[Comparison of the efficacy of 3 methods of testing for the sterility of eye ointments with antibiotics].

Efficiency of 3 methods for testing sterility of antibiotic ophthalmic ointments was compared. During storage of antibiotic ophthalmic ointments infected with bacteria some "self-sterilization" takes place mainly due to death of the antibiotic sensitive bacteria. The results of determination of the ointment non-sterility depends on the level of their bacterial loading, sensitivity of the cultures to the antibiotic and time of the culture contact with the antibiotic in the ointment before its testing. The method of the ointment solution in isopropylmiristate filtration through a membrane filter followed by washing of the filter from the antibiotic and its placing into a thioglycol medium proved to be most effective for determination of bacterial admixtures in antibiotic ointments.