Investigation of the Transfer of Septum Microbial Contamination by Hypodermic Needles

Abstract

The likelihood of the transfer of microbial contamination from the surface of a vial septum into the vial liquid, by penetration of a hypodermic syringe needle, has been investigated. Experimental work was carried out with vials containing sterile microbial growth media and the use of needles of three different diameters. Three different concentrations of microbes on the surface of the vial septum (10, 100, and 1000) were used. Microbial contamination that was transferred into the growth media was determined by incubation of the vials following penetration of the septum by the needles. Contamination was detected in 87% of all the vials tested, and was generally found to increase as the concentration of septum challenge organisms and needle diameter increased. Key words: Septum seals, hypodermic needles, multi-use vials, microbial contamination