A Modified 1H-NMR Quantification Method of Ephedrine Alkaloids in Ephedrae Herba Samples

A previous 1H-NMR method allowed the quantification of ephedrine alkaloids; however, there were some disadvantages. The cyclized derivatives resulted from the impurities of diethyl ether were identified and benzene was selected as the better extraction solvent. The locations of ephedrine alkaloids were confirmed with 2D NMR. Therefore, a specific 1H-NMR method has been modified for the quantification of ephedrine alkaloids. Accordingly, twenty Ephedrae Herba samples could be classified into three classes: (I) E. sinica-like species; (II) E. intermedia-like species; (III) others (lower alkaloid contents). The results indicated that ephedrine and pseudoephedrine are the major alkaloids in Ephedra plants, but the concentrations vary greatly determined by the plant species and the collection locations.

Ephedrae herba: A comprehensive review of its traditional uses, phytochemistry, pharmacology, and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Ephedrae herba (called Mahuang in China) is the dried herbaceous stem of Ephedra sinica Stapf, Ephedra intermedia Schrenk et C. A. Mey., and Ephedra equisetina Bge. Ephedrae herba has a long history of use as an herb, and it was originally recorded in Sheng Nong's herbal classic. Ephedrae herba has also been widely used as both medicine and food. In the clinic, Ephedrae herba is commonly used for treating colds, bronchial asthma, nasal congestion, and other diseases.

AIM OF REVIEW

This review aims to provide a systematic summary on the traditional use, chemical constituents, pharmacological effects, clinical applications, quality control, toxicology, and pharmacokinetics of Ephedrae herba to provide a theoretical basis for further reasonable development of Ephedrae herba in clinical practice and creation of new drugs.

MATERIALS AND METHODS

Information on Ephedrae herba was gathered from various sources, including the scientific databases including CNKI, PubMed, SciFinder and ScienceDirect, classical books on traditional Chinese herbal medicine, Ph.D. and M.Sc. dissertations; Baidu Scholar; and from different professional websites.

RESULTS

Ephedrae herba is distributed in regions of China and other areas. Ephedra and its compound preparations can be used for colds, bronchial asthma, nasal congestion and other diseases. Approximately 281 chemical constituents have been isolated from Ephedrae herba, including alkaloids, flavonoids, tannins, polysaccharides, volatile oils, organic acids, and other compounds. Among these constituents, alkaloids and volatile oils are the most abundant and represent the major bioactive constituents. Ephedrae herba possesses multiple pharmacological activities, including diuretic effect, anti-allergic effect, blood pressure regulatory, anti-inflammatory effect, anti-oxidation effect and anti-viral effects. Ephedrine hydrochloride and pseudoephedrine hydrochloride are generally selected as indicators for the quantitative determination of Ephedrae herba. The maximum dosage of Ephedrae herba should not exceed 10 g. If overused, adverse reactions such as palpitations, sweating, irritability and insomnia will occur.

CONCLUSIONS

Ephedrae herba is an ancient herbal medicine with a broad spectrum of pharmacological activities that has been used for thousands of years in China. It is one of the most commonly used herbal components of the TCM formulas. Hydrochloride and pseudoephedrine are the major bioactive constituents. However, there is a need to further understand the mechanisms of active components of Ephedrae herba. Future studies should perform an in-depth analyses of the pharmacokinetics and mechanisms of toxicity of Ephedrae herba. Quality standards should be developed to correspond to the various application methods to ensure the efficacy of drugs in actual treatment.

Critical Evaluation of Laboratory Potentiometric Electronic Tongues for Pharmaceutical Analysis-An Overview

Electronic tongue systems equipped with cross-sensitive potentiometric sensors have been applied to pharmaceutical analysis, due to the possibility of various applications and developing new formulations. Many studies already proved the complementarity between the electronic tongue and classical analysis such as dissolution tests indicated by Pharmacopeias. However, as a new approach to study pharmaceuticals, electronic tongues lack strict testing protocols and specification limits; therefore, their results can be improperly interpreted and inconsistent with the reference studies. Therefore, all aspects of the development, measurement conditions, data analysis, and interpretation of electronic tongue results were discussed in this overview. The critical evaluation of the effectiveness and reliability of constructed devices may be helpful for a better understanding of electronic tongue systems development and for providing strict testing protocols.

