In vitro-in vivo evaluation of a controlled release buccal bioadhesive device for oral drug delivery.

PURPOSE

To investigate the use of buccal bioadhesive device in targeting controlled drug delivery to the gastrointestinal tract.

METHODS

A three-leg crossover study was designed to evaluate the application of buccal bioadhesive device for providing controlled drug delivery to the gastrointestinal tract of a model drug cyanocobalamin in four healthy adult male beagle dogs.

RESULTS

In vitro dissolution studies using deionized water as the medium indicated that 100% of the drug was released within 15 min from a immediate release oral capsule formulation, whereas 90% of the drug was released within a period of 18 hrs from a buccal bioadhesive device formulation. Drug release from the buccal bioadhesive devices appeared to follow Higuchi's square root of time dependent model. The terminal half-life of the drug following I.V. administration in four dogs was found to be 16.4+/-2.4 hrs. Following immediate release oral capsule administration of the drug Cmax, tmax and bioavailability were 2333+/-1469 ng/L, 2.5+/-1.0 hrs and 14.1+/-7.9%, respectively. Following buccal bioadhesive device administration of the drug Cmax, t(max) and bioavailability were 4154+/-1096 ng/L, 11+/-1.2 hrs and 35.8+/-4.1%, respectively. Significantly higher bioavailability of the drug was observed with the buccal bioadhesive device administration when compared to the immediate release oral capsule.

CONCLUSIONS

The buccal bioadhesive device appears to improve the oral bioavailability of cyanocobalamin by providing controlled delivery of the drug to the gastrointestinal tract.