Investigations by means of analytical capillary isotachophoresis are possible not only for ampholytes, as peptides or amino acids, but generally for weak and strong electrolytes. Amantadine and rimantadine are determined by making use of a leading electrolyte including K+ ions at a pH range from 5.9 to 6.0 (terminating ion = creatinine+) at concentrations of the test solutions of greater than or equal to 600 nmol/ml and greater than or equal to nmol/ml, respectively, with a precision calculated as rel. S.D. (%) less than +/- 3 as a rule and a duration for one analysis less than 10 min. The tested discontinuous electrolyte system enables the determination of both the active substances simultaneously. The missing UV absorption of 1 and 2 is not disadvantageous by virtue of the application of the conductivity detector. The method was employed to carry out a content uniformity test for 2 tablets and informing experiments about the dissolution of 2 hydrochloride respectively 1 hydrochloride in water out of tablets and capsules, respectively.