Smart Spectral Processing of Data for the estimation of Commonly Used Over-the-counter (OTC) Co-formulated drug; Pseudoephedrine hydrochloride and Ibuprofen

Oral pharmaceutical preparation containing pseudoephedrine hydrochloride (PSE) and ibuprofen (IBU) is widely prescribed as over- the- counter (OTC) for treatment of common cold-sinus. Development of four precise and accurate spectrophotometric methods are established for the concurrent determination of (PSE) and (IBU)in this preparation exploiting zero and/or ratio spectra. Method I is a dual wavelength method (DW). method II is a ratio difference method (RD), method III is a constant multiplication coupled with spectrum subtraction method (CM-SS) and method IV is a constant center coupled with spectrum subtraction method (CC-SS). While, absorbance correction method (AC) is successfully established for the determination of (IBU) only exploiting zero order absorption spectra. The calibration curves are linear over the concentration range of 100.0-900.0 μg/mL for (PSE) and 200.0-1000.0 μg/mL for (IBU). No separation steps are required for the spectrophotometric procedures which augments their simplicity. Analyzing synthetic mixtures of the cited drugs evaluated the specificity of the applied methods. Validation of the analysis results have been statistically performed confirming the accuracy and reproducibility of the proposed method through recovery studies which were carried out by following ICH guidelines. Thus, the developed methods can be successfully applied routinely in quality control laboratory.

Reduction of interferences in the analysis of Children's Dimetapp using ultraviolet spectroscopy data and target factor analysis

A calibration matrix has been developed and successfully applied to quantify actives in Children's Dimetapp®, a cough mixture whose active components suffer from heavy spectral interference. High-performance liquid chromatography/photodiode array instrument was used to identify the actives and any other UV-detectable excipients that might contribute to interferences. The instrument was also used to obtain reference data on the actives, instead of relying on the manufacturer's claims. Principal component analysis was used during the developmental stages of the calibration matrix to highlight any mismatch between the calibration and sample spectra, making certain that "apples" were not compared with "oranges". The prediction model was finally calculated using target factor analysis and partial least squares regression. In addition to the actives in Children's Dimetapp® (brompheniramine maleate, phenylephrine hydrogen chloride, and dextromethorphan hydrogen bromide), sodium benzoate was identified as the major and FD&C Blue #1, FD&C Red #40, and methyl anthranilate as minor spectral interferences. Model predictions were compared before and after the interferences were included into the calibration matrix. Before including interferences, the following results were obtained: brompheniramine maleate=481.3mgL^-1±134% RE; phenylephrine hydrogen chloride=1041mgL^-1±107% RE; dextromethorphan hydrogen bromide=1571mgL^-1±107% RE, where % RE=percent relative error based on the reference HPLC data. After including interferences, the results were as follows: brompheniramine maleate=196.3mgL^-1±4.4% RE; phenylephrine hydrogen chloride=501.3mgL^-1±0.10% RE; dextromethorphan hydrogen bromide=998.7mgL^-1±1.6% RE as detailed in Table 6.

Determination of illicit drugs in aqueous environmental samples by online solid-phase extraction coupled to liquid chromatography-tandem mass spectrometry

In this study, a fully automated analytical method, based on online solid phase extraction coupled to liquid chromatography-triple quadrupole tandem mass spectrometry (online SPE-LC-MS/MS), has been developed and optimized for the quantification of 10 illicit drugs and metabolites in environmentally aqueous samples collected from China. The particular attention was devoted to minimize the matrix effects through a washing step, which washed out the interferences effectively and helped to reduce the matrix effect significantly. The key advantages of the method are high sensitivity, selectivity and reliability of results, smaller sample manipulation, full automation, and fairly high throughput. The whole procedure was then successfully applied in the analysis of various surface water and wastewater effluents samples. Pseudoephedrine have been detected at trace levels (several tens ng L(-1) or less), while MDA, MDMA, benzoylecgonine and methadone were below the LOQ in all samples. Caffeine, cotinine and paraxanthine, which may be derived from medicines and foods, were detected with the highest frequencies and concentrations.

