Antipyrine, indocyanine green, and lorazepam determined in plasma by high-pressure liquid chromatography.

1989 ◽  
Vol 35 (10) ◽  
pp. 2124-2126 ◽  
Author(s):  
W M Awni ◽  
L J Bakker
Keyword(s):  
Indocyanine Green ◽  
Low Cost ◽  
Extraction Procedure ◽  
Internal Standard ◽  
Reversed Phase ◽  
Hplc Method ◽  
Model Compounds ◽  
Clinical Measurement ◽  
One Step ◽  
Isocratic Hplc

Abstract This HPLC method for measuring antipyrine, lorazepam, and indocyanine green in 0.5 mL of plasma can be used in studies of liver function in which these "model" compounds are used. After a fast, simple, one-step extraction procedure with acetonitrile, an isocratic HPLC system is used, with a single detection wavelength (214 nm) and a single internal standard (1-acetamidopyrene). The mobile phase is a 47/53 (by vol) mixture of acetonitrile and 50 mmol/L phosphate buffer, pH 6. The three compounds are separated on an LC-18 reversed-phase column. The low cost of the HPLC method makes feasible the routine clinical measurement of all three compounds.

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.

SIMULTANEOUS ESTIMATION OF CURCUMIN AND GEFITINIB IN BULK AND TISSUE SAMPLES (PLASMA AND BRAIN HOMOGENATE) BY RP-HPLC: APPLICATION TO A DISTRIBUTION STUDY

INDIAN DRUGS ◽  
2019 ◽  
Vol 56 (07) ◽  
pp. 59-68
Author(s):  
H Mahajan ◽  
S Savale ◽  
P Nerkar ◽  
Keyword(s):  
Flow Rate ◽  
Mobile Phase ◽  
Internal Standard ◽  
Brain Homogenate ◽  
Reversed Phase ◽  
Hplc Method ◽  
Simultaneous Estimation ◽  
Bulk Analysis ◽  
Experimental Conditions ◽  
Rp Hplc

The present study was aimed at developing a Reversed-Phase High-Performance Liquid Chromatography (RP-HPLC) method for simultaneous determination of curcumin (CRM) and gefitinib (GFT) in bulk, plasma and brain homogenate. hydrochlorothiazide was used as an internal standard (IS). A new simple, rapid, selective, precise and accurate RP-HPLC method has been developed. The separation was achieved by using C-18 column (Qualisil BDS C18, 250 mm x 4.6 mm I.D.) coupled with a guard column of silica, mobile phase consisted of acetonitrile: water with 0.1% formic acid (30:70 v/v). The flow rate was 0.2 ml/min and the drug was detected using PDA detector at the wavelength of 242 nm. The experimental conditions, including the diluting solvent, mobile phase composition, column saturation and flow rate, were optimised to provide high-resolution and reproducible peaks. The method was developed and tested for linearity range of 10-60 μg/mL for bulk analysis and 200-800 ng/mL for plasma and brain homogenate. The developed method was validated as per ICH guidelines, in terms of linearity, application of the proposed method to bulk sample, recovery, precision, repeatability, ruggedness, sensitivity (LOD and LOQ) and robustness and stability study (short and long-term stabilities, freeze/thaw stability, post-preparative). The low value of % RSD showed that the method was precise within the acceptance limit of 2%. The developed method was successfully applied for the analysis of the drug in bulk as well as various marketed formulation and drug in plasma and brain distribution studies.

scholarly journals Simultaneous determination of mycophenolic acid and its glucuronide in human plasma using a simple high-performance liquid chromatography procedure

1998 ◽  
Vol 44 (7) ◽  
pp. 1481-1488 ◽  
Author(s):  
Maria Shipkova ◽  
Paul Dieter Niedmann ◽  
Victor William Armstrong ◽  
Ekkehard Schütz ◽  
Eberhard Wieland ◽  
...  
Keyword(s):  
Mycophenolic Acid ◽  
High Performance ◽  
Internal Standard ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Hplc Method ◽  
Free Concentration ◽  
Elution Chromatography ◽  
Glucuronide Metabolite

