Validation of a simple HPLC method to quantify mycophenolic acid concentrations in human plasma

MedPharmRes ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 1-6
Author(s):  
Thuan Thi Minh Nguyen ◽  
Truong Huu Tran

Introduction: Mycophenolic acid (MPA) is an active metabolite of mycophenolate mofetil and mycophenolate sodium which are widely prescribed to prevent organ rejection after solid organ transplantations. However, MPA induced many side effects on gastrointestinal tract and haematological system. Objectives: The purpose of this study is to establish a high-performance liquid chromatography (HPLC) method to determine the MPA concentration in plasma in order to optimize the treatment efficacy of MPA or apply to bioequivalence studies. MPA and visnadine (as an internal standard) were extracted from plasma samples with methanol by solid phase extraction using Osis HLB 1cc cartridge. 10 µL of sample extract was injected onto LiChroCART®125-4 (C18 reversed-phase column) at 43 °C on a Waters 2695 XE system. The signals were detected by PDA detector (photodiodes array) at 254 nm. The mobile phase was a mixture of acetonitrile and phosphate buffer (pH 3) with a flow rate of 1 mL/min. The validation criteria included: selectivity, linearity, accuracy, precision, recovery, lower limit of quantification. Results: Total chromatographic runtime was 15 min. MPA and visnadine were found at 6.45 and 10.79 min, respectively. MPA concentrations were in the linear range from 0.25 to 50 µg/mL. The coefficient of variation (CV) of mean intra-day and inter-day precision levels for MPA was less than 7.5%. The lower limit of quantification was 0.25 µg/mL. No interference was found in the assay. Conclusion: A simple and reliable HPLC method was developed to quantify the MPA concentration in plasma.

1998 ◽  
Vol 44 (7) ◽  
pp. 1481-1488 ◽  
Author(s):  
Maria Shipkova ◽  
Paul Dieter Niedmann ◽  
Victor William Armstrong ◽  
Ekkehard Schütz ◽  
Eberhard Wieland ◽  
...  

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).


1997 ◽  
Vol 43 (8) ◽  
pp. 1386-1391 ◽  
Author(s):  
Ursula Turpeinen ◽  
Helene Markkanen ◽  
Matti Välimäki ◽  
Ulf-Håkan Stenman

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 <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.


1994 ◽  
Vol 40 (7) ◽  
pp. 1312-1316 ◽  
Author(s):  
J H Nichols ◽  
J R Charlson ◽  
G M Lawson

Abstract This automated assay determines the concentration of the antidepressant fluoxetine (Prozac) and its active metabolite norfluoxetine in serum by reversed-phase HPLC with spectrophotometric detection. Extraction, injection, and quantification are performed by the Gilson Aspec automated sample handler. The patient's specimen, with added protriptyline as internal standard, is extracted with solid-phase and liquid-liquid methods. Separation is conducted isocratically on a 5-microns (particle size) Supelcosil LC-8-DB reversed-phase column with a triethylamine acetate:acetonitrile mobile phase. The detection limit is 10 micrograms/L and absorbance varies linearly with concentration between 20 and 1,000 micrograms/L for both compounds. Mean recovery was 62% for fluoxetine and 70% for norfluoxetine over linear limits. Within-run and day-to-day imprecision (CV), evaluated at three concentrations (50, 200, and 500 micrograms/L), ranged from 2% to 7%. An extensive interference study of 108 drugs was conducted. Results (n = 58) by the automated method (y) correlated well with those by a manual HPLC method (x): y = 0.96x + 10.20 (r = 0.951, Sylx = 42.9) for fluoxetine, and y = 0.95x - 1.37 (r = 0.917, Sylx = 47.2) for norfluoxetine.