Evaluating the efficiency of spectral resolution of univariate methods manipulating ratio spectra and comparing to multivariate methods: an application to ternary mixture in common cold preparation

Simple, accurate, and selective methods have been developed and validated for simultaneous determination of a ternary mixture of Chlorpheniramine maleate (CPM), Pseudoephedrine HCl (PSE) and Ibuprofen (IBF), in tablet dosage form. Four univariate methods manipulating ratio spectra were applied, method A is the double divisor-ratio difference spectrophotometric method (DD-RD). Method B is double divisor-derivative ratio spectrophotometric method (DD-RD). Method C is derivative ratio spectrum-zero crossing method (DRZC), while method D is mean centering of ratio spectra (MCR). Two multivariate methods were also developed and validated, methods E and F are Principal Component Regression (PCR) and Partial Least Squares (PLSs). The proposed methods have the advantage of simultaneous determination of the mentioned drugs without prior separation steps. They were successfully applied to laboratory-prepared mixtures and to commercial pharmaceutical preparation without any interference from additives. The proposed methods were validated according to the ICH guidelines. The obtained results were statistically compared with the official methods where no significant difference was observed regarding both accuracy and precision.

Emerging organic contaminants in coastal waters: anthropogenic impact, environmental release and ecological risk

This study provides a first estimate of the sources, distribution, and risk presented by emerging organic contaminants (EOCs) in coastal waters off southwestern Taiwan. Ten illicit drugs, seven nonsteroidal anti-inflammatory drugs (NSAIDs), five antibiotics, two blood lipid regulators, two antiepileptic drugs, two UV filters, caffeine, atenolol, and omeprazole were analyzed by solid-phase extraction and liquid chromatography coupled to tandem mass spectrometry (SPE-LC-MS/MS). Thirteen EOCs were detected in coastal waters, including four NSAIDs (acetaminophen, ibuprofen, ketoprofen, and codeine), three antibiotics (ampicillin, erythromycin, and cefalexin), three illicit drugs (ketamine, pseudoephedrine, and MDMA), caffeine, carbamazepine, and gemfibrozil. The median concentrations for the 13 EOCs ranged from 1.47 ng/L to 156 ng/L. Spatial variation in concentration of the 13 EOCs suggests discharge into coastal waters via ocean outfall pipes and rivers. Codeine and ampicillin have significant pollution risk quotients (RQ>1), indicating potentially high risk to aquatic organisms in coastal waters.

Chromatographic isolation of nanoparticles from Ma-Xing-Shi-Gan-Tang decoction and their characterization

ETHNOPHARMACOLOGICAL RELEVANCE

The herbal decoction is a complex dispersion system containing solutes, colloid, aggregates, emulsions and precipitates. In which phase bioactive phytochemicals are dispersed determines their delivery, action and metabolism. This study took ephedrine, a well-studied and widely used phytochemical, as an example to elucidate its exact distribution in the phases of Ma-Xing-Shi-Gan-Tang decoction (MXSGT), which is an Ephedra sinica Stapf. containing traditional Chinese medicinal formula, and the biological meaning of this distribution correspondingly. It may provide an important update to the safety and efficacy assessment of the herbal decoction and its active phytochemicals.

MATERIALS AND METHODS

In this study, the decoction was fractionated with size-exclusion chromatography coupled with multi-angle laser light scattering detector. The morphology of fractionated nanoparticles was observed with AFM and SEM. The bioactivities of the decoction, the ephedrine alkaloids loaded NPs (prepared by chromatography isolation) and the synthetic ephedrine were assessed by cell proliferation tests using five cell lines, namely Caco-2, L-02, Hep-G2, NR-8383, and Hela-229.

