Question

Which of the following is topical with high concentration?

(a) Lignocaine

(b) Cocaine

(c) Procaine

(d) Benzocaine

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I'm obligated to ask this question of Mechanism of Action of Local Anesthetic topic in section Local & General Anesthetics, Opioid Analgesics, Drug Addiction and Drug Abuse of Drug Biotechnology

Answer 1

Right choice is (d) Benzocaine

Best explanation: Used mainly as topical, due to its poor water solubility, and because of its low toxicity, it can be used in concentration up to 20%. Hydrolysed rapidly by plasma esterase to p-aminobenzoic acid accounting for its low toxicity. Lignocaine is an amide-type drug. It is highly lipophilic and rapidly absorbed.