Will a water gradient in oral mucosa affect transbuccal drug absorption?

• Formulations for buccal drug delivery often comprise polymers to facilitate mucoadhesion based on water sorption. The main objective of the current study was therefore to evaluate the effect of dehydration on drug uptake through oral mucosa. We have used diffusion cells with excised porcine mucosa to study uptake of three alternative drugs (i.e., Metronidazole, Benzydamine and Xylometazoline) together with polyethylene glycol (PEG) as the model polymer for adjusting water activity in the test solutions. Taking drug activity into account, we can conclude that addition of PEG results in a drug flux through mucosa that is about two times lower for Metronidazole and more than 40 times lower for Xylometazoline compared to that from a pure PBS-solution. However, for Benzydamine the uptake through mucosa was more or less the same, which could possibly be due to the high PEG-concentration (65 wt%) affecting the dissociation constant and thus the permeability. These results indicate that an increased water gradient may have the same limiting effect on permeability through oral mucosa as previously seen for skin. Thus, water gradient effects should be a factor to consider when developing buccal adhesive formulations.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Farmaceutiska vetenskaper (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Pharmaceutical Sciences (hsv//eng)

Keyword

Buccal drug delivery

Oral mucosa

Permeability

Hydration

Drug transport

Formulation

Buccal drug delivery

Drug transport

Formulation

Hydration

Oral mucosa

Permeability

Publication and Content Type

ref (subject category)

art (subject category)