Quantitative LC–MS/MS method in urine for the detection of drugs used to reverse the effects of chemical castration

4-Aminobenzoic acid, 2-phenoxyethanol and iodine used as tracers in a short-term in vivo-kinetics study for tattoo ink ingredients: Mass spectrometry method development and validation

Tattoos have been gaining popularity in recent years, leading to a growing interest in researching tattoo inks and the tattooing process itself. Since the exposure to soluble tattoo ink ingredients has not yet been investigated, we here present the method validation for a short-term biokinetics study on soluble tattoo ink ingredients. The three tracers 4-aminobenzoic acid (PABA), 2-phenoxyethanol (PEtOH) and iodine will be added to commercially available tattoo inks, which will subsequently be used on healthy study participants. Following the tattooing process, blood and urine will be sampled at specific time points and analysed for these tracers. For this purpose, a method using liquid chromatography separation coupled to a quadrupole time-of-flight mass spectrometer (LC-QTOF-MS) in positive and negative ESI mode for the quantification of PABA, PEtOH and selected metabolites and an inductively-coupled plasma (ICP)-MS method for the determination of iodine were developed and validated. For LC-QTOF-MS analysis, the most applicable additives for LC eluents (0.01 % formic acid for positive and 0.005 % acetic acid for negative mode) were identified. Protein precipitation with acetonitrile was chosen for sample preparation. The methods were validated for selectivity, specificity, carryover, linearity, limit of detection (LOD) and quantification (LOQ), matrix effects, accuracy and precision, stability under different conditions and dilution integrity according to national and international guidelines with an allowed maximum variation of ±15 %. The LC-QTOF-MS method met the imposed guideline criteria for most parameters, however, some metabolites showed strong matrix effects. Validation of the ICP-MS method revealed that the KED-H2 collision mode is superior to the standard analysis mode due to enhanced method accuracy. The methods were validated for the relevant matrices plasma, urine, tattoo ink and tattoo consumables and proved to be applicable for the main target substances in the short-term biokinetics study. A proof-of-concept study showed successful quantification of iodine and PABA metabolites. The PEtOH metabolite was also quantified, but showed strong matrix effects in urine. Therefore standard addition was selected as an alternative quantification method.

Determination of synthetic phosphodiesterase-5 inhibitors by LC-MS2 in waters and human urine submitted to dispersive liquid-liquid microextraction

High-performance liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS²) with a triple quadrupole is proposed for determining the synthetic phosphodiesterase-5 inhibitors, sildenafil, tadalafil and vardenafil, and the active metabolite N-desmethyl sildenafil. The method was successfully applied to the analysis of waters of different origins and human urine samples. Dispersive liquid-liquid microextraction (DLLME) was applied in the classical way for water analysis, whereas a previous extraction into an organic solvent was necessary for urine samples, the acetonitrile extract being used as dispersant solvent in the DLLME step. The analytes were determined by LC-ESI-MS² in the multiple reaction monitoring mode. Detection limits were in the 5-50 and 15-250ngL^-1 ranges for water and urine samples, respectively. The repeatability was calculated using the relative standard deviation, obtaining values of between 3.6% and 10.1%. The enrichment factors were between 75 and 81. Accuracy of the procedure was calculated through recovery assays and average recoveries ± SD (n = 48) of 93.6 ± 3.5 and 91.1 ± 3.5 were obtained for water and urine samples, respectively. None of the samples analyzed contained the target compounds, at least above the corresponding detection limits.

