Pharmacokinetics of heptacaine, a novel potent local anaesthetic agent, after rectal administration to rats.

The pharmacokinetics of heptacaine, N-(2-(2-heptyloxyphenylcarbamoyloxy)ethyl)-piperidinium chloride, a new long-acting potent carbanilate type local anaesthetic, proposed for local anaesthesia in complex treatment of hemorrhoids, was studied following its rectal administration to rats in the form of cocoa butter suppositories. The heptacaine plasma concentration, 0.0083% of dose/ml, peaked at 90 min post administration and the maximum rate of its bioavailability, 0.19% of dose/min, assessed by deconvolution, occurred 38 min post administration. The plasma elimination half-life of heptacaine was 133 min and its biological availability of 52% was comparable to other agents of the class.