Simple validated LC–MS/MS method for the determination of atropine and scopolamine in plasma for clinical and forensic toxicological purposes

LC-MS/MS determination of atropine toxicity: Pre-analytical effect of blood collection tube and analytical matrix

Atropine (ATR) intoxication is a recurrent case in emergency departments. The diagnosis is dependent on clinical evaluation and is supported by analytical assessment. The assay is limited by the rapid degradation/metabolism of ATR into TRP as well as the preanalytical factors impairing correct detection and diagnosis. In this study, an HPLC-MS/MS method was optimized for the simultaneous determination of ATR and TRP. The effect of analytical matrix and the impact of blood-collection tube type on the ATR analytical signal were investigated. Separation was achieved using water: 0.01% formic acid acidified methanol (40: 60, v/v) as a mobile phase and Inertsil® C18 column (5 µm; 4.6*150 mm) as a stationary phase. The retention-times were 2.6 and 6.5 min for ATR and TRP, respectively. A chromatographic shift (0.4 min) in ATR peak, but not TRP, was observed in biological samples from neat ones. The best analytical signal was observed when heparinized blood collection tubes were employed. The method was linear, accurate and precise in the ATR toxicity range enabling the detection of ATR intoxication down to a concentration of 0.1 ng/mL by applying a simple sample clean-up procedure. In conclusion, an HPLC-MS/MS method for the simultaneous determination of ATR and TRP is presented. The method highlights the chromatographic shift of ATR peak in biological samples that may induce false-negative detection and poses TRP as an alternative toxicological marker for ATR toxicity. Meanwhile the study recommends heparin tubes for blood-sample collection.

A novel atropine electrochemical sensor based on silver nano particle-coated Spirulina platensis multicellular blue-green microalga

In this work, Atropine as the anticholinergic drug was measured using the environmentally friendly sensor. In this regard, Self-cultivated Spirulina platensis with electroless silver was employed as a powder amplifier in carbon paste electrode modification. Also, 1-Hexyl-3 methylimidazolium Hexafluorophosphate (HMIM PF₆) ion liquid as a conductor binder was used in the suggested electrode construction. Atropine determination was investigated by voltammetry methods. According to voltammograms, the electrochemical behavior of atropine depends on pH, and pH 10.0 was used as the optimal condition. Moreover, the diffusion control process for the electro-oxidation of atropine was verified by the scan rate study, so the diffusion coefficient (D∼ 3.0136×10^-4cm²/sec) value was computed from the chronoamperometry study. Furthermore, responses of the fabricated sensor were linear in the concentration range from 0.01 to 800 μM, and the lowest detection limit of the Atropine determination was obtained at 5 nM. Moreover, the stability, reproducibility, and selectivity factors of the suggested sensor were confirmed by the results. Finally, the recovery percentages for atropine sulfate ampoule (94.48-101.58), and water (98.01-101.3) approve of the applicability of the proposed sensor to Atropine determination in real samples.

Analysis of scopolamine and its related substances by means of high-performance liquid chromatography

The retention behaviour of scopolamine (hyoscine) and its related compounds (norhyoscine, atropine, homatropine, and noratropine) was investigated on the silica-based HPLC stationary phase. The retention of investigated tropane alkaloids was interpreted by using the Soczewiński-Wachtmeister equation. A high correlation between the retention parameter (log k) and lipophilicity (log P) (R = 0.9923) confirms the significant influence of hydrophobic interactions on the retention behaviour of the aforementioned compounds. It was found that by increasing the acetonitrile fraction, a decrease in retention of the more polar epoxide derivatives (scopolamine, norhyoscine) and an increase in retention of the more lipophilic derivatives (atropine, noratropine, homatropine) is obtained. The best separation of the tropane alkaloids was achieved by a simple procedure that involved a mobile phase composed of acetonitrile and 40 mM ammonium acetate/0.05% TEA, pH 6.5; 50:50 v/v. Selected conditions were assumed for the determination of scopolamine hydrochloride in the eye drops (Scopolamini hydrobromidum 0.25%). The method was validated and it was found as selective, sensitive, precise, accurate, and robust for the further qualitative analysis of the scopolamine-related compounds.

