Multi-detection of corticosteroids in sports doping and veterinary control using high-resolution liquid chromatography/time-of-flight mass spectrometry

Simultaneous quantification of dexamethasone and 6β-hydroxydexamethasone in rabbit plasma, aqueous and vitreous humor, and retina by UHPLC-MS/MS

Aim: To develop and validate a fit for purpose method for the simultaneous determination of dexamethasone and its major metabolite, 6β-hydroxydexamethasone, in rabbit plasma and ocular matrices to measure the in vivo release and distribution profile of dexamethasone from intravitreal implants. Materials & methods: An UHPLC-MS/MS system was employed to perform the bioanalysis. The method was validated according to the US FDA Bioanalytical Method Validation Guidance for Industry. Results & conclusion: The method was found to be fit-for-purpose for the described biological matrices and had a LLOQ of 0.1 ng/ml.

Role of Chemical Dynamics Simulations in Mass Spectrometry Studies of Collision-Induced Dissociation and Collisions of Biological Ions with Organic Surfaces

In this article, a perspective is given of chemical dynamics simulations of collisions of biological ions with surfaces and of collision-induced dissociation (CID) of ions. The simulations provide an atomic-level understanding of the collisions and, overall, are in quite good agreement with experiment. An integral component of ion/surface collisions is energy transfer to the internal degrees of freedom of both the ion and the surface. The simulations reveal how this energy transfer depends on the collision energy, incident angle, biological ion, and surface. With energy transfer to the ion's vibration fragmentation may occur, i.e. surface-induced dissociation (SID), and the simulations discovered a new fragmentation mechanism, called shattering, for which the ion fragments as it collides with the surface. The simulations also provide insight into the atomistic dynamics of soft-landing and reactive-landing of ions on surfaces. The CID simulations compared activation by multiple "soft" collisions, resulting in random excitation, versus high energy single collisions and nonrandom excitation. These two activation methods may result in different fragment ions. Simulations provide fragmentation products in agreement with experiments and, hence, can provide additional information regarding the reaction mechanisms taking place in experiment. Such studies paved the way on using simulations as an independent and predictive tool in increasing fundamental understanding of CID and related processes.

Simultaneous Determination of Thalidomide and Dexamethasone in Rat Plasma by Validated HPLC and HPTLC With Pharmacokinetic Study

Two validated chromatographic methods have been developed for the simultaneous determination of thalidomide (THD) and dexamethasone (DEX) in rat plasma using paracetamol (PAR) as an internal standard (IS). Chromatographic analysis was achieved firstly by HPLC method on C18 column (150 × 4.6 mm2 i.d., 5 μm) and a mobile phase composed of ethanol:water (containing 0.1% acetic acid) (70:30, v/v) at the flow rate of 0.6 mL min-1. The second method was HPTLC method which depended on using a developing system of methylene chloride:acetone:ethyl acetate (7:4:1, by volume). In both methods, PAR was used as an IS. The developed methods have been validated as per FDA guidelines. All parameters were tested using quality control samples (LQC, MQC and HQC). All the obtained parameters were within the acceptance criteria. In the same way, the two methods were successfully used to study the pharmacokinetic parameters of both THD and DEX after their intra-peritoneal administration. Moreover, results obtained after administration of each drug alone were compared to those obtained after their administration together. The drugs showed drug-drug interactions when administered in combination, meaning that monitoring of such combination is very important.

Genotoxicity of selected pharmaceuticals, their binary mixtures, and varying environmental conditions - study with human adenocarcinoma cancer HT29 cell line

