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1.
Talanta ; 80(3): 1333-40, 2010 Jan 15.
Article in English | MEDLINE | ID: mdl-20006096

ABSTRACT

A new, multisyringe flow injection set-up has been developed for the completely automated determination of trace thiazide compounds with diuretic action in different types of samples. The proposed instrumental set-up exploits for the first time, a low pressure on-line solid phase extraction-liquid chromatography-chemiluminescence detection method. This novel combination of sample treatments in flow systems expands the current applicability of low pressure liquid chromatography due to the isolation/preconcentration of the target compounds, besides high selectivity and sensitivity. For the determination of three thiazide compounds named hydroflumethiazide, furosemide and bendroflumethiazide, the proposed set-up provided with the preconcentration of only 1mL of sample, limits of detection of 3, 60 and 40microgL(-1), respectively. Furthermore wide linear dynamic ranges of 6-4000, 140-20,000 and 90-40,000microgL(-1), respectively, were obtained. Besides of this, a high injection throughput of 12h(-1) was also achieved. As in sports, thiazide diuretics are prohibited substances, the proposed method has been applied to their determination in urine samples. Furthermore the potential of the proposed method as a fast-screening approach for emerging contaminants in waters has been also tested by applying it to well water and leachates from a solid waste landfill.


Subject(s)
Flow Injection Analysis/instrumentation , Online Systems , Sodium Chloride Symporter Inhibitors/analysis , Sodium Chloride Symporter Inhibitors/chemistry , Syringes , Systems Integration , Chromatography , Humans , Luminescent Measurements , Pressure , Sodium Chloride Symporter Inhibitors/isolation & purification , Sodium Chloride Symporter Inhibitors/urine , Solid Phase Extraction , Time Factors , Waste Management , Water/chemistry , Water Pollution
2.
Pharmazie ; 58(11): 796-800, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14664334

ABSTRACT

Two-component mixtures of candesartan cilexetil (CAN) and hydrochlorothiazide (HYD) were assayed by first derivative and ratio derivative spectrophotometry. The first method depends on zero-crossing and peak to base measurement. The first derivative amplitudes at 270.1 and 255.5 nm were selected for the assay of (CAN) and (HYD), respectively. The second method depends on first derivative of the ratio spectra by division of the absorption spectrum of the binary mixture by a normalized spectrum of one of the components and then calculating the first derivative of the ratio spectrum. The first derivative of the ratio amplitudes at 236, 250, 232, 267 and 280 nm were selected for the determination of (CAN) and (HYD), respectively. Calibration curves were established for 6.0-38.0 microg x ml(-1) for (CAN) and 4.0-28.0 microg x ml(-1) for (HYD) in binary mixtures. Good linearity, precision and selectivity were found, and the two methods were successfully applied to the pharmaceutical dosage form containing the above-mentioned drug combination without any interference by the excipients.


Subject(s)
Antihypertensive Agents/analysis , Benzimidazoles/analysis , Biphenyl Compounds/analysis , Hydrochlorothiazide/analysis , Sodium Chloride Symporter Inhibitors/analysis , Tetrazoles , Calibration , Diuretics , Indicators and Reagents , Spectrophotometry, Ultraviolet , Tablets
3.
J Mass Spectrom ; 37(9): 940-53, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12271437

ABSTRACT

A systematic mass spectrometric study of 10 thiazidic diuretics and related compounds was undertaken by mass spectrometry (MS) with electrospray ionization in the negative ion mode. Collisional dissociation 'in-source' (CID-MS) and in a low-pressure collision cell (CID-MS/MS) were compared in both excitation regions. Spectra obtained by CID-MS and by CID-MS/MS were matched. Using the two methods, loss of HCl and consecutive dissociations from 2HCl losses were exhibited from compounds such as methyclothiazide and trichlormethiazide but not from other thiazidic diuretics that contain chlorine substituents in the aromatic moiety. However, deprotonated dichlorphenamide gave rise to loss of HCl by CID-MS and CID-MS/MS. For other diuretics such as hydroflumethiazide and hydrochlorothiazide, the loss of HCN and [HCN + SO(2)] was relevant. Reaction mechanisms were checked by means of deuterium-hydrogen exchange, which showed that deprotonation took place regioselectively on the heterocyclic moiety. The cleavage pathways require molecular isomerization forming ion-dipole complexes prior to decompositions, allowing long-distance proton transfer for neutral elimination. Identifications of the most specific fragmentations presented in this paper were applied to the screening and unambiguous identification of diuretics for horse doping control.