Rapid LC-MS/MS method for determination of scopolamine in human plasma

Sensitive, simple, and fast LC-MS/MS method for the determination of Scopolamine in human plasma was developed and validated. Liquid-Liquid extraction technique was used for sample preparation. Cyano bonded phase column (150 × 4.6 mm, 5 µm) was used for the separation with an isocratic elution of ammonium format buffer:methanol (60:40) mobile phase at a flow rate of 1 ml.min-1 over 3.8 min run time. Scopolamine and [13C,2H3]-Scopolamine, as internal standard, were detected and quantified in positive ion mode via MRM at m/z 304/138 and m/z 308/142, respectively. The developed method was validated according to FDA and EMA guidelines. The standard calibration curve was linear over the concentration range of 3.03–315.76 pg.ml-1 (r2 = 0.999). The intra-day and inter-day precision was in the range 1.28–10.46% and accuracy 96.89–110.53%. The recovery of analyte and IS was 78.63% and 76.21%, respectively. Scopolamine in plasma was stable at benchtop (short term) for 18 h, in autosampler tray for 43 h, in instrumentation room for 43 h (post-preparative), after 4 freeze-thaw cycles (−70 °C), and 3 days in the freezer (−70 °C). The validated method was successfully applied to a bioequivalence study of scopolamine transdermal patch of 1 mg for 3 days for 16 healthy Jordanian volunteers.

Determination of Scopolamine Distribution in Plasma and Brain by LC-MS/MS in Rats

Scopolamine, as a tropane alkaloid found in plants such as belladonna and datura, is used clinically as a transdermal patch and is highly neurotoxic. This study aimed to develop a simple, sensitive, and selective LC-MS/MS method for the determination of the content and distribution of scopolamine in rat plasma and brain after drug administration. In our study, sample pretreatment consisted of protein precipitation with acetonitrile followed by nitrogen blow concentration. Gradient elution of scopolamine and internal standard was performed on a ZORBAX Eclipse Plus C18 (2.1 $\ast$ 100 mm, 3.5 μm) column with water containing 0.1% formic acid (v/v) and acetonitrile as a mobile phase. Those samples were quantified in ESI positive ion mode using an API 4000 triple quadrupole mass spectrometer. The results showed that scopolamine was linear in the calibration range of 2–2500 ng/mL, and the selectivity, accuracy, precision, matrix effect, stability, and recovery of the method were within acceptable limits. The method has been validated and has been successfully used for toxicokinetic studies of scopolamine. After intraperitoneal injection, the time to peak toxic concentrations of scopolamine in rats was 0.5 h. The concentrations of scopolamine in the hippocampus and cortex were much higher than those in the striatum, indicating that the likely targets of its neurotoxic damage were the hippocampus and cortex. Overall, this study provides the basis for the neurotoxicity of scopolamine and provides a reference for its toxicokinetic studies.

A validated LC-MS/MS method for the determination of L-hyoscyamine in human plasma: Application in clinical study

Atropine is a racemic mixture of D- and L-hyoscyamine, while L-hyoscyamine is the only effective ingredient. In this study, a new sensitive, stable, and selective LC/MS assay was developed for determination of L-hyoscyamine and applied to the clinical study. The parent-product (m/z) transition pair of L-hyoscyamine was 290.1→124.1. Chromatographic separations were performed using a Chiral MZ column (250 mm×4.6 mm, 5.0 μm) by a stepwise gradient elution mode with n-hexane, isopropanol and diethylamine as mobile phases. L-hyoscyamine in human plasma were extracted using liquid-liquid extraction process. This assay displayed a good linearity over a concentration range of 20.0-400 pg/mL for L-hyoscyamine. The accuracy of the validation assay for L-hyoscyamine ranged from -2.7% to 4.5%, and the precision were within 6.3% coefficient of variation. L-hyoscyamine in human plasma were stable at different storage conditions. The method has been successfully applied to plasma samples obtained from a safety study in human.

