High-performance liquid chromatographic optimization study for the separation of natural and synthetic anabolic steroids. Application to urine and pharmaceutical samples

Danazol

A comprehensive profile of danazol describing the nomenclatures, formulae, elemental composition, appearance, uses and applications is presented. The profile contains the method which was utilized for the preparation of the drug substance and its respective scheme is outlined. The physical characteristics of the drug including the solubility, X-ray powder diffraction pattern, differential scanning calorimetry, thermal behavior and spectroscopic studies are described. The methods which were used for the analysis of the drug substance in bulk drug and/or in pharmaceutical formulations including the compendial, spectrophotometric, electrochemical and the chromatographic methods are reported. The stability, toxicity, pharmacokinetics, bioavailability, drug evaluation and monitoring, comparisons, pharmacology, in addition to several compiled reviews on the drug substance which were involved. Finally, two hundred and seventy-nine references are listed at the end of this profile.

Rapid screening and characterization of glucosinolates in 25 Brassicaceae tissues by UHPLC-Q-exactive orbitrap-MS

Glucosinolates (GSLs) are secondary plant metabolites that occur mainly in the Brassicaceae plants, which are desirable compounds in human foods due to their diverse biological activities. In this study, we developed an integrated data filtering and identification strategy to characterize the GSLs. An in-depth GSLs profiling was performed on 25 commonly Brassicaceae tissues in Jinan, China. By comparison with the reference standards and previous researches, we tentatively identified 47 GSLs including 8 unknown ones. The GSLs profiles of 25 Brassicaceae tissues were established, and 11 markers of GSLs could be used to distinguish the Brassica and Raphanus. This approach enables accurately characterization the GSLs of Brassicaceae tissues, and demonstrates the potential of GSLs profiles for Brassicaceae species discrimination.

Data supporting the optimization of liquid chromatography tandem mass spectrometry conditions to analyze EPA-priority hormones and bisphenol A in water samples

This database presents the optimization of ultra-high-performance liquid chromatography electrospray ionization tandem mass spectrometry (UHPLC-MS/MS) for the analysis of EPA-priority endocrine disruptor compounds (13 hormones and bisphenol A). Various method parameters were tested and compared for improved sensitivity. Data related to the selection of the ionization source (heated-ESI vs. APCI) are presented, including optimization results of source parameters. Compound-dependent responses when varying the UHPLC mobile phase salt concentration of ammonium fluoride (NH₄F) are supplied. Details on the chromatographic gradient program and chromatographic data demonstrating the separation of α-estradiol and β-estradiol are provided. In addition, we supply the details on mass spectrometry parameters under the optimized conditions, relative responses of quantification and confirmation MS/MS transitions (QT/CT), and number of points present in UHPLC-MS/MS spectra. The sample preparation and instrumental analysis procedures under the retained conditions are also described. The herein dataset supports the research “Analysis of Environmental Protection Agency priority endocrine disruptor hormones and bisphenol A in tap, surface and wastewater by online concentration liquid chromatography tandem mass spectrometry” Goeury et al., 2019.

Column Characterization and Selection Systems in Reversed-Phase High-Performance Liquid Chromatography

Reversed-phase high-performance liquid chromatography (RP-HPLC) is the most popular chromatographic mode, accounting for more than 90% of all separations. HPLC itself owes its immense popularity to it being relatively simple and inexpensive, with the equipment being reliable and easy to operate. Due to extensive automation, it can be run virtually unattended with multiple samples at various separation conditions, even by relatively low-skilled personnel. Currently, there are >600 RP-HPLC columns available to end users for purchase, some of which exhibit very large differences in selectivity and production quality. Often, two similar RP-HPLC columns are not equally suitable for the requisite separation, and to date, there is no universal RP-HPLC column covering a variety of analytes. This forces analytical laboratories to keep a multitude of diverse columns. Therefore, column selection is a crucial segment of RP-HPLC method development, especially since sample complexity is constantly increasing. Rationally choosing an appropriate column is complicated. In addition to the differences in the primary intermolecular interactions with analytes of the dispersive (London) type, individual columns can also exhibit a unique character owing to specific polar, hydrogen bond, and electron pair donor-acceptor interactions. They can also vary depending on the type of packing, amount and type of residual silanols, "end-capping", bonding density of ligands, and pore size, among others. Consequently, the chromatographic performance of RP-HPLC systems is often considerably altered depending on the selected column. Although a wide spectrum of knowledge is available on this important subject, there is still a lack of a comprehensive review for an objective comparison and/or selection of chromatographic columns. We aim for this review to be a comprehensive, authoritative, critical, and easily readable monograph of the most relevant publications regarding column selection and characterization in RP-HPLC covering the past four decades. Future perspectives, which involve the integration of state-of-the-art molecular simulations (molecular dynamics or Monte Carlo) with minimal experiments, aimed at nearly "experiment-free" column selection methodology, are proposed.