Author(s):  
Astri Budikayanti ◽  
Chiswyta Chaliana ◽  
Melva Louisa ◽  
Rianto Setiabudy

Objective: To develop and validate high-performance liquid chromatography with photodiode array (HPLC-PDA) detector as a method for measuring carbamazepine plasma concentrations in epilepsy patients treated with monotherapy or polytherapy.Methods: Carbamazepine was extracted from epilepsy patients’ plasma through liquid-liquid extraction, using protein precipitation with chloroform. Analysis was performed using HPLC with Inertsil DS-4 C18 (4.6x150 mm), 5 μm particle size column. The optimal condition for separation was established in a mobile phase consisting of acetonitrile: water (50:50) at a flow rate of 1.0 ml/min, detected by PDA detector at 220 nm. Propylparaben was used as the internal standard. The retention time was 3.5 min.Results: Linearity was obtained over a concentration range of 0.5-16 μg/ml with r = 0.999. The method showed good intra-and inter-day precision and accuracy of more than 90% difference (% diff) and 95% relative standard deviation (RSD). Lower limit of quantification (LOQ) was 0.5 μg/ml and lower limit of detection (LOD) was 0.2 μg/ml with 100% accuracy and more than 90% precision. Recovery test was nearly 100%. Stability of carbamazepine plasma concentration in 3 epilepsy patients was measured on the first and third month of treatment, ranging between 83.5 to 98.7%. When used to compare carbamazepine as a monotherapy versus polytherapy, the method showed good selectivity.Conclusion: The present HPLC method was valid for measuring carbamazepine plasma concentrations in epilepsy patients treated with monotherapy or polytherapy. This method meets the standard in the EMEA guideline in terms of linearity, precision, and accuracy, also selectivity in epilepsy patients treated with polytherapy.


2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Octavian Croitoru ◽  
Adela-Maria Spiridon ◽  
Ionela Belu ◽  
Adina Turcu-Ştiolică ◽  
Johny Neamţu

A simple, sensitive, and specific reversed phase liquid chromatographic method was developed and validated for simultaneous quantification of clopidogrel, its carboxylic acid metabolite, and atorvastatin in human serum. Plasma samples were deproteinized with acetonitrile and ibuprofen was chosen as internal standard. Chromatographic separation was performed on an BDS HypersilC18column (250 × 4.6 mm; 5 μm) via gradient elution with mobile phase consisting of 10 mM phosphoric acid (sodium) buffer solution (pH = 2.6 adjusted with 85% orthophosphoric acid) : acetonitrile : methanol with flow rate of 1 mL·min−1. Detection was achieved with PDA detector at 220 nm. The method was validated in terms of linearity, sensitivity, precision, accuracy, limit of quantification, and stability tests. Calibration curves of the analytes were found to be linear in the range of 0.008–2 μg·mL−1for clopidogrel, 0.01–4 μg·mL−1for its carboxylic acid metabolite, and 0.005–2.5 μg·mL−1for atorvastatin. The results of accuracy (as recovery) with ibuprofen as internal standard were in the range of 96–98% for clopidogrel, 94–98% for its carboxylic acid metabolite, and 90–99% for atorvastatin, respectively.


2005 ◽  
Vol 51 (5) ◽  
pp. 872-877 ◽  
Author(s):  
Thomas M Annesley ◽  
Larry T Clayton

