Determination of carbamylated hemoglobin by high-performance liquid chromatography

1990 ◽  
Vol 36 (4) ◽  
pp. 607-610 ◽  
Author(s):  
J T Kwan ◽  
E C Carr ◽  
M R Bending ◽  
J L Barron
Keyword(s):  
High Performance ◽  
Hplc Method ◽  
Isocyanic Acid ◽  
Diabetic Patients ◽  
Post Translational Modification ◽  
Plasma Urea ◽  
Significant Difference ◽  
Terminal Amino ◽  
Hydrolysis Of

Abstract We have developed an HPLC method for measuring carbamylated hemoglobin (CarHb), based on the quantification of valine hydantoin formed from the released NH2-terminal carbamyl valine residue after acid hydrolysis of hemoglobin. In uremia, CarHb is produced by nonenzymatic post-translational modification of the terminal amino group of hemoglobin monomers by isocyanic acid, derived from the spontaneous dissociation of urea. We measured CarHb in 25 nonuremic control subjects, 24 nonuremic diabetic subjects, and 30 patients with stable chronic renal failure. There was no significant difference between the controls and diabetic patients, their mean (SD) CarHb values being 41 (11.5) and 38 (10.8) micrograms of carbamyl valine per gram of hemoglobin (microgram CV/gHb), respectively. Mean (SD) CarHb values in the uremic patients were much greater, 164 (87.7) microgram CV/gHb. There was significant correlation between the concentrations of CarHb and plasma urea in the uremic subjects. Thus CarHb provides a urea-derived index of chronic uremia.

scholarly journals Determination of flavones in species of Thymus L. (Lamiaceae) from Macedonian flora

2001 ◽  
Vol 47 ◽  
pp. 9-14
Author(s):  
Svetlana Kulevanova ◽  
Marina Stefova ◽  
Tatjana Kadifkova Panovska ◽  
Jasmina Tonic ◽  
Trajce Stafilov
Keyword(s):  
Ethyl Acetate ◽  
High Performance ◽  
Gradient Elution ◽  
Hplc Method ◽  
Total Flavonoids ◽  
Column Temperature ◽  
Plant Samples ◽  
Layer Chromatography ◽  
Hydrolysis Of

Assay of flavonoids in extracts of seven Thymus L. (Lamiaceae) species from Macedonia including identification and quantification was performed. Extracts obtained after hydrolysis of air dried samples (A1) were analyzed by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). Luteolin and apigenin were identified in comparison to authentic standard substances. The content of total flavonoids in plant samples determined by UV-Vis spectrometry (with AlCl3) ranged from 0.05-0.13 %. Two other extracts were prepared by extraction with a mixture of ethanol:water (7:3, V/V), evaporation until only water remained and extraction first with diethylether (A2) and secondly with ethyl acetate (A3). The content of flavonoids in diethyl-ether and ethyl acetate extracts ranged from 52.5-244.4 mg·ml-1 and 48.7 -117.5 mg·ml-1, respectively. For quantification of luteolin and total flavonoids the HPLC method was applied, using reverse phase column C18, mobile phase consisting of 5% acetic acid and methanol in gradient elution mode and column temperature set to 40 o C. The content of luteolin in the plant samples ranged from 0.23-0.48 % (m/m), while the content of total flavonoids was found to be 0.26-0.52 %.

scholarly journals A Validated High-Performance Thin-Layer Chromatographic Method for the Simultaneous Determination of Zofenopril Calcium and Hydrochlorothiazide in the Presence of the Hydrochlorothiazide Impurities: Chlorothiazide and Salamide

2018 ◽  
Vol 101 (4) ◽  
pp. 1031-1041 ◽  
Author(s):  
Mamdouh R Rezk ◽  
Ahmed S Fayed ◽  
Hoda M Marzouk ◽  
Samah S Abbas
Keyword(s):  
Simultaneous Determination ◽  
High Performance ◽  
Degradation Products ◽  
Raw Materials ◽  
Drug Product ◽  
Hplc Method ◽  
Pharmaceutical Formulation ◽  
Significant Difference ◽  
Hptlc Method

