[Sterilization of non-air evacuated infusion flasks containing little water]

Studies have been carried out in connection with the sterilization of glass infusion bottles from which air had not been evacuated and containing certain limited quantities of water. Bottles with a capacity of 500 and 1000 cm3 were filled with 1-3 cm3 distilled water and sterilized in an autoclave for 20 min. set at a temperature of 121 degrees C reaching up to 126 degrees C. The sterility was tested by introducing bags containing Bacillus stearothermophilus spores into the centre of the bottles. Following sterilization the bottles were examined for the growth of spores allowing an incubation period of 7 days at 37 degrees C. Based on the actual conditions of this investigation, it would appear that a bottle from which air has not been evacuated should contain at least 2% (V/V) distilled water, when sterilized in an autoclave. It is, however, strongly recommended that the present findings should be validated based on actual conditions prevailing for individual sterilization procedures.