scholarly journals Vitamin B1 Status Assessed by Direct Measurement of Thiamin Pyrophosphate in Erythrocytes or Whole Blood by HPLC: Comparison with Erythrocyte Transketolase Activation Assay

2000 ◽  
Vol 46 (5) ◽  
pp. 704-710 ◽  
Author(s):  
Dinesh Talwar ◽  
Helen Davidson ◽  
Josephine Cooney ◽  
Denis St. JO’Reilly
Keyword(s):  
At Risk ◽  
Whole Blood ◽  
Reference Intervals ◽  
Reversed Phase ◽  
Hplc Method ◽  
Healthy Population ◽  
Limit Of Quantification ◽  
Thiamin Deficiency ◽  
Activation Test ◽  
Activation Assay

Abstract Background: The concentration of thiamin diphosphate (TDP) in erythrocytes is a useful index of thiamin status. We describe an HPLC method for TDP and its results in patients at risk of thiamin deficiency. Methods: We used reversed-phase HPLC with postcolumn derivatization with alkaline potassium ferricyanide and fluorescence detection. Samples were deproteinized and injected directly onto a C18 column. TDP concentrations in erythrocytes were compared with those in whole blood. Reference intervals for erythrocyte TDP (n = 147; 79 males and 68 females; mean age, 54 years) and whole blood TDP (n = 124; 68 males and 56 females; mean age, 54 years) were determined in an apparently healthy population. We compared erythrocyte TDP with results of the erythrocyte transketolase activation test in 63 patients who were considered at risk of thiamin deficiency. Results: The method was linear to at least 200 μg/L. The between-run CV was <8%. The lower limit of quantification for both whole blood and packed erythrocytes was 300 pg on column with a detection limit of 130 pg on column. Recovery of TDP from blood samples was >90%. TDP in erythrocytes correlated strongly with that in whole blood (r = 0.97). Reference intervals for erythrocyte and whole blood TDP were 280–590 ng/g hemoglobin and 275–675 ng/g hemoglobin, respectively. Of the 63 patients suspected of thiamin deficiency, 46 were normal by both TDP and activation tests, 13 were deficient by both tests, 1 was deficient by the activation test but had normal erythrocyte TDP concentrations, and 4 were normal by the activation test but had low TDP. Conclusions: The HPLC method is precise and yields results similar to the erythrocyte activation assay.

scholarly journals Rapid HPLC Measurement of Thiamine and Its Phosphate Esters in Whole Blood

2008 ◽  
Vol 54 (5) ◽  
pp. 901-906 ◽  
Author(s):  
Jun Lu ◽  
Elizabeth L Frank
Keyword(s):  
Whole Blood ◽  
Clinical Laboratory ◽  
Vitamin B1 ◽  
Current Method ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Hplc Method ◽  
Phosphate Esters ◽  
Healthy Population ◽  
Limit Of Quantification

Abstract Background: Thiamine (vitamin B1) deficiency is associated with severe diseases such as beriberi and Wernicke encephalopathy. Although most Americans have sufficient dietary intake, thiamine deficiency is observed in the alcohol-dependent and elderly populations. Measurement of thiamine concentration in whole blood provides an assessment of vitamin B1 status in at-risk individuals. Method: We used TCA to precipitate proteins in whole blood. Thiamine and its phosphate esters were derivatized using potassium ferricyanide to thiochromes, which were separated by gradient elution on a reversed-phase HPLC column and detected by fluorescence. The method was validated for linearity, limit of quantification, imprecision, accuracy, and interference. Results obtained with this method were compared with those produced by the method currently used in our clinical laboratory. Reference values of thiamine and its phosphate esters were determined in samples obtained from self-reported healthy adults who were not taking vitamin supplements. To shorten analysis time, our method used whole blood rather than washed erythrocytes, did not require lengthy enzymatic dephosphorylation, and had a simple mobile phase. Results: The method was linear to 4000 nmol/L. The lower limit of quantification was 3 nmol/L. The within-run CV was <3.5% and total CV was <9.4%. This method correlated with our current method (r = 0.97). Approximately 90% of the total thiamine content in whole blood was present as thiamine diphosphate (TDP). The means (ranges) for an apparently healthy population were 114 (70–179) nmol/L for TDP and 125 (75–194) nmol/L for total thiamine. Results for separation and measurement of free thiamine and thiamine phosphate esters in whole blood were obtained within 5.5 min. Conclusion: We developed an HPLC method that allows separation and measurement of free thiamine and thiamine phosphate esters in whole blood and provides more rapid results than other methods.

