Abstract

The effect of delayed sterilization on the production of intravenous fluids using 5%(w/v) dextrose solution was studied. The 5% (w/v) dextrose was prepared with distilled water. The solution was inoculated with a laboratory isolate of Escherichia coli and thereafter divided into two: Solutions A and B. Sample A was sterilized within 1 h of innoculation, while B was incubated at 37°C for 48 h and sterilized after. The microbial load was determined before sterilization. Both samples were then tested for pyrogenicity using rabbit test of pyrogen. The results revealed a significant (P < 0.05) increase in E. coli  count in solution B from 8 ± 2 to 99 ± 5 cfu/ml after 48 h. Sample A became pyrogen-free after sterilization (sum of response (SR) of 3 rabbits, 0.75°C), while sample B contained 40 EU/ml (limit: ≤ 0.5 EU/ml for large volume parenteral). A 10 times dilution of sample B with pyrogen-free 0.9% w/v sodium chloride produced a response of 2.80°C and SR of 3 rabbits (failed limit ≥ 2.65°C). From this study, a delay of up to 48 h before sterilizing solutions intended for parenteral use could produce high pyrogenicity.

Key words: Parenterals, pyrogen, Escherichia coli, sterilization, microbial load.

Abbreviation

SDA, Sabouraud dextrose agar; EMB, eosin-methylene blue agar;NA, nutrient agar; GMP, good manufacturing practices; CFU, colony forming unit;TNTC, too numerous to count.