Scopolamine analysis in beverages: Bicolorimetric device vs portable nano liquid chromatography

Scopolamine (SCP) is often involved in sexual assaults and robberies, particularly in recreational environments. Therefore, analytical tools are required for the analysis of this compound amenable for the field. In this work, a sensor for SCP is described based on the entrapment of KMnO₄ into polydimethylsiloxane (PDMS). The possibility of using KMnO₄ in combination with the reagent 1,2-naphtoquinone-4-sulfonate (NQS) giving a double sensor acting as a bicolorimetric device is also demonstrated. In contact with the sample, the PDMS composite delivers MnO₄^-, which reacts rapidly with SCP under basic conditions causing a change of the color of the solution that can be related to the concentration of drug using both, absorbances and color coordinates, while the NQS part of the sensor remains unchanged. After an exposure time to the sensors of 10 min, satisfactory linearity was obtained for concentrations of SCP up to 865 μg/mL, being the limit of detection (LOD) 108 μg/mL. A method using a portable nano liquid chromatograph with detection at 255 nm has been also developed; in this case the LOD was 100 μg/mL and the working linear interval was 250-2000 μg/mL. The precision, expressed as relative standard deviation (RDS), was ≤8% for both methods. Different beverages (cola, cola-whisky, tonic water-vodka, red wine and green tea) were assayed. The potential of the two proposed approaches for on-site tests is discussed.

Thermal (In)stability of Atropine and Scopolamine in the GC-MS Inlet

The intoxication due to unintentional or intentional ingestion of plant material containing tropane alkaloids is quite frequent. GC-MS method is still widely used for the identification of these toxicologically important substances in human specimen. During general unknown analysis, high temperature of inlet, at least 270 °C, is commonly used for less volatile substances. Unfortunately, both tropanes are thermally unstable and could be overlooked due to their degradation. The temperature-related degradation of tropanes atropine and scopolamine was systematically studied in the inlet of a GC-MS instrument in the range 110–250 °C by increments of 20 °C, additionally also at 275 °C, and in different solvents. At inlet temperatures not higher than 250 °C, the degradation products were formed by elimination of water and cleavage of atropine’s ester bond. At higher temperatures, elimination of formaldehyde became predominant. These phenomena were less pronounced when ethyl acetate was used instead of methanol, while n-hexane proved unsuitable for several reasons. At an inlet temperature of 275 °C, tropanes were barely detectable. During systematic toxicological analysis, any tropanes’ degradation products should indicate the possible presence of atropine and/or scopolamine in the sample. It is not necessary to prepare thermally stable derivatives for confirmation. Instead, the inlet temperature can be decreased to 250 °C, which diminishes their degradation to a level where their detection and identification are possible. This was demonstrated in several case studies.

Indirect competitive enzyme-linked immunosorbent assay based on a broad-spectrum monoclonal antibody for tropane alkaloids detection in pig urine, pork and cereal flours

In this study, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on a broad-spectrum monoclonal antibody for tropane alkaloids (TAs) was established for the rapid screening of atropine, scopolamine, homatropine, apoatropine, anisodamine, anisodine and L-hyoscyamine residues in pig urine, pork and cereal flour samples through a simple sample preparation procedure. The half inhibitory concentrations of atropine, homatropine, L-hyoscyamine, apoatropine, scopolamine, anisodamine and anisodine were 0.05, 0.07, 0.14, 0.14, 0.24, 5.30 and 10.15 ng mL-1, respectivelyThe detection and quantitative limits of this method for TAs in samples were 0.18-73.18 and 0.44-74.77 μg kg-1. The spiked recoveries ranged from 69.88% to 147.93%, and the coefficient of variations were less than 14%. Good correlation (R2 = 0.9929) between the results of the ic-ELISA and the high performance liquid chromatography-tandem mass spectrometry support the reliability of the developed ic-ELISA method.

