PT  - JOURNAL ARTICLE
AU  - Tan, Tjeng Giok
AU  - Wilson, Raymond Charles
TI  - The Efficacy of Antimicrobial Agents in Parenteral Products Assessed by the USP XIX Method Compared to the USP XVIII Method
DP  - 1980 Nov 01
TA  - PDA Journal of Pharmaceutical Science and Technology
PG  - 431--435
VI  - 34
IP  - 6
4099  - http://journal.pda.org/content/34/6/431.short
4100  - http://journal.pda.org/content/34/6/431.full
SO  - PDA J Pharm Sci Technol1980 Nov 01; 34
AB  - In 1975 the USP test for assessing the efficacy of preservatives was modified. Of major significance was the change in the temperature at which the killing rate was assessed (from 32 °C to the storage temperature specified on the label, or at 20 to 25 °C if no storage temperature is specified). For most of Connaught’s products the specified storage temperature is 2–8 °C. After July 1, 1975 all microbiological efficacy testing was performed on inoculated samples that were stored at about 4 °C. The results are presented as days required to attain at least 99.9% reduction in the number of viable lest organisms in the inoculated samples and indicate that preservative efficacy decreases when storage temperature is lowered from 32 to 4 °C. In two products the preservative was found not satisfactory when tested by the USP XIX method and a change of preservative was recommended.