Evaluation of Benzodiazepines and Zolpidem in Nails and Their Stability

Home , Delorazepam

Journal of Pharmaceutical and Biomedical Analysis 152 (2018) 137–142

Contents lists available at ScienceDirect

Journal of Pharmaceutical and Biomedical Analysis

journal homepage: www.elsevier.com/locate/jpba

Evaluation of benzodiazepines and zolpidem in nails and their

stability after prolonged exposure to chlorinated water

a,∗ b a a a

Matteo Moretti , Luisa Andrello , Silvia Visonà , Claudia Vignali , Angelo Groppi ,

a a a a

Francesca Freni , Antonio Osculati , Luca Tajana , Luca Morini

Department of Public Health, Experimental and Forensic Medicine, University of Pavia, via Forlanini 12, 27100, Pavia, Italy

MedicoLegal Service of Canton Ticino, via H. Guisan 3, 6500 Bellinzona, Switzerland

a r t i c l e i n f o a b s t r a c t

Article history: The study aims the development and validation of a LC–MS/MS method for the identiﬁcation and quan-

Received 17 January 2018

tiﬁcation of benzodiazepines and zolpidem in nails as alternative keratinized matrix to hair in long-term

Received in revised form 23 January 2018

monitoring of anxiolytic and hypnotic drugs. Both ﬁngernail and toenail samples (1–2 mm) were col-

Accepted 24 January 2018

lected by clipping the excess overhang of the nail from volunteers and from postmortem cases. They were

washed twice with organic solvents, dried under nitrogen stream, pulverized, immersed in a methanol

Keywords:

solution (internal standard: diazepam-D5) and sonicated up to two hours. The solution was then direct

Benzodiazepines

injected in the LC–MS/MS system. Mass spectrometry was set in MRM mode, selecting two transitions

LC–MS/MS

Nails for each substance. 32 analytes among benzodiazepines, metabolites and hypnotics were included in the

Hypnotics list. The method fulﬁlled the internationally required criteria for validation. Limits of detection ranged

Chlorinated water from 0.03 pg/mg (zolpidem) to 13.1 pg/mg (bromazepam). 9 subjects under therapy were positive at 7

different benzodiazepines and/or metabolites (lorazepam, desalkylﬂurazepam, bromazepam, diazepam,

alprazolam, lormetazepam and prazepam), while 5 molecules were measured in 4 postmortem cases

(diazepam, desmethyldiazepam, delorazepam, 7-aminoclonazepam and zolpidem). In vitro experiments

on eight authentic samples suggested that benzodiazepines in nails are inﬂuenced by the prolonged

exposure to chlorinated water.

1. Introduction abuse and medicines [12]. The concentration of drugs in nails and

hair and the mechanisms of incorporation in keratinized matrices

Nowadays, keratinized hair matrix is no more considered a novel have been recently compared [13,14]. In particular, a study on the

matrix in forensic toxicology. Indeed, hair analysis is routinely mechanisms of incorporation of zolpidem in ﬁngernails showed

performed in several different applications, such as evaluation of that both sweat and bloodstream contribute in the accumulation

driver’s driving license eligibility [1], workplace drug testing [2], of drugs in nails, and that the portion carried by the sweat cannot be

drug facilitated sexual assaults [3] and postmortem cases [4]. How- removed by daily hygiene treatments. The hair/nail ratio appeared

ever, several studies demonstrated that xenobiotics in hair can be to partially depend on melanin afﬁnity of the drug. For example,

hydrolyzed and/or removed after cosmetic treatments, like ther- zolpidem has a great afﬁnity to melanin and, consequently, the

mal straightening [5] and bleaching [6]. Even the exposition to concentration is higher in hair than in nail [15]. On the contrary,

UVB radiation could decrease the concentration of drugs in hair the concentration of EtG in hair does not depend on melanin con-

[7]. Moreover, due to speciﬁc pathologies (e.g. alopecia) or profes- tent and the hair/nail ratio is lower than 1 [16]. Benzodiazepines

sional requirements, hair may be too short or missing. Owing to all provide a general high afﬁnity to melanin, thus theoretically result-

these limitations, nails have been evaluated as a possible alterna- ing in a lower amount detectable in nails. However, the structure

tive keratinized matrix to hair [8–10]. Engelhart et al. described the and the thickness of nail could avoid or limit the degradation or

ﬁrst method for the detection of drugs of abuse in nails [11]. Shu extraction of xenobiotics by means of cosmetic treatments and

et al. screened more than 10000 nail samples for different drugs of environmental conditions. A recent study demonstrated that pro-

longed exposure to chlorinated water provides an extensive loss

of benzodiazepines in hair [17]. Hence, the aim of this study was

∗ to develop and validate a simple and fast method for the identi-

Corresponding author.

