Human buccal absorption of flurbiprofen

Area of Science:

• Pharmacokinetics and Drug Delivery
• Biopharmaceutics
• Membrane Transport

Background:

• Understanding drug absorption through oral mucosa is crucial for developing effective drug delivery systems.
• Buccal drug administration offers an alternative route bypassing first-pass metabolism.
• Previous studies suggested pH-dependent transport, but human buccal membrane characteristics required further elucidation.

Purpose of the Study:

• To quantify the buccal absorption of flurbiprofen in humans.
• To evaluate a closed-perfusion cell apparatus for studying drug transport across accessible biological membranes.
• To characterize the mechanism and kinetics of flurbiprofen transport across the human buccal mucosa.

Main Methods:

• Investigated buccal absorption of flurbiprofen in healthy male subjects.
• Employed a closed-perfusion cell apparatus to simulate oral cavity conditions.
• Measured membrane permeability coefficients at different pH values (5.5 and 7.0).

Main Results:

• Flurbiprofen absorption via the buccal route follows a passive diffusional mechanism.
• The rate of buccal absorption of flurbiprofen is significantly pH-dependent.
• Observed membrane permeability coefficients were 4.3 x 10(-4) cm/sec at pH 5.5 and 2.1 x 10(-5) cm/sec at pH 7.0.

Conclusions:

• Human buccal membranes function as lipoidal barriers with permeability characteristics comparable to those in dogs.
• The study validated the closed-perfusion cell apparatus for assessing drug transport across buccal membranes.
• Findings support the prediction of drug absorption extent based on permeability and boundary layer characteristics.