International harmonization of cosmetic regulations requires that manufacturers provide quantitative documentation of the release levels of preservatives and sunscreens in their products. Manufacturers need analytical test procedures that quantitate the various combinations of sunscreens and preservatives found in products. This article describes a method that enables the simultaneous quantitative determination of sunscreens and preservatives contained in cosmetic emulsions. The article also describes the validation of that method.
Both sunscreens and preservatives are increasingly found in cosmetic products. Sunscreen actives are added to achieve a Sun Protection Factor (SPF) claim and preservatives are used to insure the microbial integrity of the product during consumer use. Sunscreens are considered drugs in the United States and several other countries. The U.S. Food and Drug Administration (FDA) and other global regulatory agencies mandate that drug actives be declared at the labeled level. Commonly, preservatives are added to formulas containing sunscreens. The manufacturer is required to document the release levels of the sunscreen actives and preservatives. Therefore there is a need to develop and validate the appropriate analytical test procedures.