Simultaneous determination of succinylcholine and its metabolite in animal-derived foods by solid-phase extraction combined with ultra-performance liquid chromatography/mass spectrometry.

RATIONALE: Succinylcholine has been increasingly used in the theft of animals. Because of the presence of residual levels of succinylcholine in poisoned animals, it is harmful for people to eat foods derived from these animals. Therefore, a method should be immediately established to determine succinylcholine and its metabolite in animal-derived foods. METHODS: A fast, highly sensitive method, combining solid-phase extraction (SPE) with ultra-performance liquid chromatography/electrospray ionization tandem mass spectrometry (UPLC/ESI-MS/MS), was developed for the determination of succinylcholine and its metabolite in animal-derived foods. The sample was initially extracted with heptafluorobutyric acid and then further cleaned up using an SPE cartridge. Succinylcholine and its metabolite were separated using acetonitrile: 0.1% formic acid in 5 mmol L-1 ammonium acetate as the mobile phase. Quantitative results were based on positive ion ESI multiple reaction monitoring mode. RESULTS: The results show good linearity over a wide range with correlation coefficients of determination of more than 0.998. Both the limits of detection of succinylcholine and succinylmonocholine are 0.2 µg kg-1 . The intra- and inter-day accuracies of the method are in the range 91.4%-104.6%, and the intra- and inter-day precisions are in the range 2.5%-6.6%. CONCLUSIONS: This method can be used for the determination of succinylcholine as an illicit drug in animal-derived foods. It was successfully applied to the identification and quantification of succinylcholine and succinylmonocholine in animal-derived foods collected from a local farmers market in Jilin Province of China.

Multi-charged bis(p-calixarene)/pillararene functionalized gold nanoparticles for ultra-sensitive sensing of butyrylcholinesterase.

A series of supramolecular assemblies based on multi-charged calixarene (SC4A), bis(p-calixarene) (BSC4A) and pillararene (CP5A) modified gold nanoparticles (AuNP) was constructed to realize colorimetric sensing of both succinylcholine (SuCh) and butyrylcholinesterase (BChE). With the high binding affinity of BSC4A and CP5A towards SuCh, BSC4A-AuNPs and CP5A-AuNPs could assemble with micromolar level SuCh as SuCh-BSC4A/CP5A-AuNPs. More interestingly, the enzymatic hydrolysis of SuCh by BChE could lead to the disassembly of SuCh-BSC4A/CP5A-AuNPs and provide a sensitive time-dependent color change from blue to red which could be observed by the naked eye and used to monitor BChE activity. As BChE activity is an important biomarker for diseases and poor health conditions, this novel supramolecular tandem colorimetric sensing strategy may have potential use for early diagnosis of diseases.

Spectroscopic determination of succinylcholine in dosage forms using eosin Y.

Two simple and sensitive analytical assay methods using spectrophotometry and spectrofluorimetry techniques were developed for the estimation of succinylcholine chloride (SUC) in pharmaceutical preparations. The suggested methods are based on the formation of an ion pair complex formed between the drug and eosin Y spectrophotometrically (Method I), or the suppressive effect of succinylcholine on the native fluorescence property of eosin Y (Method II). The spectrophotometric method (Method I) involves measuring the absorbance of the complex between succinylcholine and eosin Y at 550 nm in Britton Robinson buffer of pH 3. However, the spectrofluorimetric method (Method II) involves measuring the quenching effect of the studied drug on the native fluorescence property of eosin Y at the same pH at 550 nm after excitation at 480 nm. The absorbance versus concentration of the drug is rectilinear over the range of 0.5 to 15 µg/ml. The formation constant was 3.5 × 104 and the Gibb's free energy change was -2.5 × 104  J/mol. In Method II, the relative fluorescence intensity was directly proportional to SUC concentration over the range of 0.05 to 1 µg/ml. The proposed methods allowed a successful application to the estimation of succinylcholine ampoules. An explanation of the reaction pathway was postulated.

Three homicides with darts tainted with succinylcholine: autopsy and toxicology.

