Probing the hair detectability of prohibited substances in sports: an in vivo-in silico-clinical approach and analytical implications compared with plasma, urine, and faeces

Hair analysis is a crucial method in forensic toxicology with potential applications in revealing doping histories in sports. Despite its widespread use, knowledge about detectable substances in hair is limited. This study systematically assessed the detectability of prohibited substances in sports using a multifaceted approach. Initially, an animal model received a subset of 17 model drugs to compare dose dependencies and detection windows across different matrices. Subsequently, hair incorporation data from the animal experiment were extrapolated to all substances on the World Anti-Doping Agency's List through in-silico prediction. The detectability of substances in hair was further validated in a proof-of-concept human study involving the consumption of diuretics and masking agents. Semi-quantitative analysis of substances in specimens was performed using ultra-performance liquid chromatography-tandem mass spectrometry. Results showed plasma had optimal dose dependencies with limited detection windows, while urine, faeces, and hair exhibited a reasonable relationship with the administered dose. Notably, hair displayed the highest detection probability (14 out of 17) for compounds, including anabolic agents, hormones, and diuretics, with beta-2 agonists undetected. Diuretics such as furosemide, canrenone, and hydrochlorothiazide showed the highest hair incorporation. Authentic human hair confirmed diuretic detectability, and their use duration was determined via segmental analysis. Noteworthy is the first-time reporting of canrenone in human hair. Anabolic agents were expected in hair, whereas undetectable compounds, such as peptide hormones and beta-2 agonists, were likely due to large molecular mass or high polarity. This study enhances understanding of hair analysis in doping investigations, providing insights into substance detectability.

Successive ratio subtraction as a novel manipulation of ratio spectra for quantitative determination of a mixture of furosemide, spironolactone and canrenone

Furosemide and spironolactone are commonly prescribed antihypertensive drugs. Canrenone is the main degradation product and main metabolite of spironolactone. Ratio subtraction and extended ratio subtraction spectrophotometric methods were previously applied for quantitation of only binary mixtures. An extension of the above mentioned methods; successive ratio subtraction, is introduced in the presented work for quantitative determination of ternary mixtures exemplified by furosemide, spironolactone and canrenone. Manipulating the ratio spectra of the ternary mixture allowed their determination at 273.6nm, 285nm and 240nm and in the concentration ranges of (2-16μgmL^-1), (4-32μgmL^-1) and (1-18μgmL^-1) for furosemide, spironolactone and canrenone, respectively. Method specificity was ensured by the application to laboratory prepared mixtures. The introduced method was ensured to be accurate and precise. Validation of the developed method was done with respect to ICH guidelines and its validity was further ensured by the application to the pharmaceutical formulation. Statistical comparison between the obtained results and those obtained from the reported HPLC method was achieved concerning student's t-test and F ratio test where no significant difference was observed.

A new enzyme-linked chemiluminescent immunosorbent digoxin assay is virtually free from interference of spironolactone, potassium canrenoate, and their common metabolite canrenone

Spironolactone and potassium canrenoate (aldosterone antagonist diuretics) are sometimes used in conjunction with digoxin for patient management. Spironolactone, potassium canrenoate, and their common metabolite canrenone interfere with serum digoxin measurement using various immunoassays. Recently a new enzyme-linked chemiluminescent immunosorbent digoxin assay (ECLIA-Digoxin) became commercially available for application on the ADVIA IMS 800i modular system (Bayer HealthCare, Tarrytown, NY). We investigated the potential interference of spironolactone and related compounds in this assay by comparing the results with the fluorescence polarization immunoassay (FPIA), which is known to have significant cross-reactivity with these compounds as well as a turbidimetric assay for digoxin with no known cross-reactivity with spironolactone and related compounds. Aliquots of drug free serum were supplemented with therapeutic and above therapeutic concentrations of spironolactone, canrenone, and potassium canrenoate, and apparent digoxin concentrations were measured. No apparent digoxin concentration was observed using the ECLIA-Digoxin or turbidimetric assay. When serum pools prepared from patients receiving digoxin were further supplemented with these compounds, we observed no significant change in digoxin concentrations in the presence of these compounds with the ECLIA-Digoxin. We conclude that this assay is virtually free from interferences from spironolactone, potassium canrenoate and their common metabolite canrenone.

Conventional and micellar liquid chromatography method development for danazol and validation in capsules

Two isocratic liquid chromatographic methods (conventional and micellar) for the determination of danazol (DZ) in capsules using canrenone (CAN) as internal standard have been developed and validated. In conventional liquid chromatography a mobile phase 35% water:acetonitrile 65%, v:v, a flow-rate 1 ml min(-1) and a C18 Hypersil ODS (250 x 4.6 mm, 5 microm) column (25 degrees C) were used. In micellar liquid chromatography (MLC) the conditions were: mobile phase 40 mM sodium dodecyl sulfate:2% pentanol, flow-rate 0.5 ml min(-1) and C18 Hypersil ODS (150 x 3.0 mm, 5 microm) column (60 degrees C). For both methods. UV absorbance detection at 280 nm was used and a separation up to base line was achieved. Prior to HPLC analysis a simple sample preparation was required. The recoveries found in the accuracy test were 99 +/- 10 and 101 +/- 8%, in conventional liquid chromatography (CLC) and MLC, respectively. Repeatability and intermediate precision expressed as R.S.D. were lower than 5% for both methods. Detection limits obtained were 2.4 and 3.0 ng g(-1) in CLC and CLM, respectively.

