Antimicrobial efficiency of chloramphenicol incorporated into ambiphilic emulsion bases was investigated, and it was shown that the efficiency was several times greater than the efficiency of a comercially available lipophilic dosage form. The efficiency was especially pronounced when the samples with a higher aqueous-phase content and of a lower viscosity were used. All ambiphilic preparations were stable when stored at 4 degrees C for 6 months, and when storage time was prolonged up to 1 year the most stable formulations were those which were prepared with a mixture of Tagat S and Tegin M.