Development of an HPLC method for measuring orally administered 1-substituted 2-alkyl-3-hydroxypyrid-4-one iron chelators in biological fluids

1990 ◽  
Vol 36 (1) ◽  
pp. 5-8 ◽  
Author(s):  
J G Goddard ◽  
G J Kontoghiorghes
Keyword(s):  
High Performance ◽  
Biological Fluids ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
Iron Chelators ◽  
Serum Samples ◽  
Thalassemic Patient ◽  
Serum And Urine

Abstract "High-performance" liquid-chromatographic (HPLC) methods have been developed for identifying 1-substituted 2-alkyl-3-hydroxypyrid-4-one iron chelators in serum and urine. Ion pairing with heptane- or octanesulfonic acid in pH 2.0-2.2 phosphate buffer and reversed-phase chromatography were required to separate these compounds from endogenous compounds in both biological fluids. In both the 2-methyl and 2-ethyl series of 1-substituted compounds (H, methyl, ethyl, or propyl) the elution times increased in accordance with the n-octanol/water partition coefficients (propyl greater than ethyl greater than H greater than methyl). Urine samples were filtered (0.4 microns pore size) and injected either undiluted or after dilution with elution buffer. After the addition of internal standard, the plasma or serum samples were deproteinized by treatment with HCIO4, 0.5 mol/L, centrifuged, and the supernates were injected directly onto the HPLC. Using these procedures, we could identify 1,2-dimethyl-3-hydroxypyrid-4-one (L1) in the serum and urine of a thalassemic patient who had received a 3-g dose of the drug and in the urine of other patients who had received the same dose. One or more possible metabolites were also observed in the chromatograms of both urine and serum. The 24-h urinary output of L1 (0.22-2.37 g) and iron (10.6-71.5 mg) varied but there was no correlation between the two with respect to quantity or concentration. Instead, urinary iron output was higher in patients with a greater number of transfused units of erythrocytes. This is the first study in humans to show that L1 is absorbed from the gut, enters the circulation, and is excreted in the urine.

Ascorbic and dehydroascorbic acids simultaneously quantified in biological fluids by liquid chromatography with fluorescence detection, and comparison with a colorimetric assay.

1987 ◽  
Vol 33 (10) ◽  
pp. 1874-1878 ◽  
Author(s):  
A Lopez-Anaya ◽  
M Mayersohn
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Colorimetric Assay ◽  
Biological Fluids ◽  
Colorimetric Method ◽  
Internal Standard ◽  
Dehydroascorbic Acid ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Isoascorbic Acid

Abstract We describe a "high-performance" liquid-chromatographic method for separating and quantifying ascorbic acid (AA) and dehydroascorbic acid (DHA) in plasma and urine. We used a reversed-phase C18 column with an ion-pair reagent and detected the analytes by post-column reaction with 4,5-dimethyl-o-phenylenediamine to form a fluorescent derivative (measured at excitation and emission wavelengths of 365 and 440 nm, respectively). Isoascorbic acid (IA) is the internal standard. Retention times for DHA, AA, and IA are 5.6, 15.5, and 19.9 min, respectively. Between-day CVs for AA in plasma in concentrations of 8 and 20 mg/L were 9% and 7%, respectively. The limit of detection is 10 and 4 ng for AA and DHA, respectively. Results by the present method and the methoxyaniline colorimetric method for AA are comparably accurate.

Liquid-chromatographic measurement of biopterin and neopterin in serum and urine

1990 ◽  
Vol 36 (7) ◽  
pp. 1364-1368 ◽  
Author(s):  
W E Slazyk ◽  
F W Spierto
Keyword(s):  
High Performance ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
Fluorometric Detection ◽  
Preparation Step ◽  
Human Adults ◽  
Biopterin Synthesis ◽  
Liquid Chromatographic ◽  
Serum And Urine

