Extremely low frequency magnetic field modulates the level of neurotransmitters.

This study was aimed to observe that extremely low frequency magnetic field (ELF-MF) may be relevant to changes of major neurotransmitters in rat brain. After the exposure to ELF-MF (60 Hz, 2.0 mT) for 2 or 5 days, we measured the levels of biogenic amines and their metabolites, amino acid neurotransmitters and nitric oxide (NO) in the cortex, striatum, thalamus, cerebellum and hippocampus. The exposure of ELF-MF for 2 or 5 days produced significant differences in norepinephrine and vanillyl mandelic acid in the striatum, thalamus, cerebellum and hippocampus. Significant increases in the levels of serotonin and 5-hydroxyindoleacetic acid were also observed in the striatum, thalamus or hippocampus. ELF-MF significantly increased the concentration of dopamine in the thalamus. ELF-MF tended to increase the levels of amino acid neurotransmitters such as glutamine, glycine and γ -aminobutyric acid in the striatum and thalamus, whereas it decreased the levels in the cortex, cerebellum and hippocampus. ELF-MF significantly increased NO concentration in the striatum, thalamus and hippocampus. The present study has demonstrated that exposure to ELF-MFs may evoke the changes in the levels of biogenic amines, amino acid and NO in the brain although the extent and property vary with the brain areas. However, the mechanisms remain further to be characterized.

Pharmacokinetics and Safety of DW1029M, a Botanical Drug for the Treatment of Diabetic Nephropathy, Following Single Doses in Healthy Subjects.

DW1029M is a botanical extract of Morus albalinne root bark and Puerariae radix that is used for the treatment of diabetic nephropathy. This study evaluated the safety and pharmacokinetics of DW1029M following its administration in healthy Korean subjects. We conducted a randomized, open-label, single-dose, crossover phase 1 clinical study. During each period, subjects received 300, 600, or 1200 mg oral doses of DW1029M. Plasma concentrations of puerarin, daidzin, and daidzein were analyzed using a liquid chromatography-tandem mass spectrometry. Six healthy male subjects completed the study. The maximum concentration of the drug in the plasma (Cmax ) and area under the plasma drug concentration-time curve to the last measurable concentration (AUClast ) for puerarin, daidzin, and daidzein were assessed after oral administration of DW1029M. No serious adverse events or clinically or statistically significant adverse events associated with any of the drug levels were observed. The results of the measurement of vital signs, electrocardiogram, laboratory tests, and physical examinations indicated that no clinically significant changes occurred during this study. The DW1029M tablet was safe and well tolerated over a single dose range of 300-1200 mg. This pharmacokinetic study of a botanical drug may aid in the development of DW1029M.

Phase 1 and Pharmacokinetic Drug-Drug Interaction Study of Metformin, Losartan, and Linagliptin Coadministered With DW1029M in Healthy Volunteers.

We investigated botanical drug-pharmaceutical drug interactions between DW1029M (a botanical extract of Morus alba linne root bark and Puerariae radix) and metformin, losartan, and linagliptin in the steady state. Three studies were conducted as randomized, open-label, 2-period, 2-treatment, multiple-dose, 2-way crossover designs. Eligible subjects received metformin (500 mg twice daily), losartan (50 mg once daily), or linagliptin (5 mg once daily) with DW1029M (300 mg × 2T twice daily) every 12 hours on days 1 through 6 and a single dose on the morning of day 7. Coadministration of DW1029M with metformin, losartan, or linagliptin had no clinically relevant effects based on the area under the plasma concentration-time curve (AUCτ ) geometric least-squares mean ratio (GMR) - AUCτ GMR, 89.7; 90% confidence interval (CI), 81.0-99.4 for metformin; AUCτ GMR, 96.2; 90%CI, 86.3-107.1 for losartan; and AUCτ GMR, 89.7; 90%CI, 83.2-96.6 for linagliptin. In addition, coadministration of DW1029M did not have any clinically meaningful effect on the maximum plasma concentration (Cmax,ss ) - Cmax,ss GMR, 87.3; 90%CI, 76.2-100.0 for metformin; Cmax,ss GMR, 90.5; 90%CI, 78.3-104.6 for losartan; and Cmax,ss GMR, 81.4; 90%CI, 69.5-95.3 for linagliptin. Coadministration of DW1029M with metformin, losartan, or linagliptin was well tolerated.