Stability of Ophthalmic Atropine Solutions for Child Myopia Control

Myopia is an ophthalmic condition affecting more than 1/5th of the world population, especially children. Low-dose atropine eyedrops have been shown to limit myopia evolution during treatment. However, there are currently no commercial industrial forms available and there is little data published concerning the stability of medications prepared by compounding pharmacies. The objective of this study was to evaluate the stability of two 0.1 mg/mL atropine formulations (with and without antimicrobiobial preservatives) for 6 months in two different low-density polyethylene (LDPE) multidose eyedroppers. Analyses used were the following: visual inspection, turbidity, chromaticity measurements, osmolality and pH measurements, atropine quantification by a stability-indicating liquid chromatography method, breakdown product research, and sterility assay. In an in-use study, atropine quantification was also performed on the drops emitted from the multidose eyedroppers. All tested parameters remained stable during the 6 months period, with atropine concentrations above 94.7% of initial concentration. A breakdown product (tropic acid) did increase slowly over time but remained well below usually admitted concentrations. Atropine concentrations remained stable during the in-use study. Both formulations of 0.1 mg/mL of atropine (with and without antimicrobial preservative) were proved to be physicochemically stable for 6 months at 25 °C when stored in LDPE bottles, with an identical microbial shelf-life.

A randomised, double-blind, active placebo-controlled, parallel groups, dose-response study of scopolamine hydrobromide (4-6 μg/kg) in patients with major depressive disorder

Background

Depressive disorders are a leading cause of disability, but current behavioural and pharmacological therapies have a slow onset of response, typically taking several weeks before achieving efficacy. Prior studies using triplicate intravenous scopolamine infusions have been shown to reduce depressive symptomologies within days compared to saline placebo infusions. However, several parameters of scopolamine’s potential antidepressant effect remain unknown, such as its dose–response profile and its washout period. There is also the question as to whether the previously reported antidepressant responses were confounded by unblinding effects due to the lack of an active placebo control. Glycopyrronium bromide was selected as placebo for this trial given it has similar antimuscarinic properties to scopolamine hydrobromide but an inability to cross the blood–brain barrier, thereby hypothetically mimicking only the peripheral effects of scopolamine.

Methods/Design

A parallel group trial of single intravenous scopolamine infusions at three doses (4, 5, and 6 μg/kg) along with one glycopyrronium bromide 4 μg/kg group will be administered to 40 participants with major depressive disorder in a 1:1:1:2 ratio, respectively. The primary outcome measure will be the Montgomery–Åsberg Depression Rating Scale (MADRS) administered at baseline, 4 hours, 1 day, 3 days, 1 week, 2 weeks, 4 weeks, and 6 weeks post-infusion to determine antidepressant efficacy. As a secondary measure, the Quick Inventory of Depressive Symptomatology will be administered alongside the MADRS to further track potential antidepressant responses. Other secondary measures include electroencephalography, blood samples, and Bowdle visual acuity scales recorded at baseline, 5, 10, 15, 20, 30, 60, 120, and 240 min post-infusion to determine the pharmacokinetic-pharmacodynamic profile of scopolamine in depressed participants.

Discussion

This trial contributes to the literature surrounding the efficacy of scopolamine as an antidepressant. Determining the dose–response profile and washout period of scopolamine’s antidepressant effect will also provide important information for designing and conducting crossover trials. The use of an active placebo is important to reduce potentially confounding expectancy effects.

Trial registration

The trial was registered in the Australian New Zealand Clinical Trials Registry (registration number ACTRN12619000569101). Registered on 11 April 2019.

Physical, chemical, and microbiological stability study of diluted atropine eye drops

Background

Atropine eye drops are indicated for juvenile myopia progression, cycloplegia, amblyopia, and strabismus. According to the package insert, 10 mg/mL atropine eye drops must be diluted for pediatric patients to prevent systemic adverse effects. Compounding units in hospital pharmaceutical departments or community pharmacies are compelled to prepare this essential medication; however, validated atropine stability data is limited and the shelf life after preparation is extremely short. As it is a long-term treatment, a longer shelf life is necessary to improve patient care. This study aimed to demonstrate the physical, chemical, and microbiological stability of diluted atropine eye drops over a period of six months.