Determination of anabolic steroids in muscle tissue by liquid chromatography-tandem mass spectrometry

A specific and sensitive method based on liquid chromatography-tandem mass spectrometry using atmospheric pressure chemical ionization (LC-APCI-MS/MS) has been developed for the determination of four anabolic steroids [trenbolone, methylboldenone, methyltestosterone, and norethandrolone] in bovine muscle. Methyltestosterone- d 3 was used as internal standard. The procedure involved enzymatic hydrolysis, extraction with tert-butyl methyl ether, defattening, and final cleanup with solid-phase extraction with Oasis HLB cartridges. The analytes were analyzed by reversed-phase LC-MS/MS, acquiring two diagnostic product ions from the chosen precursor [M + H] (+) for the unambiguous confirmation of hormones. The method was validated according to the European Commission Decision 2002/657/EC for the detection and confirmation of residues in products of animal origin. The limits of detection (LOD) and limits of quantitation (LOQ) were found to be 0.3 ng/g and 1.0 ng/g, respectively. The accuracy and precision have been determined, with recoveries ranging from 83% to 104% and the CV factor not exceeding the value of 7%. The decision limits CCalpha were calculated and ranged from 0.05 to 0.15 ng/g while the detection capabilities CCbeta ranged from 0.09 to 0.25 ng/g. The method proved to be sensitive and reliable and thus renders an appropriate means for residue analysis studies.

Optimisation of multilinear gradient elutions in reversed-phase liquid chromatography using ternary solvent mixtures

The multilinear gradient elution theory for binary mobile phases in reversed-phase liquid chromatography presented in [P. Nikitas, A. Pappa-Louisi, A. Papageorgiou, J. Chromatogr. A 1157 (2007) 178] is extended to ternary gradients. For the evaluation of this theory and the performance of the various fitting and optimisation algorithms we used 13 o-phthalaldehyde (OPA) derivatives of amino acids with mobile phases modified by acetonitrile and methanol. It is shown that the theory can lead to high quality predictions of the retention times under gradients elutions and optimisation of ternary gradients provided that we use a six-parameter expression for the logarithm of the retention factor, lnk, and the adjustable parameters of this expression are determined from ternary isocratic data.

Liquid chromatographic method development for steroids determination (corticoids and anabolics)

A LC isocratic separation study of a complex mixture containing 18 steroids (corticoids and anabolics), used potentially as growth promoters, was carried out. For this purpose, using a Hypersil ODS column at controlled temperature, mobile phases (from binary to quaternary) prepared from water and MeOH, ACN or THF as organic modifiers and UV detection at 245 nm, were employed (dehydroepiandrosterone was detected at 200 nm). The optimum separation was achieved using water/acetonitrile (65:35, v/v) as mobile phase at 30 degrees C, allowing the separation of 16 out of 18 steroids in about 30 min. The retention scale using optimized binary mobile phases was related with steroids hydrophobicity and structure, allowing a classification into three groups for these compounds. To improve the separation several alkyl-silica packings were tested: Type A (Lichrospher C8) and Type B (Luna C18, Kromasil C18, Purospher C18 and Synergy C12). Taking into account resolution, number of separated compounds and run time analysis the Hypersil column was selected as the best choice for further applications. Calibration graphs were obtained using fluorocortisone, fluoxymesterone or methylprednisolone as internal standard. The optimized separation was applied to the analysis of piglet feed samples spiked with steroids. The sample preparation process included solvent extraction using diethyleter and solid phase extraction using silica cartridges. The recoveries were in the range 70-92%. Decision limits and detection capability were in the range 34-198 and 41-249 microg/kg, respectively. Repeatability was also evaluated.