Abstract The chromatographic analysis of either process-related impurities or degradation products is very important in the pharmaceutical industry. In this work, a simple, selective, and sensitive HPTLC method was developed and validated for the simultaneous determination of zofenopril calcium (ZOF) and hydrochlorothiazide (HCT) in the presence of the HCT impurities: A) chlorothiazide (CT) and B) salamide, in raw materials and in pharmaceutical formulation. The separation was carried out on HPTLC silica gel 60 F254 using ethyl acetate–glacial acetic acid–triethylamine (10 + 0.1 + 0.1, v/v/v) as a developing system. The separated bands were scanned densitometrically at 270 nm. Polynomial equations were used for the regression. Calibration curves were constructed for ZOF, HCT, CT, and salamide in the ranges of 0.5–10, 0.2–4, 0.05–1.4, and 0.05–1.0 μg/band, respectively. Different parameters affecting the suggested method, including developing systems of varying composition/ratios and different detection wavelengths, were studied to achieve the best resolution and precision with good sensitivity. System suitability parameters were also tested. The proposed method was validated as per the International Conference on Harmonization guidelines and was successfully applied for the quantification of the studied drugs in their pharmaceutical formulation, with no interference from excipients observed. The results obtained by the developed HPTLC method were compared statistically with those obtained by the reported HPLC method using Student’s t and F ratio tests, and no significant difference was obtained, indicating the ability of the proposed method to be used for routine analysis of drug product.

scholarly journals Valsartan in combination with metformin and gliclazide in diabetic rat model using developed RP-HPLC method

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Rasmita Patra ◽  
Yedukondalu Kollati ◽  
Sampath Kumar NS ◽  
Vijaya R. Dirisala
Keyword(s):  
High Performance ◽  
Hplc Method ◽  
Diabetic Rats ◽  
Diabetic Rat ◽  
Diabetic Patients ◽  
Single Treatment ◽  
Rp Hplc ◽  
Significant Difference ◽  
Concurrent Estimation

Abstract Background Oral administration of biguanides (metformin) and sulfonylureas (gliclazide) are the most common approach of management of type 2 diabetes in humans. Among these diabetic patients, approximately 40–60% suffers from hypertension. Hence, the need of the day is application of polytherapy. A major challenge in polytherapy is the drug-drug interactions that may arise. Hence, this study is focused to develop a reverse phase high-performance liquid chromatography (RP-HPLC) method for concurrent estimation of diabetic drug metformin and hypertension drug valsartan using C18 column and find any possible pharmacokinetic interactions between the two drug combinations strategies, i.e., metformin-valsartan and gliclazide-valsartan in streptozotocin-induced diabetic rats. Result The bioanalysis of drug-drug interaction pharmacokinetic result showed no significant difference in the tmax of single treatment of gliclazide and single treatment of metformin or upon co-administration with valsartan. Conclusion Our study has shown that polytherapy of valsartan, a drug administered for hypertension along with hypoglycemic drugs metformin and gliclazide, can be advantageous and safe in patients suffering from both diabetes and hypertension.

scholarly journals Comparison of Microbiological and UV-Spectrophotometric Assays for Determination of Voriconazole in Tablets

2006 ◽  
Vol 89 (4) ◽  
pp. 960-965 ◽  
Author(s):  
Andra I H Adams ◽  
Martin Steppe ◽  
Pedro E Frehlich ◽  
Ana M Bergold
Keyword(s):  
Quality Control ◽  
High Performance Liquid Chromatography ◽  
High Performance ◽  
Hplc Method ◽  
Average Recovery ◽  
Significant Difference ◽  
Coefficient Corrélation ◽  
Sacharomyces Cerevisiae ◽  
Routine Quality Control

