scholarly journals Electrometric measurement of plasma, erythrocyte, and whole blood cholinesterase activities in healthy human volunteers

2007 ◽  
Vol 3 (1) ◽  
pp. 25-30 ◽  
Author(s):  
F. K. Mohammad ◽  
A. S. Alias ◽  
O. A. H. Ahmed
Keyword(s):  
Whole Blood ◽  
Healthy Human ◽  
Human Volunteers ◽  
Cholinesterase Activities ◽  
Electrometric Measurement

Determination of Factors Affecting Glutamate Concentrations in the Whole Blood of Healthy Human Volunteers

2011 ◽  
Vol 23 (1) ◽  
pp. 45-49 ◽  
Author(s):  
Alexander Zlotnik ◽  
Sharon Ohayon ◽  
Benjamin F. Gruenbaum ◽  
Shaun E. Gruenbaum ◽  
Boaz Mohar ◽  
...  
Keyword(s):  
Whole Blood ◽  
Healthy Human ◽  
Factors Affecting ◽  
Human Volunteers

Pharmacokinetics of Mephedrone and Its Metabolites in Whole Blood and Plasma after Controlled Intranasal Administration to Healthy Human Volunteers

2020 ◽  
Author(s):  
Joanna Czerwinska ◽  
Mark C Parkin ◽  
Claire George ◽  
Andrew T Kicman ◽  
Paul I Dargan ◽  
...  
Keyword(s):  
Whole Blood ◽  
Intranasal Administration ◽  
Plasma Samples ◽  
Healthy Human ◽  
Rapid Absorption ◽  
Plasma Distribution ◽  
Human Volunteers ◽  
Liquid Chromatography Tandem Mass ◽  
Synthetic Cathinone ◽  
First Time

Abstract Mephedrone is a popular synthetic cathinone, known for its psychostimulant effects. At present, there is no data available on the pharmacokinetics of mephedrone and its metabolites in concurrently collected whole blood and plasma samples after a controlled intranasal administration to healthy volunteers. In this study, six healthy male volunteers nasally insufflated 100 mg of pure mephedrone hydrochloride (Day 1). Whole blood and plasma samples were collected at different time points after the administration and were analyzed for the presence of mephedrone and its metabolites, dihydro-mephedrone (DHM), nor-mephedrone (NOR), hydroxytolyl-mephedrone (HYDROXY), 4-carboxy-mephedrone (4-CARBOXY) and dihydro-nor-mephedrone (DHNM), by validated liquid chromatography–tandem mass spectrometry methods. All analytes were detected in whole blood and plasma for 6 h post administration, with mephedrone and NOR also being detectable on Day 2 in some participants. 4-CARBOXY, followed by NOR, was the most abundant metabolite in both matrices. Compared to other psychostimulants, mephedrone showed rapid absorption (mean Tmax of 52.5 ± 20.7 min in plasma and 55.0 ± 18.2 min in whole blood) and elimination (mean t1/2 of 1.98 ± 0.30 h in plasma and 2.12 ± 0.33 h in whole blood). In addition, statistical analysis showed that median whole blood to plasma distribution ratios, reported here for the first time, were statistically different from 1 (unity) for mephedrone (median: 1.11), DHM (median: 1.30) and NOR (median: 0.765). It is hoped that the study will aid forensic and clinical toxicologists in detection, identification and interpretation of cases associated with mephedrone use.

scholarly journals Pharmacokinetics of Mephedrone Enantiomers in Whole Blood after a Controlled Intranasal Administration to Healthy Human Volunteers

2020 ◽  
Vol 14 (1) ◽  
pp. 5
Author(s):  
Joanna Czerwinska ◽  
Mark C. Parkin ◽  
Agostino Cilibrizzi ◽  
Claire George ◽  
Andrew T. Kicman ◽  
...  
Keyword(s):  
Whole Blood ◽  
Intranasal Administration ◽  
Chiral Recognition ◽  
Area Under The Curve ◽  
Healthy Human ◽  
Enantiomeric Ratio ◽  
Human Volunteers ◽  
Liquid Chromatography Tandem Mass ◽  
Neurological Effects ◽  
Enantioselective Pharmacokinetics