Subject(s)
Benzothiadiazines , Sodium Chloride Symporter Inhibitors/analysis , Chromatography, High Pressure Liquid , Diuretics , Gases/chemistry , Humans , Indicators and Reagents , Sodium Chloride Symporter Inhibitors/urine , Spectrometry, Mass, Electrospray Ionization
4.
Shokuhin Eiseigaku Zasshi ; 43(2): 95-8, 2002 Apr.
Article in Japanese | MEDLINE | ID: mdl-12092419

ABSTRACT

A high-performance liquid chromatographic (HPLC) method for the simultaneous analysis of triamterene, trichlormethiazide, furosemide and spironolactone is presented for application in the examination of health food supplements advertising weight reduction and in the analysis of pharmaceuticals. The HPLC assay was performed under gradient conditions using a Wakosil ODS 5C18 column (5 microns, 150 x 4.6 mm i.d.). The mobile phase consisted of a gradient program with a mixture of water and acetonitrile containing 0.1% triethylamine adjusted with phosphoric acid to pH 3.0: from 0 to 6 min, 15% acetonitrile; from 6 to 20 min, linear gradient from 15 to 50% acetonitrile; and from 20 to 40 min, 50% acetonitrile. The column effluent was monitored from 0 to 20 min at 260 nm and from 20 to 40 min at 235 nm. The calibration curves of the four drugs showed good linearity and the correlation coefficients were better than 0.999 in all cases. The lower limits of detection were approximately 40 ng for each drug. Commercially available health food supplements and pharmaceuticals were analyzed after extraction with a mixture of methanol and acetic acid (99:1). The procedure described here is suitable for the screening of four diuretic drugs in adulterated supplements and for the quality control of pharmaceuticals with minimal sample preparation.


Subject(s)
Chromatography, High Pressure Liquid/methods , Dietary Supplements/analysis , Diuretics/analysis , Food, Organic/analysis , Furosemide/analysis , Spironolactone/analysis , Triamterene/analysis , Trichlormethiazide/analysis , Weight Loss , Sodium Chloride Symporter Inhibitors/analysis
5.
J Chromatogr A ; 924(1-2): 439-49, 2001 Jul 27.
Article in English | MEDLINE | ID: mdl-11521895

ABSTRACT

A capillary electrophoresis method was developed for the simultaneous determination of hydrochlorothiazide and several angiotensin-converting enzyme (ACE) inhibitors: enalapril, lisinopril, quinapril, fosinopril, ramipril, and cilazapril. The most critical parameter is the pH of the running buffer. Separation was performed on a fused-silica capillary (52 cm total length x 75 microm I.D.) using a sodium phosphate buffer (pH 7.25; 100 mM). The method was successfully applied to the quantitative determination of these compounds in their corresponding pharmaceutical formulation. The method was validated in terms of linearity of response, reproducibility and accuracy.


Subject(s)
Angiotensin-Converting Enzyme Inhibitors/analysis , Antihypertensive Agents/analysis , Electrophoresis, Capillary/methods , Hydrochlorothiazide/analysis , Sodium Chloride Symporter Inhibitors/analysis , Diuretics , Reference Standards , Reproducibility of Results
6.
J Pharm Biomed Anal ; 25(5-6): 923-31, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11377075

ABSTRACT

Different spectrophotometric and HPTLC-densitometric methods are presented for the simultaneous determination of lisinopril and hydrochlorothiazide in pharmaceutical tablets. The spectrophotometric methods include third derivative (3D) ultraviolet spectrophotometry with zero crossing measurement at 217.4 and 233.4 nm, second derivative of the ratio spectra with measurement at 214.3 and 228.0 nm; both classical least squares and principal component regression were applied to the UV absorption and first derivative spectra of the mixture. The HPTLC method was based on separation of both drugs followed by densitometric measurements of their spots at 210 and 275 nm for lisinopril and hydrochlorothiazide, respectively. The separation was carried out on Merck HPTLC aluminum plates of silica gel 60 F254, using chloroform-ethylacetate-acetic acid (10:3:2 by vol.) as mobile phase. The linear and second order polynomial were used for the regression equation of lisinopril and hydrochlorothiazide, respectively.


