The Absorption of Nicotine-1′-N-Oxide and its Reduction in the Gastro-Intestinal Tract in Man

Nicotine-1′-N-oxide is reduced to nicotine in the lower gastro-intestinal tract in man after oral administration.2. No reduction or metabolism in vivo occurred by other routes after administration of the N-oxide by intravenous injection.3. Rapid absorption of nicotine and nicotine-1′-N-oxide occurred from the upper gastro-intestinal tract but absorption of N-oxide was incomplete.4. The hepatic first-pass phenomenon shown by nicotine was dependent upon the site of absorption in the gastro-intestinal tract.5. No apparent lipid solubility of nicotine-1′-N-oxide could be demonstrated by the buccal absorption test.