DEVELOPMENT OF VALIDATED RP-HPLC METHOD FOR THE QUANTITATIVE ANALYSIS OF CHROMIUM PICOLINATE III IN A DIET VINEGAR FORMULATION

INDIAN DRUGS ◽  
2013 ◽  
Vol 50 (05) ◽  
pp. 48-52
Author(s):  
A Lodhi ◽  
◽  
A Jain ◽  
B. Biswal
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
Chromium Picolinate ◽  
Limit Of Quantification ◽  
Pharmaceutical Dosage Forms ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

A validated high performance liquid chromatographic method was developed for the determination of chromium picolinate in pharmaceutical dosage forms. The analysis was performed at room temperature using a reversed-phase ODS, 5µm (250×4.6) mm column. The mobile phase consisted of acetonitrile: buffer (60:40 V/V) at a flow rate of 0.5 mL/min. The PDA-detector was set at 264 nm. The developed method showed a good linear relationship in the concentration range from 1.5 – 12.5 µg/mL with a correlation coefficient from 0.999. The limit of detection and limit of quantification were 0.0540513 and 0.1637919 µg/mL respectively.

scholarly journals Routine clinical monitoring of sirolimus (rapamycin) whole-blood concentrations by HPLC with ultraviolet detection

1996 ◽  
Vol 42 (12) ◽  
pp. 1943-1948 ◽  
Author(s):  
K L Napoli ◽  
B D Kahan
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Drug Monitoring ◽  
Whole Blood ◽  
Clinical Status ◽  
Reversed Phase ◽  
Therapeutic Drug ◽  
Full Time ◽  
Limit Of Quantification ◽  
Blood Concentrations ◽  
Ultraviolet Detection

Abstract During phase I/II clinical trials of sirolimus (rapamycin; SRL), therapeutic drug monitoring was performed with a multistep liquid-liquid extraction of 1-mL aliquots of whole blood followed by reversed-phase HPLC with ultraviolet detection. Blood was sampled according to a standardized protocol and clinical status. SRL concentrations were interpolated from calibration curves with a linear range of 0-50 micrograms/L and 1 microgram/L lower limit of quantification. Quality control was monitored over 68 consecutive analytical runs by using frozen aliquots of SRL-supplemented pooled whole blood at 4, 12, and 32 micrograms/L. These samples showed mean concentrations of 3.7 +/- 0.6, 10.9 +/- 1.1, and 29.6 +/- 2.6 micrograms/L, respectively. This method for therapeutic drug monitoring of SRL permits one full-time technician to analyze 100 clinical specimens per week with a 24-h turnaround time. With this method, a strong linear relation (r2 = 0.946, Sy/x = 0.41, n = 115) between the average SRL concentration over a 24-h period and the SRL concentration at the 24th h was revealed.

scholarly journals Development and Validation of an RP-HPLC Method for CB13 Evaluation in Several PLGA Nanoparticle Systems

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
J. Álvarez-Fuentes ◽  
L. Martín-Banderas ◽  
I. Muñoz-Rubio ◽  
M. A. Holgado ◽  
M. Fernández-Arévalo
Keyword(s):  
Size Distribution ◽  
High Performance ◽  
Limit Of Detection ◽  
High Performance Liquid Chromatographic ◽  
Plga Nanoparticles ◽  
Reversed Phase ◽  
Hplc Method ◽  
Array Detector ◽  
Limit Of Quantification ◽  
Rp Hplc

