X-ray fluorescence analysis (XRF) has been employed for the identification and determination of elements with Z>18. In pharmacy, it can be used to determine the content of elements in drugs and pharmaceutical auxiliary substances. The method makes it possible to distinguish heavy metals in the tests of purity of drugs. It can also be used to verify the origin of the raw material or drug on the basis of its elemental composition. The present paper is concerned with the preparation of samples of pharmaceutical auxiliary substances for the determination of the content of the elements Fe, Cu, Zn, and Pb by the XRFmethod with the use of a radionuclide source of 238Pu. For the determination of the content of elements, three kinds of standards were prepared aiming to remove the effect of absorption properties of the sample. The results with statistical evaluations of precision of measurement are tabulated.The study carried out an analysis of 7 samples of fillers,3 samples of gelatine, 2 samples of SILOXID, and 1 sample of AEROSIL.

        Key words: X-ray fluorescence analysis (XRF) – heavy metals – drugs – pharmaceutical auxiliary substances