Pharmaceutical residues are present in the environment in mixtures and their adverse effects may also result from interactions that occur between compounds. Studies presented in this work focus on genotoxicity of pharmaceuticals from different therapeutic groups in mixtures and in individual solutions impacted with different environmental conditions assessed using comet assay (alkaline approach). Binary mixtures of pharmaceuticals (in different concentration ratios) and in individual solutions impacted with pH change (range from 5.5 to 8.5) or addition of inorganic ions, were incubated with HT29 cells and after 24 h time period cells were tested for the presence of DNA damage. To estimate whether mixtures act more (synergistic) or less (antagonistic) efficiently Concentrations Addition (CA) and Independent Action (IA) approaches were applied followed by a calculation of the Model Deviation Ratio (MDR) to determine deviation from the predicted values. Addition of inorganic ions mainly reduced their genotoxicity. Diclofenac s. was the most susceptible to potassium, fluoride, and bromide ions. Change of the pH of pharmaceutical solutions had significant impact on genotoxicity of diclofenac s. and fluoxetine h. Among mixtures, more commonly observed interactions were synergistic ones, exactly twenty-five cases (ten pairs containing chloramphenicol or oxytetracycline h.) and ten cases of antagonism (four for pairs containing chloramphenicol or fluoxetine h.). The results obtained indicate that interactions between tested compounds occur frequently and can lead to DNA damage. This topic especially concerning in vitro tests using cells is still rare, however, it should not be neglected.

Dilute-and-shoot coupled to nanoflow liquid chromatography high resolution mass spectrometry for the determination of drugs of abuse and sport drugs in human urine

In this work, a sensitive nanoflow liquid chromatography high-resolution mass spectrometry screening method has been developed for the determination of multiclass drugs of abuse and sport drugs in human urine. 81 drugs belonging to different multiclass pharmaceuticals were targeted. The method is based on the use of a nanoLC column (75 µm × 150 mm, 3 µm particle size and 100 Å pore) with the nanospray emitter tip integrated so that dead volumes are significantly minimized. Data acquisition method included both full-scan and all ion fragmentation experiments using an Orbitrap analyser (Q-Exactive) operated in the positive ionization mode. To increase laboratory throughput, a dilute-and-shoot methodology has been tested and proposed, based solely on direct urine dilution without further sample workup. Matrix effects were evaluated, showing a negligible effect for all studied compounds when a dilution 1:50 was implemented. Despite this high-dilution factor, limits of quantification were still satisfactory, with values below 5 µg L^-1 in most cases, being lower than their minimum required performance limits correspond established by the World Anti-Doping Agency. Therefore, the use of the dilute-and-shoot method with the enhanced sensitivity provided by nanoflow LC setup could be useful tool for the determination of studied compounds in drug testing, thus increasing laboratory performance, because a minimum sample treatment steps are required.

Determination of ketosteroid hormones in meat by liquid chromatography tandem mass spectrometry and derivatization chemistry

A method for the determination and quantification of ketosteroid hormones in meat by mass spectrometry, based on the derivatization of the carbonyl moiety of steroids by O-methylhydroxylamine, is presented. The quantitative assay is performed by means of multiple-reaction-monitoring (MRM) scan mode and using the corresponding labelled species, obtained by reaction with d 3-methoxylamine, as internal standard. The accuracy of the method was established by evaluating artificially spiked samples, obtaining values in the range 90-110%. Recovery tests were performed on blank matrix samples spiked with non-natural steroids including trenbolone and melengestrol acetate. The latter experiment revealed that the yield of the extraction processes was approximately 60%. Good values of LOQ and LOD were achieved, making this method competitive with current hormone assay methods.

Simultaneous determination of dexamethasone and lenalidomide in rat plasma by solid phase extraction and ultra-performance liquid chromatography-tandem mass spectrometry: application to pharmacokinetic studies

Determination of dexamethasone and lenalidomide in plasma by SPE and UPLC-MS/MS for the purpose of TDM: application to pharmacokinetic studies.

Untargeted profiling of urinary steroid metabolites after testosterone ingestion: opening new perspectives for antidoping testing

Aim: Antidoping procedures are expected to greatly benefit from untargeted metabolomic approaches through the discovery of new biomarkers of prohibited substances abuse. Results: Endogenous steroid metabolites were monitored in urine samples from a controlled elimination study of testosterone undecanoate after ingestion. A platform coupling ultra-high pressure LC with high-resolution quadrupole TOF MS was used and high between-subject metabolic variability was successfully handled using a multiblock data analysis strategy. Links between specific subsets of metabolites and influential genetic polymorphisms of the UGT2B17 enzyme were highlighted. Conclusion: This exploratory metabolomic strategy constitutes a first step toward a better understanding of the underlying patterns driving the high interindividual variability of steroid metabolism. Promising biomarkers were selected for further targeted study.

