Reversed-phase liquid chromatography analysis of imatinib mesylate and impurity product in Glivec® capsules

Determination of serum imatinib and its' metabolite in patients chronic myeloid leukemia

INTRODUCTION

Imatinib has favorable pharmacokinetic properties, but primary and secondary resistance mechanisms may cause a decrease in clinical response over time. There is a positive correlation between serum imatinib concentrations and treatment response. Our aim was to develop a method for the measurement of imatinib and its' active metabolite N-desmethyl imatinib.

METHODS

Serum imatinib and N-desmethyl imatinib levels were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and validation studies were carried out according to CLSI (The Clinical & Laboratory Standards Institute) protocols. Serum samples were collected from 40 patients with chronic myeloid leukemia (CML) and analyzed with LC-MS/MS and ultra high-performance liquid chromatography (UHPLC) methods.

RESULTS

The linearity range and correlation coefficient were 12.2-12,500 ng/mL and 0.9987 for LC-MS/MS method, respectively. Limit of quantitation was determined as 24.4 ng/mL. The retention times of imatinib and N-desmethyl imatinib were 1.66 and 1.60 min, respectively. There was no statistically significant difference between the results of both methods.

DISCUSSION

This LC-MS/MS method is cost-effective and has adavantages such as using low serum volumes, requiring simple pretreatment steps (only protein precipitation) and reduced turnaround times for analysis.

Antineoplastic drugs and their analysis: a state of the art review

We provide an overview of the analytical methods available for the quantification of antineoplastic drugs in pharmaceutical formulations, biological and environmental samples.

Using an innovative quality-by-design approach for the development of a stability-indicating UPLC/Q-TOF-ESI-MS/MS method for stressed degradation products of imatinib mesylate

Chromatography modeling softwares (DryLab®2000 plus and Design Expert®​8.0.6) were used to develop a stability indicating UPLC/Q-TOF-ESI-MS/MS method for the simultaneous determination of stressed degradation products of imatinib mesylate.​

Imatinib mesylate

Imatinib (INN), marketed by Novartis as Gleevec (United States) or Glivec (Europe/Australia/Latin America), received Food & Drug Administration (FDA) approval in May 2001 and is a tyrosine kinase inhibitor used in the treatment of multiple cancers, most notably Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia. Like all tyrosine kinase inhibitors, imatinib works by preventing a tyrosine kinase enzyme. Because the BCR-Abl tyrosine kinase enzyme exists only in cancer cells and not in healthy cells, imatinib works as a form of targeted therapy-only cancer cells are killed through the drug's action. In this regard, imatinib was one of the first cancer therapies to show the potential for such targeted action and is often cited as a paradigm for research in cancer therapeutics. This study presents a comprehensive profile of imatinib, including detailed nomenclature, formulae, physico-chemical properties, methods of preparation, and methods of analysis (including compendial, electrochemical, spectroscopic, and chromatographic methods of analysis). Spectroscopic and spectrometric analyses include UV/vis spectroscopy, vibrational spectroscopy, nuclear magnetic resonance spectrometry ((1)H and (13)C NMR), and mass spectrometry. Chromatographic methods of analyses include electrophoresis, thin layer chromatography, and high-performance liquid chromatography. Preliminary stability investigations for imatinib have established the main degradation pathways, for example, oxidation to N-oxide under oxidative stress conditions. Stability was also carried out for the formulation by exposing to different temperatures 0°C, ambient temperature, and 40°C. No remarkable change was found in the drug content of formulation. This indicates that the drug was stable at the above optimized formulation. Stability studies under acidic and alkaline conditions have established the following main degradation products: α-(4-Methyl-1-piperazinyl)-3'-{[4-(3-pyridyl)-2-pyrimidinyl] amino}-p-tolu-p-toluid-ide methanesulfonate and 4-(4-methylpiperazin-1-ylmethyl)-benzoic acid. The main degradation products under oxidation conditions, that is, 4-[(4-methyl-4-oxido-piperazin-1-yl)-methyl]-N-[4-methyl-3-(4-pyridin-3-yl-pyrimidin-2-ylamino)-phenyl]-enzamide, 4-[(4-methyl-1-oxido-piperazin-1-yl)-methyl]-N-[4-methyl-3-(4-pyridin-3-yl-pyrimidin-2-ylamino)-phenyl]-benzamide, and 4-[(4-methyl-1,4-dioxido-piperazin-1-yl)-methyl]-N-[4-methyl-3-(4-pyridin-3-yl-pyrimidin-2-ylamino)-phenyl]-enzamide. Clinical application studies for pharmacodynamics, pharmacokinetics, mechanism of action, and clinical uses of the drug were also presented. Each of the above stages includes appropriate figures and tables. More than 50 references were given as proof of the above-mentioned studies.

Reduced exposure of imatinib after coadministration with acetaminophen in mice

Purpose:

Imatinib is an efficacious drug against chronic myeloid leukemia (CML) and gastrointestinal stromal tumor (GIST) due to selective inhibition of c-KIT and BCR-ABL kinases. It presents almost complete bioavailability, is eliminated via P450-mediated metabolism and is well tolerated. However, a few severe drug-drug interactions have been reported in cancer patients taking acetaminophen.

Materials and Methods:

Male ICR mice were given 100 mg/kg single dose of imatinib orally or imatinib 100 mg/kg (orally) coadministered with acetaminophen intraperitoneally (700 mg/kg). Mice were euthanized at predetermined time points, blood samples collected, and imatinib plasma concentration measured by HPLC.

