Identification and analysis of nine metabolites of cyclosporine in whole blood by liquid chromatography. 2: Comparison of patients' results.

1987 ◽  
Vol 33 (10) ◽  
pp. 1851-1855 ◽  
Author(s):  
G L Lensmeyer ◽  
D A Wiebe ◽  
I H Carlson
Keyword(s):  
Whole Blood ◽  
High Performance ◽  
Transplant Patient ◽  
Regression Line ◽  
Correlation Coefficients ◽  
High Performance Liquid Chromatographic ◽  
Drug Concentrations ◽  
Metabolite Concentrations ◽  
Liquid Chromatographic ◽  
Transplanted Organs

Abstract We used a "high-performance" liquid-chromatographic assay [for parent cyclosporine (CsA) and nine metabolites] and a radioimmunoassay to detail the diversity of results among whole-blood samples from patients with transplanted organs. Heterogeneous populations of metabolites in samples collected just before the next dose of CsA were detected by HPLC, with CsA, M17, M1, or M8 predominating; M21, M203-218, MUNDF1, and M18 were detected in lesser amounts. Results by HPLC vs RIA for CsA or for individual metabolites vs CsA (or RIA) were diverse, with correlation coefficients (r) ranging from 0.058 to 0.933. RIA vs HPLC(sum of CsA + metabolites) gave the best comparison (slope = 0.931, y-intercept 14 micrograms/L, r = 0.933); but the scatter of data about the regression line remained significant (Sy/x = 132 micrograms/L). Most important, RIA/HPLC(CsA) vs HPLC(sum of metabolites) was remarkably poor (r = 0.222). A 12-h pharmacokinetic curve (for drug concentrations in a heart-transplant patient) displayed dissimilar times for peak concentrations of CsA and metabolites; each differed in the proportion (48% to 81% of peak concentration) eliminated from blood over the 12 h. These studies exemplify the utility of a more-inclusive, specific assay to monitor the diverse disposition of cyclosporines in patients and to demonstrate the errors associated with use of the RIA/HPLC ratio technique to predict metabolite concentrations.

Improved liquid-chromatographic determination of cyclosporine, with concomitant detection of a cell-bound metabolite.

1985 ◽  
Vol 31 (2) ◽  
pp. 196-201 ◽  
Author(s):  
G L Lensmeyer ◽  
B L Fields
Keyword(s):  
Whole Blood ◽  
High Performance ◽  
Solid Phase ◽  
Internal Standard ◽  
Correlation Coefficients ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Standard Curve ◽  
A Cell ◽  
Liquid Chromatographic

Abstract This unique extraction and isocratic "high-performance" liquid chromatographic method for measuring cyclosporine (CsA) in blood involves a Zorbax cyanopropyl analytical column maintained at 58 degrees C, with detection at 214 nm, and recycling of the water:acetonitrile mobile phase for improved long-term column stability and efficiency. Routinely, 1.0 mL of serum, plasma, or whole blood is diluted with water:acetonitrile (70:30) and applied to a disposable solid-phase cyanopropyl column to rapidly extract the drug and the internal standard cyclosporin D (CsD). Analytical recovery for this step averages 90% with whole blood and 98% with serum and plasma. Between-run CVs were 6.5 and 2.6% for means of 104 and 1128 micrograms/L, respectively. The standard curve is linear up to 1600 micrograms/L. The minimum detection limit is 10 to 15 micrograms/L. No interferences from endogenous substances or other drugs were found. In addition, a compound cross reacting with the Sandoz radioimmunoassay antibody was isolated from patients' samples with the present procedure and was tentatively identified as a CsA metabolite(s). It appears to be highly partitioned on blood cells, very little being detected in the serum or plasma. In a comparison with RIA, correlation coefficients were 0.828 and 0.652 for serum and whole blood, respectively. Results from a 12-h pharmacokinetic study in which different sample types were analyzed by RIA and liquid chromatography further exemplified major discrepancies between types of CsA determinations.

ANALYTICAL METHOD DEVELOPMENT AND VALIDATION FOR THE SIMULTANEOUS ESTIMATION OF ABACAVIR SULPHATE AND LAMIVUDINE IN TABLET DOSAGE FORM BY RP-HPLC

INDIAN DRUGS ◽  
2015 ◽  
Vol 52 (08) ◽  
pp. 12-16
Author(s):  
S Vidyadhara ◽  
◽  
L. S Reddyvalam ◽  
T. Koduri ◽  
P. K. Borra ◽  
...  
Keyword(s):  
High Performance ◽  
Dosage Form ◽  
Method Development ◽  
Correlation Coefficients ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Simultaneous Estimation ◽  
Development And Validation ◽  
Tablet Dosage ◽  
Liquid Chromatographic

A simple, accurate, precise high-performance liquid chromatographic (HPLC) method has been developed and validated for the simultaneous determination of abacavir sulphate (ABA) and lamivudine (LAM) in combined dosage form. Separation was performed on a C18 column [Agilent ODS UG 5 column, 250 mm x 4.5 mm], with methanol: water (50:50 V/V) isocratic elution using a flow rate of 1mL/min. Good sensitivity was observed with UV detection at 277 nm. After method development, the interference of other active compounds and excipients, repeatability and linearity, were investigated. Retention times of LAM and ABA were found to be 3.3 and 6.3 min, respectively. The method was validated over the range from 2.5-12.5 μg/mL for LAM and 5-25 μg/mL for ABA with correlation coefficients of 0.9997 and 0.9996, respectively. This method was shown to be accurate, robust, selective, linear, and repeatable and can be successfully employed in routine quality control for the simultaneous analysis of ABA and LAM in tablets.