Voltammetry and quantification of the contraceptive drug norethisterone in bulk form and pharmaceutical formulation

The electrochemical behavior of norethisterone at the mercury electrode was studied in the universal buffer of various pH values using dc-polarography, cyclic voltammetry and controlled-potential electrolysis. Norethisterone was reduced at the mercury electrode via the consumption of two electrons corresponding to reduction of the 3-keto-delta-4-group in the A-ring of the molecule. The pK(a) value (8.7) of norethisterone was determined from the polarographic and spectrophotometric measurements. A fully validated, simple, sensitive, precise and inexpensive square-wave adsorptive cathodic stripping (SWAdCS) voltammetry procedure was described for trace quantification of bulk norethisterone. The stripping voltammetry peak current of norethisterone in a universal buffer of pH 5 following its accumulation onto the hanging mercury drop electrode (HMDE) at -0.6 V (versus Ag/AgCl/KCl(s)) for 130 s showed a linear response with the concentration over the range 5 x 10(-9) to 3 x 10(-7)M norethisterone. Detection and quantitation limits of 1.5 x 10(-9) and 5 x 10(-9)M bulk norethisterone, respectively, were achieved. The proposed procedure was successfully applied for the assay of norethisterone in Steronate tablets without interference from excipients.

Square-wave adsorptive stripping voltammetric determination of danazol in capsules

Based on the interfacial adsorptive character of danazol onto the hanging mercury drop electrode (HMDE), a simple and sensitive square-wave adsorptive stripping voltammetric (SW-AdSV) procedure for the electrochemical analysis of this drug in pharmaceutical formulations has been developed and validated. Cyclic and SW-AdSV voltammograms showed a single well-defined irreversible cathodic peak. Various chemical and instrumental parameters affecting the monitored electroanalytical response were investigated and optimized for the danazol determination. Under these optimized conditions the SW-AdSV peak current showed a linear dependence on drug concentration over the range 7.5x10(-8)-3.75x10(-7) mol l-1 (r=0.999) with estimated detection limit (at a S/N ratio of 3) of 5.7x10(-9) mol l-1 (1.78 ng ml-1). A mean recovery of 100.9+/-1.2% and relative standard deviation of 1.07% were achieved. Possible interferences by substances usually present in the pharmaceutical tablets and formulations were also evaluated. The proposed electrochemical procedure was successfully applied for the determination of danazol in pharmaceutical capsules (Danol 100 mg) with mean recoveries of 100.48+/-0.87%. Results of the developed SW-AdSV method were comparable with those obtained by reported analytical procedures.

Retention prediction in ternary solvent reversed-phase liquid chromatography systems based on the variation of retention with binary mobile phase composition

An extension of the treatment adopted in a recent paper [P. Nikitas, A. Pappa-Louisi, P. Agrafiotou, J. Chromatogr. A 946 (2002) 33] was used to derive expressions describing the variation of solute retention k with composition in ternary reversed phase liquid chromatography, RP-LC, solvent systems. The equation of the partition model obtained in this way for a ternary mobile phase was identical to that previously derived using the solubility parameter concept. This equation as well as two new expressions of In k versus organic modifiers content were tested in a variety of ternary solvent systems in order to examine the possibility of predicting retention behavior of solutes under ternary solvent mixture elution conditions from known retention characteristics in binary mobile phases. It was demonstrated the superiority of both new equations derived in this paper to that previously proposed and applied to date in ternary solvent mixtures.

HPLC method development for testosterone propionate and cipionate in oil-based injectables

Two isocratic liquid chromatographic methods for the determination of testosterone propionate (TP) and cipionate (TC) in oil-based injectables using methyltestosterone and bolasterone as internal standards, respectively, have been developed and validated. Mobile phases 57% water:acetonitrile 43% (v:v) and 54% water:acetonitrile 46% (v:v) were used for TP and TC, respectively. For both methods, a bonded-silica Luna CN (250 mm x 4.6 mm i.d., 5 microm) (25 degrees C) column, a flow-rate 1 ml min(-1) and UV absorbance detection at 245 nm were used and two separations up to base line were achieved. Prior to HPLC analysis, sample preparation was required, including extraction of TP and TC from oil-based injectables using the surfactant sodium dodecyl sulphate.

