Use of cultured human conjunctival and other cells to assess the relative toxicity of six local anaesthetics.

The effects of six local anaesthetics on five cell types were investigated in vitro, with the objectives of assessing their toxicity to the cell types with which they would be likely to come into contact, ranking them in order of toxicity, determining whether toxicity was related to potency, and investigating a range of indices of toxicity. Procaine, lignocaine, piperocaine, amylocaine, amethocaine and cinchocaine all showed some toxicity increasing in that order. The indices of toxicity studied all led to the same ranking order of the drugs, and this order was also the order of their anaesthetic potencies. Thus cell culture was shown to be a useful means of investigating local anaesthetics for toxicity.