References: 1. McCullough JL, Principal Investigator. OMP 05-02: In vitro percutaneous absorption of Vitamin C topical formulations in human skin. April 27, 2005. OMP, Inc. Data on file. 2. Lehman PA, Investigator, PRACS Institute. Determination of the percutaneous absorption kinetics of ascorbic acid and ascorbic acid 2-glucoside, in vitro, using the human cadaver skin model (protocol R07-0278, August 2007). OMP, Inc. Data on file.