A Pharmacokinetic Study to Compare Two Simultaneous 400 μg Doses with a Single 800 μg Dose of Oral Transmucosal Fentanyl Citrate

Abstract It is unknown whether two smaller doses of oral transmucosal fentanyl citrate (OTFC) administered simultaneously are pharmacokinetically equivalent to an identical dose administered as a single unit. This issue has important practical implications when patients are attempting to identify the appropriate dosage of OTFC to control their pain. This open-label, randomized, crossover design study compared the pharmacokinetics of two simultaneously consumed 400 μg OTFC doses with one 800 μg OTFC dose in 12 healthy volunteers. The two treatments were pharmacokinetically equivalent. The maximum concentration produced for each dosage group (Cmax) was 1.09 ng/ml for two 400 μg dose and 1.10 ng/ml for one 800 μg dose. Area under the curve (AUC) was 8.2 ng/ml·pChr (SE=1.1) and 7.2 ng/ml·pChr (SE=1.0). There were no significant differences between the treatment groups in either the time to peak concentration (Tmax) or the mean residence time (MRT). The results demonstrate the bioequivalence of two 400 μg with one 800 μg OTFC units.