RESULTS

Nanoparticles with radii of gyration ranged from 50 to 150 nm were isolated, in spherical shape. Further analysis of nanoparticles on the subsequent reversed phase chromatography revealed that the majority of ephedrine (99.7%) and pseudoephedrine (95.5%) were associated with these nanoparticles, rather than dispersed freely in the real solution. The addition of both the herbal decoction and the separated ephedrine-loaded nanoparticles reserved higher cell viability/proliferation than that of the sole synthetic ephedrine among the Caco-2, L-02, Hep-G2, and NR-8383 cells. In contrast, the nanoparticles reduced the proliferating power of ephedrine on Hela-229 cells. In general, the ephedrine-loaded NPs conducted the intermediate influences on the cell viability, in either way.

CONCLUSIONS

The colloidal nanoparticles were separated from the decoction. The association of ephedrine alkaloids with nanoparticles was demonstrated and may have changed the bioactivity of the alkaloids. The naturally occurred colloidal nanoparticles may play an important role in the pharmacological properties of both the decoction and its active phytochemicals, therefore warrant further studies.

[Simultaneous determination of scopolamine hydrobromide, atropine sulfate, ephedrine hydrochloride and pseudoephedrine hydrochloride in Zhichuanling oral liquid with HPLC]

OBJECTIVE

To establish an HPLC method for determining the contents of scopolamine hydrobromide, atropine sulfate, ephedrine hydrochloride and pseudoephedrine hydrochloride in Zhichuanling oral liquid.

METHOD

Agela Durashell RP-C18 (4. 6 mm x250 mm, 5 microm) was adopted, with acetonitrile-sodium phosphate buffer solution (0. 07 mol L-1 sodium phosphate solution with 17.5 mmol L-1 sodium dodecylsulfate adjusted to pH 6.0 with phosphoric acid solution) (30:70) as the mobile phase. The flow rate was 0. 9 mL min -1, the detection wavelength was 207 nm, and the column temperature was 25 degree C.

RESULT

Scopolamine hydrobromide, atropine sulfate, ephedrine hlvdrochloride and pseudoephedrine hydrochloride showed good linear relations with peak areas within the concentration range of 0. 021 21-1. 060 5 pg (r =0. 999 3) , 0. 011 14-0. 557 microg (r = 0. 999 6) , 0. 200 56-10. 028 microg (r =0. 999 7) and 0.070 33-3. 516 5 gg (r =0. 999 6), respectively, with the average recoveries of 101.9% , 99. 80%, 100. 3%, 100. 2% (n=6).

CONCLUSION

The method was so quick, simple, highly reproducible and specific that it could be used as one of quality control methods of Zhichuanling oral liquid.

Wipe sampling of amphetamine-type stimulants and recreational drugs on selected household surfaces with analysis by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry

Sorption characteristics of eight drugs related to recreational and clandestine activity-amphetamine, cocaine, heroin, N-formyl amphetamine, N-formyl methamphetamine, methamphetamine, 3, 4-methylenedioxymethamphetamine (MDMA), and pseudoephedrine-were evaluated on selected kitchen countertop surfaces. Methanol-dampened Whatman 40 filter paper wipes were used to collect samples from eleven surfaces including alkyd resin, ceramic tiles, glass, granite, laminate, limestone, marble, quartz compac, quartz real, soap stone, and stainless steel. The filter paper wipes were analyzed by a rapid three-minute UPLC-QTOF method, following ammonium acetate buffer (pH 5.8-6.2) extraction. The average percentage recoveries after 15 h of exposure to the surface materials tested, was found to be highest for cocaine and MDMA and lowest for amphetamine and methamphetamine. Among the eleven countertop surfaces, overall recoveries for marble were observed to be the least, whereas soapstone, quartz compac and stainless steel were among the highest. Scanning electron microscopic images of the surfaces provided a unique view of surface irregularities that potentially influenced drug recovery. Aging, migration, solvent composition, and volatility were examined. The variation in recovery of drugs was attributed to four key factors: compound volatility, surface composition, surface-compound interaction, and solvent composition.

