Rapid and sensitive liquid chromatography–tandem mass spectrometry method for the quantitation of colchicine in human plasma

Pharmacokinetics of low doses of colchicine in the leukocytes of Japanese healthy individuals

The venerable drug colchicine has garnered significant recent attention due to its endorsement by the United States Food and Drug Administration as an anti-inflammatory medication for cardiovascular diseases. However, the administration of this drug at its minimal available dose of 0.5 mg has been associated with certain adverse reactions. Once colchicine is administered, the drug disappears from blood in a short time and distributes in the leukocytes for a certain period of time that elicits anti-inflammatory effect. Consequently, an in-depth comprehension of the pharmacokinetics of lower dosages within leukocytes assumes important for its broader application in routine clinical contexts. In this study, we present a comprehensive analysis of the pharmacological disposition of colchicine in the plasma, polymorphonuclear leukocytes, and mononuclear leukocytes among healthy Japanese male subjects, following both single and multiple oral administrations of 0.5 mg and 0.25 mg doses of colchicine. Our investigation reveals that colchicine persists within leukocyte populations even when administered at reduced dosages. The findings herein hold promise for mitigating the adverse effects associated with its use in the treatment of inflammatory cardiovascular disorders.

In-syringe dispersive solid phase filter extraction cleanup followed by liquid chromatography-triple quadrupole mass spectrometry for fast determination of colchicine in plasma/urine

As an effective treatment for acute gouty arthritis and cardiovascular disease, colchicine is also a toxic alkaloid and may cause poisoning or even death in overdose. The study of colchicine elimination and the diagnosis of poisoning etiology need the rapid and accurate quantitative analysis method in biological matrix. An analytical method was developed for colchicine in plasma and urine by in-syringe dispersive solid phase extraction (DSPE) followed by liquid chromatography-triple quadrupole mass spectrometry (LC-MS/MS). Sample extraction and protein precipitation were proceeded with acetonitrile. The extract was cleaned by in-syringe DSPE. An XBridge™ BEH C₁₈ column（100 mm × 2.1 mm, 2.5 µm）was used to separate colchicine by gradient elution with mobile phase of 0.01% (v/v) ammonia-methanol. The amount and filling sequence of magnesium sulfate (MgSO₄) and primary secondary amine (PSA) suitable for in-syringe DSPE were studied. Scopolamine was screened as the quantitative internal standard (IS) for colchicine analysis according to the consistency of recovery rate, chromatographic retention time and matrix effects. The limits of detection for colchicine in plasma and urine were both 0.06 ng mL^-1 and the limits of quantitation were both 0.2 ng mL^-1. The linear range was 0.04 - 20 ng mL^-1 (Equivalent to 0.2-100 ng mL^-1 in plasma or urine) with a correlation coefficient r > 0.999. By IS calibration, the average recoveries at three spiking levels in plasma and urine were 95.3-102.68% and 93.9-94.8% with the relative standard deviations (RSDs) of 2.9-5.7% and 2.3-3.4%, respectively. The matrix effects, stability, dilution effects and carryover for determination of colchicine in plasma and urine were also evaluated. The elimination of colchicine within 72-384 h post-ingestion was studied for a poisoning patient with the doses of 1 mg d^-1 for 39 days and then 3 mg d^-1 for 15 days).

Easily Operable Quantification Method of 21 Plant-Derived Alkaloids in Human Serum by Automatic Sample Preparation and Liquid Chromatography–Tandem Mass Spectrometry

In this study, we developed an easily operable quantification method for 21 plant-derived alkaloids in human serum by automatic sample preparation and liquid chromatography–tandem mass spectrometry. We designed to perform parallel sample preparation by a developed apparatus, which increased sample throughput. We conducted an automatic sample preparation through de-proteinization with 0.1% formic acid in methanol and achieved recovery rates of 89–107% (2.0–14% RSD) for all targeted analytes, demonstrating its high repeatability. The method validation results were satisfactory as follows: the linearity (r²) of each calibration curve ranged from 0.978 to 1.000; the inter- and intra-day accuracies were 89.0–125% and 82.1–110%, respectively; the inter- and intra-day precisions were below 13% and 10%, respectively. Additionally, the lower limits of detection and quantification were 0.0044–0.047 and 0.013–0.14 ng/mL, respectively. Finally, the developed method was applied to pseudo-protoveratrine A poisoning serum and pseudo-colchicine poisoning serum, which were prepared by diluting acute-poisoning mice serum with human serum. Our method successfully quantitated protoveratrine A (0.15–0.25 ng/mL) and colchicine (4.8–6.0 ng/mL). Thus, our method is essential for prompt clinical treatment and critical care on patient in acute intoxication cases caused by plant-derived alkaloids.

