Objective: To optimize the formulation of osthole solid dispersible tablets and investigate its in vitro release characteristics. Method: Taking composite score of disintegration and hardness as index

formulation of osthole solid dispersible tablets was optimized by orthogonal test.Release characteristics of osthole solid dispersible tablets and osthole were investigated by RP-HPLC. Result: The proportion of each adjuvant in optimal formulation was 40% of microcrystalline cellulose (MCC)

4% of low-substituted hydroxypropyl cellulose (L-HPC)

12% of crosslinked polyvidone (PVPP)

43.5% of osthole solid dispersion and 0.5% of aerosil.The tablets disintegrated in 80.5 s

the hardness was 4.4 kg

the dispersible uniform was excellent.Release parameters of osthole solid dispersible tablets were remarkly better than these of osthole group;tmax of osthole solid dispersible tablets group was1 h

its Cmax was 37.42 mg·L-1

AUC0-t was 43.04 mg·L-1·h. Conclusion: Osthole solid dispersible tablets has characteristics of uniformly dispersing and quick releasing of active constituents

it can significantly inprove the bioavailability of osthole in rats.