In emergency departments, intoxication with the muscle relaxant succinylcholine (SUX) often leads to a potentially lethal respiratory paralysis or other deleterious side effects. However, homicide cases with SUX poisoning are very rare because the toxic or lethal concentration ranges of SUX have not yet been determined. We described three uncommon homicide cases due to acute poisoning by darts contaminated with SUX. All the victims died quickly (less than 30 min) after being shot by an especially designed dart gun. Succinylmonocholine (SMC), a metabolite of SUX, was used as a marker to detect the latter. HPLC-MS/MS analysis demonstrated the presence of SUX in the droplet residues of the darts and SMC in the blood and urine in all cases. SMC concentrations of 0.45, 14.0, and 17.9 ng/ml were detected in the victims' blood and 259.0 ng/ml in the urine from the third case. The main pathological changes consisted of hemorrhage of the injured soft tissues, visceral congestion, severe pulmonary edema, and multifocal petechial hemorrhage of the heart and lungs. Taken together, the findings supported a diagnosis of fatal SUX poisoning. Futhermore, our study provided a reference for the lethal concentrations of SUX poisoning.

Impact of temperature exposure on stability of drugs in a real-world out-of-hospital setting.

STUDY OBJECTIVE: The aim of this study is to determine the content of 5 important emergency medical services (EMS) drugs after being stored at the recommended refrigerated temperature, room temperature, or in an emergency physician transport vehicle operating under real-world working conditions. METHODS: Adrenaline hydrochloride, cisatracurium besylate, lorazepam, methylergonovine maleate, and succinylcholine chloride were stored for 1 year under the 3 conditions. For each storage condition, samples of the drugs were taken after 1, 2, 3, and 4 weeks and after 2, 4, 6, 8, 10, and 12 months. For adrenaline hydrochloride, however, the samples were taken after 1, 2, 4, 6, 8, 10, and 12 months. The samples were analyzed with a validated high-performance liquid chromatography assay. A drug was considered stable if its content was above 90%. RESULTS: Adrenaline hydrochloride and methylergonovine maleate remained stable for 1 year at room temperature and in the emergency physician transport vehicle. At room temperature and in the emergency physician transport vehicle, lorazepam became unstable within 4 weeks. Succinylcholine chloride was stable for 2 months at room temperature and for 1 month in the emergency physician transport vehicle. Cisatracurium besylate became unstable within 4 months at room temperature. However, it remained stable for 4 months in the emergency physician transport vehicle. CONCLUSION: When stored at room temperature or in the emergency physician transport vehicle, lorazepam became unstable within weeks, whereas succinylcholine chloride and cisatracurium besylate became unstable within months. Adrenaline hydrochloride and methylergonovine maleate remained stable for several months, even under room temperature and emergency physician transport vehicle conditions. Thus, real-world EMS working conditions pose challenges for maintaining optimal efficacy of these important EMS drugs.

[Progress on suxamethonium chloride analysis].

Abstract: Suxamethonium chloride is a depolarizing muscle relaxant used in general anesthesia. In overdose, it causes adverse reactions such as bradycardia, arrhythmia, cardiac arrest, and death. The article reviews the progress on testing methods of suxamethonium chloride such as infrared spectroscopy, chemical color reaction, chemical titration, enzyme electrode, chromatography and mass spectrometry.

Determination of suxamethonium in a pharmaceutical formulation by capillary electrophoresis with contactless conductivity detection (CE-C(4)D).

A simple method based on capillary electrophoresis with a capacitively coupled contactless conductivity detector (CE-C(4)D) was developed for the determination of suxamethonium (SUX) in a pharmaceutical formulation. A hydro-organic mixture, consisting of 100mM Tris-acetate buffer at pH 4.2 and acetonitrile (90:10, v/v), was selected as background electrolyte (BGE). The applied voltage was 30kV, and the sample injection was performed in the hydrodynamic mode. All analyses were carried out in a fused silica capillary with an internal diameter of 50 microm and a total length of 64.5cm. Under these conditions, a complete separation between SUX, sodium ions and the main degradation products (choline) was achieved in less than 4min. The presence of acetonitrile in the BGE allowed a reduction of SUX adsorption on the capillary wall. The CE-C(4)D method was validated, and trueness values between 98.8% and 101.1% were obtained with repeatability and intermediate precision values of 0.7-1.3% and 1.2-1.6%, respectively. Therefore, this method was found appropriate for controlling pharmaceutical formulations containing suxamethonium and degradation products.

