Pharmacokinetics and tissue distribution of schizonepetin in rats.

Schizonepetin, a natural monoterpene from Herba Schizonepetae, is a potential antiviral agent. In this paper, a simple, rapid and sensitive HPLC-UV method was first developed and validated for the determination of schizonepetin in rat plasma and tissue homogenates after oral and intravenous administration. The results showed that schizonepetin was absorbed and eliminated rapidly, and its oral absolute bioavailability in rats achieved about 75%. The drug distributed widely in various tissues of rats, and had no long-term accumulation in vivo. The research provides reliable scientific data for designing drug treatment regimens of schizonepetin.