Pharmacokinetics of norethisterone following its oral administration and by spraying it nasally or sublingually to male bonnet monkeys

Abstract

Pharmacokinetic parameters of norethisterone (NET) were studied in eight adult male bonnet monkeys following the administration of a single dose of 300 ug. The animals were crossed over between the following three routes of administration: oral ingestion, nasal and sublingual spraying. The results indicate that NET was readily absorbed by all three routes but the Cmax and AUC of NET were significantly greater by the sublingual route. No significant difference in the t 1 2 α or t 1 2 β was observed between the three routes. These findings suggest that the sublingual route offers the possibility of reducing the effective dose of NET, which is widely used for contraceptive purposes.