Abstract Two methods have been developed for the determination of voriconazole, a new antifungal drug, in tablets. A UV method, with detection at 255 nm, was compared with a diffusion agar bioassay, which used Sacharomyces cerevisiae ATCC 2601 as the assay organism. The developed methods were linear in the range of 3.0-12.0 and 12.0-24.0 μg/mL, for the microbiological and UV methods, respectively, both exhibiting a coefficient correlation of 0.9999. The UV method demonstrated an improved precision compared to the bioassay method (1.0 versus 2.4%). The average recovery, 99.8 and 100.9%, was suitable in both methods. The results obtained by these 2 methods were compared with those of a high-performance liquid chromatography (HPLC) method published previously, and no evidence of significant difference was observed. The proposed methods are appropriate for the determination of voriconazole in tablets and can be used in routine quality control.

scholarly journals High-Performance Liquid Chromatographic and First Derivative of the Ratio Spectrophotometric Determination of Amlodipine and Valsartan in Their Binary Mixtures

2010 ◽  
Vol 93 (3) ◽  
pp. 882-890 ◽  
Author(s):  
Dilek Kul ◽  
Burcu Dogan-Topal ◽  
Tugba Kutucu ◽  
Bengi Uslu ◽  
Sibel A Ozkan
Keyword(s):  
Spectrophotometric Method ◽  
High Performance ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Time Saving ◽  
Pharmaceutical Dosage Form ◽  
First Derivative ◽  
Significant Difference ◽  
Long Acting

Abstract Amlodipine besylate (AML) is a long-acting calcium channel blocker used as an antihypertensive agent. Valsartan (VAL) is also used to treat hypertension, either alone or in combination with other agents. Two-component mixtures of AML and VAL were analyzed by HPLC and the ratio spectra of the first derivative spectrophotometric technique. The spectrophotometric method depends on the first derivative of the ratio-spectra by measurements of the amplitudes at 234.0 nm for VAL and 351.0 nm for AML. Calibration graphs were established for 0.520 g/mL AML and 132 g/mL VAL using the ratio spectra of the first derivative spectrophotometric method. In the HPLC method, an ACE 5 C18 (4.6 150 mm, 5 m) RP column at 30C with the mobile phase methanolacetonitrileNaH2PO4H2O buffer, including 5 mL/L triethylamine and adjusted to pH 3.0 (42 + 18 + 40, v/v/v) at 2.0 mL/min flow rate was used to separate both compounds with detection at 254.0 nm. Linearity was obtained in the concentration range of 0.5500 g/mL for AML and 5.0900 g/mL for VAL. The proposed methods have been extensively validated. These methods allow a number of cost- and time-saving benefits. They were successfully applied to the determination of AML and VAL in synthetic mixtures and in a pharmaceutical dosage form. There was no significant difference between the performance of the proposed methods regarding the mean and SD values. The proposed methods are simple, rapid, and suitable for QC applications.

scholarly journals A Reliable Semiautomated Method for the Determination of Total Thiamine in Whole Blood by the Thiochrome Method with High-Performance Liquid Chromatography

1982 ◽  
Vol 19 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Jaap Schrijver ◽  
Andries J Speek ◽  
Jan A Klosse ◽  
Herman J M Van Rijn ◽  
Wil H P Schreurs
Keyword(s):  
Whole Blood ◽  
High Performance ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Coefficients Of Variation ◽  
Analytical Recovery ◽  
On Line ◽  
Liquid Chromatographic ◽  
Hydrolysis Of

A sensitive and reliable method for the determination of total thiamine (vitamin B1) in whole blood has been developed which is suited for routine analysis. After extraction, and enzymatic hydrolysis of thiamine phosphate esters, thiamine is separated from interfering compounds by a fully automated high-performance liquid chromatographic (HPLC) system. Thiamine is detected fluorometrically as thiochrome. By calculating the concentration of thiamine on-line with the aid of a computer, it is possible to complete one analysis within four hours. Routine thiamine determinations can be carried out in a series of 120 samples within 48 hours. The within-assay and between-assay coefficients of variation of the analysis of total thiamine in whole blood were 4·2 and 4·4%, respectively. The between-assay analytical recovery of thiamine diphosphate added to blood samples was 99·9 ± 11·7% (mean ± SD). The HPLC method described has been applied also to the analysis of thiamine in plasma and erythrocytes. In agreement with other reports, it was found that about 80% of total thiamine of whole blood is present in the erythrocytes. Reference values of thiamine in whole blood of the human were found in the range 95–155 nmol/l.

