Comparison of two distinct phenolic antioxidants in γ‐sterilized NR compounds used as rubber pistons in syringes for single use

Abstract

AbstractThe effects of γ‐irradiation and aging on pharmaceutical NR compounds have been studied mainly by DSC. The extent of aging was measured quantitatively by enthalpy changes and peak temperature shifts of the primary oxidation exotherm. Quantitative thermal evaluations were supplemented by extraction tests and mechanical testing. The NR compound formula has been kept constant and only the type and concentration of antioxidant was varied. Two distinct phenolic antioxidants, BHT and Wingstay‐L at four different concentration levels, have been employed for this purpose. The most effective antioxidant package for a given elastomeric compound, subjected to γ‐irradiation and aging, giving the lowest changes in physical properties, is evaluated. © 1992 John Wiley & Sons, Inc.