 1 hour and 4 hours, and on urine sample 12 hours after oral administration of 100 mg MB12066, a synthetic β-lapachone, in healthy adult male. All samples were analyzed using liquid chromatography-tandem mass spectrometry. Only β-lapachone peaks existed in the spectra obtained from SGF and SIF. No isomerization of β-lapachone was observed in the analysis of any of the human samples. In the current study, the possibility of pH-dependent isomerization of β-lapachone in the human body was not confirmed.

This study compared the pharmacokinetics of a fixed-dose combination (FDC) of candesartan (16 mg) and amlodipine (10 mg) versus coadministration of individual formulations to clarify the bioequivalence of the FDC. In this randomized, open-label, single-dose, 2-treatment, 2-way crossover study, healthy Korean volunteers received a single dose of candesartan (16 mg) with amlodipine (10 mg) as either an FDC or single agents concomitantly administered, with a 2-week washout period. Serial blood samples were collected up to 72 hours after dosing for each treatment period, and plasma concentrations of candesartan and amlodipine were measured using a validated liquid chromatography-tandem mass spectrometry method. A total of 39 subjects completed the study. The geometric mean ratios (GMRs) and 90% confidence intervals (CIs) for the area under the plasma concentration-time curve from time 0 to the last measurement (AUC0-t) and the peak plasma concentration (Cmax) for candesartan were 1.0182 (0.9562–1.0841) and 0.9492 (0.8726–1.0324), respectively. The GMR and 90% CI for the AUC0-t and Cmax for amlodipine were 1.0552 (1.0255–1.0857) and 1.0668 (1.0259–1.1094), respectively. In conclusion, the new FDC formulation of candesartan (16 mg) and amlodipine (10 mg) was bioequivalent to the concomitant administration of single agents. A single dose of candesartan/amlodipine as the FDC or as single agents was well tolerated.

This study describes the development of an analytical method to determine sumatriptan levels in human plasma using high performance liquid chromatography (HPLC) coupled with triple quadrupole tandem mass spectrometry (MS/MS) and its application to a pharmacokinetic study in healthy Korean volunteers. A single 50 mg dose of sumatriptan was orally administered to twelve healthy volunteers (nine women and three men). The HPLC-MS/MS analytical method was validated with respect to its specificity, linearity, sensitivity, accuracy, precision, recovery, and stability. The calibration curve was linear over a concentration range of 0.3–100 ng/mL (r > 0.999). The lower limit of quantitation for sumatriptan in plasma was 0.3 ng/mL. The accuracy and precision of the analytical method were acceptable within 15% at all quality control levels. We compared plasma concentration-time curves as well as pharmacokinetic parameters such as the area under the curve (AUC) and maximum plasma concentration (C(max)). Both the mean AUC and C(max) of sumatriptan were 1.56 times higher in women than in men. These differences could be largely explained by the difference in body weight (44%) between women and men. The outcomes may provide insights into developing appropriate individualized treatment strategies.
Area Under Curve ; Body Weight ; Calibration ; Chromatography, Liquid ; Female ; Healthy Volunteers ; Humans* ; Male ; Methods ; Plasma* ; Quality Control ; Sensitivity and Specificity ; Spectrum Analysis* ; Sumatriptan* ; Tandem Mass Spectrometry ; Volunteers*

Glimepiride, a third generation sulfonylurea, is an antihyperglycemic agent widely used to treat type 2 diabetes mellitus. In this study, an untargeted urinary metabolomic analysis was performed to identify endogenous metabolites affected by glimepiride administration. Urine samples of twelve healthy male volunteers were collected before and after administration of 2 mg glimepiride. These samples were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and then subjected to multivariate data analysis including principal component analysis and orthogonal partial least squares discriminant analysis. Through this metabolomic profiling, we identified several endogenous metabolites such as adenosine 3′, 5′-cyclic monophosphate (cAMP), quercetin, tyramine, and urocanic acid, which exhibit significant metabolomic changes between pre- and posturine samples. Among these, cAMP, which is known to be related to insulin secretion, was the most significantly altered metabolite following glimepiride administration. In addition, the pathway analysis showed that purine, tyrosine, and histidine metabolism was affected by pharmacological responses to glimepiride. Together, the results suggest that the pharmacometabolomic approach, based on LC-MS/MS, is useful in understanding the alterations in biochemical pathways associated with glimepiride action.
Adenosine ; Diabetes Mellitus, Type 2 ; Histidine ; Humans* ; Insulin ; Least-Squares Analysis ; Male ; Mass Spectrometry* ; Metabolism ; Metabolomics* ; Principal Component Analysis ; Quercetin ; Statistics as Topic ; Tyramine ; Tyrosine ; Urocanic Acid ; Volunteers

