First automatic radiosynthesis of 11C labeled Telmisartan using a multipurpose synthesizer for clinical research use.

OBJECTIVE: Telmisartan, a nonpeptide angiotensin II AT1 receptor antagonist, is an antihypertensive drug. Positron emission tomography (PET) imaging with [(11)C]Telmisartan is expected to provide information about the whole body pharmacokinetics of telmisartan as well as the transport function of hepatic OATP1B3. We developed a first automatic preparation system of [(11)C]Telmisartan to applicable clinical research using a new (11)C and (18)F multipurpose synthesizer. METHODS: Two milligrams of precursor (1) in 5 µl of 1 M KOH in 0.5 ml of dimethyl sulfoxide was reacted with [(11)C]CH(3)I for 5 min at 120°C. The resultant solution was hydrolyzed with 1 M NaOH at 100°C for 3 min. The neutralization was carried out with acetic acid, followed by purification with high-performance liquid chromatography. The desired radioactive fraction was collected and solvent was replaced by 10 ml saline containing 0.3 ml of EtOH and 0.5 ml of PEG400, and then passed through a sterile 0.22 µm filter (Millex-GV, Millipore) to a pyrogen-free vial as the final product. RESULTS: The yield of [(11)C]Telmisartan for clinical research use was 16.8 ± 2.9% EOB as decay corrected (n = 8, mean ± SD) in 32-36 min. The radiochemical purity of [(11)C]Telmisartan was >97%, and specific activity was higher than 86.3 MBq/nmol. CONCLUSIONS: We succeeded in the first synthesis of [(11)C]Telmisartan for clinical research use by appropriate quality tests.

Quantitative determination of hippuric and benzoic acids in urine by LC-MS/MS using surrogate standards.

An LC-MS/MS method for simultaneous determination of hippuric acid (HA) and benzoic acid (BA) in monkey urine after direct injection was developed. Since HA and BA are endogenous compounds in urine, surrogate standards ((13)C(6)-hippuric and (13)C(6)-benzoic acid) were employed to generate calibration curves. l-Phenylalanine-ring-D5 served as an internal standard. Multiple reaction monitoring in the negative ionization mode with an APCI source was used for detection of all components in the assay. The developed method is intended for determination of HA and BA in the range of 0.25-250 and 0.1-100microg/ml, respectively. Weighted (1/x) quadratic regression (r(2)>0.99) was used to generate calibration curves. Precision and accuracy of the method were assessed by analyzing 3 quality control samples (concentrations at low, medium, and high range of calibration curve) prepared in monkey urine. Stability for 48h at room temperature and after 3 freeze-thaw cycles was also evaluated. The proposed method was successfully utilized for analysis of urine samples from female monkeys following the administration of everninomicin alone and in combination with gentamicin. The concentrations of endogenous HA and BA were calculated based on the peak area ratio of the analyte to the internal standard using a regression equation for corresponding surrogate standard.

Telmisartan is more effective than losartan in reducing proteinuria in patients with diabetic nephropathy.

In patients with diabetic nephropathy, lowering blood pressure and reducing proteinuria by over 30% correlates with a slower progression to kidney failure. We compared two different angiotensin receptor-blockers in a double blind, prospective trial of 860 patients with type 2 diabetes whose blood pressure levels was over 130/80 mmHg or who were receiving antihypertensive medication(s) and who had a morning spot urinary protein to creatinine ratio of 700 or more. Patients were randomized to telmisartan (a highly lipophilic agent with a long half-life) or losartan (with low lipophilicity and short half-life). The primary endpoint was the difference in the urinary albumin to creatinine ratio between the groups at 52 weeks. The geometric coefficient of variation and the mean of the urinary albumin to creatinine ratio fell in both groups at 52 weeks but both were significantly greater for the telmisartan compared to the losartan cohort. Mean systolic blood pressure reductions were not significantly different between groups at trial end. We conclude that telmisartan is superior to losartan in reducing proteinuria in hypertensive patients with diabetic nephropathy, despite a similar reduction in blood pressure.

Capillary electrophoretic method for the determination of inorganic and organic anions in real samples. Strategies for improving repeatability and reproducibility.

Selectivity and robustness of the pyromellitic acid (PMA) based background electrolyte was improved in order to increase its applicability for routine analysis of inorganic and organic anions in real samples. An electrolyte composed of 6.75 mM PMA, 0.5 mM hexamethonium hydroxide as electroosmotic flow (EOF) modifier, Ca(2+) 0.05 mM as complexation agent and pH adjusted to 7.6 with TEA 1M allows for the separation of 22 inorganic and organic anions in less than 17 min. Good RSDs for within-day migration time reproducibility (0.03-0.9%) and day-to-day analyses (0.04-1.4%) were obtained by the use of two internal standards, allowing for an accurate compound identification. The detection limits ranged from 0.1 to 0.4 mgL(-1) (S/N=3) for hydrodynamic injection (1250 mbars). The applicability of the proposed method was demonstrated by the analysis of inorganic and organic anions in diverse real samples. The recoveries obtained ranged from 93 to 106%.

[Paeoniflorin Reference Standard (Control 021) of National Institute of Health Sciences].

