Biological disposition of noscapine I. Kinetics of metabolism, urinary excretion, and organ distribution

✍ Scribed by K. P. Nayak; E. Brochmann-Hanssen; E. Leong Way

• Publisher: John Wiley and Sons
• Year: 1965
• Tongue: English
• Weight: 386 KB
• Volume: 54
• Category: Article
• ISSN: 0022-3549
• DOI: 10.1002/jps.2600540206

✦ Synopsis

Biologic dis osition studies of noscapine in the rabbit, rat, and mouse indicate a rapid rate o f biotransformation of this compound. When noscapine was administered intravenously to rabbits, it disappeared from the blood by first-order kinetics with a half-life of about 9 minutes. I n mice, the drug was found to have a half-life of 8.8 minutes and a first-order rate constant of 7.9 X minutes-'. Tissue distribution of noscapine in rats indicates that it is taken up by various organs within 1 minute after intravenous administration. High concentrations were found in the brain and the kidneys. However, the drug disappeared rapidly from most of the organs studied, especially from the brain which, at the end of 30 minutes, was virtually free of noscapine. Less than 1 per cent of the injected dose can be recovered unchanged from the urine of rabbits. OSCAPINE IS one of the principal alkaloids of N opium where i t occurs in concentrations ranging from 4 to 10%. It was isolated in 1817 by Robiquet, who named it narcotine. Actually, the narcotic properties of noscapine are rather insignificant. Its most important pharmacological activity is its antitussive effect, which was pointed out first by Chopra et al. in 1930 (1). In (2, 3).