Simultaneous Determination and Identification of Penicillin Residues by High-Performance Liquid Chromatographic Analysis

1997 ◽  
Vol 60 (8) ◽  
pp. 1006-1009 ◽  
Author(s):  
CHIH-CHUN HONG ◽  
FUSAO KONDO
Keyword(s):  
Simultaneous Determination ◽  
Bovine Serum ◽  
High Performance ◽  
Gradient Flow ◽  
Correlation Coefficients ◽  
High Performance Liquid Chromatographic ◽  
Penicillin G ◽  
Reaction Products ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic

A new method was developed for simultaneous determination and identification of seven penicillins (amoxicillin, ampicillin, methicillin, penicillin G, oxacillin, cloxacillin, and dicloxacillin) in bovine serum. Each sample was simply extracted with acetonitrile, and identification of the reaction products of penicillins after treatment with 1,2,4-triazole-HgCl2 solution was then carried out by high-performance liquid chromatography (HPLC) with on ultraviolet spectrophotometric detector at 325 nm. Separation of the penicillin reaction products by HPLC was carried out by using a mobile phase of 0.1 M phosphate buffer and acetonitrile in ratios of 85:15 and 60:40 (vol/vol) in a gradient flow. The retention times of the seven penicillins ranged from 4.3 to 24.6 min, and the detection limits of penicillin concentration ranged from 0.04 to 0.2 μg/ml. The calibration curves for individual penicillins extracted from bovine serum were linear, and the correlation coefficients for each of the drugs were over 0.99. The determination of penicillins extracted from bovine serum spiked with each drug gave a recovery rate from 82.0 ± 5.6% to 105.6 ± 4.6%. This detection method may be useful for routine laboratory testing of residual penicillins.

scholarly journals Simultaneous Determination of Clopidogrel and Pioglitazone by High Performance Liquid Chromatography in Bulk Drug and Dosage Forms

2013 ◽  
Vol 2 (1) ◽  
pp. 1-9 ◽  
Author(s):  
V Phani Kumar ◽  
Y Sunandamma
Keyword(s):  
Simultaneous Determination ◽  
High Performance ◽  
Correlation Coefficients ◽  
High Performance Liquid Chromatographic ◽  
Uv Detection ◽  
Isocratic Elution ◽  
Liquid Chromatographic Method ◽  
Bulk Drug ◽  
Liquid Chromatographic

A high performance liquid chromatographic method with UV detection was developed and validated for simultaneous determination of Pioglitazone and Clopidogrel. Separation was performed on a C18 column by isocratic elution with a mobile phase of Methanol: Acetonitrile: Water (80:10:10) at pH 4.6. The UV detection was set at 230 nm. The method proved to be specific, accurate, precise and linear over the concentration ranges of 20-120ppm for both Pioglitazone and Clopidogrel with correlation coefficients always >0.999 for both drugs. The intra-day and inter-day precision and accuracy were less than 2 for both analytes. DOI: http://dx.doi.org/10.3329/ijpls.v2i1.14580 International Journal of Pharmaceutical and Life Sciences Vol.2(1) 2013: 1-9

Analysis of spectinomycin in fermentation broth by reversed-phase chromatography

2009 ◽  
Vol 63 (6) ◽  
Author(s):  
Hong Yan ◽  
Pei Xu ◽  
Hai Huang ◽  
Juan Qiu
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Fermentation Broth ◽  
Correlation Coefficients ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
Standard Curve ◽  
Relative Standard ◽  
Liquid Chromatographic

AbstractA pre-column derivatized high-performance liquid chromatographic (HPLC) method with ultraviolet-visible detection was developed to measure the concentrations of spectinomycin in fermentation broth. Derivatization reagents, 2,4-dinitrophenylhydrazine in acetonitrile (5 mg mL−1) and trifluoroacetic acid in acetonitrile (0.8 mol L−1), were added to an aliquot of the fermentation broth, and the mixture was incubated for 60 min at 70°C. The resulting derivative was separated from other compounds by isocratic elution in a reversed-phase column Zorbax SB-C18 (250 mm × 4.6 mm, 5 µm). Mobile phase consisted of acetonitrile, tetrahydrofuran, and water (φ r = 40: 35: 25) and the flow rate was 1.0 mL min−1. The detection wavelength was 415 nm. The standard curve for spectinomycin sulfate was linear with correlation coefficients of 0.9997 in the range of 25 µg mL−1 to 600 µg mL−1. The relative standard deviation values ranged from 0.43 % to 2.18 % depending on the concentration of samples. The average recovery was 101.5 %. The limit of detection was 50 ng mL−1.

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