Many cosmetics and personal care products are now available in the form of pre-saturated towelettes or wipes. Like the majority of personal care products having an aqueous base, pre-saturated towelettes are susceptible to microbial contamination and require a preservation system to protect them from degradation. Cosmetics and personal care products made in the form of towelettes or wipes can harbor harmful microorganisms just like any other consumer product that is not properly preserved. Their preservation system must also be verified as appropriate through empirical challenge testing. The efficacy of such preservatives could be evaluated on the liquid formulation, however, this alone cannot be considered as good representation for the formulation when added to the towelettes or wipes.
Cosmetic Test Labs has modified methods for the USP <51> challenge test method, and the Preservative Challenge Screen, along with the CTFA M-5 method to include cosmetics and personal care products in the form of pre-saturated towelettes or wipe products. These modified methods allow the efficacy of preservatives used in towelette and wipe products to be evaluated while being kept in their original form.