Abstract We report an improved "high-performance" liquid-chromatographic (HPLC) method for measuring biopterin and neopterin in serum and urine. Specimens are acidified, treated with iodine in 0.2 mol/L trichloroacetic acid, party purified on Bio-Rad MP-50 cation-exchange columns, and analyzed by reversed-phase HPLC with fluorometric detection. The minimal concentration of biopterin detectable is 0.3 micrograms/L in a 50-microL injection. The total CV is less than or equal to 10%. Improvements over other reported methods include the use of a single, simplified sample-preparation step with a Baker-10 SPE System, and a guard column to increase analytical column stability and analyte recovery. The assay is semiautomated to reduce technician time and improve precision. Mean observed values for biopterin and neopterin in sera of normal human adults were 1.64 and 5.52 micrograms/L, respectively. The mean ratio of neopterin to biopterin in acidified adult urine samples was lower than that found in matched nonacidified samples (n = 10). Serum specimens from diagnosed phenylketonuric (PKU) and hyperphenylalaninemic patients were also analyzed for biopterin and neopterin; the findings agreed with reported values for similar patients. One patient, previously identified as an atypical PKU patient, showed serum values of neopterin and biopterin suggestive of a defect in biopterin synthesis.

Simultaneous liquid-chromatographic determination of prednisone and prednisolone in plasma.

1988 ◽  
Vol 34 (9) ◽  
pp. 1897-1899 ◽  
Author(s):  
M H Cheng ◽  
W Y Huang ◽  
A I Lipsey
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
Liquid Chromatographic Determination ◽  
Standard Solution ◽  
Liquid Chromatographic

Abstract This high-performance liquid-chromatographic (HPLC) method for simultaneous determination of prednisone and its metabolite, prednisolone, in plasma is a modification of the method of Frey et al. (Clin Chem 1979;25:1944-7). Heparinized plasma (1.0 mL) with 0.1 mL of internal standard solution (11-deoxy-17-hydroxycorticosterone, 2 mg/L) is extracted with 7.0 mL of dichloromethane, then washed sequentially with 0.1 mol/L HCl, 0.1 mol/L NaOH, and deionized water, 2.0 mL each. The extract is evaporated and the residue reconstituted with 75 microL of mobile phase, methanol/H2O (40/60 by vol). Thirty microliters of this is injected onto a reversed-phase C6 column, which is eluted at 1.4 mL/min. Analytical recoveries of prednisone and prednisolone were 94-98% and 102-106%, respectively. Day-to-day precision (CV) was 3.8% for prednisone, 6.1% for prednisolone. We encountered no interference from the 21 other steroids and 25 drugs tested. This method is simple, accurate, and precise.

Liquid-chromatographic assay of cefamandole in serum, urine, and dialysis fluid.

1986 ◽  
Vol 32 (1) ◽  
pp. 197-200 ◽  
Author(s):  
M Bliss ◽  
M Mayersohn
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Biological Fluids ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Pharmacokinetic Studies ◽  
Dialysis Fluid ◽  
Serum Samples ◽  
Liquid Chromatographic ◽  
Phase Column

Abstract We describe a "high-performance" liquid-chromatographic assay for quantifying cefamandole in biological fluids from patients with renal impairment. Serum samples are deproteinized with acetonitrile, then extracted with dichloromethane; dialysis-fluid samples are injected directly; urine samples are diluted appropriately before injection onto the reversed-phase column. The mobile phase is a methanol/aqueous solution (31/69 by vol) containing 500 microL of phosphoric acid, 20 mmol of sodium sulfate, and 200 microL of triethylamine per liter, the mixture being adjusted to pH 6.0 with NaOH. Retention time for cefamandole is 12 min. Its peak is well resolved in highly contaminated samples from renally impaired subjects. The assay's selectivity, reproducibility (within-day and between-day CVs less than 8% in all three sample fluids), and sensitivity--0.5 mg/L in serum, 1.0 mg/L in dialysis fluid, and 5.0 mg/L in urine--make it applicable to pharmacokinetic studies.

scholarly journals Spectrophotometric and Column High-Performance Liquid Chromatographic Methods for Simultaneous Estimation of Metoprolol Tartrate and Hydrochlorothiazide in Tablets

2008 ◽  
Vol 91 (5) ◽  
pp. 1045-1050 ◽  
Author(s):  
Gopal Garg ◽  
Shailendra Saraf ◽  
Swarnlata Saraf
Keyword(s):  
High Performance ◽  
Dosage Form ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
Simultaneous Estimation ◽  
Metoprolol Tartrate ◽  
Significant Difference ◽  
Liquid Chromatographic