A simple, fast, and reversed-phase high-performance liquid chromatographic (RP-HPLC) method has been developed and validated for determining of a cannabinoid derivate, which displays potent antihyperalgesic activity, 1-naphthalenyl[4-(pentyloxy)-1-naphthalenyl]methanone (CB13) into PLGA nanoparticles. Separation was achieved in a C18 column using a mobile phase consisting of two solvents: solvent A, consisting of acetonitrile : water : acetic acid (75 : 23.7 : 1.3 v/v), and solvent B, consisting of acetonitrile. An isocratic method (70 : 30 v/v), with a flow rate of 1.000 mL/min, and a diode array detector were used. The developed method was precise, accurate, and linear over the concentration range of analysis with a limit of detection and a limit of quantification of 0.5 and 1.25 μg/mL, respectively. The developed method was applied to the analysis of CB13 in nanoparticles samples obtained by three different procedures (SEV, FF, and NPP) in terms of encapsulation efficiency and drug release. Nanoparticles size and size distribution were also evaluated founding that NPP method presented the most lowest particle sizes with narrow-size distribution (≈320 nm) and slightly negative zeta potential (≈−25 mV) which presumes a suitable procedure for the synthesis of PLGA-CB13 nanoparticles for oral administration.

scholarly journals STABILITY INDICATING VALIDATED HPLC METHOD FOR THE DETERMINATION OF ZANUBRUTINIB IN BULK AND PHARMACEUTICAL DOSAGE FORM

2020 ◽  
pp. 159-162
Author(s):  
M. VIJAYA KUMARI ◽  
CH. BALASEKHAR REDDY
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Reversed Phase ◽  
Hplc Method ◽  
Limit Of Quantification ◽  
Intermediate Precision ◽  
Pharmaceutical Dosage Form ◽  
Acceptable Limit ◽  
Relative Standard

Objective: An accurate, rapid economical and straight forward, reliable assay technique was evolved and showed for the evaluation of zanubrutinib using reversed-phase high-performance liquid chromatography. Methods: In the proposed method, efficient chromatographic separation was achieved applying acetonitrile and 0.1% orthophosphoric acid (50:50 v/v) as a mobile phase with a flow of 1 ml/min and the wavelength was observed at 220 nm. Chromatography was administered isocratically at ambient temperature and run time was approximately 6 min and the retention time (Rt) was observed as 4.358 min. Results: The method was justified as per ICH guidelines. System suitability parameters were studied by injecting the quality six fold and results were well under acceptance criteria. Linearity study was administered between 10% and 150% levels, regression coefficient value was observed as 0.999. Limit of detection and limit of quantification were observed as 0.02 μg/ml and 0.2 μg/ml, respectively. Precision was found to be 0.74 for repeatability and 0.68 for intermediate precision. Recovery of the drug was found to be 98–102%, indicates that the recovery is in the acceptable limit. Validation results were found to be satisfactory and the method applicable for bulk and formulation analysis. Hence, it was evident that the proposed method was said to be suitable for regular analysis and quality control of pharmaceutical preparations. Conclusion: The validation results were in good agreement with the acceptable limit. Relative standard deviation values which are <2.0% indicating the accuracy and precision of this method. Assay of retail formulation was administered and found to be 100.24% was present using the above method. Stress conditions of degradation in acidic, alkaline, peroxide, and thermal were studied. This developed method showed reliable, precise, accurate results under optimized conditions.

