A rapid and simple procedure for the determination of ephedrine alkaloids in dietary supplements by gas chromatography–mass spectrometry

Determination of pholcodine alone or in combination with ephedrine in human plasma using fluorescence spectroscopy

In this study, sensitive, facile, and cost-effective spectrofluorimetric approaches were developed for the determination of pholcodine and ephedrine. Method I is a novel spectrofluorimetric method depending on measuring the native fluorescence of pholcodine at 337 nm after excitation at 284 nm over a concentration range of 0.01-2.4 μg/mL. The method sensitivity reached quantitation and detection limits down to 10.0 and 5.0 ng/mL, respectively. Method II relied on the simultaneous estimation of pholcodine and ephedrine using synchronous fluorimetry for the first time. The cited drugs were measured concurrently at 286 and 304 nm for pholcodine and ephedrine, respectively at Δλ of 40 nm without interference. Excellent linear relationship between concentration and response was obtained over the ranges of 0.05-6.0 μg/mL and 0.02-1.0 μg/mL for pholcodine and ephedrine, respectively. The method showed distinct sensitivity and exhibited quantitation limits of 20.0 and 10.0 ng/mL and detection limits of 10.0 and 5.0 ng/mL, respectively. The method was successfully applied to the syrup dosage form. The two developed approaches were also applied to in-vitro plasma samples, showing good bioanalytical applicability and providing further insights for monitoring drug abuse. The proposed methods were validated according to ICHQ2(R1) guidelines. The proposed methodologies' greenness profiles were evaluated using two greenness assessment tools.

Voltammetric Analysis of Ephedrine in Pharmaceutical Dosage Forms and Urine Using poly(Nile Blue A) Modified Glassy Carbon Electrode

OBJECTIVE

The electrochemical analysis of ephedrine which is a sympathometric drug has been studied using poly(Nile blue A) modified glassy carbon electrodes, cyclic voltammetry, differential pulse voltammetry and square wave voltammetry.

METHODS

The modified electrodes were prepared by potential cycling electropolymerization of Nile blue A in 0.1 M phosphate buffer solution at pH 6.0. The redox behavior of ephedrine was investigated in different buffer solutions at pH values between 5.5 and 9.0.

RESULTS

Scan rate studies showed that the electron transfer reaction of ephedrine was diffusion controlled. A linear response was obtained between the peak current and the ephedrine concentration in the range of 0.6 to 100 μM with a limit of detection of 2.91×10^-3 μM for differential pulse voltammetry in Britton-Robinson buffer solution at pH 9.0. The linearity range of ephedrine in human urine was between 1.0 and 100 μM with a detection limit of 8.16 nM.

CONCLUSION

The recovery studies in both pharmaceutical dosage forms and urine showed that the proposed method ensured good selectivity, precision and accuracy without any interference from inactive excipients.

Validation of a rapid and simple high-performance liquid chromatography-electrospray ionization-mass spectrometry method for simultaneous analysis of 15 key chemicals in slimming foods and herbal products

A rapid and simple high-performance liquid chromatography/electrospray ionization tandem mass spectrometry method was developed for simultaneous analysis of 15 key chemicals in slimming foods and herbal products. These chemicals were strictly restricted adulterants (phenolphthalein, sibutramine, fenfluramine, clopamide, ephedrine, norpseudoephedrine, caffeine and phenformin) and physiologically relevant active components (l-carnitine, nuciferine, aloe-emodin, rhein, emodin, chrysophanol and physcion). In multi-day validations, intra- (n = 5) and inter-day precision (n = 3), limits of detection and limits of quantification for all analytes were 0.60-7.22%, 0.75-9.45%, 0.09-10 μg/L and 0.30-33.3 μg/L, respectively. Mean recovery ranged from 71.4% to 116% for all analytes in three representative samples. The method was validated on 17 samples including 12 kinds of slimming foods and five kinds of herbal products, and was shown to be ideal for routine quantification of 15 key chemicals in slimming foods and herbal products, providing an efficient strategy for quality control and food safety evaluation of weight reducing supplements.