Development of a comprehensive spectral library of sildenafil and related active analogues using LC-QTOF-MS and its application for screening counterfeit pharmaceuticals

The abuse or misuse of forged erectile-dysfunction drugs, containing phosphodiesterase type 5 inhibitors (e.g. sildenafil), is a serious issue globally. Therefore, the detection of sildenafil and related active analogues in counterfeit pharmaceuticals or the differentiation between counterfeit and authentic drugs has been performed with a variety of analytical techniques. Recently, a liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF-MS)-based in-house library, consisting of accurate mass ion fragmentation information and retention times, was effectively applied to screen a large number of compounds in field of forensic toxicology. However, a comprehensive LC-QTOF-MS spectral library of sildenafil and related active analogues has not yet been reported. In the present study, a spectral library of 40 compounds of sildenafil and related analogues was developed with accurate mass spectra and retention times using LC-QTOF-MS, and applied to screen nine marketed counterfeit products. The in-house library successfully identified sildenafil, dimethylsildenafil, hydroxyhomosildenafil, demethylhongdenafil, pseudovardenafil and vardenafil in the samples. Our LC-QTOF-MS-based spectral library search is considered a powerful approach for identifying sildenafil and related active analogues in counterfeit pharmaceuticals.

Pharmacological interventions for those who have sexually offended or are at risk of offending

BACKGROUND

Sexual offending is a serious social problem, a public health issue, and a major challenge for social policy. Victim surveys indicate high incidence and prevalence levels and it is accepted that there is a high proportion of hidden sexual victimisation. Surveys report high levels of psychiatric morbidity in survivors of sexual offences.Biological treatments of sex offenders include antilibidinal medication, comprising hormonal drugs that have a testosterone-suppressing effect, and non-hormonal drugs that affect libido through other mechanisms. The three main classes of testosterone-suppressing drugs in current use are progestogens, antiandrogens, and gonadotropin-releasing hormone (GnRH) analogues. Medications that affect libido through other means include antipsychotics and serotonergic antidepressants (SSRIs).

OBJECTIVES

To evaluate the effects of pharmacological interventions on target sexual behaviour for people who have been convicted or are at risk of sexual offending.

SEARCH METHODS

We searched CENTRAL (2014, Issue 7), Ovid MEDLINE, EMBASE, and 15 other databases in July 2014. We also searched two trials registers and requested details of unidentified, unpublished, or ongoing studies from investigators and other experts.

SELECTION CRITERIA

Prospective controlled trials of antilibidinal medications taken by individuals for the purpose of preventing sexual offences, where the comparator group received a placebo, no treatment, or 'standard care', including psychological treatment.

DATA COLLECTION AND ANALYSIS

Pairs of authors, working independently, selected studies, extracted data, and assessed the risk of bias of included studies. We contacted study authors for additional information, including details of methods and outcome data.

MAIN RESULTS

We included seven studies with a total of 138 participants, with data available for 123. Sample sizes ranged from 9 to 37. Judgements for categories of risk of bias varied: concerns were greatest regarding allocation concealment, blinding of outcome assessors, and incomplete outcome data (dropout rates in the five community-based studies ranged from 3% to 54% and results were usually analysed on a per protocol basis).Participant characteristics in the seven studies were heterogeneous, but the vast majority had convictions for sexual offences, ranging from exhibitionism to rape and child molestation.Six studies examined the effectiveness of three testosterone-suppressing drugs: cyproterone acetate (CPA), ethinyl oestradiol (EO), and medroxyprogesterone acetate (MPA); a seventh evaluated two antipsychotics (benperidol and chlorpromazine). Five studies were placebo-controlled; in two, MPA was administered as an adjunctive treatment to a psychological therapy (assertiveness training or imaginal desensitisation). Meta-analysis was not possible due to heterogeneity of interventions, comparators, study designs, and other issues. The quality of the evidence overall was poor. In addition to methodological issues, much evidence was indirect.

PRIMARY OUTCOME

recividism. Two studies reported recidivism rates formally. One trial of intramuscular MPA plus imaginal desensitisation (ID) found no reports of recividism at two-year follow-up for the intervention group (n = 10 versus one relapse within the group treated by ID alone). A three-armed trial of oral MPA, alone or in combination with psychological treatment, reported a 20% rate of recidivism amongst those in the combined treatment arm (n = 15) and 50% of those in the psychological treatment only group (n = 12). Notably, all those in the 'oral MPA only' arm of this study (n = 5) dropped out immediately, despite treatment being court mandated.Two studies did not report recidivism rates as they both took place in one secure psychiatric facility from which no participant was discharged during the study, whilst another three studies did not appear directly to measure recividism but rather abnormal sexual activity alone.