Current status and bioanalytical challenges in the detection of unknown anabolic androgenic steroids in doping control analysis

Androgenic anabolic steroids (AAS) are prohibited in sports due to their anabolic effects. Doping control laboratories usually face the screening of AAS misuse by target methods based on MS detection. Although these methods allow for the sensitive and specific detection of targeted compounds and metabolites, the rest remain undetectable. This fact opens a door for cheaters, since different AAS can be synthesized in order to evade doping control tests. This situation was evidenced in 2003 with the discovery of the designer steroid tetrahydrogestrinone. One decade after this discovery, the detection of unknown AAS still remains one of the main analytical challenges in the doping control field. In this manuscript, the current situation in the detection of unknown AAS is reviewed. Although important steps have been made in order to minimize this analytical problem and different analytical strategies have been proposed, there are still some drawbacks related to each approach.

Urinary profile of methylprednisolone and its metabolites after oral and topical administrations

Methylprednisolone (MP) is prohibited in sports competitions when administered by systemic routes; however its use by topical administration is allowed. Therefore, analytical approaches to distinguish between these different administration pathways are required. A reporting level of 30ng/mL was established for this purpose. However, the suitability of that reporting level for MP is not known. In the present work, excretion profiles of MP and different metabolites after oral and topical administrations have been compared. A method for the quantification of MP and the qualitative detection of fifteen previously reported metabolites has been validated. The method involved an enzymatic hydrolysis, liquid-liquid extraction and analysis by liquid chromatography coupled to tandem mass spectrometry. The method was found to be linear, selective, precise and accurate. The high sensitivity (limit of detection 0.1ng/mL) and linear range (0.1-250ng/mL) achieved allowed for the quantification of MP at both the low concentrations present after topical administration and the high concentrations detected after oral intake. The method was applied to samples collected after oral (4 or 40mg) and topical administration (10mg of MP aceponate/day for 5 consecutive days) to healthy volunteers. After oral administration, MP and all metabolites were detected in urines collected up to at least 36h. Only MP and five metabolites were detected in samples obtained after topical treatment. As expected, concentrations of MP after topical administration were well below current reporting level (30ng/mL), however 3 out of 4 samples in range 8-24h after the low oral dose (4mg) were also below that concentration. Taking into account metabolites detected after both administration routes, metabolites 16β,17α,21-trihydroxy-6α-methylpregna-1,4-diene-3,11,20-trione (M8) and 17α,20α,21-trihydroxy-6α-methylpregna-1,4-diene-3,11-dione (M11) are best markers to differentiate between topical and oral administrations. Their signals after topical administration were lower than those obtained in the first 48h after all oral doses.

A simple TLC and HPTLC method for separation of selected steroid drugs

Chromatographic properties of five steroid drugs: cortisone, hydrocortisone, methylprednisolone, prednisolone and norgestrel have been studied by normal-, reversed-phase and hydrophilic neutral cyano-bonded silica stationary phase with five binary mobile phases (acetonitrile-water, acetonitrile-DMSO, acetonitrile-methanol, acetone-petroleum ether, acetone-water) in which the concentration of organic modifier was varied from 0 to 100% (v/v). This study reports the optimization of steroid hormones separation. Chromatographic retention data and possible retention mechanisms are discussed. Separation abilities of mobile and stationary phases were studied using the principal component analysis method. The best separation of methylprednisolone and prednisolone is with a chromatographic system included silica gel as stationary phase and mixture of acetonitrile and DMSO (10:90 v/v). These two anti-inflammatory drugs can be fast separated from norgestrel when CN is used as stationary phase and acetone and water (40:60 v/v) as mobile phase. The highest values of the parameter Δ(ΔG°) and alfa for cortisone and hydrocortisone was observed in case of using CN as stationary phase and water-acetonitryle (40:60 v/v) as mobile phase.