Abstract Background: The potent immunosuppressant mycophenolic acid (MPA) is metabolized to an inactive glucuronide (MPAG). The extent of metabolism varies among individuals, and the MPAG formed can be hydrolyzed to MPA and can displace MPA from serum albumin, creating a potential need to monitor both MPA and MPAG. Methods: After addition of the carboxybutoxy ether of MPA (MPAC) as internal standard, MPA and MPAG were isolated from serum by acidification followed by solid-phase extraction. Gradient chromatographic separation was performed on a Waters Atlantis reversed-phase liquid chromatography (HPLC) column, and the compounds were quantified by electrospray ionization tandem mass spectrometry (MS/MS) in the multiple-reaction monitoring mode. Results obtained by HPLC-MS/MS were compared with an HPLC assay using ultraviolet detection (HPLC-UV) performed at a reference laboratory. Results: MPAG, MPA, and MPAC were fully separated during a 7.0-min run time. Precision at both low and high concentrations of MPA ad MPAG met the suggested method validation criteria from a consensus panel report on MPA. The extraction efficiencies were 99% for MPA and MPAG. The assay was linear to 16 mg/L for MPA and 200 mg/L for MPAG. Limits of quantification were 0.1 mg/L for MPA and 1 mg/L for MPAG. Regression analysis gave the following results: HPLC-MS/MS = 1.03(HPLC-UV) − 0.03 mg/L (R2 = 0.982) for MPA; and HPLC-MS/MS = 0.93(HPLC-UV) + 0.89 mg/L (R2 = 0.967) for MPAG. Conclusion: This HPLC-MS/MS assay can be used to reproducibly quantify MPA and MPAG across a large analytical range in serum from organ transplant patients.


2020 ◽  
Vol 44 (6) ◽  
pp. 580-588
Author(s):  
A López-Rabuñal ◽  
E Lendoiro ◽  
M Concheiro ◽  
M López-Rivadulla ◽  
A Cruz ◽  
...  

Abstract An LC–MS-MS method for the determination of 14 benzodiazepines (BZDs) (alprazolam, α-hydroxyalprazolam, clonazepam, bromazepam, diazepam, nordiazepam, lorazepam, lormetazepam, oxazepam, flunitrazepam, 7-aminoflunitrazepam, triazolam, midazolam and zolpidem) and 15 antidepressants (ADs) (amitriptyline, nortriptyline, imipramine, desipramine, clomipramine, norclomipramine, fluoxetine, norfluoxetine, sertraline, norsertraline, paroxetine, venlafaxine, desmethylvenlafaxine, citalopram and desmethylcitalopram) in meconium was developed and validated. Meconium samples (0.25 ± 0.02 g) were homogenized in methanol and subjected to mixed-mode cation exchange solid-phase extraction. Chromatographic separation was performed in reversed phase, with a gradient of 0.1% formic acid in 2 mM ammonium formate and acetonitrile. Two different chromatographic gradient methods were employed, one for the separation of ADs and another for BZDs. Analytes were monitored by tandem mass spectrometry employing electrospray positive mode in MRM mode (2 transitions per compound). Method validation included: linearity [n = 5, limit of quantification (LOQ) to 400 ng/g], limits of detection (n = 6, 1–20 ng/g), LOQ (n = 9, 5–20 ng/g), selectivity (no endogenous or exogenous interferences), accuracy (n = 15, 90.6–111.5%), imprecision (n = 15, 0–14.6%), matrix effect (n = 10, −73 to 194.9%), extraction efficiency (n = 6, 35.9–91.2%), process efficiency (n = 6, 20.1–188.2%), stability 72 h in the autosampler (n = 3, −8.5 to 9%) and freeze/thaw stability (n = 3, −1.2 to −47%). The method was applied to four meconium specimens, which were analyzed with and without hydrolysis (enzymatic and alkaline). The authentic meconium samples tested positive for alprazolam, α-hydroxyalprazolam, clonazepam, diazepam, nordiazepam, fluoxetine, norfluoxetine, clomipramine and norclomipramine. Therefore, the present LC–MS-MS method allows a high throughput determination of the most common BZDs and ADs in meconium, which could be useful in clinical and forensic settings.


1990 ◽  
Vol 36 (1) ◽  
pp. 5-8 ◽  
Author(s):  
J G Goddard ◽  
G J Kontoghiorghes

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.


INDIAN DRUGS ◽  
2019 ◽  
Vol 56 (07) ◽  
pp. 59-68
Author(s):  
H Mahajan ◽  
S Savale ◽  
P Nerkar ◽  

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.


INDIAN DRUGS ◽  
2013 ◽  
Vol 50 (05) ◽  
pp. 48-52
Author(s):  
A Lodhi ◽  
◽  
A Jain ◽  
B. Biswal

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.


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