Voltammetric study of danazol and its determination in capsules and spiked biological fluids

The voltammetric behaviour of danazol DZ (antigonadotropin) was studied using cyclic voltammetry, direct current, differential pulse polarography (DPP) and alternating current polarography. Danazol exhibited irreversible cathodic waves over the pH range of 1-5 in Britton Robinson buffers. At pH 1 (the analytical pH), a well-defined wave with E1/2 of -1.04 V versus Ag/AgCl reference electrode was obtained. The diffusion current constant (Id) was 4.8+/-0.14 microA.L.m mole(-1) and the current-concentration plot was rectilinear over the range from 5 x 10(-6) to 1 x 10(-4) M with correlation coefficient (n = 11) of 0.995. The calculated detection limit was 1 x 10(-6) M using the DPP mode. The wave was characterized as being irreversible, diffusion-controlled although adsorption phenomenon played a limited role in the electrode process. The proposed method was applied to commercial capsules and the average percentage recovery was in agreement with that obtained by the official USP method. The method was extended to the in vitro determination of DZ in spiked human urine and plasma samples, the percentage recoveries were 96+/-4 and 97+/-5, respectively. A proposal of the electrode reaction was postulated.

Screening of free 17-alkyl-substituted anabolic steroids in human urine by liquid chromatography-electrospray ionization tandem mass spectrometry

A qualitative liquid chromatography-electrospray ionization tandem mass spectrometry method was developed for screening of the abuse of 4-chlorodehydromethyltestosterone, danazol, fluoxymesterone, formebolone, metandienone, oxandrolone, and stanozolol. The introduced method measures simultaneously nine different 17-alkyl-substituted anabolic androgenic steroids or their unconjugated metabolites in human urine, using methyltestosterone as an internal standard. Sample preparation involved one-step liquid extraction. Liquid chromatographic separation was achieved on a reversed-phase column with methanol-water gradient containing 5 mmol/l ammonium acetate and 0.01% (v/v) acetic acid. Compounds were ionized in the positive mode and detected by multiple reaction monitoring. All steroids within the study could be selectively detected in urine with detection limits of 0.1-2.0 ng/ml. The method showed good linearity up to 250 ng/ml with correlation coefficients higher than 0.9947. With simple and fast sample preparation, low limits of detection, and high selectivity and precision, the developed method provides advantages over the present testing methods and has the potential for routine qualitative screening method of unconjugated 17-alkyl-substituted anabolic steroids in human urine.

Recent Advances in the Analysis of Steroid Hormones and Related Drugs

The development during the last 15 years and the state-of-the-art in the analysis of bulk steroid hormone drugs and hormone-like structures and pharmaceutical formulations made thereof are summarized. Other steroids (sterols, bile acids, cardiac glycosides, vitamins D) as well as biological-clinical aspects and pharmacokinetic and metabolic studies are excluded from this review. The state-of-the-art is summarized based on comparisons of monographs in the latest editions of the European Pharmacopoeia, United States Pharmacopoeia and the Japanese Pharmacopoeia. This is followed by sections dealing with new developments in the methodology for the fields of spectroscopic and spectrophotometric, chromatographic, electrophoretic and hyphenated techniques as well electroanalytical methods. The review is terminated by two problem-oriented sections: examples on impurity and degradation profiling as well as enantiomeric analysis.

Method development for corticosteroids and anabolic steroids by micellar liquid chromatography

A systematic optimization of the HPLC separation of a complex mixture containing urinary steroids (anabolics and corticoids), boldenone and bolasterone (synthetic anabolics) by micellar liquid chromatography has been carried out. The isocratic micellar mobile phases (from binary to quaternary) consisted of sodium dodecyl sulphate and organic modifiers such as acetonitrile, tetrahydrofuran, propanol, butanol or pentanol. The effect of the organic modifiers, surfactant concentration, temperature, ionic strength and flow-rate on the separation has been studied. A micellar mobile phase made of 5% propanol and 40 mM surfactant allowed the separation of 13 steroids in about 23 min. A bivariant optimization method for the micellar mobile phase surfactant-propanol corroborated the above results. The separations obtained show good perspectives for future developments.