Liquid Chromatography Tandem Mass Spectrometric Analytical Method for Study of Colchicine in Rats Given Low Doses

A selective and sensitive assay was developed for colchicine in rat specimens. Colchicine and its deuterated analog (as internal standard, IS) were extracted from rat specimens (minimal 0.1 mL plasma, whole blood, or urine) using liquid-liquid extraction with n-hexane:dichloromethane:isopropanol. The mobile phase (formic acid: ammonium acetate: methanol) was pumped with uniform flow through an octadecylsilane analytical column. Detection was carried out by electrospray positive ionization in the multiple-reaction monitoring mode. The assay (total run time <3 min) had excellent linearity over a wide (400–800-fold) concentration range. The mean absolute recovery was >96.8%. The intra- and inter-day coefficients of variation were ˂15%, with lower limits of quantitation of 0.5 ng/mL in 0.1 mL of rat plasma. The method also provided the same lower limits of quantitation in urine and whole blood with 0.1 mL volumes, and 0.1 ng/mL using 0.5 mL of rat plasma. The blood-to-plasma ratio was >1. Rats had measurable colchicine blood concentrations for at least 24 h after intravenous doses of 0.1 mg/kg. The method possessed suitable measures of sensitivity and selectivity for detecting colchicine in several specimen types in rats given low doses.

N-Doped Carbon Dots as a Fluorescent Nanosensor for Determination of Colchicine Based on Inner Filter Effect

In this study, a novel and simple fluorescent carbon quantum dots (CQDs) based nano-sensor for colchicine determination has been prepared. The nitrogen doped CQDs probe was prepared using uric acid as a carbon/nitrogen source via a one-step pyrolysis. The sensor is based on inner filter effect (IFE) where colchicine acts as a powerful absorber that affects the excitation of the fluorescer (CQDs). This overlap results in a quantitative attenuation of the fluorescence of CQDs with increasing colchicine concentration in the range of 2-25 μM. The developed sensor has the advantages of simplicity, less time-consuming, convenience and satisfactory selectivity for colchicine determination in pharmaceutical dosage forms.

Two fatal intoxications by colchicine taken for saffron. Clinical, medico-legal and forensic toxicological implications

Although fatal colchicine intoxications are rare and mostly related to suicidal intake or accidental overdose, other hypotheses should be considered when dealing with colchicine poisoning. We present a case of double, acute, and subacute, fatal colchicine intoxication in a married couple. The 70-year-old male victim suddenly died after vomiting and diarrhea. The next day his wife showed aggravating gastrointestinal symptoms and was hospitalized with a diagnosis of septic shock. A complete postmortem examination on the man was performed, together with histopathological analysis. Toxicological examination performed through liquid chromatography coupled to mass spectrometry revealed a colchicine blood peripheral concentration of 33 ng/mL. A few days after hospitalization, the woman showed a colchicine plasma concentration of 32 ng/mL. Despite veno-venous hemofiltration, she ultimately died of septic shock and multi-organ failure. Death scene investigation revealed that, a few days before the death of the male victim, the couple had collected wild saffron and had eaten a presumed saffron risotto. The integrated analysis of circumstantial, clinical, postmortem and toxicological data allowed to establish that the couple had died of a fatal accidental intoxication due to the ingestion of natural colchicine, mistaken for saffron. The death of the male was deemed caused by acute cardiovascular collapse induced by acute intoxication, while the female had suffered a subacute poisoning by antimitotic agent, resulting in immunosuppression and systemic infection. Toxicological analyses, promptly performed on the man for forensic purposes, directed the investigations and suggested the clinical diagnosis on the woman.

MOF-5(Zn)-Fe2O4 nanocomposite based magnetic solid-phase microextraction followed by HPLC-UV for efficient enrichment of colchicine in root of colchicium extracts and plasma samples

In present work, facile method is developed for determination of colchicine in human plasma sample, autumn and spring root of colchicium extracts by ultrasound assisted dispersive magnetic solid phase microextraction followed by HPLC-UV method (UAD-MSPME-HPLC-UV). Magnetic (Fe₂O₄-nanoparticles) metal organic framework-5, (MOF-5(Zn)-Fe₂O₄NPs) was synthesized by dispersing MOF-5 and Fe(NO₃)₃.9H₂O in ethylene glycol (as capping agent) and NaOH (pH adjustment agent) by hydrothermal method. The prepared sorbent was characterized via XRD and SEM analysis and applied as magnetic solid phase in UAD-MSPME-HPLC-UV method. In this method, colchicine molecules were sorbed on MOF-5(Zn)-Fe₂O₄NPs sorbent by various mechanisms like ion exchange, hydrogen bonding and electrostatic, ᴨ-ᴨ, hard-hard and dipole-ion interaction followed by exposing sonication waves as incremental mass transfer agent and then the sorbent was separated from the sample matrix by an external magnetic fields. Subsequently, accumulated colchicine were eluted by small volume of desorption organic solvent. Influence of operational variables such as MOF-5(Zn)-Fe₂O₄NPs mass, volume of extracting solvent and sonication time on response property (recovery) were studied and optimized by central composite design (CCD) combined with desirability function (DF) approach. Under optimum condition, the method has wide linear calibration rang (0.5-1700ngmL^-1) with reasonable detection limit (0.13ngmL^-1) and R²=0.9971. Finally, the UAD-MSPME-HPLC-UV method was successfully applied for determination of colchicine autumn and spring root of colchicium extracts and plasma samples.