E-mail address: [email protected] (M. Moretti). fication and quantification of benzodiazepines in fingernails and

https://doi.org/10.1016/j.jpba.2018.01.051

138 M. Moretti et al. / Journal of Pharmaceutical and Biomedical Analysis 152 (2018) 137–142

Table 1

toenails and the consequent application of the analytical proce-

MRM transitions for each substance. Quantiﬁer transitions in bold.

dure to authentic samples collected by volunteers and postmortem

cases. Finally, we investigated the inﬂuence of chlorinated water on Substance Parent ion Fragments DP CE

m/z m/z (V) (eV)

the stability of some benzodiazepines and zolpidem in nails.

7-amino-Clonazepam 286.2 121.2, 222.2 90 42,35

7-amino-Flunitrazepam 284.1 135.1, 226.1 92 40,42

2. Material and methods ␣

-hydroxy-ethyl-Flurazepam 333.3 109.3, 211.3 90 53,41

␣-hydroxy-Triazolam 359.1 341.4, 314.4 94 38,53

2.1. Reagents Alprazolam 309.4 205.4, 281.4 93 58,35

Bromazepam 316.4 182.4, 209.4 90 46,36

Brotyzolam 395.3 314.3, 316.3 102 34,33

Thirty-two compounds among benzodiazepines, their metabo-

Camazepam 372.4 255.4, 283.4 47 33,19

lites and zolpidem were monitored. Lorazepam, alprazolam, bro-

Delorazepam 305.1 140.2, 206.2 92 56,81

␣

mazepam, flurazepam, -hydroxy-ethylflurazepam, desalkyflu- Chlordiazepoxide 300.1 227.1, 192.1 61 36,56

razepam, ﬂunitrazepam, 7-amino-ﬂunitrazepam, clonazepam, Clobazam 301.2 259.3, 224.3 87 30,46

Clonazepam 316.2 270.4, 214.4 89 36,52

7-amino-clonazepam, lormetazepam, clobazam, demoxepam,

Clotiazepam 319.1 291.4, 154.4 90 33,41

prazepam, chlordiazepoxide, midazolam, nitrazepam, zolpidem,

Demoxepam 287.2 269.2, 180.2 93 40,34

medazepam, oxazepam, diazepam, desmethyldiazepam, triazolam

Desalkylﬂurazepam 288.8 140.2, 226.2 99 44,40

and temazepam were purchased by Lipomed (Nova Chimica, Milan, Desmethyldiazepam 271.1 140.3, 165.3 96 40,41

Diazepam 285.2 154.2, 193.2 93 37,47

Italy), clotiazepam, estazolam, etizolam were obtained by For-

Estazolam 295.3 205.3, 267.3 86 57,35

menti (Formenti SPA, Milan, Italy) delorazepam and brotizolam

Etizolam 343.3 314.3, 259.3 110 36,47

were purchased by Ravizza (Ravizza Farmaceutici SPA, Milan, Italy),

Flunitrazepam 314.4 239.4, 268.4 95 48,36

ketazolam and pinazepam were obtained by Ciba-geigy (Basel, Flurazepam 388.1 315.4, 287.4 85 35,47

Switzerland). Water was puriﬁed by ﬁltering deionized water on Ketazolam 285.1 193.3, 154.3 91 46,40

Lorazepam 321.4 275.4, 303.4 78 30,22

a Milli-Q Simplicity 185 ﬁltration system from Millipore (Bedford,

Lormetazepam 335.3 289.3, 177.3 74 30,58

MA, USA). Formic acid for mass spectrometry was obtained from

Medazepam 271.4 91.4, 207.4 70 45,38

Sigma-Aldrich (St. Louis, MI, USA). HPLC-grade methanol and ace-

Midazolam 326.1 291.3, 249.3 102 39,54

tonitrile were purchased from Mallinkrodt Baker (Milan, Italy). Nitrazepam 282.4 180.5, 207.5 96 52,48

Oxazepam 287.4 241.3, 269.3 85 32,24

Diazepam-D5 was purchased by LGC Standard (Milan, Italy).

