A possible relation between pKa 1 and lipid solubility and the amounts excreted in urine of some tobacco alkaloids given to man

The amount of unchanged (—)-nicotine, (—)-nornicotine, (—)-methylanabasine and (—)-anabasine excreted in the urine after oral administration to man was dependent on urinary pH while that of (—)-cotinine depended on urinary pH and on urine flow rate. No unchanged β-nicotyrine, β-nornicotyrine or myosmine was detected in urine. More nornicotine and anabasine than their corresponding tertiary amines nicotine and methylanabasine were excreted unchanged in the urine. Correlations of pKa1 and lipid solubility and the urinary excretion of these compounds were made.

The analysis of nicotine-1'-N-oxide in urine, in the presence of nicotine and cotinine, and its application to the study of in vivo nicotine metabolism in man

A rapid quantitative assay for nicotine-1′-N-oxide in urine, in the presence of nicotine and cotinine, is reported. The urinary excretion of nicotine, cotinine and nicotine-1′-N-oxide was determined after nicotine had been administered in cigarette smoke, orally, or intravenously to subjects with either fluctuating, controlled acidic or controlled alkaline urinary pH. The urinary excretion of the N-oxide in 24 h from smokers under normal conditions was about half that of the cotinine excretion; more trans- than cis-diastereoisomer of nicotine-1′-N-oxide was excreted.

The effect of smoking on nicotine metabolism in vivo in man

Nicotine and a basic metabolite, cotinine, were determined in the urine by gas-liquid chromatography after intravenous administration of (—)-nicotine hydrogen (+)-tartrate to groups of male and female smokers and non-smokers in whom the urine was maintained at an acid pH. The urinary recoveries of nicotine and cotinine from male smokers fell in two groups. One showed a lower recovery of both alkaloids than was seen with male non-smokers. The other showed a similar recovery of nicotine but more cotinine than the male non-smokers. Female smokers excreted less nicotine but more cotinine than female non-smokers. More nicotine but less cotinine was excreted by female non-smokers than by male non-smokers. The results show sex dependent metabolism of nicotine occurs in non-smoking humans and that smoking causes alterations in nicotine metabolism.

Metabolism of small multiple doses of (14C) nicotine in the cat

1. The distribution and metabolism of (2'-(14)C) nicotine given as a series of small intravenous injections (4 mug/kg every 60 s for 20 min) have been studied in the cat.2. Blood concentrations of ((14)C) nicotine reached a maximum of 100 ng/ml at 20 min whereas blood concentrations of cotinine were maximal shortly afterwards.3. The maximum concentration of nicotine in the blood was greater than that obtained by giving the same total dose as a continuous infusion ((4 mug/kg)/min for 20 min).4. Urinary excretion accounted for 90% of the total multiple dose in 72 hours. After 24 h, however, only 2.5% of the radioactivity as ((14)C) nicotine and 0.05% as ((14)C) cotinine was excreted.5. Gastric juice after 2 h contained significant amounts of activity which was almost entirely composed of ((14)C) nicotine and ((14)C) cotinine.6. There were significant regional differences in the concentration of ((14)C) nicotine in the brain; amounts were greatest in cerebral hemispheres and smallest in the spinal cord. The hypothalamus and thalamus contained significantly higher concentrations of ((14)C) nicotine than the whole mid brain. ((14)C) Cotinine concentrations were highest in the cerebellum.

Routine detection and identification in urine of stimulants and other drugs, some of which may be used to modify performance in sport

A general procedure for the analysis in urine of basic drugs (and their metabolites), some of which may be misused as stimulants in sport, has been developed. The techniques used include gas-liquid and thin-layer chromatography and linked gas-liquid chromatography—mass spectroscopy. It is recommended that international control of drug-taking in sport be based primarily upon urine analysis by gas-liquid chromatography systems and also derivative formation followed by gas-liquid chromatography. The principles outlined in the procedure can be applied in a much wider forensic context.