Investigating the sterility of ophthalmic preparations

Abstract

Investigations were made to prove the sterility of 290 ophthalmic preparations. 240 collyria were sterile, thus representing 82.75% of the examined samples. In the 50 contaminated collyria, there were present aerobic microorganisms in 37; fungi in 17 and aerobic microorganisms and fungi in 6 samples. Some of the collyria, containing silver or zinc salts, antibiotics and sulfanilamides, revealed the presence of contaminated microorganisms. The determination of ionic concentration presented in 7 collyria a pH under 5; in 99 between 5 and 8 (limit of the Brazilian Pharmacopoeia) and in 29 above 8. Values of the minimum pH observed: 2.5 (0.5% zinc sulfate collyrium) and maximum 9.1 (sodium sulfathiazole collyrium).