ISSN:
1573-739X
Keywords:
Bacillus
;
Colony-forming units, assay
;
Heating
;
Infusions, parenteral
;
Spores, bacterial
;
Sterilization
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract In order to calculate the minimum sterilization process conditions to obtain the generally accepted sterility level (less than 1·10−6 probability of microbial survival), we determined the bioburden and its heat resistance of 500 ml large-volume parenteral bottles over a period of 5 years. For the bioburden determination 1,832 bottles were examined by the membrane filtration method. Mean bioburden was 9.36 colony-forming units/bottle. Of the colony-forming units isolated 118 were heat resistant (0.69%). These were spore-formingBacillus species. Of the isolatedBacillus species heat resistance was determined in 5% glucose, 0.9% sodium chloride and 8% amino acids solution.D values greater than 1 min at 105°C were found for 2, 5 and 4 differentBacillus species in glucose 5%, sodium chloride 0.9% and amino acids 8%, respectively. 2Bacillus species showed aD value over 2 min at 105°C in all three media.D values at 110°C in sodium chloride 0.9% for these 2Bacillus species were 1.8 and 2.6 min and in amino acids 8% 0.9 and 1.7 min, respectively. The minimum sterilization process time at 110°C, calculated with the experimentally determined bioburden andD values is less than 25 min. When introducing reduced exposure times/temperatures, each individual manufacturer should assess the bioburden. The time-consuming determination of the heat resistance of bioburden isolates is not always necessary. By dividing the isolated colony-forming units in a ‘heat-resistant’ group and a ‘not-heat-resistant’ group, changing from standard overkill sterilization procedures to processes with lowerF 0 values is possible.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01981530
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