Pseudoephedrine In Plasma Research Articles

A randomized placebo controlled trial demonstrates the effect of dl-methylephedrine on brain functions is weaker than that of pseudoephedrine

Intellectual drug doping in athletics by using stimulants that affect central nervous system functions has been diversified. Stimulants are regulated by the World Anti-Doping Agency according to their levels of urinary concentration. Positron emission tomography could evaluate how stimulants affect central nervous system functions. We aimed to evaluate the effect of stimulants on brain function by examining the difference in brain dopamine transporter occupancy by PET after administration of dl-methylephedrine or pseudoephedrine at the clinical maximum daily dose. Four PET scans without and with drug administration (placebo, dl-methylephedrine 150 mg and pseudoephedrine 240 mg) were performed. The concentrations of dl-methylephedrine and pseudoephedrine in plasma and urine were measured. DAT occupancies in the striatum with placebo, dl-methylephedrine and pseudoephedrine were calculated by PET images. The urinary concentration of dl-methylephedrine (12.7 µg/mL) exceeded the prohibited concentration (10 µg/mL), but the DAT occupancy with dl-methylephedrine (6.1%) did not differ (p = 0.92) from that with placebo (6.2%). By contrast, although the urinary concentration of pseudoephedrine (144.8 µg/mL) was below the prohibited concentration (150 μg/mL), DAT occupancy with pseudoephedrine was 18.4%, which was higher than that with placebo (p = 0.009). At the maximum clinical dose, dl-methylephedrine was shown to have weaker effects on brain function than pseudoephedrine.

Analysis of dextromethorphan and pseudoephedrine in human plasma and urine samples using hollow fiber-based liquid–liquid–liquid microextraction and corona discharge ion mobility spectrometry

We report on the use of hollow fiber liquid-liquid-liquid microextraction (HF-LLLME) followed by corona discharge ion mobility spectrometry for the determination of dextromethorphan and pseudoephedrine in urine and plasma samples. The effects of pH of the donor phase, stirring rate, ionic strength and extraction time on HF-LLLME were optimized. Under the optimized conditions, the linear range of the calibration curves for dextromethorphan in plasma and urine, respectively, are from 1.5 to 150 and from 1 to 100 ng mL−1. The ranges for pseudoephedrine, in turn, are from 30 to 300 and from 20 to 200 ng mL−1. Correlation coefficients are better than 0.9903. The limits of detection are 0.6 and 0.3 ng mL−1 for dextromethorphan, and 8.6 and 4.2 ng mL−1 for pseudoephedrine in plasma and urine samples, respectively. The relative standard deviations range from 6 to 8%.

Direct injection of plasma to determine pseudoephedrine by high performance liquid chromatography with column switching.

An HPLC method has been developed for the determination of pseudoephedrine in plasma using column switching. Preparation of the sample was simple in that only 1000 microL of water was added to 200 microL of plasma before injection. A 900 microL aliquot was injected onto the precolumn. Double distilled water was used to elute and remove proteins and polar components in the sample. The components retained on the precolumn were flushed forward onto the analytical column by the mobile phase (acetonitrile-0.2 mol/L ammonium sulphate, 10:90 v/v) with automated column switching. The limit of determination of pseudoephedrine in plasma was 12 ng/mL. The relative standard deviations of intra- and inter-assay for the determination of pseudoephedrine in plasma were 1.2-9.8% over the concentration range 1020-21.8 ng/mL. The mean recovery by on-line solid phase extraction was 94.76% (RSD = 1.1%).

Separation and Determination of (I)-Ephedrine and (d)-Pseudoephedrine in Plasma by High-Performance Liquid Chromatography with Fluorescence Detection

Abstract The separation and determination of (l)-ephedrine (l-Ep) and (d)-pseudoephedrine (d-Ps) in Plasma by high-performance liquid chromatography (HPLC) is described. The newly developed method is based on precolumn derivatization with 5-dimethylaminonaphthalene-l-sulfonyl chloride (DNSCl) in 0.03% triethylamine in acetonitrile at 50 C°. The diastereomers formed were separated on a reversed phase column by HPLC with fluorescence detection employing 0.6 % phosphate buffer (pH 6.5)-methanol (3:8, v/v) as mobile phase. Clean-up of the ephedrine stereoisomers in plasma was efficiently attained by the combined use of a Sep-pak C18 cartridge and an ion-exchange gel, Carboxymethyl Sephadex LH-20 (CM-LH-20). The detection limit of each ephedrine stereoisomer was 100 pg at a signal-to-noise ratio of 3:1. The plasma-level profile of l-Ep and d-Ps in a guinea pig was investigated by the newly developed method. The determination of l-Ep and d-Ps in a volunteer's plasma after oral administration of Xiao Qing-long H...

Determination of Plasma Pseudo-Ephedrine by Fluorescence Detection and High Performance Liquid Chromatography

Abstract A sensitive and specific high-performance liquid chromatographic method has been developed for the determination of pseudoephedrine in plasma. The assay was based on the production of a highly fluorescent derivative of pseudoephedrine using 4-chloro-7-nitrobenzo-2, 1, 3-oxadiazole (NBD-Cl) as the derivatization agent. The fluorescent derivatives were separated using normal phase liquid chromatography after an automated, column-switching, sample clean-up procedure. Pseudoephedrine determination was accurate and precise at concentrations as low as 10 nanograms per milliliter of plasma. The chromatographic step separated derivatives of pseudoephedrine from those of norpseudoephedrine and several other amines. Measurement of pseudoephedrine concentrations in plasma following a single 120 milligram oral dose is illustrated.

Sensitive high-performance liquid chromatographic determination of pseudoephedrine in plasma and urine

Sensitive high-performance liquid chromatographic determination of pseudoephedrine in plasma and urine

Steady-State Bioavailability of Dexbrompheniramine and Pseudoephedrine from a Repeat-Action Combination Tablet

The steady-state bioavailabilities of dexbrompheniramine and pseudoephedrine were evaluated following multiple-dose administrations of a repeat-action combination tablet containing 6mg of dexbrompheniramine maleate with 120mg of pseudoephedrine sulfate every 12h for 7 d compared with reference standards. The reference standards used in this study were concomitant administration of conventional 2-mg dexbrompheniramine maleate tablets every 4h and 120-mg pseudoephedrine sulfate repeat-action tablets every 12 h, each for 7 d. Twelve healthy adult male volunteers completed this randomized two-way crossover study. Blood samples for subsequent assay were obtained at frequent time intervals throughout each 7-d dosing phase. Sensitive and specific gas-liquid chromatographic methods were used for the determination of dexbrompheniramine and pseudoephedrine in plasma. Based on the plasma levels, the times to reach steady state were determined. In addition, the major bioavailability parameters (Cmin, Cmax, tmax, and AUC) for days 6 and 7 of dosing were determined and statistically evaluated. The results of this study demonstrate that, at steady state, the repeat-action combination tablet and concomitant administration of the reference standards are bioequivalent.

The influence of urinary pH on the plasma half‐life of pseudoephedrine in man and dog and a sensitive assay for its determination in human plasma

A sensitive method has been developed which allows estimation of pseudoephedrine in plasma at drug concentrations as low as 0.05 fLg per milliliter, making possible, for the first time, the measurement of pseudoephedrine in human plasma. In 3 normal volunteers, the plasma ty, of pseudoephedrine was 5.2,7.6, and 8.0 hours, respectively. When urinary pR was decreased by the administration of NR,Cl, the plasma ty, of pseudoephedrine decreased markedly. In contrast, when urinary pR was increased by the ingestion of NaRCOs, the plasma ty, of pseudoephedrine increased.