DEVELOPMENT AND VALIDATION OF RP-HPLC METHOD FOR THE ESTIMATION OF LERCANIDIPINE IN BIOLOGICAL MATRICES

INDIAN DRUGS ◽  
2012 ◽  
Vol 49 (07) ◽  
pp. 49-53
Author(s):  
A Singla ◽  
◽  
Y. Paul ◽  
B. Singh
Keyword(s):  
Limit Of Detection ◽  
Quantitative Estimation ◽  
Reversed Phase ◽  
Hplc Method ◽  
Biological Matrices ◽  
Limit Of Quantification ◽  
Rp Hplc ◽  
Uv Visible ◽  
Development And Validation ◽  
Isocratic Mode

A simple, precise, accurate, reproducible and robust analytical method was developed using reversed phase HPLC for quantitative estimation of lercanidipine in biological matrices. The method was validated as per the ICH and FDA guidelines. Analysis of the drug was performed in an isocratic mode employing methanol and acetonitrile (74:26) as the mobile phase on a C18 column. UV-Visible detector at 219 nm was found to be suitable for drug estimation. Linearity was observed in the range of 5 and 500 ng/mL (p<0.001). Recovery was found to range between 96.26% and 100.67%. The % RSD values for method precision and system precision were found to be 0.437 and 1.58, respectively. Limit of detection (LOD) and limit of quantification (LOQ) were observed to be 0.20 ng/mL and 0.68 ng/mL, respectively.

A Bioanalytical Method for Quantification of Telmisartan in rat Plasma; Development, Validation and Application to Pharmacokinetic Study

2021 ◽  
pp. 2139-2144
Author(s):  
Khater Ahmed Saeed AL-Japairai ◽  
Bappaditya Chatterjee ◽  
Syed Mahmood ◽  
Samah Hamed Almurisi
Keyword(s):  
Pharmacokinetic Study ◽  
Limit Of Detection ◽  
Plasma Concentrations ◽  
Rat Plasma ◽  
Reversed Phase ◽  
Hplc Method ◽  
Pharmacokinetic Parameters ◽  
Sprague Dawley ◽  
Linear Calibration ◽  
Limit Of Quantification

The telmisartan was determined in a rat plasma using developed and validated a reversed-phase high performance liquid chromatographic (HPLC). The pre-treatment of the plasma sample involving liquid-liquid extraction using ethanol as the extracting solvent. The HPLC method validation has been shown a linear calibration curve over a plasma concentrations range of 0.7 to 10µg/mL with a correlation coefficient of 0.9979, the limit of detection and the limit of quantification were determined to be 0.025µg/ml and 0.07µg/ml, respectively. The precision and accuracy were in an acceptable limit. The pharmacokinetic parameters of telmisartan were adequately evaluated following a single oral dose (4mg/kg) in Sprague-Dawley rats. The results observed conclude that the developed bioanalytical HPLC method is appropriate and applicable as an analytical tool in the pharmacokinetic study of telmisartan.

scholarly journals Stability-Indicating Assay for the Determination of Pentobarbital Sodium in Liquid Formulations

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Myriam Ajemni ◽  
Issa-Bella Balde ◽  
Sofiane Kabiche ◽  
Sandra Carret ◽  
Jean-Eudes Fontan ◽  
...  
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Drug Stability ◽  
Reversed Phase ◽  
Hplc Method ◽  
Limit Of Quantification ◽  
Reliable Determination ◽  
Pentobarbital Sodium ◽  
Stability Indicating

A stability-indicating assay by reversed-phase high performance liquid chromatography (RP-HPLC) method was developed for the determination of pentobarbital sodium in oral formulations: a drug used for infant sedation in computed tomography (CT) or magnetic resonance imaging (MRI) scan. The chromatographic separation was achieved on a reversed-phase C18 column, using isocratic elution and a detector set at 214 nm. The optimized mobile phase consisted of a 0.01 M potassium buffer pH 3 and methanol (40 : 60, v/v). The flow rate was 1.0 mL/min and the run time of analysis was 5 min. The linearity of the method was demonstrated in the range of 5 to 250 μg/mL pentobarbital sodium solution (r2= 0.999). The limit of detection and limit of quantification were 2.10 and 3.97 μg/mL, respectively. The intraday and interday precisions were less than 2.1%. Accuracy of the method ranged from 99.2 to 101.3%. Stability studies indicate that the drug is stable to sunlight and in aqueous solution. Accelerated pentobarbital sodium breakdown by strong alkaline, acidic, or oxidative stress produced noninterfering peaks. This method allows accurate and reliable determination of pentobarbital sodium for drug stability assay in pharmaceutical studies.

