title: Developing a modified preservative efficacy testing approach as a predictive tool for the evaluation of preservative systems in liquid home care products under variable test conditions.
abstract: How can a formulator have confidence that a preservative system will perform as expected under adverse conditions? Extreme conditions that can lead to the development of "off odors" in the product can be a serious challenge for companies providing home care products in the global market. Formulation and stability testing occur under controlled parameters that simulate limited environmental conditions and microbial challenges are typically performed with a standard inoculum level. While this is an acceptable and dependable process, it does not necessarily assess how well a preservative system can perform under extreme environmental conditions or against unusually high levels of bacterial challenges. This is especially true when formulations are diluted and stored by the end-user. By modifying microbial challenge testing of a liquid dishwashing product to include unexpected dilution schemes, increased microbial assaults, and elevated temperatures, a pattern of preservative efficacy was established. The resulting approach proved to be a useful tool when developing use directions, recommended dilution levels, the overall surfactant system, preservative type, and storage restrictions.
authors.affiliation: Access Business Group LLC, 7575 Fulton East, Ada, MI 49355, USA. anne.hoyt@amway.com
authors.forename: Anne L
authors.initials: AL
authors.lastname: Hoyt
authors.forename: Don
authors.initials: D
authors.lastname: Bushman
authors.forename: Nathan
authors.initials: N
authors.lastname: Lewis
authors.forename: Robert
authors.initials: R
authors.lastname: Faber
mesh_terms: D001419:Bacteria; D058491:Bacterial Load; D015169:Colony Count, Microbial; D003902:Detergents / Q000032:analysis; D024881:Drug Resistance, Bacterial; D005612:Freeze Drying; D006795:Household Products / Q000032:analysis*; D011237:Predictive Value of Tests; D011310:Preservatives, Pharmaceutical; D015203:Reproducibility of Results; D013048:Specimen Handling; D013242:Sterilization; D013501:Surface-Active Agents; D013696:Temperature; D015003:Yeasts
chemical_list: D003902:Detergents; D011310:Preservatives, Pharmaceutical; D013501:Surface-Active Agents