The pharmaceutical agent comprises a particulate inorganic matrix, which contains portions of positron-emitting nuclides besides natural isotopic distribution of the structural type-forming elements of anions or cations. The inorganic matrix has a diameter ranging from 0.1 nm to 100 mu m. An independent claim is also included for a method for producing pharmaceuticals, which involves: (1) mixing of two solutions of soluble salts according to a precipitation reaction equation (2) forming a suspension in accordance with a precipitation reaction equation containing the particulate inorganic matrix and (3) mixing the two solutions of soluble salts to form an inorganic matrix and subsequently addition of the positron-emitting nuclides in anionic or cationic form.