scholarly journals DEVELOPMENT AND VALIDATION OF RP-HPLC METHOD FOR THE ESTIMATION OF DOLUTEGRAVIR AND RILPIVIRINE IN BULK AND PHARMACEUTICAL DOSAGE FORM AND ITS APPLICATION TO RAT PLASMA

2019 ◽  
pp. 267-271
Author(s):  
VEERASWAMI B ◽  
NAVEEN VMK
Keyword(s):  
High Performance ◽  
Dosage Form ◽  
Limit Of Detection ◽  
Rat Plasma ◽  
Reversed Phase ◽  
Hplc Method ◽  
Limit Of Quantification ◽  
Pharmaceutical Dosage Form ◽  
Study Results ◽  
Relative Standard

Objective: The present paper describes a simple, accurate, and precise reversed-phase high-performance liquid chromatography (HPLC) method for rapid and simultaneous quantification of dolutegravir (DTG) and rilpivirine (RPV) in bulk and pharmaceutical dosage form and rat plasma. Methods: The chromatographic separation was achieved on Phenomenex C18 (150x4.6mm, 5μm). Mobile phase contained a mixture of 0.1% Ortho phosphoric acid and acetonitrile in the rato of 60:40 v/v, flow rate 1.0ml/min and ultraviolet detection at 262nm. Results: The retention time of DTG and RPV was 4.35 min and 7.73 min, respectively. The proposed method shows a good linearity in the concentration range of 10–150 μg/ml for DTG and 5–75 μg/ml for RPV under optimized conditions. Precision and recovery study results are in between 98 and 102%. In the entire robustness conditions, percentage relative standard deviation is <2.0%. Degradation has minimum effect in stress condition and solutions are stable up to 24 h. DTG and RPV drugs are release 98% at 2 h in rat body. Conclusion: This method is validated for different analytical performance parameters like linearity. Precision, accuracy, limit of detection, limit of quantification, robustness, and pharmacokinetic study were determined according to the International Conference of Harmonization (ICH) Q2B guidelines. All the parameters of validation were found in the acceptance range of ICH guidelines. The same method is also applied for plasma samples study in bioanalytical work.

scholarly journals RP-HPLC Determination of Atomoxetine Hydrochloride in Bulk and Pharmaceutical Formulations

2011 ◽  
Vol 8 (4) ◽  
pp. 1958-1964 ◽  
Author(s):  
H. R. Prajapati ◽  
P. N. Raveshiya ◽  
J. M. Prajapati
Keyword(s):  
Flow Rate ◽  
High Performance ◽  
Pharmaceutical Formulations ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
Limit Of Quantification ◽  
Rp Hplc ◽  
Liquid Chromatographic

A reversed phase high performance liquid chromatographic (RP–HPLC) method was developed and subsequently validated for the determination of atomoxetine hydrochloride in bulk and pharmaceutical formulation. The separation was done by a PerkinElmer Brownlee analytical C8 column (260 mm x 4.6 mm, 5 µm) using methanol: 50 mM KH2PO2buffer (PH adjusted to 6.8 with 0.1 M NaOH), 80:20 v/v as an eluent. UV detection was performed at 270 nm at a flow rate 1.0 mL/min. The validation of the method was performed, and specificity, reproducibility, precision accuracy and ruggedness were confirmed. The correlation coefficient was found to be 0.997 for atomoxetine hydrochloride. The recovery was in the range of 99.94 to 100.98% and limit of quantification was found to be 5.707 µg/mL. The method is simple, rapid, selective and economical too and can be used for the routine analysis of drug in pharmaceutical formulations.

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