Patent ID: 8496910

Claim:
A method for improving stability of a non radiolabelled nucleoside derivative which comprises storage of a formulation of a non radiolabelled nucleoside derivative of formula (I): wherein P 1 is selected from the group consisting of hydrogen, triphenylmethyl, tri-C 1-6 alkylmethyl, triphensilyl, phenyl carbonyl, and tri-C 1-6 alkylsilyl wherein phenyl groups are optionally substituted by one to five substituents independently selected from the group consisting of C 1-6 alkyl, C 1-6 alkoxy, and halogen; P 2 is selected from the group consisting of hydrogen, C 2-10 alkyloxycarbonyl, and benzyl optionally substituted with one to five substituents independently selected form C 1-6 alkyl, C 1-6 alkoxy, and halogen; and L is selected from the group consisting of halogen, arylsulphonate, halo C 1-6 alkyl sulphonate, and C 1-6 alkyl sulphonate and wherein said formulation consists essentially of said non radiolabelled nucleoside derivative, and a solvent in a sealed container and wherein the solvent has a water content of 1000 ppm or less.