We developed an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the determination of acetaminophen concentration in human plasma. Following protein precipitated extraction, the analytes were separated and analyzed using an UPLC-MS/MS in the multiple reaction monitoring (MRM) mode with the respective [M+H]+ ions, m/z 152.06 → 110.16 for acetaminophen and m/z 180.18 → 138.12 for phenacetin (internal standard, IS). The method showed a linear response from 1 to 100 µg/mL (r > 0.9982). The limit of quantitation for acetaminophen in plasma was 1 µg/mL. The intra- and inter-day accuracy ranged in the ranges of 94.40–99.56% and 90.00–99.20%, respectively. The intra- and inter-day precision ranged in the ranges of 2.64–10.76% and 6.84–15.83%, respectively. This method was simple, reliable, precise and accurate and can be used to determine the concentration of acetaminophen in human plasma. Finally, this fully validated method was successfully applied to a pharmacokinetic study of acetaminophen in healthy volunteers following oral administration.
Acetaminophen* ; Administration, Oral ; Healthy Volunteers ; Humans* ; Ions ; Mass Spectrometry ; Phenacetin ; Plasma*

We intended to determine that virtual endoscopy and laparoscopy of the stomach based on serially sectioned cadaver images is beneficial. Therefore, the outlines between the gastric wall and lumen were traced using the new female data of the Visible Korean to build a volume model. While the outlines were expanded at appropriate thicknesses, the stomach was observed endoscopically and laparoscopically in comparison with a chosen sectioned image. Four layers (mucosa, submucosa, muscular layer, and serosa) of the stomach were discernible by their proper colors in the sectioned images. All layers except the submucosa were identified in the endoscopic and laparoscopic views by using consistent colors. The stepwise expansion of the outlines revealed thickness of each layer as well as whether the thickness was uniform. Our ideas and the Visible Korean images could be a robust resource of virtual reality learning for medical students and clinicians.
Adult ; Cadaver ; Female ; *Gastroscopy ; Humans ; Imaging, Three-Dimensional ; *Laparoscopy ; Models, Anatomic ; Stomach/*pathology

BACKGROUND: To evaluate the pharmacokinetic properties of daily oral doses of tamsulosin administered to fasted healthy Korean male volunteers for 5 days. METHODS: In a randomized, open-label, multiple-dose, two-period, crossover study, all 44 subjects were randomly assigned in a 1:1 ratio to receive a newly developed generic capsule formulation (test) or a branded capsule formulation (reference) of tamsulosin 0.2 mg, followed by a 10-day washout period and administration of the other formulation. Plasma concentrations of tamsulosin were assessed after administration of five-day multiple doses, using HPLC-MS/MS. Clinical and laboratory adverse events (AE) were assessed. RESULTS: The mean (SD) pharmacokinetic properties with the test and reference formulations were as follows: Css,max, 9.0 (2.9) and 8.4 (2.6) ng/mL, respectively; median (range) tmax, 4 (2-6) and 5 (2-7) hours; AUCtau, 93.7 (31.5) and 88.2 (29.3) ng x h/mL; and t(1/2), 9.5 (2.6) and 10.0 (2.7) hours. The volume of distribution and clearance after oral administration of tamsulosin were 0.5 L/kg, and 0.04 L/h/kg, respectively. The accumulation ratios for 0.2 mg once-daily dosing regimen were 1.2. The 90% CIs of the geometric mean ratios for the log-transformed AUCtau (1.005-1.131) and Css,max (1.000-1.136) values were within the acceptable range for bioequivalence. No serious AE was reported during the study. Both formulations were well tolerated. CONCLUSION: The results demonstrate that the Css,max and AUCtau values in the fasted subjects were higher than those in the fed from other study, with a shorter tmax values.
Administration, Oral ; Cross-Over Studies ; Healthy Volunteers ; Humans ; Male* ; Pharmacokinetics ; Plasma ; Therapeutic Equivalency

In the Visible Korean project, 642 three-dimensional (3D) surface models have been built from the sectioned images of a male cadaver. It was recently discovered that popular PDF file enables users to approach the numerous surface models conveniently on Adobe Reader. Purpose of this study was to present a PDF file including systematized surface models of human body as the beneficial contents. To achieve the purpose, fitting software packages were employed in accordance with the procedures. Two-dimensional (2D) surface models including the original sectioned images were embedded into the 3D surface models. The surface models were categorized into systems and then groups. The adjusted surface models were inserted to a PDF file, where relevant multimedia data were added. The finalized PDF file containing comprehensive data of a whole body could be explored in varying manners. The PDF file, downloadable freely from the homepage (http://anatomy.co.kr), is expected to be used as a satisfactory self-learning tool of anatomy. Raw data of the surface models can be extracted from the PDF file and employed for various simulations for clinical practice. The technique to organize the surface models will be applied to manufacture of other PDF files containing various multimedia contents.
Cadaver ; Human Body ; Humans ; Image Processing, Computer-Assisted ; Male ; *Models, Biological ; *Software ; User-Computer Interface