Subject(s)
Angiotensin-Converting Enzyme Inhibitors/analysis , Chromatography, Thin Layer/methods , Drug Combinations , Hydrochlorothiazide/analysis , Lisinopril/analysis , Sodium Chloride Symporter Inhibitors/analysis , Spectrophotometry, Ultraviolet/methods , Diuretics , Reproducibility of Results , Tablets/chemistry
7.
J Pharm Biomed Anal ; 25(5-6): 1009-13, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11377086

ABSTRACT

First-derivative ultraviolet spectrophotometry and high-performance liquid chromatography (HPLC) were used to determine valsartan and hydrochlorothiazide simultaneously in combined pharmaceutical dosage forms. The derivative procedure was based on the linear relationship between the drug concentration and the first derivative amplitudes at 270.6 and 335 nm for valsartan and hydrochlorothiazide, respectively. The calibration graphs were linear in the range of 12.0-36.1 microg x ml(-1) for valsartan and 4.0-12.1 microg x ml(-1) for hydrochlorothiazide. Furthermore, a high- performance liquid chromatographic procedure with ultraviolet detection at 225 nm was developed for a comparison method. For the HPLC procedure, a reversed phase column with a mobile phase of 0.02 M phosphate buffer (pH 3.2)-acetonitrile (55: 45; v/v), was used to separate for valsartan and hydrochlorothiazide. The plot of peak area ratio of each drug to the internal standard versus the respective concentrations of valsartan and hydrochlorothiazide were found to be linear in the range of 0.06-1.8 and 0.07-0.5 microg x ml(-1), respectively. The proposed methods were successfully applied to the determination of these drugs in laboratory-prepared mixtures and commercial tablets.


Subject(s)
Antihypertensive Agents/analysis , Hydrochlorothiazide/analysis , Sodium Chloride Symporter Inhibitors/analysis , Tablets/chemistry , Tetrazoles/analysis , Valine/analysis , Chromatography, High Pressure Liquid/methods , Diuretics , Drug Combinations , Reproducibility of Results , Spectrophotometry, Ultraviolet , Valine/analogs & derivatives , Valsartan
8.
J Pharm Biomed Anal ; 23(1): 185-9, 2000 Aug 01.
Article in English | MEDLINE | ID: mdl-10898169

ABSTRACT

A method for the simultaneous determination of losartan potassium and hydrochlorothiazide in tablets is described. The procedure, based on the use of reversed-phase high-performance liquid chromatography, is linear in the concentration range 3.0-7.0 microg ml(-1) for losartan and 0.5-2.0 microg ml(-1) for hydrochlorothiazide, is simple and rapid and allows accurate and precise results. The limit of detection was 0.08 microg ml(-1) for losartan and 0.05 microg ml(-1) for hydrochlorothiazide.


Subject(s)
Antihypertensive Agents/analysis , Chromatography, High Pressure Liquid/methods , Hydrochlorothiazide/analysis , Losartan/analysis , Sodium Chloride Symporter Inhibitors/analysis , Calibration , Diuretics , Reproducibility of Results , Sensitivity and Specificity , Spectrophotometry, Ultraviolet
9.
J Pharm Biomed Anal ; 22(1): 1-6, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10727117

ABSTRACT

A method has been developed for the separation of hydrochlorothiazide and amiloride by high-performance liquid chromatographic (HPLC) method on a C18 column with detection at 280 nm. The optimal conditions of separation were determined with the aid of 'window diagram' technique of Laub and Purnell. The effect of simultaneously varying the pH, proportion aqueous acetic acid and methanol in the mobile phase were studied to optimize the separation. A response surface diagram was used to optimize the experimental conditions for the separation. The mobile phase composition that provides an acceptable resolution hydrochlorothiazide and amiloride in a short elution time is water:methanol (60:40) and pH 3.2 (pH adjusted to 3.2 with CH3COOH). A method is applied for the quantitative analysis of Moduretic tablets (Merck Sharp & Dokme International). The powdered tablets are extracted with methanol, containing caffeine as the internal standard, and assayed by comparison of peak areas after liquid chromatography.