Mephedrone, which is one of the most popular synthetic cathinones, has one chiral centre and thus exists as two enantiomers: R-(+)-mephedrone and S-(−)-mephedrone. There are some preliminary data suggesting that the enantiomers of mephedrone may display enantioselective pharmacokinetics and exhibit different neurological effects. In this study, enantiomers of mephedrone were resolved via chromatographic chiral recognition and the absolute configuration was unambiguously determined by a combination of elution order and chiroptical analysis (i.e., circular dichroism). A chiral liquid chromatography tandem mass spectrometry method was fully validated and was applied to the analysis of whole blood samples collected from a controlled intranasal administration of racemic mephedrone hydrochloride to healthy male volunteers. Both enantiomers showed similar kinetics, however, R-(+)-mephedrone had a greater mean Cmax of 48.5 ± 11.9 ng/mL and a longer mean half-life of 1.92 ± 0.27 h compared with 44.6 ± 11.8 ng/mL and 1.63 ± 0.23 h for S-(−)-mephedrone, respectively. Moreover, R-(+)-mephedrone had a lower mean clearance and roughly 1.3 times greater mean area under the curve than S-(−)-mephedrone. Significant changes in the enantiomeric ratio over time were observed, which suggest that the analytes exhibit enantioselective pharmacokinetics. Even though the clinical significance of this finding is not yet fully understood, the study confirms that the chiral nature, and consequently the enantiomeric purity of mephedrone, can be a crucial consideration when interpreting toxicological results.

Effects of the malononitrilamide FK778 on immune functions in vitro in whole blood from non-human primates and healthy human volunteers

2003 ◽  
Vol 11 (2) ◽  
pp. 163-167 ◽  
Author(s):  
Tudor Bı̂rsan ◽  
Camille Dambrin ◽  
Jochen Klupp ◽  
Mario Stalder ◽  
William E. Fitzsimmons ◽  
...  
Keyword(s):  
Whole Blood ◽  
Immune Functions ◽  
Healthy Human ◽  
Human Volunteers

Gastroretentive Floating Capsules of Risedronate Sodium: Development, Optimization, in vitro and in vivo Evaluation in Healthy Human Volunteers

2015 ◽  
Vol 8 (2) ◽  
pp. 2835-2842
Author(s):  
Bhikshapathi D. V. R. N. ◽  
Arun Kumar Jarathi ◽  
Suresh Gande ◽  
Viswaja Medipally ◽  
Ramesh Bomma
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Zero Order ◽  
Wet Granulation ◽  
Capsule Formulation ◽  
In Vivo Evaluation ◽  
Healthy Human ◽  
X Ray ◽  
Human Volunteers

Background and the purpose of the study: Risedronate sodium inhibits osteoclast bone resorption and modulates bone metabolism. Risedronate has a high affinity for hydroxyapatite crystals in bone and is a potent antiresorptive agent. In the present investigation efforts were made to improve the bioavailability of risedronate sodium by increasing the residence time of the drug through sustained-release matrix capsule formulation via gastroretentive mechanism. Capsules were prepared by wet granulation technique. The influence of gel forming agents, amount of risedronate and total weight of capsules on physical properties, in vitro buoyancy, drug release, FTIR, DSC, X-ray studies were investigated. The release mechanisms were explored and explained by applying zero order, first order, Higuchi and Korsmeyer equations. The selected formulations were subjected to stability study at 40 °C/75% RH, 25 °C/60% RH for the period of three months. For all formulations, kinetics of drug release from capsules followed Higuchi’s square root of time kinetic treatment heralding diffusion as predominant mechanism of drug release. Formulation containing 25 mg HPMC K4M and 75 mg HPMC K100 LV (F-8) showed zero order release profile. There was no significant change in the selected formulation, when subjected to accelerated stability conditions over a period of three months. X-ray imaging in six healthy human volunteers revealed a mean gastric retention period of 5.60 ± 0.77 hrs for the selected formulation. Stable, sustained release effervescent floating capsules of risedronate sodium could be prepared by wet granulation technique.  

Synthetic Nanoclay Gels Do Not Cause Skin Irritation in Healthy Human Volunteers

2021 ◽  
Author(s):  
Luciana E. Bostan ◽  
Claire E. Clarkin ◽  
Mohamed Mousa ◽  
Peter R. Worsley ◽  
Daniel L. Bader ◽  
...  
Keyword(s):  
Skin Irritation ◽  
Healthy Human ◽  
Human Volunteers
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