Abstract
The idea is generally accepted by most pharmacologists that the physiological activity and toxicity of powerful alkaloids are practically the same as that of their salts, provided allowance is made for the slight increase in molecular weight of the salts due to the acid radicles, and for the difference in solubility between the alkaloids and their salts. The chief exception to the rule, in a limited way, is cocaine. The addition of sodium bicarbonate to cocaine solution increases its efficiency as a local anesthetic when applied directly to nerve trunks, and this is claimed to be due to the greater penetration of the alkaloid for the nerve tissue. Such a difference is not noted after hypodermic or intradermal injections. 1 , 2 , 3
In connection with a comparative pharmacological and toxicological study of β-pyridyl-α(N-methyl)-pyrrolidine, or nicotine, and a new series of related chemical derivatives of pyrrolidine, the writers noted a marked difference in the physiological activity of the alkaloid itself and its salts. Previous writers have noted a difference in toxicity between nicotine and its salts but their work dealt mostly with the effects of these chemicals as insecticides. Del Quercio, 4 reporting some experiments on silkworms sprayed with aqueous solutions of nicotine and its salts, states that acidulated nicotine was less active than the alkaline substance itself. Moore and Graham, 5 comparing the effects of nicotine sulphate with and without sodium carbonate on certain aphids, found that the sulphate was less active than nicotine solution containing sodium carbonate. Moore and Row 6 found nicotine itself more toxic for the frog than nicotine hydrochloride.
De Ong 7 showed that free nicotine administered orally to chickens was more toxic than nicotine sulphate; and Langley and Dickinson noted that nicotine solution was more active for ganglion cells and nerve fibers than nicotine sulphate. 8
Get full access to this article
View all access options for this article.