Subject(s)
Amiloride/analysis , Diuretics/analysis , Hydrochlorothiazide/analysis , Sodium Chloride Symporter Inhibitors/analysis , Chromatography, High Pressure Liquid , Data Interpretation, Statistical , Drug Combinations , Factor Analysis, Statistical , Hydrogen-Ion Concentration , Methanol , Pharmaceutical Solutions , Solvents , Tablets
10.
J Pharm Biomed Anal ; 20(1-2): 155-67, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10704019

ABSTRACT

Procedures were developed for the simultaneous determination of pharmaceuticals in binary mixtures, containing hydrochlorothiazide-benazepril hydrochloride, hydrochlorothiazide triamterene and hydrochlorothiazide cilazapril by ratio spectra derivative spectrophotometry and Vierordt's method. Mean recoveries, relative standard deviations and linearity ranges in calibration graphs of the methods were compared. These procedures were successfully applied to three pharmaceutical formulations for the determination of active ingredients.


Subject(s)
Angiotensin-Converting Enzyme Inhibitors/analysis , Benzazepines/analysis , Cilazapril/analysis , Diuretics/analysis , Hydrochlorothiazide/analysis , Sodium Chloride Symporter Inhibitors/analysis , Triamterene/analysis , Drug Combinations , Indicators and Reagents , Solvents , Spectrophotometry, Ultraviolet , Tablets
13.
Kidney Int ; 50(4): 1180-90, 1996 Oct.
Article in English | MEDLINE | ID: mdl-8887276

ABSTRACT

We studied the effects of inhibition of apical NaCl entry on the structural correlates for electrolyte transport in the distal convoluted tubule (DCT) of rats. Thiazide diuretics were used to block NaCl entry specifically in the DCT. Metolazone or hydrochlorothiazide (HCTZ) were applied for three days subcutaneously via osmotic minipumps. The renal epithelial structure of control and treated rats was studied by light and electron microscopy. Distribution of the thiazide-sensitive NaCl cotransporter (rTSC1), calbindin D28K and Ca(2+)-Mg(2+)-ATPase was examined by immunohistochemistry, and the content of rTSC1 transcripts by Northern blot and in situ hybridization. In treated rats the DCT epithelium had lost the structural characteristics of electrolyte transporting epithelia and the cells were in different stages of apoptosis. In damaged cells calbindin D28K and Ca(2+)-Mg(2+)-ATPase were strongly decreased; the rTSC1 was shifted from the luminal membrane to the basal cell half and was found additionally in small membrane vesicles in intercellular and peritubular spaces. Transcripts of rTSC1 were drastically reduced in homogenates of kidney cortex and almost absent in damaged DCT cells. All other tubular segments were unaffected by the treatment. Focal inflammatory infiltrates were found to be specifically surrounding DCT profiles. Thus, inhibition by thiazides of apical NaCl entry into DCT cells is associated with apoptosis of DCT cells and focal peritubular inflammation.


Subject(s)
Apoptosis/physiology , Benzothiadiazines , Kidney Tubules, Distal/pathology , Sodium Chloride Symporter Inhibitors/pharmacology , Symporters , Analysis of Variance , Animals , Ca(2+) Mg(2+)-ATPase/analysis , Calbindin 1 , Calbindins , Carrier Proteins/analysis , Diuretics , Fluorescent Antibody Technique, Indirect , Immunohistochemistry , In Situ Hybridization , Kidney/pathology , Kidney/ultrastructure , Kidney Tubules, Distal/drug effects , Male , Microscopy, Electron , RNA/analysis , Rats , Rats, Wistar , Receptors, Drug/analysis , S100 Calcium Binding Protein G/analysis , Sodium Chloride Symporter Inhibitors/analysis , Sodium Chloride Symporters , Solute Carrier Family 12, Member 3
14.
J Pharm Biomed Anal ; 12(7): 917-22, 1994 Jul.
Article in English | MEDLINE | ID: mdl-7981321

ABSTRACT

Ethanolic solutions of three thiazide diuretics, chlorothiazide, hydrochlorothiazide and trichlormethiazide, were irradiated with a high-pressure mercury lamp. The products were isolated and their first-derivative UV spectra in ethanol were recorded and compared to those of the parent compounds. The determination of the parent compounds in the presence of the decomposition products was carried out at wavelengths near 220 nm using the zero-crossing technique. Three reversed-phase HPLC methods were also developed for the analysis of the parent compounds. In parallel analyses of the reaction mixtures a good correlation was achieved between these two methods in the determination of hydrochlorothiazide and trichlormethiazide while there was greater variation in the results of chlorothiazide.