Methods

Preparation consists of dilution of a 10 mg/mL atropine solution (Nitten Atropine Ophthalmic Solution 1%; Nitten Pharmaceutical Co., Ltd.) in 0.9% NaCl to concentrations of 0.1, 1.0, 2.5, and 5.0 mg/mL, followed by a sterilizing filtration procedure and then an aseptic filling process of 5 mL in 5 mL polyethylene eyedropper bottles. The entire process is carried out in an overpressure isolator. All concentration products were kept for six months at 25 °C or 5 °C. Visual inspection was conducted and pH, osmolality, and atropine concentration were measured at day 0, day 14, day 28, and every month until six months. Atropine concentration was measured using liquid chromatography tandem mass spectrometry. The sterility was monitored using a method adapted from the Japanese Pharmacopoeia sterility assay.

Results

Atropine remained within ±5% of the target value in the six batches. Osmolality (285 mOsm/kg) as well as pH (5.88) were kept constant. No variations in solution characteristics (crystallization, discoloration) were noted. Sterility was maintained.

Conclusions

This study validated the physical, chemical, and microbiological stability of 0.1, 1.0, 2.5, and 5.0 mg/mL atropine sulfate eye drops conserved inside polyethylene eyedroppers for six months at 25 °C or 5 °C.

Selective recognition of atropine in biological fluids and leaves of Datura stramonium employing a carbon nanotube–chitosan film based biosensor

This paper demonstrates a selective, expeditious and facile electrochemical approach for the ultrasensitive detection of atropine in complex matrices.

Bithiophenic MALDI matrices as valuable leads for the selective detection of alkaloids

Alkaloids represent a group of biologically most interesting compounds commonly used in modern medicines but also known for exhibiting severe toxic effects. Therefore, the detection of alkaloids is an important issue in quality control of plants, dietary supplements, and herbal pharmaceutical and mostly facilitated by methods such as GC or LC-MS. However, benefitting from the development of selective matrices as well as requiring very little sample preparation, MALDI-MS may also provide a valuable supplement to these standard analytical methods. With this in mind, the present study highlights recent advances in the development of bithiophenic matrix molecules designed for the selective detection of alkaloids. Overall four new bithiophenic matrix molecules (BMs) were tested on different analytes belonging to various chemical families such as alkaloids, curcuminoids, benzopyrones, flavonoids, steroids, and peptides (I). All BMs were further compared to the commercial matrices α-cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB) in terms of their signal response as well as their matrix noise formation (II). Based on these results the most promising candidate, 3-(5'-pentafluorophenylmethylsulfanyl-[2,2']bithiophenyl-5-ylsulfanyl)propionitrile (PFPT3P), was tested on highly complex samples such as the crude extracts of Colchicum autumnale, RYTMOPASC ® solution (a herbal pharmaceutical containing sparteine and rubijervine), as well as strychnine-spiked human plasma (III). For the latter, an evaluation of the limit of detection was performed. Eventually, a simplified protocol for the direct MALDI detection of major alkaloids from pulverized plant material of Atropa belladonna and Senecio vulgaris is presented (IV). Graphical abstract Selective MALDI MATRICES for Alkaloid Detection.

Active fragments-guided drug discovery and design of selective tropane alkaloids using ultra-high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry coupled with virtual calculation and biological evaluation

Tropane alkaloids (TAs), rich in the plant of Physochlaina infundibularis Kuang, which is named Huashanshen (HSS) in China, showed good effects on types of spasms. However, no data were collected to explore the relationship between the specificity for muscarinic receptor subtypes and the structures of these TAs. To address this issue, an extracted ion chromatogram (EIC) strategy using ultra-high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-Q/TOF-MS) based on the fragmentation behavior of the TA standards was established to rapidly capture the varied TAs from HSS. Based on the provided structural information of diagnostic ions or neutral loss, 29 TAs were efficiently profiled, especially some trace ingredients. In additional, via virtual validation combined with molecular dynamic simulation, approximately a dozen alkaloids were found with high selectivity for muscarinic receptors. In additional, N-acetyl convolicine was chosen for selectivity evaluation of M₂ or M₃ receptors through the use of a dual-luciferase reporter assay system at the cellular level and an ACh-induced constricted strip test in vitro. After summarizing the active fragments and the structure-activity relationship (SAR) information, a new modified TA that takes advantage of both the high affinity and high selectivity for M₃ receptors was proposed and evaluated successfully. This study provided an effective approach for the discovery and design of natural products based on highly selective drugs by UPLC-Q/TOF-MS coupled with virtual calculation and biological evaluation. Graphical Abstract Active fragments-guided strategy for selective inhibitors from HSS.