Identification and analysis of drugs in the solid state by 13C CPMAS NMR: suxamethonium chloride and hydrocortisonum (Corhydron).

Cross-polarization (CP) magic angle spinning (MAS) 13C NMR spectroscopy has become a routine tool in pharmacy, employed to identify and characterize drugs in the solid phase. 13C CPMAS NMR spectra were recorded for solid hydrocortisone 21-hemisuccinate and suxamethonium chloride. White crystalline substances, such as these two drugs, can be easily distinguished; and solid-state 13NMR spectra of remarkably good quality are obtained in less than half an hour. 13C CPMAS chemical shifts for solid suxamethonium chloride and hydrocortisone sodium hemisuccinate are given, as well as cross-polarization kinetic parameters for suxamethonium chloride.

Stability of suxamethonium in pharmaceutical solution for injection by validated stability-indicating chromatographic method.

STUDY OBJECTIVE: To assess the stability of pharmaceutical suxamethonium (succinylcholine) solution for injection by validated stability-indicating chromatographic method in vials stored at room temperature. METHODS: The chromatographic assay was achieved by using a detector wavelength set at 218 nm, a C18 column, and an isocratic mobile phase (100% of water) at a flow rate of 0.6 mL/min for 5 minutes. The method was validated according to the International Conference on Harmonization guidelines with respect to the stability-indicating capacity of the method including linearity, limits of detection and quantitation, precision, accuracy, system suitability, robustness, and forced degradations. RESULTS: Linearity was achieved in the concentration range of 5 to 40 mg/mL with a correlation coefficient higher than 0.999. The limits of detection and quantification were 0.8 and 0.9 mg/mL, respectively. The percentage relative standard deviation for intraday (1.3-1.7) and interday (0.1-2.0) precision was found to be less than 2.1%. Accuracy was assessed by the recovery test of suxamethonium from solution for injection (99.5%-101.2%). CONCLUSION: Storage of suxamethonium solution for injection vials at ambient temperature (22°C-26°C) for 17 days demonstrated that at least 95% of original suxamethonium concentration remained stable.

Identification of Drugs in Parenteral Pharmaceutical Preparations from a Quality Assurance and a Diversion Program by Direct Analysis in Real-Time AccuTOFTM-Mass Spectrometry (DART-MS).

In healthcare settings drug diversion and impairment of physicians are major concerns requiring a rapid and efficient method for surveillance and detection. A Direct Analysis in Real Time ion source coupled to a JEOL AccuTOFTM time-of-flight mass spectrometer (DART-MS) method was developed to screen parenteral pharmaceutical formulations for potential drug diversion. Parenteral pharmaceutical formulations are also known as injectable formulations and are used with intravenous, subcutaneous, intramuscular and intra-articular administration. A library was created using the mass spectra data collected by a DART-MS operated in switching mode at 20, 60 and 90 V settings. This library contained 17 commonly encountered drugs in parenteral pharmaceutical formulations that included the surgical analgesic: fentanyl, hydromorphone and morphine; anesthetic: baclofen, bupivacaine, ketamine, midazolam, ropivacaine and succinylcholine; and a mixture of other drug classes: caffeine, clonidine, dexamethasone, ephedrine, heparin, methadone, oxytocin and phenylephrine. Randomly selected 200 de-identified parenteral pharmaceutical formulations containing one or more drugs were submitted for analysis to the FIRM Toxicology Laboratory at Virginia Commonwealth University Health and were screened using the DART-MS. The drug contents of the de-identified formulations were previously confirmed by a published high performance liquid chromatography (HPLC) method. The drugs in the formulations were rapidly and successfully identified using the generated library. The DART-MS and HPLC results were in complete agreement for all 200 parenteral pharmaceutical formulations.

Determination of choline in pharmaceutical formulations by reversed-phase high-performance liquid chromatography and postcolumn suppression conductivity detection.

Choline is a primary degradation product of succinylcholine chloride. Determination of low concentration choline in succinylcholine chloride bulk drug and formulation is a challenge, due to the lack of sensitive detection methods. A reversed-phase separation method with postcolumn suppression conductivity detection is described for the determination of choline. Hexanesulfonic acid is employed as an ion-pair reagent in the mobile phase, which allows the accomplishment of both reversed-phase separation and a sensitive conductivity detection. Detection sensitivity is significantly enhanced by passing the mobile phase through a postcolumn cation suppressor, where hexanesulfonic acid is removed and the background conductance is reduced. This method is simple and sensitive. No sample derivatization procedure is required. The detection limit for choline is about 10 pmol.

