HPLC Analysis of Oxytetracycline Residues in Honey

1986 ◽  
Vol 49 (5) ◽  
pp. 383-388 ◽  
Author(s):  
PETER SPORNS ◽  
SUET KWAN ◽  
LAWRENCE A. ROTH

Oxytetracycline (OTC), also known commercially as Terramycin, was determined to be more stable in honey than in buffered aqueous solutions at similar pH values and temperatures. A rapid high performance liquid chromatography (HPLC) method was developed to detect and quantitate OTC using a 1:1 dilution (wt/wt) of honey samples in water. Using 355 nm as the wavelength of detection, amounts as low as 0.5 μg/ml could be detected in the above solution. The limits of detection were lowered considerably by a double extraction procedure.

Author(s):  
RAGAA EL SHEIKH ◽  
WAFAA S HASSAN ◽  
EMANH YOUSSEF ◽  
ABDULRAHMAN Y HAMDI ◽  
NAIF AHMED BADAHDAH ◽  
...  

Objective: A new, simple, rapid, sensitive, and accurate stability-indicating high-performance liquid chromatography (HPLC) method was developed and validated for the quantitative determination of linagliptin (LNG) and empagliflozin (EMP) in pure and tablet dosage forms. Methods: An isocratic HPLC method, using a C18 reversed-phase column (150 mm×4.6 mm i.d., particle size 5 μm) with an isocratic binary mobile phase consisting of phosphate buffer and acetonitrile (65:35, v/v), was investigated to separate the drug from its stress degradation products. The flow rate was 1.0 mL/min at ambient temperature and photodiode array detector is used at 226 nm for detection. The developed method was validated for system suitability, linearity, accuracy, precision, limits of detection and quantitation, specificity, stability, and robustness. Results: The retention time of LNG and EMP was found to be 3.276±0.002 and 6.966±0.0006 min, respectively. The calibration curve was found to be linear with the equation y=158926.39X+11.139, with a correlation coefficient of R2=0.9991 for LNG and y=22688.45X+4.259, with a correlation coefficient of R2=0.9994 for EMP over a concentration range of 2.5–7.5 μg/mL and 5.0–15 μg/mL for LNG and EMP, respectively. The limits of detection were 0.29 and 0.48 μg/mL for LNG and EMP, respectively, and the limits of quantification were 0.89 and 1.5 μg/mL for LNG and EMP, respectively. The recovery values of this method are 101.11% and 101.48% for LNG and EMP, respectively, and the reproducibility is within 0.070 and 0.277 for LNG and EMP, respectively. Conclusion: The proposed method is a rapid stability-indicating HPLC method that can be applied for the determination of LNG and EMP in pure and tablet dosage forms.


2012 ◽  
Vol 59 (1) ◽  
Author(s):  
Daniel Garama ◽  
Phil Bremer ◽  
Alan Carne

Sea urchin gonad (roe) is a highly valued food in Japan and North America. Gonad price is strongly influenced by quality, with appearance, especially colour being a major determinant. Previous attempts to extract a carotenoid profile from the New Zealand sea urchin species Evechinus chloroticus have been challenging due to the large amount of lipid present in the gonad. A carotenoid extraction and high performance liquid chromatography (HPLC) analysis method was developed to reduce lipid contamination by incorporating a saponification and lipid cold precipitation in the extraction procedure. This method enabled greater carotenoid purity and enhanced analysis by HPLC. Echinenone was found to be the main carotenoid present in all E. chloroticus gonads. Dark coloured gonads contained higher levels of fucoxanthin/fucoxanthinol, β-carotene and xanthophylls such as astaxanthin and canthaxanthin. This information on the modification and deposition of carotenoids will help in the development of diets to enhance gonad colour.


2021 ◽  
Vol 26 (3) ◽  
pp. 265-270
Author(s):  
Jesse Cramer ◽  
Mackenzie Bevry ◽  
Stephanie Handler ◽  
Kathryn Tillman ◽  
Ehab A. Abourashed

OBJECTIVE Ambrisentan, an endothelin receptor antagonist FDA-approved for the treatment of pulmonary arterial hypertension in adult patients, lacks an acceptable pediatric dosage form. The objective of this investigation was to determine the stability of an extemporaneously compounded ambrisentan suspension. METHODS Ambrisentan suspension was compounded to a concentration of 1 mg/mL using commercially available suspending agents. The suspension was then evenly split into 2 plastic amber prescription bottles. One bottle was stored at room temperature and under continuous fluorescent light while the other bottle was stored under refrigeration and protection from light. A fast and selective reversed-phase high-performance liquid chromatography (HPLC) method was developed and validated for the analysis of ambrisentan. HPLC analysis was performed on samples withdrawn from the stock bottles at predetermined time intervals, up to 90 days. RESULTS The developed HPLC method enabled the elution and detection of ambrisentan peak at 4.4 minutes. HPLC analysis revealed that all samples from both storage conditions retained >90% potency throughout the study timeframe. There were no signs of any ambrisentan breakdown products on HPLC analysis. Color and odor of the final product was also consistent throughout the 90-day storage period. CONCLUSION Ambrisentan suspension, compounded to 1 mg/mL, is stable at room temperature or under refrigeration for up to 90 days.