Abstract We describe a reversed-phase HPLC method for determination of total mycophenolic acid (MPA), its free concentration (MPAf), and the glucuronide metabolite (MPAG), based on simple sample preparation and gradient elution chromatography. The compounds were quantified in parallel by absorbance at 254 nm and 215 nm in the internal standard mode. Linearity was verified up to 50 mg/L for MPA and up to 500 mg/L for MPAG (r >0.999). Detection limits at 215 and 254 nm were, respectively, 0.01 and 0.03 mg/L for MPA, and 0.03 and 0.1 mg/L for MPAG. The recovery of MPA was 95–106%;recovery of MPAG was 96–106%. The imprecision (CV) for MPA (0.2–25 mg/L) was <8.4% (254 nm) and <4.4% (215 nm) within day (n = 12) and <9.2% (254 nm) and <6.2% (215 nm) between days (n = 12). The imprecision for MPAG (10–250 mg/L) was <4.9% (254 nm) and <3.4% (215 nm) within day, and <6.1% (254 nm) and <5.9% (215 nm) between days. For quantification of MPAf, 100 μL of ultrafiltrate was applied directly to the column. The detection limit was 0.005 mg/L at 215 nm and 0.015 mg/L at 254 nm. In the range between 18–210 μg/L, the within-day CVs were <11.8% (n = 12) and the between-day CVs were <15.8% (n = 12).

scholarly journals Reversed-Phase HPLC Analysis of Levetiracetam in Tablets Using Monolithic and Conventional C18 Silica Columns

2010 ◽  
Vol 93 (4) ◽  
pp. 1077-1085 ◽  
Author(s):  
Nafiz O Can ◽  
Goksel Arli
Keyword(s):  
Monolithic Column ◽  
Stationary Phases ◽  
Internal Standard ◽  
Reversed Phase ◽  
Hplc Method ◽  
Array Detector ◽  
Pharmaceutical Tablets ◽  
System Suitability ◽  
Development And Validation

Abstract Development and validation of an RP-HPLC method for determination of levetiracetam in pharmaceutical tablets is described. The separation and quantification of levetiracetam and caffeine (internal standard) were performed using a single analytical procedure with two different types of stationary phases, conventional Phenomenex Gemini C18 (100 4.6 mm, 5 m) and Merck Chromolith Performance RP18e (100 4.6 mm, macropore size 2 mm, micropore size 13 nm) monolithic silica. Five-microliter aliquots of samples were injected into the system and eluted using wateracetonitrile (90 + 10, v/v) mobile phase pumped at the rate of 1 mL/min. The analyte peaks were detected at 200 nm using a diode array detector with adequate resolution. Validation studies were performed using the method recommended by the International Conference on Harmonization, the U.S. Pharmacopeia, and AOAC INTERNATIONAL, which includes accuracy, precision, range, limits, robustness, and system suitability parameters. Levetiracetam and caffeine were detected in about 7 min using the conventional column, whereas less than 5 min was required when the monolithic column was used. Calibration plots had r values close to unity in the range of 0.88.0 g/mL. Assay of levetiracetam in a tablet formulation was demonstrated as an application to real samples.

Liquid-chromatographic determination of fleroxacin in serum and urine.

1988 ◽  
Vol 34 (11) ◽  
pp. 2330-2332 ◽  
Author(s):  
W M Awni ◽  
J A Maloney ◽  
K L Heim-Duthoy
Keyword(s):  
Extraction Procedure ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Hplc Method ◽  
Serum Samples ◽  
Fluorescence Detector ◽  
Pharmacokinetic Assessment ◽  
Standard Serum ◽  
Liquid Chromatographic ◽  
Serum And Urine

Abstract This highly sensitive, accurate, and reproducible HPLC method for determining fleroxacin in human serum and urine makes use of a common C18 column, a fluorescence detector, and an internal standard. Serum samples require a simple extraction procedure; urine must be diluted. The method, which we have used extensively for pharmacokinetic assessment of fleroxacin in patients, measures concentrations as low as 5 micrograms/L.

scholarly journals Determination of Sulfamethazine in Swine and Cattle Feed by Reversed-Phase Liquid Chromatography with Post-Column Derivatization: Pre-Collaborative Study

2000 ◽  
Vol 83 (2) ◽  
pp. 255-259 ◽  
Author(s):  
Kendrick Albert ◽  
Robert L Smallidge
Keyword(s):  
Collaborative Study ◽  
Extraction Procedure ◽  
Internal Standard ◽  
Reversed Phase ◽  
Feed Additives ◽  
Official Method ◽  
Cattle Feed ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic

Abstract In-house validation of a liquid chromatographic method for determination of sulfamethazine in swine and cattle feed was performed to verify that the method was ready for collaborative study under AOAC INTERNATIONAL guidelines. In this method, sulfamerazine is added during the extraction procedure and is used as an internal standard to correct for variable recovery of sulfamethazine from a variety of swine and cattle feed matrixes. The determinative step involves the use of post-column derivatization with dimethylaminobenzaldehyde which reacts with the primary amine group on the sulfonamides. Detection is at 450 nm, a wavelength at which most co-extracted matrix materials and other feed additives do not absorb light. The results indicate that the method recovery, precision, and ruggedness meet normal criteria to be ready for a collaborative study. Fortification experiments over a range of sulfamethazine concentrations from 0.006 to 0.26% showed an overall recovery relative to the internal standard of 100 ± 2%. These studies include both swine and cattle feed matrixes. The mean recovery in the analysis of 3 beef cattle experimental feeds was 98.9%. The method results agreed with the AOAC INTERNATIONAL Official Method for colorimetric analysis of swine feed. Method precision was excellent during in-house validation studies, with coefficients of variation (CVs) ranging from about 0.5 to 3%. The method ruggedness was verified with an overall CV of 3.5%.

DEVELOPMENT AND VALIDATION OF NEW RP–HPLC METHOD FOR DETERMINATION OF BESIFLOXACIN IN ANIMAL MODEL

INDIAN DRUGS ◽  
2015 ◽  
Vol 52 (01) ◽  
pp. 26-32
Author(s):  
A Singh ◽  
◽  
C. L Singh ◽  
S. Kumar ◽  
M. Kumar
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Rat Plasma ◽  
Reversed Phase ◽  
Hplc Method ◽  
Standard Curve ◽  
Absorbance Detection ◽  
Rp Hplc ◽  
Ich Guidelines ◽  
Development And Validation

A sensitive and accurate reversed– phase high performance liquid chromatography (RP-HPLC) method with UV absorbance detection at 289 nm was developed and validated for the determination and quantification of besifloxacin (BSF) in rat plasma. Ofloxacin was used as an internal standard (IS). The sample was prepared by liquid extraction of BSF from plasma, using methanol and acetonitrile (70:30). The chromatographic separation was achieved with octadecylsilane (ODS-3), Hypersil® C18 column (250 mm×6mm×5μm). The chromatographic runtime was less than 5 minutes where the retention time of internal standard and the drug was 2.15 min and 3.30 min respectively. A standard curve with a regression coefficient (r2) 0.999 was obtained in the range of 0.025-20 μg/mL. The method was validated with respect to linearity, range, precision, accuracy and robustness according to ICH guidelines. The method was found to be accurate and robust with a runtime of less than 5 minutes. Hence, the present method was rapid and economical to use for clinical studies as well as to analyze the drug in different plasma samples.

Simultaneous Determination of Dopamine, Serotonin and Their Metabolites in the Rat Brain by HPLC Method with Coulometric Detection

2000 ◽  
Vol 65 (10) ◽  
pp. 1677-1682 ◽  
Author(s):  
Marcela Bielavská ◽  
Jiří Kassa
Keyword(s):  
Rat Brain ◽  
Simultaneous Determination ◽  
Ethylenediaminetetraacetic Acid ◽  
Inhalation Exposure ◽  
Internal Standard ◽  
Reversed Phase ◽  
Hplc Method ◽  
Disodium Salt ◽  
Total Recovery

A rapid and sensitive method for simultaneous determination of 3-hydroxytyramine (dopamine), 5-hydroxytryptamine (serotonin) and their metabolites - 3,4-dihydroxyphenylacetic acid, 3-methoxytyramine, 4-hydroxy-3-methoxyphenylacetic acid (homovanillic acid) and 5-hydroxyindole-3-acetic acid in the rat brain was developed. Brain samples with the internal standard and heparin were deproteinized by perchloric acid with ethylenediaminetetraacetic acid disodium salt and sodium sulfite. Following homogenization, centrifugation and filtration, the supernatant was directly injected into a reversed-phase HPLC system with coulometric detector. The response of the detected substances was linear in the range 12-700 ng/g of cerebellum homogenate (24-1 400 pg on column). Total recovery of the method was higher than 95%. The method was used for the determination of catecholamines and their metabolites in the chosen part of rat brain following the inhalation exposure to sarin (organophosphate).

scholarly journals A Rapid and Sensitive HPLC Method for Quantitation of Paclitaxel in Biological Samples using Liquid-Liquid Extraction and UV Detection: Application to Pharmacokinetics and Tissues Distribution Study of Paclitaxel Loaded Targeted Polymeric Micelles in.....