A validated analytical method to study the long-term stability of natural and synthetic glucocorticoids in livestock urine using ultra-high performance liquid chromatography coupled to Orbitrap-high resolution mass spectrometry

Due to their growth-promoting effects, the use of synthetic glucocorticoids is strictly regulated in the European Union (Council Directive 2003/74/EC). In the frame of the national control plans, which should ensure the absence of residues in food products of animal origin, in recent years, a higher frequency of prednisolone positive bovine urines has been observed. This has raised questions with respect to the stability of natural corticoids in the respective urine samples and their potential to be transformed into synthetic analogs. In this study, a ultra high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) methodology was developed to examine the stability of glucocorticoids in bovine urine under various storage conditions (up to 20 weeks) and to define suitable conditions for sample handling and storage, using an Orbitrap Exactive™. To this end, an extraction procedure was optimized using a Plackett-Burman experimental design to determine the key conditions for optimal extraction of glucocorticoids from urine. Next, the analytical method was successfully validated according to the guidelines of CD 2002/657/EC. Decision limits and detection capabilities for prednisolone, prednisone and methylprednisolone ranged, respectively, from 0.1 to 0.5μgL(-1) and from 0.3 to 0.8μgL(-1). For the natural glucocorticoids limits of detection and limits of quantification for dihydrocortisone, cortisol and cortisone ranged, respectively, from 0.1 to 0.2μgL(-1) and from 0.3 to 0.8μgL(-1). The stability study demonstrated that filter-sterilization of urine, storage at -80°C, and acidic conditions (pH 3) were optimal for preservation of glucocorticoids in urine and able to significantly limit degradation up to 20 weeks.

Application of LC-MS/MS for quantitative analysis of glucocorticoids and stimulants in biological fluids

Liquid chromatography tandem mass chromatography (LC-MS/MS) is an important hyphenated technique for quantitative analysis of drugs in biological fluids. Because of high sensitivity and selectivity, LC-MS/MS has been used for pharmacokinetic studies, metabolites identification in the plasma and urine. This manuscript gives comprehensive analytical review, focusing on chromatographic separation approaches (column packing materials, column length and mobile phase) as well as different acquisition modes (SIM, MRM) for quantitative analysis of glucocorticoids and stimulants. This review is not meant to be exhaustive but rather to provide a general overview for detection and confirmation of target drugs using LC-MS/MS and thus useful in the doping analysis, toxicological studies as well as in pharmaceutical analysis.

Fragmentation of toxicologically relevant drugs in negative-ion liquid chromatography-tandem mass spectrometry

Negative-ion LC-MS analysis of drugs is applied far less frequently than positive-ion LC-MS. Data on the interpretation of negative-ion MS-MS spectra are even more scarce. Therefore, following the recent review on the class-specific fragmentation of toxicologically relevant compounds in positive-ion MS-MS, it was decided to perform a similar study in negative-ion MS-MS. To this end, a set of over 500 negative-ion MS-MS spectra was collected from three libraries applied in toxicological general unknown screening and systematic toxicological analysis. The compounds involved were classified by chemical and therapeutic class. The MS-MS spectra were manually interpreted and relevant interpretation data were searched for in the scientific literature. The emphasis in the discussion is on class-specific fragmentation, because discussing fragmentation of all individual compounds would take far too much space. Negative-ion MS-MS fragmentation is discussed for a wide variety of toxicologically relevant compounds, including dihydropyridine calcium channel blockers, diuretics, barbiturates, anti-inflammatory drugs, anti-diabetics, sulfonamide and betalactam antibiotics, and a number of classes of pesticides.

Analytical investigations about the presence of prednisolone in cow urine

Since 2008, the analyses carried out in the Lombardia region as part of National Residue Control Plans have evidenced unexpected frequent detection of the corticosteroid prednisolone (PRED) in cow urine samples taken to the slaughterhouse. Considering the scarce plausibility of these high frequent findings, analytical investigations were started to ascertain the real presence of this corticosteroid. The applied confirmatory method involved liquid-chromatography low-resolution tandem mass spectrometry (triple quadrupole) as instrumental technique, and it was validated in compliance with the requirements of the Commission Decision 2002/657/EC. However, recently some criticism regarding Commission Decision 2002/657/EC identification criteria has been pointed out, experimentally demonstrating false positive results (wrong identification) although these criteria have been strictly observed. Therefore, considering the serious implications (i.e. the possibility that PRED could be considered endogenous in particular animal conditions), studies were carried out to investigate the reliability of PRED identification through the change of the chromatographic conditions (mobile phases, gradient and analytical column) of the confirmatory procedure routinely applied. Further confirmation came from the application of high-resolution mass spectrometry technique (MS(2) and MS(3) experiments) to analyze incurred cow urines samples. All the obtained results confirmed definitively the real presence of this corticosteroid excluding false-positive findings in routine analysis. In addition, other experiments demonstrated that high-resolution mass spectrometers (Time of Flight and Orbitrap technologies) could be successfully applied to routine determination of steroid residues in biological fluids at very low concentrations (< 1 µg L(-1)).

