Objective: In order to improve the oral bioavailability of cantharidin and get in vivo sustained release effect

carbomer and chitosan were used as bioadhesive materials to prepare stomach bioadhesive sustained release tablets of cantharidin. Method: Cantharidin was firstly prepared into inclusion with β-cyclodextrin to increase its solubility.Adhesive materials were screened by single factor tests.Orthogonal test was used to optimize prescription of stomach bioadhesive sustained release tablets of cantharidin.Adhesive effect of this preparation in rats was evaluated

in vitro release properties and oral bioavailability in Beagle dogs of this preparation were investigated. Result: Carbomer 934 and chitosan were used as adhesive material.Prescription of each tablet was cantharidin of 5 mg

β-cyclodextrin of 175 mg

carbomer 934 of 50 mg

chitosan of 50 mg

crospovidone of 80 mg

magnesium stearate of 4 mg.In vitro release of cantharidin in stomach bioadhesive sustained release tablets was 25%-35% after 3 h

it was more than 85% after 12 h.The tablets could adhered on surface of the gastric mucosa in Wistar rats after 8 h.The relative bioavailability of cantharidin in Beagle dog was 172%. Conclusion: Adhesive tablets of cantharidin has good stomach bioadhesive properties and sustained release.Cantharidin from the tablets releases stable and durable in Beagle dogs

its bioavailability significantly improves.