scholarly journals Quantitative Analysis of the Cholesterol-Lowering Drugs Ezetimibe and Simvastatin in Pure Powder, Binary Mixtures, and a Combined Dosage Form by Spectrophotometry, Chemometry, and High-Performance Column Liquid Chromatography

2010 ◽  
Vol 93 (6) ◽  
pp. 1844-1855 ◽  
Author(s):  
Hayam Mahmoud Lotfy ◽  
Amal Mahmoud Aboul Alamein ◽  
Maha Abdel Monem Hegazy
Keyword(s):  
Least Squares ◽  
High Performance ◽  
Dosage Form ◽  
Least Squares Method ◽  
Hplc Method ◽  
Isosbestic Point ◽  
Prediction Ability ◽  
Spectrophotometric Methods ◽  
Significant Difference

Abstract Simple, accurate, sensitive, and precise UV spectrophotometric, chemometric, and HPLC methods were developed for simultaneous determination of a two-component drug mixture of ezetimibe (EZ) and simvastatin (SM) in laboratory-prepared mixtures and a combined tablet dosage form. Four spectrophotometric methods were developed, namely, ratio spectra derivative, ratio subtraction, isosbestic point, and mean centering of ratio spectra. The developed chemometric-assisted spectrophotometric method was the concentration residual augmented classical least-squares method; its prediction ability was assessed and compared to the conventional partial least-squares method. The developed HPLC method used an RP ZORBAX C18 column (5 m particle size, 250 4.6 mm id) with isocratic elution. The mobile phase was acetonitrilepH 3.5 phosphate buffer (40 60, v/v) at a flow rate of 1.0 mL/min, with UV detection at 230 nm. The accuracy, precision, and linearity ranges of the developed methods were determined. The developed methods were successfully applied for determination of EZ and SM in bulk powder, laboratory-prepared mixtures, and a combined dosage form. The results obtained were compared statistically with each other and to those of a reported HPLC method; there was no significant difference between the proposed methods and the reported method regarding both accuracy and precision.

HPLC method for the determination of the S- and R-diastereomers of telaprevir for treatment of patients with hepatitis C

2015 ◽  
Vol 39 (3) ◽  
Author(s):  
Werner J. Heinz ◽  
Dieter Kuschak ◽  
Diana Schirmer ◽  
Anna Grau ◽  
Daniela Keller ◽  
...  
Keyword(s):  
Hepatitis C ◽  
High Performance ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Clinical Samples ◽  
Coefficients Of Variation ◽  
Significant Difference ◽  
High Degree ◽  
Liquid Chromatographic

AbstractTelaprevir (TVR) was approved by the FDA in May 2011 for the treatment of hepatitis C. This protease inhibitor converts into two diastereomers with significant difference in antiviral activity. Clinical efficacy has been correlated with serum concentrations. Therefore, a sensitive and selective high-performance liquid chromatographic method for the simultaneous determination of both clinically relevant diastereomers of TVR was developed. Linearity ranged from 20 to 10,000 ng/mL. The coefficients of variation were <7.3%, and accuracy was between −4.0 and 5.4%. In 105 clinical samples, both diastereomers of TVR had a high degree of correlation to each other, but concentrations showed a broad range and an increase during therapy.

Developing a High-performance Liquid Chromatography Method for Simultaneous Determination of Loratadine and its Metabolite Desloratadine in Human Plasma

2020 ◽  
Vol 20 (13) ◽  
pp. 1053-1059
Author(s):  
Mahmoud M. Sebaiy ◽  
Noha I. Ziedan
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Human Plasma ◽  
High Performance ◽  
Allergic Diseases ◽  
Reversed Phase ◽  
Hplc Method ◽  
H1 Receptor ◽  
Chromatography Method