[Simultaneous determination of ephedrine hydrochloride, D-pseudoephedrine and amygdalin in xiao'er pingchuan qutan granule by HPLC]

OBJECTIVE

To establish an HPLC method for the determination of ephedrine hydrochloride, D-pseudo-ephedrine and amygdalin in Xiao'er Pingchuan Qutan granule.

METHOD

Pheny ether chromatographic column (4.6 mm x 250 mm, 5 microm) was adopted, with acetonitrile-0.1% phosphoric acid (containing 0.1% three ethylamine) (3:97) as the mobile phase. The UV detection wavelength was at 210 nm, with the flow rate of 1 mL x min(-1), and column temperature was at 35 degrees C.

RESULT

The linearity of ephedrine hydrochloride, D-pseudo-ephedrine and amygdalin ranged between 0.078 60-3.144 microg (r = 1.000 0), 0.103 4-2.068 microg (r = 0.999 7) and 0.430 5-3.157 microg (r = 0.999 8), respectively. Their average recoveries were 98.46% (RSD 1.1%), 103.0% (RSD 1.5%) and 97.15% (RSD 2.1%), respectively.

CONCLUSION

The method is simple, stable and reliable that it can be used to determine the content of ephedrine hydrochloride, D-pseudo-ephedrine and amygdalin in Xiao'er Pingchuan Qutan granule.

[Rapid identification 15 effective components of anti common cold medicine with MRM by LC-MS/MS]

This paper reports the establishment of a method for rapid identification 15 effective components of anti common cold medicine (paracetamol, aminophenazone, pseudoephedrine hydrochloride, methylephedrine hydrochloride, caffeine, amantadine hydrochloride, phenazone, guaifenesin, chlorphenamine maleate, dextromethorphen hydrobromide, diphenhydramine hydrochloride, promethazine hydrochloride, propyphenazone, benorilate and diclofenac sodium) with MRM by LC-MS/MS. The samples were extracted by methanol and were separated from a Altantis T3 column within 15 min with a gradient of acetonitrile-ammonium acetate (containing 0.25% glacial acetic acid), a tandem quadrupole mass spectrometer equipped with electrospray ionization source (ESI) was used in positive ion mode, and multiple reaction monitoring (MRM) was performed for qualitative analysis of these compounds. The minimum detectable quantity were 0.33-2.5 microg x kg(-1) of the 15 compounds. The method is simple, accurate and with good reproducibility for rapid identification many components in the same chromatographic condition, and provides a reference for qualitative analysis illegally added chemicals in anti common cold medicine.

Spectrophotometric studies of reactions between pseudo-ephedrine with different inorganic and organic reagents and its micro-determination in pure and in pharmaceutical preparations

Two simple, sensitive, cheep and reliable spectrophotometric methods are suggested for micro-determination of pseudoephedrine in its pure form and in pharmaceutical preparation (Sinofree Tablets). The first one depends on the drug reaction with inorganic sensitive reagent like molybdate anion in aqueous media via formation of ion-pair mechanism. The second one depends on the drug reaction with π-acceptor reagent like DDQ in non-aqueous media via formation of charge transfer complex. These reactions were studied under various conditions and the optimum parameters were selected. Under proper conditions the suggested procedures were successfully applied for micro-determination of pseudoephedrine in pure and in Sinofree Tablets without interference from excepients. The values of SD, RSD, recovery %, LOD, LOQ and Sandell sensitivity refer to the high accuracy and precession of the applied procedures. The results obtained were compared with the data obtained by an official method, referring to confidence and agreement with DDQ procedure results; but it referred to the more accuracy of the molybdate data. Therefore, the suggested procedures are now successfully being applied in routine analysis of this drug in its pharmaceutical formulation (Sinofree) in Saudi Arabian Pharmaceutical Company (SPIMACO) in Boridah El-Qaseem, Saudi Arabia instead of imported kits had been previously used.

