Abstract

HPLC Analysis and Identification of Compounds Inhibiting Bacterial Growth in Ozone Gas Sterilized Polysulfone and Polycarbonate

Hideharu Shintani and Akikazu Sakudo

Healthcare products must be sterilized before shipping. During sterilization the quality of the products must be maintained. Polysulfone (PS) and polycarbonate (PC) are often used as materials for medical devices. It has been observed that compounds inhibiting bacterial growth are produced when PS or PC are sterilized by autoclaving or by use of ozone gas, especially when ozone gas is used to sterilize PS. This study was conducted to identify the compounds inhibiting bacterial growth. An ethanol extract of the sterilized PS or PC was analyzed by liquid chromatography-moss spectrometry-UV photodiode array (210-350 nm) for identification and determination of the inhibitors. Bisphenol A, 4,4’-dihydroxydiphenyl sulfone (bisphenol S), and 4-chloro-4’-hydroxydiphenyl sulfone were identified in PS sterilized with ozone gas. Bisphenol A was also identified in PC sterilized with ozone gas. Bisphenol A was not a major inhibitor of bacterial growth because the extent of inhibition did not correlate with the amount of bisphenol A produced. Inhibition by 4-chloro-4’-hydroxydiphenyl sulfone was greater than by bisphenol S and correlated with the amount produced; the major inhibitor might therefore be 4-chloro-4’-hydroxydiphenyl sulfone. The synergistic effect of bisphenol S and 4-chloro-4’-hydroxydiphenyl sulfone might be a more realistic measure of the exact amount of inhibition.