The method of capillary isotachophoresis was employed to analyse the active ingredients in the ophthalmic drops Tetrakain 0.5% and Atropin 1%. A method has been worked out which represents simplification and increases selectivity in comparison with titration determination according PhBs 4. The pre-adjustment of samples only consists in necessary dilution with demineralised water, the length of determination not exceeding ten minutes. The method was applied to the investigation of stability of eye drops.

        Key words: tetracainium chloride – atropinium sulfate – ophthalmic drops – capillary isotachophoresis