[Simultaneous determination of 5 kinds of alkaloids in Kechuanning tablets by SPE-UPLC under different UV-vis wavelength]

The paper is to establish a method for simultaneous determination of 5 kinds of alkaloids in ephedra and poppy which are in Kechuanning tablets. Solid-phase extraction (SPE) was adopted in pretreatment, and a UPLC method with 2 different wavelengths had been developed: 210 nm for the detection of morphine, codeine phosphate, ephedrine hydrochloride and pseudoephedrine hydrochloride, and 251 nm for papaverine hydrochloride. The column used was Acquity UPLC BEH C18 (100 mm x 2.1 mm ID, 1.7 microm) with linear gradient elution using acetonitrile and 0.1% phosphoric acid. The flow rate was 0.4 mL.min-1, and the column temperature was 30 degrees C. The linear response range was 0.375 0 - 12.50 microg.mL-1 for morphine, 0.064 32 - 2.144 microg.mL-1 for codeine phosphate, 0.030 06 - 1.002 microg.mL-1 for papaverine hydrochloride, 1.126 - 37.52 microg.mL-1 for ephedrine hydrochloride, 0.287 8 - 9.592 microg.mL-1 for pseudoephedrine hydrochloride (r = 0.999 7). The average recoveries of these compounds were 99.26%, 100.6%, 95.29%, 100.1% and 97.48%, respectively. This is a more reasonable and credible method of quality control for Kechuanning tablets.

[Determination of ephedrine hydrochloride, pseudoephedrine hydrochloride and methylephedrine hydrochloride in maxingshigan decoction by CE]

OBJECTIVE

To establish the method for determination of ephedrine hydrochloride, pseudoephedrine hydrochloride and methylephedrine hydrochloride in maxingshigan decoction by capillary electrophoresis.

METHODS

The separation was performed on a fused silica capillary of 60 cm x 55 microcrpm ID (52 cm of effective length). 60 mmol/L NaB4O7 + 10% (V/V) CH3OH (pH 9.0) was selected as the running buffer. The separation voltage was 12 kV. The samples was injected by gravity (10 s, 15 cm). The detection wavelength was 210 nm and berberine hydrochloride was the internal standard.

RESULTS

The linear range of determination for ephedrine hydrochloride, pseudoephedrine hydrochloride and methylephedrine hydrochloride were 20.0-160.0 microg/mL (r = 0.9999), 7.5-60.0 microg/mL (r = 0.9991) and 2.0-10.0 microg/mL (r = 0.9993). The average recoveries were 98.0%, 97.0% and 97.8%, the precisions of the method were 2.31%, 2.21% and 2.00% (n=6), respectively.

CONCLUSION

The method is convenient, rapid and accurate for the quality control of maxingshigan decoction.

[Simultaneous determination of ibuprofen and pseudoephedrin hydrochloride and chlorpheniramine maleate in the compound buluoweimanamin tablets by HPLC]

OBJECTIVE

An HPLC method was developed to determinate Ibuprofen and Pseudoephedrine Hydrochloride and Chlorpheniramine Maleate in Compound BuluoWeimaNamin Tablets.

METHODS

Using HPLC with Kromasil C18 column, and acetonitrile -0.5% SDS- phosphate (580:420:1) as the mobile phase. The wavelength for detection was 262 nm.

RESULTS

Better linearities and good correlation coefficients were obtained: the concentration ranges of ibuprofen, pseudoephedrine hydrochloride and chlorpheniramine maleate were over 2.062-14.434 microg (r=0.9999), 0.296-2.072l microg (r=0.9999), and 0.0204~0.1428 microg (r=0.9998), respectively. The recoveries of ibuprofen, pseudoephedrine hydrochloride and chlorpheniramine maleate were 99.98% (RSD=0.52%), 99.72 (RSD=0.82%) and 99.545 (RSD=0.76%), respectively.

CONCLUSION

The method was convenient, accurate and specific. It can be used as a method to control quality of Compound Buluoweimanamin Tablets.

