Search results for "Thiazide"
showing 10 items of 40 documents
Solid-Phase Extraction Techniques for Assay of Diuretics in Human Urine Samples
1991
Abstract Solid-phase extraction techniques were evaluated for the treatment of urine samples in the analysis of diuretics before injection into an HP-Hypersyl ODS-C18 column. Six different reversed-phase extraction columns were tested, and the results obtained are compared with those obtained in a classical liquid-liquid extraction with ethyl acetate. The solid-phase extraction procedures are the best overall choice for all the diuretics tested, due to their versatility, the minor time-consuming, and the good recovery percentages obtained. C18 and C8 packings give the highest recoveries for a majority of the diuretics studied. However, CH or PH columns, due to their greater selectivity, can…
Evaluation of several global resolution functions for liquid chromatography
1999
Abstract An interpretative approach, that makes use of the overlapped fraction of each chromatographic peak as elementary resolution criterion, was applied to the separation of mixtures of compounds. The elementary resolution measurements for all peaks in the chromatogram were reduced to a single numerical value using several functions: normalised by the mean resolution product, unnormalised product, geometrical mean of the unnormalised product, and worst elementary resolution value. The descriptive capability of these reduction functions was evaluated through the observation of global resolution diagrams and the change in the shape of the chromatograms in the selected factor space. michrom…
Spectrophotometric Determination of Hydralazine with 2-Hydroxy-1-naphthaldehyde in Pharmaceuticals
1991
Abstract A new extraction-spectrophotometric method for the determination of hydralazine, based on its reaction with 2-hydroxy-1-naphthaldehyde at 25 °C, is described. The calibration curve was linear between 0.4 and 6 mg/mL of hydralazine. The molar absorbtivity of the product at 408 nm is 40 900 L · mol − 1 · cm − 1 . The method described was applied to the analysis of hydralazine in pharmaceutical preparations containing reserpine, hydrochlorothiazide, bendrofluorthiazine, propranolol, and other substances. The agreement with the U.S.P. XXI method was satisfactory for tablets and injections, but not for pellets.
Estimating population size in wastewater-based epidemiology. Valencia metropolitan area as a case study.
2017
Wastewater can provide a wealth of epidemiologic data on common drugs consumed and on health and nutritional problems based on the biomarkers excreted into community sewage systems. One of the biggest uncertainties of these studies is the estimation of the number of inhabitants served by the treatment plants. Twelve human urine biomarkers —5-hydroxyindoleacetic acid (5-HIAA), acesulfame, atenolol, caffeine, carbamazepine, codeine, cotinine, creatinine, hydrochlorothiazide (HCTZ), naproxen, salicylic acid (SA) and hydroxycotinine (OHCOT)— were determined by liquid chromatography-tandem mass spectrometry (LC–MS/MS) to estimate population size. The results reveal that populations calculated fr…
Distribution of chlorpromazine in a simplified blood influenced by various drugs
1973
The binding of chlorpromazine to erythrocytes and to albumin as influenced by other drugs was studied in a simplified blood (31.5±0.3% bovine erythrocytes, 4 g-% bovine serum albumin in 0.02 M phosphate buffer solution containing 0.15 M NaCl). the total concentration of chlorpromazine in the simplified blood was 10−4 M, the concentration of the displacing drugs was 10−3 M. After an incubation period of 3 h at 22° C the chlorpromazine concentration was determined in the albumin solution after centrifugation of the blood at 3000×g and in the aqueous phase after ultracentrifugation at 150000×g. Under control conditions 68.1±0.9% of chlorpromazine was bound to the erythrocytes, 28.5±0.9% was bo…
Micellar liquid Chromatographic determination of diuretics by diazotization and coupling with the Bratton-Marshall reagent
1997
Abstract A Chromatographic procedure that uses micellar mobile phases of sodium dodecyl sulphate (SDS) and propanol at pH 3 is reported for the determination, in urine samples, of thiazide diuretics (althiazide, bendroflumethiazide, chlorothiazide, hydrochlorothiazide, hydroflumethiazide, and trichloromethiazide), and other diuretics having a sulphonamide substituent in the benzene ring. Precolumn derivatization with sodium nitrite and N -(1-naphthyl)ethylenediamine, to form the coloured azo dyes of the hydrolyzed diuretics, decreased the polarity of the compounds and, consequently, their retention in the micellar eluents, and permitted detection in the visible region, eliminating thus the …
Automated simultaneous triple dissolution profiles of two drugs, sulphamethoxazole-trimethoprim and hydrochlorothiazide-captopril in solid oral dosag…
2003
This article deals with the simultaneous determination of three dissolution profiles with the aid of the new and emerging continuous-flow methodology known as multicommutation. This methodology is based on a flow network of a set of solenoid valves controlled by the computer and acting as independent multicommutators to allow the easy and automated control of flowing solutions. The obtained three dissolution profiles from one dosage form are the whole formulation profile or "global profile" recommended by pharmacopoeias, and, at same time, are recorded two "individual" profiles from two drugs present in the formulation. This is the second attempt to obtain simultaneously three dissolution p…
Functional Synaptic Projections onto Subplate Neurons in Neonatal Rat Somatosensory Cortex
2002
Subplate neurons (SPn) play an important role in the formation of thalamocortical connections during early development and show glutamatergic and GABAergic spontaneous synaptic activity. We characterized these synaptic inputs by performing whole-cell recordings from SPn in somatosensory cortical slices of postnatal day 0-3 rats. At -70 mV, electrical stimulation of the thalamocortical afferents elicited in 68% of the SPn a monosynaptic CNQX-sensitive postsynaptic current (PSC). These fast PSCs were mediated by AMPA receptors, because they were prolonged by cyclothiazide and blocked by GYKI 52466. On membrane depolarization, thalamocortical stimulation elicited in 50% of the cells an additio…
Ambulatory monitoring of systolic hypertension in the elderly: Eprosartan/hydrochlorothiazide compared with losartan/hydrochlorothiazide (INSIST tria…
2010
Introduction: Systolic hypertension is very common in the elderly and is strongly associated with the risk of cardiovascular and cerebrovascular events. The control of systolic hypertension is difficult and most patients require combination antihypertensive therapy. Few data are available regarding the efficacy of angiotensin II receptor antagonists on systolic hypertension of the elderly. The aim of this double-blind, double-dummy, randomized, parallel-group, multicenter study was to assess the efficacy of eprosartan 600 mg in combination with hydrochlorothiazide (HCTZ)12.5 mg in comparison with losartan 50 mg in combination with HCTZ 12.5 mg, in reducing blood pressure in elderly patients…
The effects of telmisartan alone or with hydrochlorothiazide on morning and 24-h ambulatory BP control: results from a practice-based study (SURGE 2)
2012
Observational studies have shown that 24-h and morning ambulatory blood pressure (BP) control is low. This large-scale, practice-based study evaluated the effects of telmisartan 40 or 80 mg alone or in combination with hydrochlorothiazide (HCTZ) 12.5 mg on these BP parameters over 8 weeks; treatment was adjusted if clinic BP remained ≥140/90 mm Hg. A total of 863 patients were evaluated (baseline mean clinic BP, morning and 24-h ambulatory BP: 155±15/93±10 mm Hg, 137±15/83±11 mm Hg, 133±14/79±10 mm Hg, respectively; 68% were previously treated at baseline). Telmisartan with/without HCTZ significantly reduced the mean morning ambulatory BP (-8.2/-4.9 mm Hg), daytime ambulatory BP (-8.0/-4.7 …