Abstract Simple, accurate, economical, and reproducible UV spectrophotometric and column high-performance liquid chromatographic (HPLC) methods were developed for simultaneous estimation of a 2-component drug mixture of metoprolol tartrate and hydrochlorothiazide in combined tablet dosage form. The first method used the simultaneous equation method with 7 mixed standards and the absorption maxima at 223 and 271 nm, respectively, for metoprolol tartrate and hydrochlorothiazide in methanol. Linearity was observed in the concentration ranges of 424 and 216 g/mL for metoprolol tartrate and hydrochlorothiazide, respectively. The developed HPLC method used a reversed-phase C18 column and methanolwater (95 + 5) mobile phase at an ambient temperature of 27 2C and UV detection at 225 nm; the run time was 10 min, and quantification was based on peak area. The injection repeatability and intraday and interday repeatability were calculated. Paracetamol was used as an internal standard for the HPLC method, and linearity was observed in the concentration range of 550 g/mL for metoprolol and 220 g/mL for hydrochlorothiazide. The proposed methods were successfully applied for the determination of metoprolol tartrate and hydrochlorothiazide in bulk powder and dosage form. The results obtained were analyzed statistically, and there was no significant difference between the 2 methods. The validation was performed according to International Conference on Harmonization guidelines.

High-performance liquid-chromatographic assay for chloramphenicol in biological fluids.

1978 ◽  
Vol 24 (5) ◽  
pp. 778-781 ◽  
Author(s):  
R L Thies ◽  
L J Fischer
Keyword(s):  
Biological Sample ◽  
High Performance ◽  
Biological Fluids ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Single Extraction ◽  
Specific Analysis ◽  
Liquid Chromatographic ◽  
Phase Column

Abstract We describe a method for measuring chloramphenicol by high-performance liquid chromatography. The assay involves a single extraction of the biological sample with ether, evaporation of the extract, and chromatography of the residue, redissolved in methanol. A reversed-phase column with an eluting solvent of methanol/water (30/70 by vol) is used. Chloramphenicol is eluted from the column in about 4 min and is well separated from the internal standard (mephenesin), which is eluted at 5.5 min. Absorption of the effluent at 278 nm is monitored and measured. As little as 0.1 microgram of the antibiotic can be analyzed after its extraction from a 0.1-ml sample. The method is suitable for rapid and specific analysis for the drug in plasma, urine, cerebrospinal fluid, and other biological fluids.

Reversed-Phase High Performance Liquid Chromatographic Analysis of Three First Line Anti-Tuberculosis Drugs

2019 ◽  
Vol 69 (12) ◽  
pp. 3590-3592
Author(s):  
Nela Bibire ◽  
Romeo Iulian Olariu ◽  
Luminita Agoroaei ◽  
Madalina Vieriu ◽  
Alina Diana Panainte ◽  
...  
Keyword(s):  
High Performance ◽  
Biological Fluids ◽  
Gradient Elution ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Assay Method ◽  
Active Pharmaceutical Ingredients ◽  
First Line ◽  
Pharmaceutical Ingredients ◽  
Liquid Chromatographic

Active pharmaceutical ingredients such as isoniazid, pyrazinamide and rifampicin are among the most important first-line anti-tuberculosis drugs. A simple, rapid and sensitive reversed phase-high performance liquid chromatographic assay method for the simultaneous determination of isoniazid, pyrazinamide and rifampicin has been developed. Separation of the interest compounds was achieved in a 10 min chromatographic run in gradient elution mode on a Zorbax SB-C18 stainless steel column (150 � 4 mm, 5 mm) using a guard column containing the same stationary phase. The gradient elution was carried out with a mobile phase of 10% CH3CN aqueous solution for channel A and 50% CH3CN in pH = 6.8 phosphate buffer (20 mM), to which 1.5 mL triethylamine were added for channel B. Quantification of the analyzed substances was carried out spectrophotometrically at 269 nm. Detection limits of 0.48 mg/L for isoniazid, 0.52 mg/L for pyrazinamide and 0.48 mg/L for rifampicin were established for the developed assay method. The present work showed that the proposed analysis method was advantageous for simple and rapid analysis of the active pharmaceutical ingredients in pharmaceuticals and biological fluids.

scholarly journals A Simple and Sensitive HPLC Method for Simultaneous Analysis of Nabumetone and Paracetamol in Pharmaceutical Formulations

