Pharmacokinetic comparison of the buprenorphine sublingual liquid and tablet

Buprenorphine is a mu opioid partial agonist being developed as a treatment for opioid dependence. Buprenorphine, usually administered as a sublingual liquid, is now being developed as a sublingual tablet for clinical use. The present study compared participants' plasma concentrations after daily maintenance on three buprenorphine liquid doses (2, 4 and 8 mg) and one tablet dose (8 mg). Fourteen opioid-dependent individuals (11 males, three females) participated. Plasma samples were collected over a 24-h period after at least 7 days of maintenance on each dose. Results showed that the liquid doses produced dose-related increases in plasma concentrations. The 8-mg tablet produced mean plasma concentrations significantly lower than those of the 8-mg liquid, although there was substantial individual variability. Thus, the buprenorphine tablet dose might have to be adjusted to produce plasma concentrations equivalent to those of the liquid.