Chemiluminometric determination of choline-related substances in pharmaceutical preparations by dot-blot.

A simple and reliable method of assaying succinylcholine chloride, oxtriphylline (choline theophyllinate) and acetycholine chloride in pharmaceutical preparations, based on conversion to choline, is provided by combination of chemiluminometry of choline and dot-blot technique. Recoveries of 102 and 97% for choline chloride in Quelicin injection and Choledyl 200 tablets matrices, respectively, and of 99% for acetylcholine chloride in Miochol solution matrix could be achieved using simple choline chloride standards in phosphate buffer pH 8.6. Accordingly, matrix-matched standards were found redundant. Favourable results obtained in preparations-matched media including limits of detection of 37-39 pmol microliters-1 of choline chloride, together with accuracies of 0-2% and RSDs ranging from 4 to 7% are the further evidence of the suitability of the method.

Determination of succinyldicholine in different tissue samples from guinea pigs after injection of a single intravenous dose.

The distribution and postmortem stability of succinyldicholine in different tissues and urine from guinea-pigs has been studied. Succinyldicholine was extracted from tissue homogenates and urine samples from animals sacrificed by intravenous injections of succinyldicholine hydrochloride (40 mg/kg). The bis-quaternary ammonium compound was demethylated and the tertiary amine was analysed by gas chromatography/mass spectrometry. The concentrations found in muscle, kidney and urine were often low; in muscle below 5 pmol/g, in kidney from 5 to 1500 pmol/g and in urine from 5 to 650 pmol/ml. The eye proved to be the best tissue sample, with a rather high and constant concentration (280 +/- 36 pmol/g) of succinyldicholine. The postmortem stability was studied by storing the bodies at 4 degrees C. After 6 days storage the drug concentrations in the eyes started to decline. Four weeks after death it was not possible to detect any succinyldicholine in this tissue.

Determination of succinylcholine in tissues by TLC, GC/NPD, and GC/MS.

Succinylcholine, a bis-quaternary ammonium compound, is considered an elusive analyte due to rapid hydrolysis by pseudocholinesterase in plasma. However, tissue acetylcholinesterase is relatively inactive toward this substrate. Hence, analysis of tissues of succinylcholine-treated animals may reveal the presence of unchanged drug. This report describes three chromatographic techniques (TLC, GC/NPD, and GC/MS) which may be applied to the analysis of this substance in human tissues. Validation of the techniques was accomplished using tissues from rats treated with succinylcholine.

The detection and identification of quaternary nitrogen muscle relaxants in biological fluids and tissues by ion-trap LC-ESI-MS.

Quaternary nitrogen muscle relaxants pancuronium, rocuronium, vecuronium, gallamine, suxamethonium, mivacurium, and atracurium and its metabolites were extracted from whole blood and other biological fluids and tissues by using a solid-phase extraction procedure. The extracts were examined by using high-performance liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS). The drugs were separated on a ODS column in a gradient of ammonium acetate buffer (pH 5.0) and acetonitrile. Full-scan mass spectra of the compounds showed molecular ions, and MS-MS spectra showed fragments typical of the particular compounds. LC-ESI-MS allowed an unequivocal differentiation of all muscle relaxants involved. The method was applied in a case of rocuronium and suxamethonium administration in a Caesarian section and in a case of intoxication by pancuronium injection. In both cases, the administered drugs could be detected and identified in the supplied samples.

The influence of storage temperature and chemical preservation on the stability of succinylcholine in canine tissue.