Recent developments in MS for small molecules: application to human doping control analysis

Recent developments in MS for the detection of small molecules in the context of doping control analysis are reviewed. Doping control analysis is evolving together with MS, which is the technique of choice in order to accomplish the analytical requirements in this field. Since these analytical requirements for the detection of a doping agent depend on the substance, in the first section we review the different scenarios. The commonly established approaches, together with their achievements and drawbacks are described. New developments in hyphenated MS techniques (both GC–MS/MS and LC–MS/MS) concerning interfaces and analyzers are mentioned. The use (or potential use) of these developments in order to minimize the limitations of the commonly established approaches in the doping control field is discussed. Finally, a brief discussion about trends and remaining limitations is presented.

Detection of synthetic glucocorticoids by liquid chromatography-tandem mass spectrometry in patients being investigated for Cushing's syndrome

Background

We report a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the detection of four commonly prescribed steroid drugs (prednisolone, dexamethasone, betamethasone and beclomethasone dipropionate) while simultaneously measuring 24-h urine free cortisol and cortisone in patients.

Methods

Two hundred and fifty microlitre aliquots of urine were spiked with internal standard and extracted with dichloromethane. The MS instrument was operated with positive electrospray and multiple reaction monitoring. Two transitions were monitored for each analyte of interest and the ratio of the intensities of the product ion fragments was established.

Results

The LC-MS/MS method for the measurement of urine free cortisol and cortisone was established. The assay was linear up to 788 nmol/L for cortisol and 777 nmol/L for cortisone, with a limit of quantitation of 5.0 nmol/L for both. Analysis time per sample was seven minutes. Transitions for four synthetic glucocorticoids were included, and they were identified based on the ratio of the intensities of product ion fragments. Analysis of 219 samples collected from 154 patients (55 male and 99 female) revealed the presence of prednisolone in five samples from three patients. Dexamethasone was detected in samples from four patients, and betamethasone was detected in one sample.

Conclusion

This is the first LC-MS/MS method in routine use to combine quantification of urinary cortisol and cortisone and detection of synthetic glucocorticoids in patients being investigated for Cushing's syndrome. Since the most common quoted cause of Cushing's syndrome is steroid treatment, this is a valuable diagnostic tool.

Analytical aspects in doping control: challenges and perspectives

Since the first anti-doping tests in the 1960s, the analytical aspects of the testing remain challenging. The evolution of the analytical process in doping control is discussed in this paper with a particular emphasis on separation techniques, such as gas chromatography and liquid chromatography. These approaches are improving in parallel with the requirements of increasing sensitivity and selectivity for detecting prohibited substances in biological samples from athletes. Moreover, fast analyses are mandatory to deal with the growing number of doping control samples and the short response time required during particular sport events. Recent developments in mass spectrometry and the expansion of accurate mass determination has improved anti-doping strategies with the possibility of using elemental composition and isotope patterns for structural identification. These techniques must be able to distinguish equivocally between negative and suspicious samples with no false-negative or false-positive results. Therefore, high degree of reliability must be reached for the identification of major metabolites corresponding to suspected analytes. Along with current trends in pharmaceutical industry the analysis of proteins and peptides remains an important issue in doping control. Sophisticated analytical tools are still mandatory to improve their distinction from endogenous analogs. Finally, indirect approaches will be discussed in the context of anti-doping, in which recent advances are aimed to examine the biological response of a doping agent in a holistic way.

