Active charcoal is one of important adsorbents capable of binding on their surface other substances in a relatively large amount. This property is often used in pharmacy as well as in the studies of the structure – biological activity relationships, where active charcoal serves as a model substance for the study of hyrophobic interactions. The present paper investigates the adsorptivity of eight potential local anaesthetics from the group of 1-methyl-2-piperidinoethylesters of 2-, 3- and 4-alkoxyphenylcarbamic acids to adjusted active charcoal, which complies with the requirements of Slovak Pharmacopoeia 1. Adsorptivity of substances is evaluated according to Freundlich model and according to theamount of the bound substance β in per cents in dependence on time.The dependence of adsorptivity of substances β on local anaesthetic activity in topical local anaesthesia, which increases with increasing lipophilicity, is evaluated.

        Key words: adsorption – active charcoal – esters of phenylcarbamic acid – local anaesthetic agents