Optimization and validation of conventional and micellar LC methods for the analysis of methyltestosterone in sugar-coated pills

Two isocratic liquid chromatographic methods (conventional and micellar) for the determination of methyltestosterone in sugar-coated pills using fluoxymesterone as internal standard have been developed and validated. In conventional liquid chromatography a mobile phase 45% water:acetonitrile 55% (v:v), a flow-rate 1 mlmin(-1) and a C(18) Hypersil ODS (250 x 4.6 mm, 5 microm) column (25 degrees C) were used. In micellar liquid chromatography the conditions were: mobile phase 40 mM sodium dodecyl sulfate: 10% propanol, flow-rate 0.5 mlmin(-1) and C(18) Hypersil ODS (150 x 3.0 mm, 5 microm) column (60 degrees C). For both methods, UV absorbance detection at 245 nm was used and a separation up to base line was achieved. Prior to HPLC analysis a simple sample preparation was required.

Prediction of internal standards in reversed-phase liquid chromatography. II. Selectivity optimization and internal standard prediction for the quantitation of estradiol and levonorgestrel in a transdermal drug delivery formulation based on the linear solvation energy relationships

This paper describes the results of selectivity optimization and internal standard prediction for the quantitation of estradiol and levonorgestrel in transdermal patches by reversed-phase liquid chromatography (RPLC) based on the linear solvation energy relationships (LSERs). The patch samples are prepared by swelling with acetonitrile (ACN) and the separation is performed by Zorbax Eclipse XDB ODS columns. A proper retention range is first determined with a binary mobile phase of ACN and water based on the general resolution equation. The interference to estradiol from a levonorgestrel impurity is then eliminated by a ternary mobile phase of acetonitrile-methanol-water with a composition predicted by LSERs. When the resolution is optimized and the "open window" in the chromatogram for an internal standard is selected, LSERs are used to predict the candidate compounds to be evaluated as the internal standard. The approach described in this study can be used, in general, to considerably improve the efficiency of RPLC method development, particularly for neutral samples. Finally, the LSER approach for the selectivity optimization is compared with a statistical response surface methodology (RSM) based on a central composite design (CCD) in terms of the effectiveness and number of experiments. It is concluded that, although the predicted mobile phase composition to achieve the desired selectivity is about the same, the LSER approach is more efficient and fewer experiments are required.

High-performance liquid chromatographic analysis of dehydroepiandrosterone

Qualitative and quantitative analysis of dehydroepiandrosterone and its conjugates in biological matrices and establishment of their relationships with physiological functions is a very active field. This review article discusses methods of separation and quantification of dehydroepiandrosterone and its conjugates using high-performance liquid chromatographic techniques.

Gas chromatography and high-performance liquid chromatography of natural steroids

This review article underlines the importance of gas chromatography (GC), high-performance liquid chromatography (HPLC) and their hyphenated techniques using mass spectrometry (MS) for the determination of natural steroids, especially in human biological fluids. Steroids are divided into eight categories based on their structures and functions, and recent references using the above methodologies for the analysis of these steroids are cited. GC and GC-MS are commonly used for the determination of volatile steroids. Although HPLC is a widely used analytical method for the determination of steroids including the conjugated type in biological fluids, LC-MS is considered to be the most promising one for this purpose because of its sensitivity, specificity and versatility.

Solvent and solid-phase extraction of natural and synthetic anabolic steroids in human urine

Liquid-liquid (using dichloromethane) and liquid-solid extraction processes (using disposable C18 cartridges) were applied to human urine samples spiked with 15 androgenic anabolic steroids (natural and synthetic). The extraction recoveries were assessed from different HPLC separations of anabolic steroids using water-acetonitrile mobile phase, and using calibration graphs obtained by injection into HPLC of standard samples of these compounds before and after extraction. The procedures, including sample preconcentration, showed extraction efficiencies over 90% which were independent on a wide range of concentrations tested. Solid phase extraction yielded poor results for oximetolone, danazol and dehydroepiandrosterone. For real urine samples, hydrolysis using beta-glucuronidase and washing using sodium hydroxide before and after solvent extraction, respectively, is recommended.