SECONDARY OUTCOMES

The included studies report a variety of secondary outcomes. Results suggest that the frequency of self reported deviant sexual fantasies may be reduced by testosterone-suppressing drugs, but not the deviancy itself (three studies). Where measured, hormonal levels, particularly levels of testosterone, tended to correlate with measures of sexual activity and with anxiety (two studies). One study measured anxiety formally; one study measured anger or aggression. Adverse events: Six studies provided information on adverse events. No study tested the effects of testosterone-suppressing drugs beyond six to eight months and the cross-over design of some studies may obscure matters (given the 'rebound effect' of some hormonal treatments). Considerable weight gain was reported in two trials of oral MPA and CPA. Side effects of intramuscular MPA led to discontinuation in some participants after three to five injections (the nature of these side effects was not described). Notable increases in depression and excess salivation were reported in one trial of oral MPA. The most severe side effects (extra-pyramidal movement disorders and drowsiness) were reported in a trial of antipsychotic medication for the 12 participants in the study. No deaths or suicide attempts were reported in any study. The latter is important given the association between antilibidinal hormonal medication and mood changes.

AUTHORS' CONCLUSIONS

We found only seven small trials (all published more than 20 years ago) that examined the effects of a limited number of drugs. Investigators reported issues around acceptance and adherence to treatment. We found no studies of the newer drugs currently in use, particularly SSRIs or GnRH analogues. Although there were some encouraging findings in this review, their limitations do not allow firm conclusions to be drawn regarding pharmacological intervention as an effective intervention for reducing sexual offending.The tolerability, even of the testosterone-suppressing drugs, was uncertain given that all studies were small (and therefore underpowered to assess adverse effects) and of limited duration, which is not consistent with current routine clinical practice. Further research is required before it is demonstrated that their administration reduces sexual recidivism and that tolerability is maintained.It is a concern that, despite treatment being mandated in many jurisdictions, evidence for the effectiveness of pharmacological interventions is so sparse and that no RCTs appear to have been published in two decades. New studies are therefore needed and should include trials with larger sample sizes, of longer duration, evaluating newer medications, and with results stratified according to category of sexual offenders. It is important that data are collected on the characteristics of those who refuse and those who drop out, as well as those who complete treatment.

An LC-MS/MS method for the determination of five erectile dysfunction drugs and their selected metabolites in hair

The abuse of sildenafil and its analogous, accelerated by their inappropriate or illegal distribution, is a serious social issue globally. However, no studies have been conducted to monitor these drugs simultaneously in hair, which can provide valuable information on chronic drug use. In the present study, an LC-MS/MS method was developed for the simultaneous determination in hair of five erectile dysfunction drugs having a high risk for abuse (mirodenafil, sildenafil, tadalafil, udenafil and vardenafil) and their selected metabolites (SK3541, desmethylsildenafil, DA8164 and desethylvardenafil). The novel method was fully validated after optimizing matrix effects and extraction efficiency. The optimized sample preparation included acidic methanol extraction followed by solid phase extraction using C18 mixed mode strong cation exchange polymeric cartridges. The prepared samples were analyzed by LC-MS/MS with electrospray ion source in the positive ionization mode. The validation results proved the method to be selective, sensitive, accurate and precise, with acceptable linearity within calibration ranges. LODs ranged from 0.05 (DA8164) to 1 ng/10 mg hair (tadalafil). LOQs were 1 ng/10 mg hair except for DA8164 and vardenafil, of which they were 2.5 ng/10 mg hair. No significant variations were observed by different sources of matrices in both human and rat hair, except for tadalafil, for which a stable isotope-labeled internal standard was effective. The animal study suggested hair pigmentation was a major factor for the incorporation of the drugs and metabolites into hair. However, a wide variation of the sildenafil-to-desmethylsildenafil ratios was observed in human hair samples. The developed method will be very useful for monitoring the abuse of erectile dysfunction drugs for both legal and public health aspects.