Enhancement of exfoliating efficacy of L-carnitine with ion-pair method monitored by nuclear magnetic resonance spectroscopy.

Carnitine (CAR), an amino acid derivative, has great potential as a facial exfoliating agent owing to its calcium chelating property under weakly acidic or neutral conditions. However, its application is limited by its poor transdermal penetration. To optimise its exfoliation efficacy with minimal concentration, we propose the ion-pair method.