The raw material of paeoniflorin was examined for the preparation of the "Paeoniflorin Reference Standard". The analytical data obtained were: UV spectrum, lambda max, 231.9 nm; and specific absorbance (E(1 cm)1%) in methanol at 230 nm = 263.4 IR spectrum, specific absorptions of the raw material were consistent with those of the Paeoniflorin Reference Standard Standard (Control 012); High-performance liquid chromatography(HPLC), several impurities were detected. The total amount of impurities was 0.86%. Based on the above results, the candidate material was authorized as the Paeoniflorin Reference Standard (Control 021) of the National Institute of Health Sciences.

NOR-1: a nitric oxide releasing agent for calibrating low levels of nitric oxide by the chemiluminescence method.

Nitric oxide (NO) is formed in small amounts in vivo and is rapidly oxidized by interacting with oxygen, making measurement of its level difficult. The chemiluminescence assay is the most widely used method for detecting NO and is extremely sensitive to very small amounts of NO. However, it is difficult to prepare small amounts of NO to be used as a standard for NO analysis. NOR-1, a derivative of NOR-3, is a newly discovered NO donor with rapid NO-releasing activity. We assessed the dynamics of NO release and decomposition using NOR-1. Our results demonstrate that NOR-1 is stable in dimethylsulfoxide (DMSO) and is able to dilute at lower concentration (to picomolar levels) by DMSO without decomposition. NOR-1 released persistently 1.4 more excess of NO with 15 min of incubation. There was a linear relationship between the concentration of NOR-1 and that of NO released from NOR-1 (r=0.997) These findings suggest that NOR-1 is a useful reagent for the calibration of lower NO detection.

[Paeoniflorin Reference Standard (Control 011) of National Institute of Health Sciences].

The raw material of paeoniflorin was examined for preparation of the "Paeoniflorin Reference Standard". The analytical data obtained were: UV spectrum: lambda max, 231.7 nm; and specific absorbance (E1% 1 cm) in methanol at 230 nm, 265.4; IR spectrum, specific absorptions of raw material were consistent with that of Standard (Control 985). High-performance liquid chromatography, several impurities were detected. The amount of each impurity was estimated at less than 0.1% and total amount of impurities was less than 0.2%. Based on the above results, the candidate material was authorized as the Paeoniflorin Reference Standard (Control 011) of the National Institute of Health Sciences.

Use of ambulatory blood pressure monitoring to evaluate the selective angiotensin II receptor antagonist, telmisartan, and other antihypertensive drugs.

Telmisartan (Micardis (R)) is a new, orally active, long-acting angio-tensin (Ang) II receptor antagonist that is effective in the treatment of hypertension. Ambulatory blood pressure monitoring (ABPM) has emerged as an important method for evaluating the consistency of the antihypertensive effects of a drug throughout the dosing interval. ABPM was used to evaluate the antihypertensive efficacy of telmisartan in several placebo-controlled, double-blind, multicenter studies. Patients with mild-to-moderate hypertension were allocated randomly to groups to receive telmisartan 40 or 80 mg, losartan 50 mg, or placebo, once daily in a 6-week, fixed-dose study, or telmisartan 40-120 mg, amlodipine 5-10 mg, or placebo, once daily in a 12-week, dose-titration study. Patients treated with telmisartan 40 and 80 mg or placebo in a separate 4-week, fixed-dose study were included in an additional analysis. Telmisartan 40 and 80 mg significantly decreased mean ambulatory systolic blood pressure (SBP) and diastolic blood pressure (DBP) relative to placebo for the entire 24 h period and in the following intervals: day (6 a.m. to 10 p.m.), morning (6 a.m. to noon), night (10 p.m. to 6 a.m), and the last 4 h of the dosing interval (P<0.01). Notably, telmisartan 40 or 80 mg was more effective than losartan, especially during the last 4-6 h of the dosing interval (P<0.05). Telmisartan 40- 120 mg tended to be more effective than amlodipine 5-10 mg in reducing SBP and DBP in each time interval, with significant differences between treatments noted for DBP in the last 4 h of the dosing interval and in the morning (P < 0.05). ABPM also revealed that the magnitude of the blood pressure decreasing effect with telmisartan was consistent throughout the dosing interval. These results demonstrate that telmisartan maintains a normal circadian blood pressure pattern and provides full 24 h blood pressure control with once-daily dosing.

Good prognosis of patients with acute promyelocytic leukemia who achieved second complete remission (CR) with a new retinoid, Am80, after relapse from CR induced by all-trans-retinoic acid.

A new synthetic retinoid, Am80, is effective in treating acute promyelocytic leukemia relapsed from all-trans-retinoic acid-induced complete remission (CR). We report here the long-term clinical outcomes of patients who achieved second CR with Am80. Of 24 evaluable patients, 14 achieved a second CR by Am80 therapy. Of those patients, 4 relapsed within 6 months, despite subsequent consolidation chemotherapy. Six patients underwent sibling or unrelated HLA-matched allogeneic bone marrow transplantation (BMT), and 4 are alive without relase for more than 49 months after achieving second CR. Four of 8 patients who did not receive BMT are alive without relapse for more than 49 months. Promyelocytic leukemia-retinoic acid receptor alpha (PML-RAR alpha) fusion transcript was undetectable by reverse transcriptase-polymerase chain reaction in all living patients. Therefore, if patients achieve second CR with Am80 and HLA-matched donors are available, BMT is the treatment of choice. However, it is noteworthy that CR was maintained for more than 49 months in half of the patients who did not receive BMT.

Internal standards for gas chromatographic analysis of metabolic end products from anaerobic bacteria.

2-Methylpentanoic acid and benzoic acid are suggested for use as routine internal standards for gas chromatographic analysis of microbial end products.