LC-MS/MS quantification of free and Fab-bound colchicine in plasma, urine and organs following colchicine administration and colchicine-specific Fab fragments treatment in Göttingen minipigs

Clinical evaluation of a colchicine specific antigen-binding fragment (Fab) in order to treat colchicine poisoning required the development of an accurate method allowing quantification of free and Fab-bound colchicine in plasma and urine, and free colchicine in tissues, to measure colchicine redistribution after Fab administration. Three methods have been developed for this purpose, and validated in plasma, urine and liver: total colchicine was determined after denaturation of Fab by dilution in water and heating; free colchicine was separated from Fab-bound colchicine by filtration with 30KDa micro-filters; tissues were homogenized in a tissue mixer. Deuterated colchicine was used as internal standard. Samples were extracted by liquid-liquid extraction and analyzed with a LC-MS/MS. LOQ were 0.5ng/mL in plasma and urine for free and total colchicine and 5pg/mg in tissues. The methods were linear in the 0.5-100ng/mL range in plasma and urine, and 5-300pg/mg in tissues with determination coefficients>0.99. Precision and accuracy of QC samples presented a CV<9.4%. The methods require only 200μL of sample and allow a high throughput due to short analytical run (2min). These methods were successfully applied to a pig intoxicated with colchicine and treated with colchicine specific Fab fragments.

Rugged and accurate quantitation of colchicine in human plasma to support colchicine poisoning monitoring by using turbulent-flow LC–MS/MS analysis

Background: Colchicine is a common drug used in inflammatory diseases. The narrow therapeutic index requires fast and reliable techniques for its quantitation. An online, automated sample preparation using TurboFlow™ technology combined with triple-stage quadrupole MS detection was applied to identify colchicine in human plasma and follow intoxications. Methodology: Plasma samples (200 µl) were mixed with deuterated colchicine and protein precipitation ZnSO4 solutions. After centrifugation, supernatants were extracted onto a Cyclone P TurboFlow column and eluted onto a narrowbore Hypersil™ GOLD column with a methanol/water gradient. Analytes were monitored in SRM mode (positive electrospray). Results: Total run time was 9.5 min. Calibration curves ranged from 0.342 to 17.1 ng/ml, with significant linearity (R2 >0.99). Inter- and intra-assay precisions were <16.8% and accuracy was 84.4–110%. Conclusion: This method is suitable for monitoring intoxication in patients undergoing chronic treatment and is routinely applied to toxicological samples.

Competitive mass spectrometry binding assay for characterization of three binding sites of tubulin

Tubulin is an attractive and established target for anticancer therapy. To date, the only method to determine the binding of inhibitor to tubulin has been competitive radioligand binding assays. We developed a non-radioactive mass spectrometry (MS) binding assay to study the tubulin binding of colchicine, vinblastine and paclitaxel and to identify which of these three binding sites that a novel inhibitor binds. The method involves a very simple step of separating the unbound ligand from macromolecules using ultrafiltration. The unbound ligand in the filtrate can be accurately determined using highly sensitive and specific liquid chromatography tandem mass spectrometry (LC-MS/MS) method using multiple reaction monitoring (MRM) mode. The assay was validated using podophyllotoxin, vincristine and docetaxel, drugs that compete to the colchicine-, vinblastine- and paclitaxel-binding sites in tubulin, respectively. This competitive binding assay allowed the reliable detection of interactions of these drugs with three binding sites on tubulin. This method was subsequently applied to determine the tubulin-binding site of 4-substituted methoxylbenzoyl-aryl-thiazoles (SMART-H), a potent antitubulin agent developed in our laboratory. The results indicated that SMART-H specifically and reversibly bound only to the colchicine-binding site, but not to vinblastine- or paclitaxel sites. This new non-radioligand binding method to determine the binding site on tubulin will function as a useful tool to study the binding sites of tubulin inhibitors.