Background: Allergic diseases are considered as the major burden on public health with increased prevalence globally. Histamine H1-receptor antagonists are the foremost commonly used drugs in the treatment of allergic disorders. The target drug in this study, loratadine, belongs to this class of drugs and its biometabolite desloratadine which is also a non-sedating H1 receptor antagonist with anti-histaminic activity being 2.5 to 4 times greater than loratadine. This study aimed to develop and validate a novel isocratic Reversed-phase High-Performance Liquid Chromatography (RP-HPLC) method for rapid and simultaneous separation and determination of loratadine and its metabolite, desloratadine in human plasma. Methods: The drug extraction method from plasma was based on protein precipitation technique. The separation was carried out on a Thermo Scientific BDS Hypersil C18 column (5μm, 250 x 4.60 mm) in a mobile phase of MeOH: 0.025M KH2PO4 adjusted to pH 3.50 using orthophosphoric acid (85: 15, v/v) at an ambient temperature. The flow rate was maintained at 1 mL/min and maximum absorption was measured using the PDA detector at 248 nm. Results: The retention times of loratadine and desloratadine in plasma samples were recorded to be 4.10 and 5.08 minutes, respectively, indicating a short analysis time. Limits of detection were found to be 1.80 and 1.97 ng/mL for loratadine and desloratadine, respectively, showing a high degree of sensitivity of the method. The method was then validated according to FDA guidelines for the determination of the two analytes in human plasma. Conclusion: The results obtained indicate that the proposed method is rapid, sensitive in the nanogram range, accurate, selective, robust and reproducible compared to other reported methods.

Determination of Selected Phthalates in Some Commercial Cosmetic Products by HPLC-UV

2020 ◽  
Vol 23 (10) ◽  
pp. 1010-1022
Author(s):  
Emrah Dural
Keyword(s):  
High Performance ◽  
Phthalate Esters ◽  
High Sensitivity ◽  
Hplc Method ◽  
Cosmetic Products ◽  
Limit Of Quantification ◽  
Nail Polish ◽  
Accuracy And Precision ◽  
Butyl Phthalate

Aim and scope: Due to the serious toxicological risks and their widespread use, quantitative determination of phthalates in cosmetic products have importance for public health. The aim of this study was to develop a validated simple, rapid and reliable high-performance liquid chromatography (HPLC) method for the determination of phthalates which are; dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), di(2- ethylhexyl) phthalate (DEHP), in cosmetic products and to investigate these phthalate (PHT) levels in 48 cosmetic products marketing in Sivas, Turkey. Materials and Methods: Separation was achieved by a reverse-phase ACE-5 C18 column (4.6 x 250 mm, 5.0 μm). As the mobile phase, 5 mM KH2PO4 and acetonitrile were used gradiently at 1.5 ml min-1. All PHT esters were detected at 230 nm and the run time was taking 21 minutes. Results: This method showed the high sensitivity value the limit of quantification (LOQ) values for which are below 0.64 μg mL-1 of all phthalates. Method linearity was ≥0.999 (r2). Accuracy and precision values of all phthalates were calculated between (-6.5) and 6.6 (RE%) and ≤6.2 (RSD%), respectively. Average recovery was between 94.8% and 99.6%. Forty-eight samples used for both babies and adults were successfully analyzed by the developed method. Results have shown that, DMP (340.7 μg mL-1 ±323.7), DEP (1852.1 μg mL-1 ± 2192.0), and DBP (691.3 μg mL-1 ± 1378.5) were used highly in nail polish, fragrance and cream products, respectively. Conclusion: Phthalate esters, which are mostly detected in the content of fragrance, cream and nail polish products and our research in general, are DEP (1852.1 μg mL-1 ± 2192.0), DBP (691.3 μg mL-1 ± 1378.5) and DMP (340.7 μg mL-1 ±323.7), respectively. Phthalates were found in the content of all 48 cosmetic products examined, and the most detected phthalates in general average were DEP (581.7 μg mL-1 + 1405.2) with a rate of 79.2%. The unexpectedly high phthalate content in the examined cosmetic products revealed a great risk of these products on human health. The developed method is a simple, sensitive, reliable and economical alternative for the determination of phthalates in the content of cosmetic products, it can be used to identify phthalate esters in different products after some modifications.

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