Objective   To prepare thermosensitive in situ gel of ibuprofen (IBU) inclusion complex with poloxamer and evaluate its release behavior in vitro and in vivo.     Methods   The IBU inclusion complexes were prepared by lyopyilization. The poloxamer 407 and 188 were added as a base for the preparation of gel. The release of inclusion complex gel was evaluated by membraneless models. The pharmacokinetics was evaluated after intramuscular injecting IBU solution or IBU inclusion complex gel to New Zealand white rabbits. The drug concentrations in the plasma were measured by HPLC.    Results   The loading amount of IBU was 10.24%. The corrosion of gel a

nd the release of IBU correspond to zero-order kinetics. Compared with IBU solution

the t

max

and t

1/2

were prolonged and C

max

was degraded while AUC was enhanced obviously.    Conclusion   The IBU inclusion complex gel is used as a good injection with sustained-release which can improve the analgesia and anti-inflammatory effect of ibuprofen. And our study builds up the foundation for the use of water-insoluble drug in thermosensitive in situ gel.