Rapid Detection of Six Glucocorticoids Added Illegally to Dietary Supplements by Combining TLC with Spot-Concentrated Raman Scattering

The objective of this study was to establish a novel method for rapid detection of six glucocorticoids (prednisone, prednisone acetate, prednisolone, hydrocortisone, hydrocortisone acetate, and dexamethasone) added illegally in dietary supplements simultaneously by combining thin layer chromatography (TLC) with spot-concentrated Raman scattering (SCRS). The doping ingredients were separated by TLC, and viewed and located with UV light (254 nm), enriched by chromatography, then Raman spectra were directly detected by a Raman Imagine microscope with 780 nm laser source. This method had complementary advantages of TLC and Raman spectroscopy, which enhanced the specificity of the test results. The limit of detection (LOD) of the reference substances were 4 μg, 4 μg, 4 μg, 6 μg, 6 μg, and 4 μg, respectively. The method was used to study the six glucocorticoids added illegally in five dietary supplements. Fake drugs had been detected. The study showed that the TLC-SCRS method is simple, rapid, specific, sensitive, and reliable. The method could be used for effective separation and detection of six chemical components used in dietary supplement products, and would have good prospects for on-site qualitative screening of dietary supplement products for adulterants.

Expression of Cytochrome P450s in the Liver of Rats Administered with Socheongryong-tang, a Traditional Herbal Formula

OBJECTIVE

The purpose of this study was to investigate the potential influences of Socheongryong-tang (SCRT) on the messenger ribonucleic acid (mRNA) and protein expression of cytochrome P450 (CYP450) in vivo.

MATERIALS AND METHODS

SCRT was orally administered to either male or female Sprague-Dawley rats once daily at doses of 0, 1000, 2000, or 5000 mg/kg/day for 13 weeks. The mRNA expression of CYP450s (CYP1A1, 1A2, 2B1/2, 2C11, 2E1, 3A1, 3A2, and 4A1) in liver tissues was measured by reverse transcription polymerase chain reaction. And then, the protein expression of CYP1A1 and CYP2B1/2 in liver tissues was analyzed by the Western blot.

RESULTS

We found no significant influence in the mRNA expression of hepatic CYP1A2, 2C11, 2E1, 3A1, 3A2, and 4A1 after repeated administration of SCRT for 13 weeks. By contrast, the mRNA and protein expression of hepatic CYP1A1 was increased by repeated SCRT treatment in male rats, but not in female rats. The mRNA and protein expression of hepatic CYP2B1/2 in both genders was increased by administration of SCRT.

CONCLUSION

A caution is needed when SCRT is co-administered with substrates of CYP2B1/2 for clinical usage. In case of male, an attention is also required when SCRT and drugs metabolized by CYP1A1 are taken together. Our findings provide information regarding the safety and effectiveness of SCRT when combined with conventional drugs.

SUMMARY

Oral administration of Socheongryong-tang for 13 weeks did not affect the mRNA expression of hepatic CYP1A2, 2C11, 2E1, 3A1, 3A2, and 4A1In male rats, oral administration of Socheongryong-tang for 13 weeks induced the mRNA and protein expression of hepatic CYP1A1 and CYP2B1/2In female rats, oral administration of Socheongryong-tang for 13 weeks induced the mRNA and protein expression of hepatic CYP2B1/2. Abbreviations used: SCRT: Socheongryong-tang, CYP450: Cytochrome P450, HPLC: High performance liquid chromatography,

RT-PCR

Reverse transcription polymerase chain reaction.

Evaluation of multivariate calibration models with different pre-processing and processing algorithms for a novel resolution and quantitation of spectrally overlapped quaternary mixture in syrup

A novel approach for the resolution and quantitation of severely overlapped quaternary mixture of carbinoxamine maleate (CAR), pholcodine (PHL), ephedrine hydrochloride (EPH) and sunset yellow (SUN) in syrup was demonstrated utilizing different spectrophotometric assisted multivariate calibration methods. The applied methods have used different processing and pre-processing algorithms. The proposed methods were partial least squares (PLS), concentration residuals augmented classical least squares (CRACLS), and a novel method; continuous wavelet transforms coupled with partial least squares (CWT-PLS). These methods were applied to a training set in the concentration ranges of 40-100 μg/mL, 40-160 μg/mL, 100-500 μg/mL and 8-24 μg/mL for the four components, respectively. The utilized methods have not required any preliminary separation step or chemical pretreatment. The validity of the methods was evaluated by an external validation set. The selectivity of the developed methods was demonstrated by analyzing the drugs in their combined pharmaceutical formulation without any interference from additives. The obtained results were statistically compared with the official and reported methods where no significant difference was observed regarding both accuracy and precision.