Simultaneous quantitative determination of butizide, potassium canrenoate and canrenone in tablets by high-performance liquid chromatography

A procedure for the simultaneous quantitative determination and selective identification of potassium canrenoate and butizide is proposed. The amount of canrenone, the degradation product of potassium canrenoate, is also determined. Elution of these compounds is investigated on LiChrosorb RP-18 and RP-8 columns. The analysis time was shorter on a RP-8 column while the specific identification was still possible. Therefore, the LiChrosorb RP-8 column was chosen. The eluent consisted of an acetonitrile--0.05 M phosphate buffer, pH 4 (45:55) mixture. Quantitative determination was performed at the absorption maximum of each compound: 286 nm for potassium canrenoate and for canrenone, 271 nm for butizide. This change in wavelength is performed automatically by the computer that controls the spectrophotometric diode array detector.

Determination of canrenone, the major metabolite of spironolactone, in plasma and urine by high-performance liquid chromatography

An assay procedure for measuring plasma and urine levels of canrenone is described. The drug is extracted with n-hexane-toluene (1:1, v/v) after adding spirorenone as internal standard, and is then separated from plasma constituents and metabolites by high-performance liquid chromatography followed by UV detection at 285 nm. The limit of detection is less than 5 ng/ml. Interference with a series of spironolactone and canrenone metabolites was not observed. Plasma levels and renal excretion of canrenone after oral administration of 200 mg of spironolactone and intravenous injection of 200 mg of potassium canrenoate to a healthy male volunteer were measured.

Spironolactone: relationship between concentrations of dethioacetylated metabolite in human serum and milk

The concentration of canrenone, a principal metabolite of spironolactone, was determined in human serum and milk. The milk to serum concentration ratios of this metabolite were 0.72 at 2 hr and 0.51 at 14.5 hr after ingestation of spironolactone. It was estimated that the maximum quantity of canrenone ingested daily by a human infant via its mother's milk would be approximately 0.2% of the daily dose of spironolactone given to the mother.

Validation of plasma and urinary canrenone for determination of bioavailability of spironolactone--comparison of tablets with solution/suspension

Data showing a linear relationship between spironolactone dose and the levels of canrenone in plasma and urine are presented to support the use of canrenone levels as a measure of the bioavailability of spironolactone. The bioavailability of a selected batch of spironolactone 25 mg tablets was compared to that of an oral aqueous suspension of spironolactone in a separate balanced cross-over study involving 10 healthy subjects. The tablets were equivalent to suspension as regards area under the plasma concentration-time curve and total urinary excretion of canrenone, the prinicipal unconjugated metabolite of spironolactone. Peak plasma concentrations of canrenone were higher, and were attained significantly earlier, after treatment with spironolactone in suspension. The results indicate that spironolactone was absorbed more rapidly from the suspension, but that the total absorption did not differ between the two formulations.

Syntheses and ultraviolet absorption of aza-steroids

A series of aza-steroids was synthesized containing chromophoric groups, such as a, beta-unsaturated ketones and doubly unsaturated conjugated and monoconjugated heteroannular dienones with the heteroatom in the D ring at the 20 and 17a positions. The effect of an appositely placed electronegative center in these molecules upon their ultraviolet absorptions was studied. In order to obtain a basis for the observed spectral changes, the corresponding carbocyclic compounds were also synthesized. The maximum absorptions of the aza-steroids were hypsochromically shifted relative to the carbocyclic compounds in all cases (n=8). The displacement caused by the electronegative center on absorption maximum of the chromophores is, however, highly dependent on its location within the molecules.

High-speed liquid chromatographic determination of canrenone in pharmaceutical dosage forms

Canrenone can be determined by high-speed liquid chromatography in pharmaceutical dosage forms without interference from common excipients or degradation products. This stability-indicating assay, using o-nitroaniline as the internal standard, is rapid and accurate.

Spironolactone metabolism in man studied by gas chromatography-mass spectrometry

Gas chromatography-mass spectrometry was used to identify metabolites of spironolactone in human blood and urine. In three healthy men about 20% of the radioactivity was excreted in the urine within 24 hr after an oral dose of [20-3H]spironolactone (200 mg + 200 muCi). About half of this radioactivity was extracted with chloroform at pH 3 and from this extract four stable metabolites were isolated by use of column and thin-layer chromatography. Two of these were the previously identified metabolites, canrenone (VII; 2.9% of dose) and the 6beta-hydroxy-sulfoxide (X; 1.8% of the dose). The remaining were the new metabolites, 15alpha-hydroxycanrenone (XI; 0.8% of dose) and the 6beta-hydroxy-thiomethyl derivatives (VI; 0.5% of dose). The principal water-soluble urinary metabolite was canrenoate ester glucuronide (XII; 4.5% of dose). In the 24- to 32-hr pooled serum, canrenone (VII) was the principal metabolite in the organic-extractable fraction; VI was present in appreciable amounts but X and XI were present at extremely low levels.