A porous graphitized carbon column HPLC method for the quantification of paracetamol, pseudoephedrine, and chlorpheniramine in a pharmaceutical formulation

A simple, rapid, and stability-indicating HPLC method has been developed, fully validated, and applied to the quantification of paracetamol, pseudoephedrine hydrochloride, and chlorpheniramine maleate in a pharmaceutical formulation, using hydrochlorothiazide as an internal standard. Chromatographic separation was achieved isocratically on an RP porous graphitized carbon analytical column (125 x 2.1 mm id, particle size 5 microm) using 5.0 mM ammonium acetate-acetonitrile (35 + 65, v/v) mobile phase at a flow rate of 0.50 mL/min. UV spectrophotometric detection at 220 nm was used. The method had linear calibration curves over the range of 30-70 microg/mL for paracetamol, 1.8-4.2 microg/mL for pseudoephedrine hydrochloride, and 120-280 ng/mL for chlorpheniramine maleate. The intraday and interday RSD values were less than 3.2% for all compounds, while the relative error was less than 2.9%. Accelerated stability studies performed under various stress conditions proved the selectivity of the method. The developed method was applied successfully to QC and content uniformity tests of commercial tablets.

Stimulants and doping in sport

Stimulants have been frequently detected in doping control samples and represent a structurally diverse class of compounds. Comprehensive sports drug-testing procedures have been developed using gas or liquid chromatography combined with mass spectrometric detection, and they have revealed various adverse analytical findings, as demonstrated with 2 examples, 4-methylhexan-2-amine and methoxyphenamine. Moreover, the necessity of controlling the use or misuse of stimulating agents is outlined by means of pseudoephedrine, a compound that was prohibited in sports until the end of 2003. Since the ban was lifted, monitoring programs proved a significant increase in pseudoephedrine applications as determined from urine samples collected in competition. As a consequence, a reimplementation of this drug in future doping controls was decided.

[Determination of ephedrine and pseudoephedrine in Herba Ephedrae and Maxing Shigan Tang by capillary zone electrophoresis]

OBJECTIVE

To establish a method for the determination of ephedrine and pseudoephedrine in Herba Ephedrae and Maxing Shigan Tang by capillary zone electrophoresis.

METHOD

The conditions of the experiment were optimized with a fused-silica capillary of 60 cm x 50 microm (50 cm effective length) in a running buffer of 50 mmol x L(-1) borax-20 mmol x L(-1) threonine (pH 9.27) and an applied voltage of 15 kV (room temperature). Samples were introduced by hydrodynamic injections (10 cm x 20 s)and determined with on-column UV monitoring at 210 nm. Phenobarbital was chosen as the internal standard.

RESULT

Ephedrine and pseudoephedrine are separated successfully within 8 min. The linear responses covered the ranges from 21.3 to 213 mg x L(-1) (r = 0.9996) for ephedrine and from 8.4 to 84 mg x L(-1) (r = 0.9995) for pseudoephedrine. The detection limits (S/N = 3) of ephedrine and pseudoephedrine were shown to be 1.45 and 1.48 microg x mL(-1), respectively, The quantitation limits (S/N = 10) of ephedrine and pseudoephedrine were shown to be 4.81 and 4.93 mg x L(-1), respectively. The average recoveries for ephedrine and pseudoephedrine were 97.5% and 98.6% with RSD less than 5.0%.

CONCLUSION

The method is simple, rapid, cost-effective and precise with satisfactory results.

[Determination of the synthetic route based on impurity profiling of methamphetamine]

OBJECTIVE

Impurity profiling of seized methamphetamine may play an important role in the determination of the synthetic method employed and the criminal investigations of drug traffic routes.

METHODS

A sample of methamphetamine was dissolved in buffer solution. Impurities were extracted with ethyl acetate containing four internal standards (n-decane, n-pentadecane, n-eicosane and n-octacosane) and analyzed by GC-MS.

RESULTS

These data are suggestive of ephedrine/pseudoephedrine as the main precursor of the methamphetamine samples seized during 2006-2007. Six samples of selected eight samples were synthesized via the more specific ephedrine/hydriodic acid/red phosphorus method.

CONCLUSION

Ephedrine/pseudoephedrine is common material used to synthesize methamphetamine.

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.