Adulteration of Dietary Supplements by the Illegal Addition of Synthetic Drugs: A Review

In the last few years, the consumption of dietary supplements, especially those having plants as ingredients, has been increasing due to the common idea that they are natural products posing no risks to human health. In the European Union and the United States, dietary supplements are legally considered as foods/special category of foods, thus are not being submitted to any safety assessment prior to their commercialization. Among the issues that can affect safety, adulteration by the illegal addition of pharmaceutical substances or their analogs is of major concern since unscrupulous producers can falsify these products to provide for quick effects and to increase sales. This review discusses the various classes of synthetic drugs most frequently described as being illegally added to dietary supplements marketed for weight loss, muscle building/sport performance and sexual performance enhancement. Information regarding regulation and consumption is also presented. Finally, several conventional and advanced analytical techniques used to detect and identify different adulterants in dietary supplements and therefore also in foods, with particular emphasis on plant food supplements, are critically described. This review demonstrates that dietary supplement adulteration is an emerging food safety problem and that an effective control by food regulatory authorities is needed to safeguard consumers.

Rapid on-site detection of ephedrine and its analogues used as adulterants in slimming dietary supplements by TLC-SERS

Ephedrine and its analogues are in the list of prohibited substance in adulteration to botanical dietary supplements (BDS) for their uncontrollable stimulating side effects. However, they were always adulterated illegally in BDS to promote losing weight. In order to avoid detection, various kinds of ephedrine analogues were added rather than ephedrine itself. This has brought about great difficulties in authentication of BDS. In this study, we put forward for the first time a method which combined thin-layer chromatography (TLC) and surface-enhanced Raman scattering (SERS) to directly identify trace adulterant. Ephedrine, pseudoephedrine, methylephedrine, and norephedrine were mixed and used in this method to develop an analytical model. As a result, the four analogues were separated efficiently in TLC analysis, and trace-components and low-background SERS detection was realized. The limit of detection (LOD) of the four analogues was 0.01 mg/mL. Eight common Raman peaks (△υ = 620, 1003, 1030, 1159, 1181, 1205, 1454, 1603 cm(-1)) were extracted experimentally and statistically to characterize the common feature of ephedrine analogues. A TLC-SERS method coupled with common-peak model was adopted to examine nine practical samples, two of which were found to be adulterated with ephedrine analogues. Identification results were then confirmed by UPLC-QTOF/MS analysis. The proposed method was simple, rapid, and accurate and can also be employed to trace adulterant identification even when there are no available reference derivatives on-site or unknown types of ephedrine analogues are adulterated.

A rapid method for simultaneous determination of 52 marker compounds in Xiao-Qing-Long-Tang by ultra high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry

Xiao-Qing-Long-Tang (XQLT) is a classical Chinese medicine formula. It is generally used for the treatment of common cold, bronchial asthma, and allergic rhinitis in Asia. In this study, a multicomponent quantification fingerprinting approach based on ultra high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry has been developed for the analysis of compounds in XQLT in 14.5 min. A total of 52 compounds were identified by co-chromatography of sample extract with authentic standards and comparing the retention time, UV spectra, molecular ions and characteristic fragment ions with those of authentic standards, or tentatively identified by MS(E) determination along with Mass Fragment software. Moreover, the method was validated for the simultaneous quantification of 16 components in XQLT commercial products. The method is practical for comprehensive standardization of XQLT and holistic comparison of its commercial products from different manufacturers.

Extractive determination of ephedrine hydrochloride and bromhexine hydrochloride in pure solutions, pharmaceutical dosage form and urine samples

Simple, rapid, sensitive, precise and accurate spectrophotometeric methods for the determination of ephedrine hydrochloride (E-HCl) and bromhexine hydrochloride (Br-HCl) in bulk samples, dosage form and in spiked urine samples were investigated. The methods are based on the formation of a yellow colored ion-associates due to the interaction between the examined drugs with picric acid (PA), chlorophyllin coppered trisodium salt (CLPH), alizarin red (AR) and ammonium reineckate (Rk) reagents. A buffer solution had been used and the extraction was carried out using organic solvent, the ion associates exhibit absorption maxima at 410, 410, 430 and 530 nm of (Br-HCl)with PA, CLPH, AR and Rk respectively; 410, 410, 435 and 530 of (E-HCl) with PA, CLPH, AR and Rk respectively. (E-HCl) and (Br-HCl) could be determined up to 13, 121, 120 and 160; 25, 200, 92 and 206 μg mL(-1), using PA, CLPH, AR and Rk respectively. The optimum reaction conditions for quantitative analysis were investigated. In addition, the molar absorptivity, Sandell sensitivity were determined for the investigated drug. The correlation coefficient was ≥0.995 (n=6) with a relative standard deviation (RSD) ≤1.15 for five selected concentrations of the reagents. Therefore the concentration of Br-HCl and E-HCl drugs in their pharmaceutical formulations and spiked urine samples had been determined successfully.