2015 ◽  
Vol 18 (5) ◽  
pp. 647 ◽  
Author(s):  
Mahboubeh Rezazadeh ◽  
Jaber Emami ◽  
Abolfazl Mostafavi ◽  
Mahboubeh Rostami ◽  
Farshid Hassanzadeh ◽  
...  
Keyword(s):  
Polymeric Micelles ◽  
Internal Standard ◽  
Reversed Phase ◽  
Hplc Method ◽  
Acetate Buffer Solution ◽  
Tissue Homogenate ◽  
Buffer Solution ◽  
Column Temperature ◽  
Distribution Study ◽  
Tissue Homogenates

A simple, rapid, and sensitive reversed-phase HPLC method was developed and validated for determination of paclitaxel (PTX) in plasma, various organs and tumor tissues of tumor-bearing mice. Tissue specimens of liver, kidneys, spleen, lungs, heart and tumor were separately homogenized in normal saline. Plasma or tissue homogenate (250 µl) containing PTX and internal standard (diazepam) were extracted by diethyl ether (6 ml). The separation was achieved on a µ-Bondapak C18 HPLC column using sodium acetate buffer solution (0.01 M)/acetonitrile (58/42 v/v) at pH 5 ± 0.1 and flow rate of 1.9 mL/min. The effluent was monitored at 227 nm and column temperature was adjusted at 58ºC. The internal standard and PTX were eluted at 4.2 and 5.2 min, respectively and no interfering peaks were observed.  Calibration curves were linear over the concentration range of 0.25-10 µg/ml of PTX in plasma and 0.3-20 µg/ml PTX in tissue homogenates with acceptable precision and accuracy (<15%).  The mean recoveries of the drug after plasma extraction was 87.4% ± 3.6 while those of tissue homogenates ranged from 62.1± 4.5 to 75.5± 3.2 depending on the type of tissues studied.  PTX was stable in samples with no evidence of degradation during 3 freeze–thaw cycles and 3 months storage at −70 °C.  The developed HPLC method was applied to quantify PTX in the mouse plasma and tissues after intravenous administration of 10 mg equivalent PTX/Kg dose of PTX-loaded tocopherol succinate-chitosan-polyethylene glycol-folate (TS-CS-PEG-FA) micelles formulation or Anzatax® (Cremophor® EL- based formulation of PTX) to female Balb/c mice. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

scholarly journals Determination of urinary free cortisol by HPLC

1997 ◽  
Vol 43 (8) ◽  
pp. 1386-1391 ◽  
Author(s):  
Ursula Turpeinen ◽  
Helene Markkanen ◽  
Matti Välimäki ◽  
Ulf-Håkan Stenman
Keyword(s):  
Solid Phase Extraction ◽  
Mobile Phase ◽  
Solid Phase ◽  
Internal Standard ◽  
Reversed Phase ◽  
Hplc Method ◽  
Extraction Column ◽  
Phase Extraction ◽  
Free Cortisol

Abstract We here report a reversed-phase HPLC method for the determination of free cortisol in human urine, using methylprednisolone as the internal standard. Before chromatography, samples were extracted with a C18 solid-phase extraction column and the steroids were separated on a LiChrospher 100 C18 column with a mobile phase of methanol/acetonitrile/water (43/3/54 by vol). Linearity, precision, and accuracy of the method were established. The detection limit was 10 pmol of cortisol, and total CVs were &lt;8%. With various solid-phase extraction columns the recovery of cortisol was 36–97%; recovery of the internal standard was 43–85%. Study of interference by 6 other steroids and metabolites and 24 drugs showed that carbamazepine and digoxin partly overlapped with cortisol, but this interference could be reduced by modification of the mobile phase. The HPLC method was compared with an RIA and an automated immunoassay method. The results obtained by HPLC averaged 40% of the RIA values.

Sign in / Sign up

Export Citation Format

Share Document