The pharmacokinetics and acceptability of benoxaprofen following rectal administration.

The bioavailability of a single 300 mg dose of benoxaprofen was compared after rectal and oral administration in 5 subjects. The total absorption rectally from a suppository was 83% of that achieved orally from a capsule. Six further subjects took a 300 mg benoxaprofen suppository twice daily for 12 d. Steady state plasma levels (mean level 94 microgram/ml) were reached at about 120 h, while the elimination half-life for benoxaprofen was approximately 38 h in this study. The suppositories were well tolerated. The plasma levels obtained compared very favorably with theoretically expected levels and levels obtained after comparable oral doses.