Author(s):  
S Maguire ◽  
F Kyne ◽  
D Uaconaill

Cyclosporin A (CyA) was assayed by high performance liquid chromatography (HPLC) following extraction of the whole blood or plasma with diethyl ether and chromatography on a Sep-Pak Silica cartridge. Using carefully chosen volumes and ratios of ethyl acetate and hexane in the eluting sequences on the Sep-Pak, the major interferent present in normal blood and serum was eliminated.


2020 ◽  
Vol 20 (13) ◽  
pp. 1053-1059
Author(s):  
Mahmoud M. Sebaiy ◽  
Noha I. Ziedan

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.


2006 ◽  
Vol 89 (6) ◽  
pp. 1552-1556
Author(s):  
ArmaĞan Önal ◽  
Olcay SaĞiri ◽  
S Müge Çetin ◽  
Sidika Toker

Abstract Reboxetine is used as a selective noradrenaline reuptake inhibitor for the treatment of major depressive disorders. It is effective in the treatment of severe depression and safer to use than traditional tricyclic antidepressants. In this study, a novel, simple, and rapid stability-indicating high-performance liquid chromatography (HPLC) method for reboxetine methansulfonate was successfully developed and validated for the assay of tablets. The method was used to quantify reboxetine in tablets; it employed a C18 column (150 4.6 mm id) with an isocratic mobile phase consisting of methanolphosphate buffer (pH 7, 0.02 M; 55 + 45, v/v) at a flow rate of 1.0 μmL/min. Reboxetine was detected by an ultraviolet detector at 277 nm. The retention time of reboxetine was about 4.5 min. The developed HPLC method was validated with respect to linearity, precision, sensitivity, accuracy, and selectivity. The method was linear over the concentration range 150 g/mL (r 0.9999). The limits of detection and the quantitation of reboxetine were 0.1 and 0.3 μg/mL, respectively. The relative standard deviation values for intraday and interday precision were 0.781.01 and 1.081.37%, respectively. Selectivity was validated by subjecting a stock solution of reboxetine to neutral, acid, and alkali hydrolysis, as well as oxidation, dry heat treatment, and photodegradation. The peaks of the degradation products did not interfere with the peak of reboxetine. The results indicated that the proposed method could be used in a stability assay. The proposed method was successfully applied to the determination of reboxetine in tablets. Excipients present in the tablets did not interfere with the analysis.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Katso Binang ◽  
David T. Takuwa

Abstract The aim of the study was to develop a rapid, efficient, and cheap chromatographic method for determining four selected antihypertensive active flavonoid compounds in medicinal plants in Botswana. The determination of rutin, quercetin, and kaempferol in selected medicinal plants was conducted in less than 6 min using the developed reverse phase-high performance liquid chromatography (RP-HPLC) method with a 2.7 µm Ascentis C18 express column (150 × 4.60 mm i.d) at 340, 360, and 368 nm detection wavelengths and mobile phase of methanol and 0.068% of formic acid solution in isocratic elution. Validation results showed good selectivity, linearity (r 2 > 0.99), high percentage recoveries (90.2–104.7%), and precision (% RSD < 2) for n = 3, confirming suitability of the method for determination of the investigated flavonoids in Zingiber officinale (ginger). Application of the developed RP-HPLC method was performed in selected medicinal plants (Lippia javanica ) (mosukujane), Myrothanmus flabellious (galalatshwene), and Elephantorrhiza elephantina (mositsana) used to manage hypertension by herbalists in Botswana. M. flabellious a very commonly used plant for managing hypertension was found to contain highest amounts of rutin and myricetin, whereas nothing was detected for E. elephantina.


2021 ◽  
pp. 1-11
Author(s):  
Sultan M. Alshahrani ◽  
John Mark Christensen

This study was designed to develop and validate a simple and efficient high performance liquid chromatography (HPLC) method to determine flunixin concentrations in Asian elephant’s (Elephas maximus) plasma. Flunixin was administered orally at a dose of 0.8 mg/kg, and blood samples were collected. Flunixin extraction was performed by adding an equal amount of acetonitrile to plasma and centrifuging at 4500 rpm for 25 minutes. The supernatant was removed, and flunixin was analyzed using HPLC-UV detection. Two methods were developed and tested utilizing two different mobile phases either with or without adding methanol (ACN: H2O vs. ACN: H2O: MeOH). Both methods showed excellent linearity and reproducibility. The limit of detection was 0.05 ug/ml and limit of quantification was 0.1 ug/ml. the efficiency of flunixin recovery was maximized by the addition of methanol to mobile phase (ACN: H2O: MeOH as 50:30:20) at 95% in comparison to 23% without methanol. In conclusion, adding methanol to HPLC methods for extraction of flunixin from elephants’ plasma yielded higher recovery rate than without methanol.


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