[en] Samarium-153-ethylenediaminetetramethylenephosphonate (¹⁵³Sm-EDTMP) has been used to palliate pain resulting from bone cancer. This paper describes the preparation of ¹⁵³SmCl₃ from irradiated natural samarium and the ability of ¹⁵³Sm to complex with EDTMP in liquid and in freeze-dried forms. The evaluation of radiolabeled EDTMP was done by paper chromatography. A rapid evaluation of free ¹⁵³SmCl₃ and ¹⁵³Sm-EDTMP was developed using a miniaturized chromatographic system. (author) 7 refs.; 4 figs.; 3 tabs