Sensitivity Differences in Testing of Polyurethane Condoms’ Lubricant Compatibility

Abstract

Abstract Over-the-counter (OTC) personal lubricants (PLs) generally have less potent effects on condoms’ mechanical properties than do appropriate positive controls. Therefore, to assess the compatibility of OTC PLs with condoms, a test method must be more sensitive than those employed to capture the effect of a strong positive control. Using various percent compositions of selected common ingredients in commercial PLs, we attempted to differentiate between the sensitivities of different methods for testing lubricant effects on polyurethane (PU) condoms. After discrete applications of each composition, we studied induced stresses and stress-to-strain ratios at various strain rates, and stress reduction at a constant stretch, in PU condom coupons at 37°C. Swelling was studied at room temperature (RmT). Changes in the induced stress and stress-to-strain ratio because of low percent composition of a potent surrogate component were detectable only at low strain rates. A few low percent compositions of potent ingredients – though they induced insignificant changes in the material as detected by tensile testing and did not swell the PU material – noticeably reduced the percent stress at a constant stretch. Slower strain rates in tensile testing were necessary to detect the effects of low potency combinations, whereas stress reduction was the most efficient detector of change at a constant physiologically relevant strain. Absence of swelling and insignificant changes in tensile properties at high strain rates did not guarantee an absence of interactions. Manufacturers now have a more sensitive method for capturing the interactions of PU condoms with OTC PLs, which are generally less potent than appropriate positive controls.