HPLC-DAD-Q-TOF-MS/MS analysis and HPLC quantitation of chemical constituents in traditional Chinese medicinal formula Ge-Gen Decoction

Ge-Gen Decoction (GGD) is a classical formula of traditional Chinese medicine. It is generally used for treating common cold, fever and influenza in China and South East Asia. In this study, a systematic method was established for the qualitative and quantitative analysis of the major constituents in GGD. For qualitative analysis, a method of liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS) was developed for identification of multi-constituents. Based on the UV spectra, retention time and MS spectra, sixty compounds in GGD extract were identified or tentatively characterized by comparing with reference substances or literatures. According to the qualitative results, a new quantitative analysis method of GGD was established by HPLC-DAD. Fourteen representative compounds unequivocally identified were chosen as marker components which were derived from five herbs in GGD excluding Zingiberis Rhizoma Recens and Jujubae Fructus. The analytical method was validated through intra- and inter-day precision, repeatability and stability, and the R.S.D. was less than 3.18%, 4.48%, 3.36% and 3.54%, respectively. The LODs and the LOQs for the analytes were less than 1.06 and 3.12μgmL(-1), respectively. The overall recoveries ranged from 94.8% to 105.6%, with the R.S.D. ranging from 0.68% to 3.23%. Then the new method was applied to determine twelve batches of GGD commercial products of three dosage forms. The results indicated that the new approach was applicable in the routine analysis and quality control of GGD products. The study might provide a basis for quality control of GGD, and further study of GGD in vivo.

Biosynthesis of amphetamine analogs in plants

Amphetamine analogs are produced by plants in the genus Ephedra and by Catha edulis, and include the widely used decongestants and appetite suppressants pseudoephedrine and ephedrine. A combination of yeast (Candida utilis or Saccharomyces cerevisiae) fermentation and subsequent chemical modification is used for the commercial production of these compounds. The availability of certain plant biosynthetic genes would facilitate the engineering of yeast strains capable of de novo pseudoephedrine and ephedrine biosynthesis. Chemical synthesis has yielded amphetamine analogs with myriad functional group substitutions and diverse pharmacological properties. The isolation of enzymes with the serendipitous capacity to accept novel substrates could allow the production of substituted amphetamines in synthetic biosystems. Here, we review the biology, biochemistry and biotechnological potential of amphetamine analogs in plants.

Interconversion of ephedrine and pseudoephedrine during chemical derivatization

Gas chromatography-mass spectrometry (GC-MS) analysis after heptafluorobutyric anhydride (HFBA) derivatization was one of the published methods used for the quantification of ephedrine (EP) and pseudoephedrine (PE) in urine. This method allows the clear separation of the derivatized diastereoisomers on a methyl-silicone-based column. Recently the authors came across a human urine sample with apparently high levels (µg/ml) of EP and PE upon initial screening. However, duplicate analyses of this sample using the HFBA-GC-MS method revealed an unusual discrepancy in the estimated levels of EP and PE, with the area response ratios of EP/PE at around 29% on one occasion and around 57% on another. The same sample was re-analyzed for EP and PE using other techniques, including GC-MS after trimethylsilylation and ultra-high-performance liquid chromatography-tandem mass spectrometry. Surprisingly, the concentration of EP in the sample was determined to be at least two orders of magnitude less than what was observed with the HFBA-GC-MS method. A thorough investigation was then conducted, and the results showed that both substances could interconvert during HFBA derivatization. Similar diastereoisomeric conversion was also observed using other fluorinated acylating agents (e.g. pentafluoropropionic anhydride and trifluoroacetic anhydride). The extent of interconversion was correlated with the degree of fluorination of the acylating agents, with HFBA giving the highest conversion. This conversion has never been reported before. A mechanism for the interconversion was proposed. These findings indicated that fluorinated acylating agents should not be used for the unequivocal identification or quantification of EP and PE as the results obtained can be erroneous.