Pinazepam 309.3 241.3, 269.3 83 48,45

Prazepam 325.4 271.4, 140.4 80 54,34

2.2. Instrumentation Temazepam 301.3 255.4, 193.4 70 30,48

Triazolam 343.4 239.4, 308.4 93 59,37

Zolpidem 308.2 235.4, 263.4 96 51,38

LC–MS/MS analyses were performed with an Agilent 1100-1200

Diazepam-D5 (I.S.) 290.1 198.1 93 47

Series system (Agilent Technologies, Santa Clara, CA, USA) coupled

DP: declustering potential; CE: collision energy.

with a 4000 Q-TRAP (AB SCIEX, Foster City, CA, USA) with an elec-

trospray (ESI) Turbo V Ion Source. The LC instrumentation was

composed of a binary pump, an isocratic pump and an autosam-

the sample, together with 300 ␮l methanol. After two-hour ultra-

◦

pler maintained at 4 C during analysis. The injector needle was

sonication, 5 ␮l were directly injected in the LC–MS/MS system.

externally washed with methanol prior to any injection. A kinetex

The method was applied to 35 authentic samples. 15 samples

C18 column (100 × 2.1 mm i.d., 5 ␮m particle size) (Phenomenex,

were collected from volunteers that denied any use of benzodi-

◦

Castelmaggiore, BO, Italy) was kept at 25 C during the analysis.

azepines and zolpidem within the last two years; 9 were collected

Mobile phase consisted of formic acid 0.1% (v/v – A) and acetoni-

by volunteers declaring, at least, an occasional use of sedatives

trile (B). Chromatographic elution was the following: constant ﬂow

during the last month; 11 nails samples were collected from post-

of 0.25 mL/min; gradient elution: 90%–10% A within 5.0 min, main-

mortem cases where clinical records reported a therapy with

taining of 10% A up to 12.0 min, and re-equilibration up to 20 min.

psychoactive substances. All the volunteers denied any nail infec-

The ESI source settings were: ion-spray voltage: +5000 V, source

tion during at least a 3-month period before sample collection.

◦

temperature: 350 C, nebulization and heating gas (air): 20 psi and

25 psi, respectively. Multiple reaction monitoring was optimized

2.4. Validation

using nitrogen as collision gas (with pressure set at level 5) and a

dwell time of 30 ms. Two transitions for each substance were cho-

International guidelines were used to validate the method [18].

sen for identiﬁcation; the most intense was used for quantiﬁcation

Limits of detection (LOD) and quantiﬁcation (LOQ) were established

purposes (Table 1). To increase instrument sensitivity the MRM

by measuring the signal/noise (S/N) ratio of ﬁve replicates for each

transitions were equally divided into two groups and each sam-

analyte at decreasing concentrations (from 100 to 1 pg/mg). LOD

ple was injected twice in the LC–MS/MS system. Data acquisition

® was ﬁxed at the concentration providing a S/N > 3 while S/N > 10

and elaboration were performed by the Analyst software (version

was chosen as LOQ threshold.

1.5.2, AB SCIEX).

Standards were prepared by dissolution of each analyte in

methanol at the concentration of 1 mg/mL. Working solutions were

2.3. Sample treatment eventually prepared in methanol at 5 different concentrations rang-

ing from LOQ to 1000 ng/mL by independent dilution. QC samples

The excess overhang of ﬁngernails and toenails (depending were prepared by a different operator by independent dilution at

on the availability and the consent) were collected by means of three levels: LOQ, 50 ng/mL and 500 ng/mL (for bromazepam it was

commercial clippers (washed and clean before each collection) evaluated only the QC at 50 and 500 ng/mL). All standard solutions

◦

−

from volunteers after informed consent and from postmortem were stored at 20 C. Ten blank nail samples from 10 volunteers

cases. About 10 mg nails were washed with dichloromethane and were analyzed for possibly interfering peaks during the ﬁrst-step

methanol, taken to dryness under nitrogen stream, cut into small validation of the method. Solution containing 80 drugs among com-

pieces and pulverized using a Precellys Evolution, Bertin (AlfaTech, monly prescribed drugs, drugs of abuse and metabolites, at the

GE, Italy). Then, 10 ␮l Diazepam-D5 (I.S. 100 ng/mL) was added to concentration of 1000 ng/mL was added to samples. Speciﬁcity was Download English Version: https://daneshyari.com/en/article/7627009

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