Assessment of drug content uniformity of atropine sulfate triturate by liquid chromatography-tandem mass spectrometry, X-ray powder diffraction, and Raman chemical imaging

Background

Atropine sulfate is an anticholinergic agent for treatment of hypertrophic pyloric stenosis and is orally administrated as a triturate with lactose hydrate. Because of the low safety margin of atropine sulfate, triturate uniformity is a key safety factor. In this study, we assessed the uniformity of atropine sulfate in 1000-fold triturates prepared by wet mixing and dry mixing methods and discussed the cause of the difference in uniformity between two preparation methods.

Methods

A 1000-fold triturate of atropine sulfate with lactose hydrate was prepared by two different methods: wet mixing and dry mixing. The wet mixing was performed according to Kurashiki Central Hospital protocol and the dry mixing was a simple physical mixing by a rocking mixer. The uniformity of atropine sulfate content in aliquots of a 1000-fold triturate with lactate hydrate was assessed by liquid chromatography–tandem mass spectrometry (LC–MS/MS) quantification. Solid-state analyses of the triturates by Raman chemical imaging and X-ray powder diffraction (XRPD) were performed to investigate the difference in uniformity.

Results

The LC–MS/MS quantification showed that the uniformity of atropine sulfate in the 1000-fold triturate was excellent for wet mixing but was significantly variable for dry mixing. On the basis of the Raman chemical imaging and XRPD analyses, it was indicated that an amorphous thin film of atropine sulfate coated the surfaces of the lactose hydrate particles during wet mixing and contributed to the uniformity of the triturate. In contrast, clusters of the crystalline atropine sulfate were found in the dry mixing samples.

Conclusion

The results showed that better atropine sulfate triturate uniformity was achieved using the wet mixing method rather than the dry method and the cause of the uniformity difference between two mixing methods was indicated by the multilateral assessment.

Separation and detection of tropane alkaloids in Anisodus tanguticus by capillary electrophoresis-electrochemiluminescence

Anisodine and anisodamine in different parts of Anisodus tanguticus are separated and determined using a chemically modified Pt electrode.

Simultaneous determination of atropine, scopolamine, and anisodamine from Hyoscyamus niger L. in rat plasma by high-performance liquid chromatography with tandem mass spectrometry and its application to a pharmacokinetics study

In order to investigate the pharmacokinetics of tropane alkaloids in Hyoscyamus niger L., a sensitive and specific high-performance liquid chromatography with tandem mass spectrometry method for the simultaneous determination of atropine, scopolamine, and anisodamine in rat plasma is developed and fully validated, using homatropine as an internal standard. The separation of the four compounds was carried out on a BDS Hypersil C18 column using a mobile phase consisting of acetonitrile and water (containing 10 mmol ammonium acetate). Calibration curves were linear from 0.2 to 40 ng/mL for atropine, scopolamine, and from 0.08 to 20 ng/mL for anisodamine. The precision of three analytes was <5.89% and the accuracy was between -1.04 to 2.94%. This method is successfully applied to rat pharmacokinetics analysis of the three tropane alkaloids after oral administration of H. niger extract. The maximum concentration of these three tropane alkaloids was reached within 15 min, and the maximum concentrations were 31.36 ± 7.35 ng/mL for atropine, 49.94 ± 2.67 ng/mL for scopolamine, and 2.83 ± 1.49 ng/mL for anisodamine. The pharmacokinetic parameters revealed areas under the curve of 22.76 ± 5.80, 16.80 ± 3.08, and 4.31 ± 1.21 ng/h mL and mean residence times of 2.08 ± 0.55, 1.19 ± 0.45, and 3.28 ± 0.78 h for atropine, scopolamine, and anisodamine, respectively.