Optimized ultrasound-assisted extraction procedure for the analysis of opium alkaloids in papaver plants by cyclodextrin-modified capillary electrophoresis

This study investigated the use of ultrasound-assisted extraction to improve the extraction efficiency of morphine, codeine and thebaine from the papaver plants. Extraction conditions such as type of solvent, temperature, duration, frequency and power level of ultrasonic were optimized and the influences of different parameters on resolution of alkaloids in CE were studied. The optimized condition for CE separation includes a sodium phosphate buffer (100 mM, pH 3.0) containing 5 mM alpha-CD. The optimized extraction conditions for ultrasound-assisted extraction was an extraction time of 1 h, an ultrasonic frequency of 60 kHz with water-methanol (80:20) at 40 degrees C as the extraction solvent. The LOD for alkaloids was found to be 0.1 microg/mL at a signal-to-noise ratio of 3:1. The RSDs for peak areas were in the range of 1.4-4.4%. The amounts of opium alkaloids (mg/100 g dried sample) in four Iranian papaver plants were found to be in the range of 7.8-8.7 (morphine), 5.5-9.5 (codeine) and 1.4-10.4 (thebaine). It should be emphasized that no cleanup of the filtered extract was required; hence, direct determination after extraction drastically simplifies the analytical process.

Qualitative confirmation procedure for ephedrines as acetonide derivatives in doping urine samples by gas chromatography/electron ionization mass spectrometry

Ephedrines are sympathomimetic amines which have central nervous system stimulating properties and, for this reason, some of them are forbidden in sport by the World Antidoping Agency (WADA). They are screened and quantitated in urine by several published techniques and confirmed by gas chromatography/mass spectrometry (GC/MS). In this paper, a simple and easy confirmation procedure for norpseudoephedrine, norephedrine, ephedrine and pseudoephedrine in human urine by GC/electron ionization (EI)-MS is described. After the addition of diphenylamine as internal standard, a liquid-liquid extraction procedure under alkaline conditions with tert-butyl methyl ether was applied to the samples. The analytes were derivatized with acetone and pyridine to form the correspondent oxazolidine derivatives (acetonide). The EI mass spectra of all the studied substances have many diagnostic ions with relative abundance in accordance with WADA requirements and show great structural information content. The fragmentation of theses derivatives is discussed.

Rapid selective screening and determination of ephedrine alkaloids using GC-MS footnote mark

Ephedra (ma huang) has been widely used as an herb or herbal extract in both traditional Chinese medicine and Western world dietary supplements. The effects of Ephedra have been attributed to a series of six ephedrine alkaloids including ephedrine and pseudoephedrine. A GC-MS method for the ephedrine alkaloids is described which couples ammoniacal chloroform as the extraction solvent with a two-stage derivatisation scheme. This scheme produces the O-trimethylsilyl, N-trifluoracetyl derivatives (O-TMS, N-TFA) for the primary and secondary amine alkaloids, and the O-TMS derivatives for the tertiary amine alkaloids. Relatively clean extracts are obtained from complex matrices, and the six ephedrine alkaloids are effectively separated and identified. This approach was also evaluated for quantitative analysis, and was shown to provide quantitative results for ephedrine and pseudoephedrine, and good estimates for the four minor alkaloids. Figures of merit are presented for linearity, detection limits, precision and accuracy. We have applied this approach to the rapid screening and profiling of the ephedrine alkaloids in whole Ephedra plants, liquid plant extracts, dried powder plant extracts and a variety of Ephedra-containing dietary supplements.

Electron ionization mass spectra of ephedrines in a doping confirmatory procedure: a curious migration of the trimethylsilyl group in the N-acetyl-O-trimethylsilyl derivatives

Ephedrines have central nervous system stimulating properties and, for this reason, some of them are forbidden in sport by the World Antidoping Agency (WADA). They are screened and quantitated in urine by several published techniques and confirmed by gas chromatography/mass spectrometry (GC/MS). In this paper, a simple confirmation procedure for norpseudoephedrine, norephedrine, ephedrine and pseudoephedrine in human urine by GC/electron ionization (EI)-MS is described. After the addition of levallorphane as internal standard, a liquid-liquid extraction procedure under alkaline conditions with tert-butyl methyl ether was applied to the samples. The analytes were derivatized with acetic acid anhydride and N-methyl-N-trimethylsilyltrifluoroacetamide to form N-acetyl-O-trimethylsilyl derivatives. The EI mass spectra of all the studied substances have many diagnostic ions with relative abundance in accordance with WADA requirements and show great structural information content. A curious migration of the trimethylsilyl group is proposed.