Lyophilised dabigatran

Abstract

The invention relates to a lyophilised form of dabigatran of formula I its use as a calibrator in the assays for the determination of pharmacodinamic effects of dabigatran etexilate as well as such assays per se.

1 - 4 . (canceled) 
     
     
         5 . The lyophilized dabigatran made by the process comprising the steps of:
 (1) dissolving dabigatran in 1M HCl and diluting with purified water to make a dabigatran stock solution,   (2) diluting aliquots of dabigatran stock solution with human anticoagulated plasma to provide final solutions having different nanomolar concentrations of dabigatran, wherein the human anticoagulated plasma is human citrated plasma or EDTA-anticoagulated plasma, and   (3) freeze-drying aliquots of the thus obtained final solutions to be used as lyophilized calibrator agents or lyophilized calibrator agents in an anticoagulant assay, optionally storing lyophilized calibrators at −20 ° C.   
     
     
         6 . The lyophilized dabigatran according to  claim 5 , wherein the lyophilised dabigatran is used as a calibrator agent or a calibrator agent in an anticoagulation assay. 
     
     
         7 - 10 . (canceled) 
     
     
         11 . A kit for the determination of the concentration of dabigatran in a blood sample consisting of an assay for the determination of the concentration of dabigatran in a blood sample together with lyophilised dabigatran according to  claim 5 . 
     
     
         12 . The kit according to  claim 11  wherein the assay for the determination of the concentration of dabigatran in a blood sample comprises a reagent 1 which is human anticoagulated plasma and a reagent 2 which comprises highly purified human thrombin in the a form. 
     
     
         13 . The kit according to  claim 11  wherein reagent 1 and reagent 2 are lyophilised. 
     
     
         14 - 15 . (canceled) 
     
     
         16 . The lyophilized dabigatran according to  claim 5 , wherein the lyophilised dabigatran is used to determine the accuracy of an assay or an anticoagulation assay.