Detection of the misuse of steroids in doping control

The list of prohibited substances of the World Anti-Doping Agency (WADA) classifies the administration of several steroids in sports as doping. Their analysis is generally performed using urine specimen as matrix. Lots of the steroids are extensively metabolised in the human body. Thus, knowledge of urinary excretion is extremely important for the sensitive detection of steroid misuse in doping control. The methods routinely used in steroid screening mainly focus on substances, that are excreted unconjugated or as glucuronides. Common procedures include deconjugation using a beta-glucuronidase enzyme. Following extraction and concentration the analytes are submitted to LC-MS(/MS) analysis and/or GC-MS(/MS) analyses. Besides the classical steroids, more and more products appear on the market for "dietary supplements" containing steroids that have never been marketed as approved drugs, mostly without proper labelling of the contents. To cover the whole range of potential products comprehensive screening tools have to be utilised in addition to the classical methods. Endogenous steroids, e.g. testosterone, represent a special group of compounds. As classical chemical methodology is incapable of discriminating synthetic hormones from the biosynthesised congeners, the method of steroid profiling is used for screening purpose. Additionally, based on isotope signatures a discrimination of synthetic and natural hormones can be achieved.

Generic sample preparation combined with high-resolution liquid chromatography-time-of-flight mass spectrometry for unification of urine screening in doping-control laboratories

A unification of doping-control screening procedures of prohibited small molecule substances--including stimulants, narcotics, steroids, beta2-agonists and diuretics--is highly urgent in order to free resources for new classes such as banned proteins. Conceptually this may be achieved by the use of a combination of one gas chromatography-time-of-flight mass spectrometry method and one liquid chromatography-time-of-flight mass spectrometry method. In this work a quantitative screening method using high-resolution liquid chromatography in combination with accurate-mass time-of-flight mass spectrometry was developed and validated for determination of glucocorticosteroids, beta2-agonists, thiazide diuretics, and narcotics and stimulants in urine. To enable the simultaneous isolation of all the compounds of interest and the necessary purification of the resulting extracts, a generic extraction and hydrolysis procedure was combined with a solid-phase extraction modified for these groups of compounds. All 56 compounds are determined using positive electrospray ionisation with the exception of the thiazide diuretics for which the best sensitivity was obtained by using negative electrospray ionisation. The results show that, with the exception of clenhexyl, procaterol, and reproterol, all compounds can be detected below the respective minimum required performance level and the results for linearity, repeatability, within-lab reproducibility, and accuracy show that the method can be used for quantitative screening. If qualitative screening is sufficient the instrumental analysis may be limited to positive ionisation, because all analytes including the thiazides can be detected at the respective minimum required levels in the positive mode. The results show that the application of accurate-mass time-of-flight mass spectrometry in combination with generic extraction and purification procedures is suitable for unification and expansion of the window of screening methods of doping laboratories. Moreover, the full-scan accurate-mass data sets obtained still allow retrospective examination for emerging doping agents, without re-analyzing the samples.

Searching for in silico predicted metabolites and designer modifications of (cortico)steroids in urine by high-resolution liquid chromatography/time-of-flight mass spectrometry

Glucocorticosteroids are a restricted class of substances and appear on the 'in-competition' prohibited list of the World Anti-Doping Agency (WADA). Analysis of glucocorticosteroids is complicated since they show significant phase 1 and 2 metabolism in the human body and are excreted into urine in concentrations in the microg/L range. Full scan, high-resolution time-of-flight mass spectrometry analysis generates information on all ionisable components in urine, including known and unknown metabolites of steroids and even designer modifications of anabolic steroids. However, evaluation of the data obtained can be difficult and time-consuming because of the need to differentiate between endogenous components and compounds of interest. MetaboLynx, a spectral and chromatographic search program, was modified for the determination of in silico predicted metabolites of glucocorticosteroids and designer modifications of anabolic steroids in human urine. Spiked urine samples were successfully screened for known components in a targeted approach and for unknown species in a non-targeted approach using data filtering to limit potential false-positives. A simplified combined approach of targeted and untargeted screening was used for the detection of metabolites and designer modifications of existing compounds. This approach proved successful and showed its strength in the detection of tetrahydrogestrinone (THG), a designer modification of gestrinone. THG was positively detected in a spiked urine sample and correctly identified as a twofold hydrogenation of gestrinone. The developed screening method can easily be adapted to specific needs and it is envisaged that a similar approach would be amendable to the discovery of metabolites or designer modifications of other compounds of interest.