Alternative and improved method for the simultaneous determination of fexofenadine and pseudoephedrine in their combined tablet formulation

An alternative method for the determination of fexofenadine (FEX) and pseudoephedrine (PSE) in their combined tablet formulation has been developed, employing the partial least squares (PLS) analysis of spectral data of the analytes in their pharmaceutical association. A full-factorially designed set of 16 synthetic samples was employed for calibration purposes. The calibration models were constructed with wavelengths selection, in the ultraviolet region, according to their predictive ability. These were validated internally by the leave-one-out procedure and externally, employing appropriate sets of validation samples. The described method was linear for both analytes, over the range 160.6-301.2 mg L(-1) for FEX (R(2)=0.9993) and between 325.6 and 610.5 mg L(-1) for PSE (R(2)=0.9992). It was accurate, exhibiting 99.8% and 99.9% drug recoveries for FEX and PSE, respectively (N=9), while in the intermediate precision experiment relative standard deviations were 1.4% for FEX and 1.2% for PSE. The contents of both analytes were assayed in commercial tablets employing this method and the results were compared with those furnished by HPLC, being in good statistical agreement. The method represents an improvement over the first derivative of spectral ratio (DSR) technique and allows high sample throughput with minimum reagent consumption and waste generation. The obtained results confirm that the method is highly suitable for its intended purpose.

[Study on characteristics of bias caused by flow injection-capillary electrophoresis with split-flow electrokinetic injection]

The characteristics of bias caused by split-flow electrokinetic injection (SEKI), a new sample injection method applied in coupled flow injection-capillary electrophoretic system (FI-CE), was investigated using pseudoephedrine hydrochloride, a basic drug and ibuprofen, an acidic drug, as model analytes. It was found that bias imposed by SEKI under the conditions of continuous sample matrix/running buffer was similar to that did by electrokinetic injection (EKI). The linearity of calibration curve provided by SEKI was similar to that offered by non-bias hydrodynamic injection (HDI) but significantly better than that obtained by EKI. These features were exploited to improve analytical performances in simultaneous determination of the minor ingredient of pseudoephedrine hydrochloride and the major ingredient of ibuprofen in pharmaceutical preparation. Detectability of 0.7 mg/L for pseudoephedrine hydrochloride, was achieved at a sample throughput rate of 24 times per hour which is 30% lower than that obtained by HDI-based conventional CE. Eleven runs of a test solution containing 13.1 mg/L pseudoephedrine hydrochloride and 81.4 mg/L ibuprofen produced relative standard deviations (RSDs) of 2.8% for the minor ingredient and 1.2% for the major ingredient, which were improved in comparision to that obtained by HDI-based conventional CE. Analytical results for two batches of compound ibuprofen tablets by the SEKI-based FI-CE approach were in good agreement with that obtained by a conventional high performance liquid chromatographic method.

[Simultaneous determination of pseudoephedrine hydrochloride and dextromethorphan hydrobromide in composite pseudoephedrine hydrochloride dry suspension by HPLC]

A simple and reliable reversed-phase high performance liquid chromatographic method (HPLC) for the routine analysis of pseudoephedrine hydrochloride and dextromethorphan hydrobromide in composite pseudoephedrine hydrochloride dry suspension has been established. HPLC determination for the drug was performed in a Lichrospher C6H6 column and detected at 220 nm. Acetonitrile-H2O-H3PO4 (50:50:0.1, v/v, pH 2.5, containing 1 g/L sodium dodecyl sulfate) was used as the mobile phase and the flow rate was 1.2 mL/min. The method was proved to be linear in the ranges of 1.03-206 mg/L and 5-200 mg/L for dextromethorphan hydrobromide and pseudoephedrine hydrochloride, respectively. The relative standard deviations of intra-assay (n = 7) and inter-assay (n = 5) were 1.0% and 1.5% for pseudoephedrine hydrochloride analysis and 1.8% and 2.2% for dextromethorphan hydrobromide analysis. The recoveries of pseudoephedrine hydrochloride and dextromethorphan hydrobromide were 95.7%-98.7% and 100.0%-101.8%, respectively. The method has been successfully applied to the simultaneous determination of pseudoephedrine hydrochloride and dextromethorphan hydrobromide in composite pseudoephedrine hydrochloride dry suspension.