Results:

Imatinib AUC_0-12 was 27.04 ± 0.38 mg·h/ml, C_max was 7.21 ± 0.99 mg/ml and elimination half-life was 2.3 hours. Acetaminophen affected the imatinib disposition profile: AUC_0-12 and C_max decreased 56% and 59%, respectively and a longer half-life was observed (5.6 hours).

Conclusions:

The study shows a pharmacokinetic interaction between acetaminophen and imatinib which may render further human studies necessary if both drugs are administered concurrently to cancer patients.

Plasma pharmacokinetics and CYP3A12-dependent metabolism of c-kit inhibitor imatinib in dogs

Imatinib is a highly selective tyrosine kinase inhibitor, and is used for the treatment of chronic myeloid leukaemia (CML) and gastrointestinal stromal tumours (GISTs) in humans. The aim of this study is to determine the in vitro and in vivo pharmacokinetics of imatinib in dogs and which cytochrome P450 (CYPs) contribute to its metabolism. Imatinib was administered orally or intravenously to dogs and the time of the peak concentration (T(max)) of imatinib was 4-9 h. The mean half-life was 622 +/- 368 min, and the AUC was 1256 +/- 809 microM * min after oral administration. The range of C0 of intravenously injected dogs was 12-24 microM. The half-life and AUC after intravenous injection were 206 +/- 112 min and 1026 +/- 371 microM * min, respectively. Recombinant system of dog CYP3A12 and CYP2C21 showed that CYP3A12 contributed to the metabolism of imatinib. The inhibition of CYP3A-dependent activity using a rat anti-CYP3A antibody or ketoconazole revealed that CYP3A12 plays a major role in the metabolism of imatinib in dog liver microsomes.

High-performance liquid chromatography method with ultraviolet detection for the quantification of the BCR-ABL inhibitor nilotinib (AMN107) in plasma, urine, culture medium and cell preparations

An isocratic and sensitive HPLC assay was developed allowing the determination of the new anticancer drug nilotinib (AMN107) in human plasma, urine, culture medium and cell samples. After protein precipitation with perchloric acid, AMN107 underwent an online enrichment using a Zirchrom-PBD precolumn, was separated on a Macherey-Nagel C18-HD column and finally quantified by UV-detection at 258 nm. The total run time is 25 min. The assay demonstrates linearity within a concentration range of 0.005-5.0 microg/ml in plasma (r(2)=0.9998) and 0.1-10.0 microg/ml in urine (r(2)=0.9913). The intra-day precision expressed as coefficients of variation ranged depending on the spiked concentration between 1.27-9.23% in plasma and 1.77-3.29% in urine, respectively. The coefficients of variation of inter-day precision was lower than 10%. Limit of detection was 0.002 microg/ml in plasma and 0.01 microg/ml in urine. The described method is stable, simple, economic and is routinely used for in vivo and in vitro pharmacokinetic studies of AMN107.

Identification of imatinib mesylate degradation products obtained under stress conditions

In this paper, the decomposition of imatinib mesylate (ImM) under hydrolytic (neutral, acidic, alkaline), oxidative and photolytic conditions was studied. The imatinib mesylate is practically photostable and stable under neutral conditions. The main degradation products under acidic and alkaline conditions are compounds: 4-methyl-N3-(4-pyridin-3-yl-pyrimidyn-2-yl)-benzene-1,3-diamine (2) and 4-(4-methyl-piperazin-1-ylmethyl)-benzoic acid (3). The main degradation products under oxidation conditions, i.e. 4-[(4-methyl-4-oxido-piperazin-1-yl)-methyl]-N-[4-methyl-3-(4-pyridin-3-yl-pyrimidin-2-ylamino)-phenyl]-benzamide (6), 4-[(4-methyl-1-oxido-piperazin-1-yl)-methyl]-N-[4-methyl-3-(4-pyridin-3-yl-pyrimidin-2-ylamino)-phenyl]-benzamide (7) and 4-[(4-methyl-1,4-dioxido-piperazin-1-yl)-methyl]-N-[4-methyl-3-(4-pyridin-3-yl-pyrimidin-2-ylamino)-phenyl]-benzamide (8), were isolated from the reaction mixtures and identified by the HPLC, 1H NMR and MS techniques. During stress study the suitability of the proposed HPLC method to control purity of the samples was verified.

Stability-indicating HPTLC determination of imatinib mesylate in bulk drug and pharmaceutical dosage form

A simple, selective, precise and stability-indicating high-performance thin-layer chromatographic method of analysis of imatinib mesylate both as a bulk drug and in formulations was developed and validated. The method employed HPTLC aluminium plates precoated with silica gel 60F-254 as the stationary phase. The solvent system consisted of chloroform:methanol (6:4, v/v). The system was found to give compact spot for imatinib mesylate (R(f) value of 0.53+/-0.02). Densitometric analysis of imatinib mesylate was carried out in the absorbance mode at 276 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r(2)=0.9966+/-0.0013 with respect to peak area in the concentration range 100-1000 ng per spot. The mean value+/-S.D. of slope and intercept were 164.85+/-0.72 and 1168.3+/-8.26 with respect to peak area. The method was validated for precision, recovery and robustness. The limits of detection and quantitation were 10 and 30 ng per spot, respectively. Imatinib mesylate was subjected to acid and alkali hydrolysis, oxidation and thermal degradation. The drug undergoes degradation under acidic, basic, oxidation and heat conditions. This indicates that the drug is susceptible to acid, base hydrolysis, oxidation and heat. Statistical analysis proves that the method is repeatable, selective and accurate for the estimation of said drug. The proposed developed HPTLC method can be applied for identification and quantitative determination of imatinib mesylate in bulk drug and dosage forms.