Succinylcholine (SCh) has been detected six months postmortem in liver, kidney, and injection site muscle of rats given 10 to 200 mg/kg by intramuscular injection. SCh stability was studied in canine tissue to evaluate three storage temperatures and two chemical preservatives at three time periods after injection. Nine mongrel dogs weighing 17.2 to 28 kg were divided equally into three groups and administered either 0.5, 1.0, or 5.0 mg SCh/kg intravenously into the cephalic vein. Liver, kidney, and gastrocnemius muscle were removed 90 min post-injection and divided into twelve portions. Each portion was treated with embalming fluid, physostigmine, the combination (50/50), or nothing. Chemically treated tissues and nontreated tissues were then stored at either 27, 5, or -20 degrees C for a period of up to forty days. Tissue portions were analyzed using ion-pair extraction, chemical demethylation, and gas chromatography with nitrogen phosphorous detection. Stability of SCh was greatest for samples stored at -20 degrees C and preserved with the combination of embalming fluid plus physostigmine. Kidney concentrations of SCh were significantly higher than those in liver or muscle at all doses. SCh was detected 24 h post-injection in all cases. By 40 days, only trace amounts of SCh, if any, could be detected in samples stored at room temperature with no chemical preservatives.

[Analysis and stability of suxamethonium chloride. 1. Detection and quantitative determination of the intact active agent with its degradation products]. / Zur Analytik und Stabilität von Suxamethoniumchlorid. Teil 1: nachweis und quantitative bestimmung des intakten wirkstoffs neben zersetzungsprodukten.

The authors developed methods permitting to follow the course of degradation in injectable solutions of suxamethonium chloride. The qualitative detection of the active agent in the presence of degradation products is achieved by thin-layer chromatography and spraying with Dragendorff's reagent and bromocresol green indicator solution. The same separation technique may be used for determining with sufficient accuracy the intact agent in the eluate, using the method of Okken and Haas. Furthermore, a modified Draganic procedure (which is based on the spectrophotometric determination of the hydrolysis products succinic acid monocholine chloride and succinic acid as a Cu-benzidine complex) is suited for estimating the degree of degradation. No previous separation is required because the molar extinction efficients of the monoester and of the acid are in agreement, so that the degree of degradation can be calculated from the sum of the molar concentrations. The value of these methods is demonstrated by analyzing experimental mixtures of the intact agent and degradation products.

[The stability and quality control of ditilin preparations (a review of the literature)]. / Stabil'nost' i kontrol' kachestva preparatov ditilina (obzor literatury).

In aqueous solutions dithylinum decomposes with formation iodine, choline, succinic acid and its monoether. The rate of decomposition depends on the conditions of storage, and also upon the concentration and ion force of solution, existence of ion metals and some other factors. The article proposes methods for identification and quantitative analysis of dithylinum and the products of its hydrolysis. The requirements imposed for storage or transportation of dithylinum solutions: not frost and temperature level not higher than 5 degrees C.

Applicability of succinylmonocholine as a marker for succinylcholine administration--comparative analysis of samples from a fatal succinylcholine-intoxication versus postmortem control specimens.

Doubts concerning the applicability of succinylmonocholine (SMC) as a succinylcholine (SUX) marker have been issued. A comparative analysis of previously discussed tissues, i.e. brain, liver and kidney, was conducted to further elucidate this question by searching for diagnostically useful differences in analyte content in samples of SUX- versus non-SUX-associated fatalities. Furthermore, possible advantages of vitreous humor as a novel and promising target matrix for SUX analytics were assessed. Sample material of SUX-negative controls as well as the fatal SUX-intoxication was derived from frozen archive material and current autopsies. Samples were analyzed according to a modified protocol of a previously published and validated method employing ion-pairing solid-phase extraction and subsequent HPLC-MS/MS analysis. Standard addition was employed for quantification as well as an estimation of the analytical limits of the method. In all tested matrices, the method was proven to be sufficiently sensitive for the intended application. No indication of native SMC was found in controls of fresh tissues, nor in fresh or frozen vitreous humor. However, most of the samples were found to be positive for a previously reported interference with SMC's main ion transition, thereby falsely suggesting an SMC content of up to 139 ng/g, 126 ng/g, 165 ng/g and 93 ng/ml in brain, liver, kidney and vitreous humor, respectively. Contrasting the results for fresh sample material, SMC was detectable in some of the initially non-putrefied liver samples after long-term storage, as well as in massively decomposed SUX-negative control bodies. In this context, a microbial origin of the analyte may be assumed. All tissues as well as the vitreous humor of the fatal SUX-intoxication were negative for SUX and SMC. Just like serum, tissue and vitreous humor samples therefore do not allow a reliable diagnosis of a SUX-intoxication: in tissues this is due to the pronounced instability of both target analytes in these esterase-containing matrices, for vitreous humor an additional reason could be their insufficient incorporation into this medium.