To evaluate the aseptic efficacy of prefilled syringes compared with ampules when used in a polluted environment similar to that at a disaster site.

The researchers tested epinephrine, 0.1%, atropine sulfate, 0.05%, and lidocaine hydrochloride solutions, 2% (Group A) as well as lidocaine hydrochloride, 10%, sodium bicarbonate, 8.4%, and glucose solutions, 50% (Group B), that frequently are used for intravenous injection and intravenous infusion respectively in Disaster Medicine.

Each of these solutions in 10 prefilled syringes (PFSs) and 10 ampules was placed in a box of contaminated soil along with needles and empty syringes for ampules. In the box, each was taken out of its package, all syringes were connected with a needle, and empty syringes were filled with a solution. After this procedure, all syringes were taken out of the box to check their contents for bacterial contamination.

No bacterium was observed in any of the 10 Prefilled syringes samples of Group A and B solutions. In contrast, out of 10 ampule samples, six of the 10 samples containing epinephrine, nine of the 10 containing atropine sulfate, all 10 samples containing lidocaine hydrochloride, 2%, and all of the ampule samples containing Group B solutions tested positive for bacteria. A statistically significant difference was observed between the PFS and ampule samples in all six solutions.

Results indicate that, in environments with airborne contaminants, the use of prefilled syringes may be useful for preventing bacterial contamination of the medicine inside.