Adsorption of Substances on Active CharcoalPart 1: Basic Esters of Phenylcarbamic Acid with Local Anaesthetic Effect

Overview

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

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