Subject(s)
Sodium Chloride Symporter Inhibitors/analysis , Chlorothiazide/analysis , Chlorothiazide/chemistry , Chromatography, High Pressure Liquid , Diuretics , Hydrochlorothiazide/analysis , Hydrochlorothiazide/chemistry , Light , Photolysis , Sodium Chloride Symporter Inhibitors/chemistry , Sodium Chloride Symporter Inhibitors/radiation effects , Spectrophotometry, Ultraviolet , Trichlormethiazide/analysis , Trichlormethiazide/chemistry
16.
J Chromatogr ; 384: 259-78, 1987 Jan 02.
Article in English | MEDLINE | ID: mdl-3818855

ABSTRACT

A method has been developed for the separation of thiazide diuretics and a number of related drugs by high-performance liquid chromatography on an ODS-Hypersil column with acetonitrile-1% aqueous acetic acid as the eluent. The effects caused by changes in the separation conditions on the reproducibility and robustness of alternative methods for recording retentions (including capacity factors, retention indices based on the alkyl aryl ketone scale, and relative capacity factors compared to a thiazide standard) have been examined. The results confirm that good interlaboratory reproducibility will only be achieved when operators control the temperature of the column and use the same brand of column packing material. The retentions should be recorded using a relative method, as these were found to be virtually independent of minor variations in the eluent composition.


Subject(s)
Benzothiadiazines , Sodium Chloride Symporter Inhibitors/analysis , Acetates , Acetonitriles/analysis , Chromatography, High Pressure Liquid , Diuretics/analysis , Hydrogen-Ion Concentration , Solvents , Temperature
18.
Pharmazie ; 41(8): 565-6, 1986 Aug.
Article in German | MEDLINE | ID: mdl-3786376

ABSTRACT

Studies of the stability of hydrochlorothiazide (1) in N-methylacetamide prove that a temperature dependent equilibrium is found in the isothermic short-term test as well as in the longterm stability test. Whereas the kinetic reaction evaluation after Arrhenius doesn't allow a forecast, the 25 degrees C-values, extrapolated after the Van't Hoff-equation, were confirmed using the long-term test. By adding the decomposition product aminodisulfamide (2) the hydrolysis is restricted.


Subject(s)
Cyclopenthiazide/analysis , Hydrochlorothiazide/analysis , Sodium Chloride Symporter Inhibitors/analysis , Diuretics , Drug Stability , Hydrolysis , Injections , Kinetics , Solutions
19.
J Chromatogr ; 354: 367-73, 1986 Feb 28.
Article in English | MEDLINE | ID: mdl-3700531

ABSTRACT

A procedure for the simultaneous quantitative determination and selective identification of potassium canrenoate and butizide is proposed. The amount of canrenone, the degradation product of potassium canrenoate, is also determined. Elution of these compounds is investigated on LiChrosorb RP-18 and RP-8 columns. The analysis time was shorter on a RP-8 column while the specific identification was still possible. Therefore, the LiChrosorb RP-8 column was chosen. The eluent consisted of an acetonitrile--0.05 M phosphate buffer, pH 4 (45:55) mixture. Quantitative determination was performed at the absorption maximum of each compound: 286 nm for potassium canrenoate and for canrenone, 271 nm for butizide. This change in wavelength is performed automatically by the computer that controls the spectrophotometric diode array detector.


Subject(s)
Canrenoic Acid/analysis , Canrenone/analysis , Hydrochlorothiazide/analogs & derivatives , Pregnadienes/analysis , Sodium Chloride Symporter Inhibitors/analysis , Chromatography, High Pressure Liquid , Diuretics , Drug Stability , Hydrochlorothiazide/analysis , Indicators and Reagents , Spectrophotometry, Ultraviolet , Tablets
20.
Pharmazie ; 40(7): 467-9, 1985 Jul.
Article in German | MEDLINE | ID: mdl-4048250

ABSTRACT

Checking-up the stability of hydrochlorothiazid tablets (Disalunil), chemical and especially pharmaceutical-technological analyses were forming part of the adequate test programme. The pharmaceutical and chemical properties of the Disalunil tablets will be regarded as sufficient ones at normal conditions of their storage. In case the tablets will be stored, however, in their original packing under conditions of an increased humidity or with additional water, the water sorption will result in prolonged disintegration rates as well as in a reduced radial breaking strength and dissolution rate. This significant depreciation of the drug cannot be recognized by chemical-analytical methods.


Subject(s)
Cyclopenthiazide/analysis , Hydrochlorothiazide/analysis , Sodium Chloride Symporter Inhibitors/analysis , Diuretics , Drug Stability , Tablets , Time Factors
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