2011 ◽  
Vol 8 (s1) ◽  
pp. S41-S46
Author(s):  
Prafulla Kumar Sahu ◽  
M. Mathrusri Annapurna ◽  
Dillipkumar Sahoo
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Pharmaceutical Formulations ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Simultaneous Estimation ◽  
Aqueous Acetic Acid ◽  
Linear Calibration ◽  
Acceptance Range ◽  
Liquid Chromatographic

This paper describes a high-performance liquid chromatographic method for simultaneous estimation of nabumetone and paracetamol in binary mixture. The method was based on RP-HPLC separation and quantitation of the two drugs on hypersil C-18 column (250 mm × 4.6 mm) using a mobile phase consisting of acetonitrile and 0.05% aqueous acetic acid (70:30v/v) at flow rate of 1 mL min-1. Quantitation was achieved with PDA detector at 238 nm based on peak area with linear calibration curves at concentration ranges 5-25 µg mL-1for both the drugs. Naproxen sodium was used as internal standard. The method has been successively applied to pharmaceutical formulation. No chromatographic interference from the tablet excipients was found. The method was validated in terms of precision, robustness, recovery and limits of detection and quantitation. The intra and inter-day precision and accuracy values were in the acceptance range as per ICH guidelines.

scholarly journals Determination of Finasteride in Tablets by High Performance Liquid Chromatography

2007 ◽  
Vol 4 (1) ◽  
pp. 109-116 ◽  
Author(s):  
K. Basavaiah ◽  
B. C. Somashekar
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Calibration Graph ◽  
Official Method ◽  
Pharmaceutical Dosage Forms ◽  
Bulk Drug ◽  
Liquid Chromatographic

A rapid, highly sensitive high performance liquid chromatographic method has been developed for the determination of finasteride(FNS) in bulk drug and in tablets. FNS was eluted from a ODS C18reversed phase column at laboratory temperature (30 ± 2°C) with a mobile phase consisting of methanol and water (80+20) at a flow rate of 1 mL min-1with UV detection at 225 nm. The retention time was ∼ 6.1 min and each analysis took not more than 10 min. Quantitation was achieved by measurement of peak area without using any internal standard. Calibration graph was linear from 2.0 to 30 μg mL-1with limits of detection (LOD) and quantification (LOQ) being 0.2 and 0.6 μg mL-1, respectively. The method was validated according to the current ICH guidelines. Within-day co efficients of variation (CV) ranged from 0.31 to 0.69% and between-day CV were in the range 1.2-3.2%. Recovery of FNS from the pharmaceutical dosage forms ranged from 97.89 – 102.9 with CV of 1.41-4.13%. The developed method was compared with the official method for FNS determination in its tablet forms.

FORCED DEGRADATION STUDIES OF OLMESARTAN MEDOXOMIL AND CHLORTHALIDONE: DEVELOPMENT AND VALIDATION OF STABILITY-INDICATING RP‑HPLC METHOD

INDIAN DRUGS ◽  
2019 ◽  
Vol 56 (03) ◽  
pp. 39-45
Author(s):  
A Sherje ◽  
A. Sonalkar ◽  
Keyword(s):  
High Performance ◽  
Dosage Form ◽  
Olmesartan Medoxomil ◽  
The United States ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
Forced Degradation ◽  
Uv Detector ◽  
Tablet Dosage

A reversed-phase high-performance liquid chromatographic method was developed for the simultaneous determination of olmesartan medoxomil (OLME) and chlorthalidone (CHLOR) in tablet dosage form. The analysis was performed on Inertsil ODS C18 (250 x 4.6 mm, 5 μ) using KH2PO4 phosphate buffer (pH) and acetonitrile as mobile phase in the proportion of 60: 40 v/v at flow rate of 1.0 mL/min. Detection of drugs was carried out in isocratic mode using UV detector at 275 nm. The retention time of OLME and CHLOR was 13.9 ± 0.1 min. and 4.4 ± 0.5 min., respectively and the total run time was 20 min. The method was validated according to the requirements of the United States Pharmacopeia. The percentage recoveries was found to be in the range of 98.9 - 100.7%. The method was successfully applied to the assay of OLME and CHLOR in tablet dosage form.

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