Single-dose, randomized, open-label, 2-way crossover study of the pharmacokinetics of amitriptyline hydrochloride 10- and 25-mg tablet in healthy male Korean volunteers.

PURPOSE: Amitriptyline is the most widely used tricyclic antidepressant (TCA). Although amitriptyline hydrochloride 10 and 25 mg has been marketed in Korea, no data on the dose proportionality of amitriptyline in Korean subjects are available. This clinical trial was designed to evaluate and compare the relative bioavailability with regard to dose proportionality between the two marketed strengths of amitriptyline hydrochloride tablets after a single-dose, oral administration under fasting conditions in healthy, male, Korean volunteers. METHODS: This single-dose, randomized, open-label, 2-way crossover study was conducted in healthy male Korean subjects. Subjects were randomly assigned to 1 of 2 dose groups and received a single dose of 10 or 25 mg amitriptyline hydrochloride under fasting conditions, followed by the alternate dose in the subsequent study period. High performance liquid chromatography (HPLC)-mass spectrometry (MS)/MS detection was applied to determine plasma concentrations. Pharmacokinetic parameters were calculated, C(max), AUC(last), AUC(0-∞), t(½), and T(max). Statistical analysis was performed for the assessment of dose proportionality. Tolerability was assessed for up to 96 hours after administration. FINDINGS: Twelve healthy Korean subjects completed this trial (mean [SD] age, 21.7 [1.9] years; height, 174.5 [5.0] cm; and weight, 66.7 [9.4] kg). Although 4 subjects experienced a total 5 adverse events (AEs), no serious AEs were reported during the study. The mean values of C(max) and AUC were proportional to the doses of 10 and 25 mg. The C(max), AUC(last), and AUC(0-∞) of amitriptyline hydrochloride 10 mg were 5.96 ng/mL, 91.35 ng·h/mL and 109.74 ng·h/mL, respectively. The C(max), AUC(last), and AUC(0-∞) of amitriptyline hydrochloride 25 mg were 17.69 ng/mL, 260.68 ng·h/mL, and 296.87 ng·h/mL, respectively. IMPLICATIONS: Our results suggest that the 2 strengths of amitriptyline hydrochloride (10 and 25 mg) exhibited linear (dose-dependent) pharmacokinetics in these healthy, male, Korean subjects. Based on these results, a predictable and linear increase in systemic exposure can be expected. ClinicalTrials.gov identifier: NCT01367080.

UPLC-UV method for determination of risedronate in human urine.

This study was designed to develop a sensitive and rapid method for the quantitation of risedronate in human urine using ultra-performance liquid chromatography with ultra-violet detector (UPLC-UV) and to compare bioavailability parameter of 5, 35 and 150 mg risedronate. The mobile phase consisted of sodium phosphate buffer, 1 mM etidronate-acetonitrile (95:5, v/v), pH 9.0, and was pumped at a flow rate of 0.3 mL/min. Detection of risedronate in human urine by the UPLC-UV was accurate and precise from 20 ng/mL to 5 µg/mL (a correlation coefficient of 0.99) with 97.16% in mean recovery. The intra-day accuracy was 89.17-110.43% with precision of 0.04-3.16% and the inter-day accuracy was 89.23-110.19% with precision of 1.63-9.72%. Aet (accumulated excretion amount) of risedronate in the urine after 5, 35 and 150 mg administration was 35.08, 246.67 and 1.413.85 µg within 36 h and Umax (maximal excretion rate) was 12.11, 77.7 and 374.24 µg/h, respectively. The assessed dose proportionality of Umax and Aet with three single doses of risedronate was found in an approximately linear manner. These results indicate that the developed simple, rapid and robust assay enables the complete processing of large samples for pharmacokinetic studies of risedronate in biological fluid.