Validation of analytical methodology for quantification of octyl methoxycinnamate and avobenzone in sunscreen using 1H NMR spectroscopy

Abstract

The sunscreens are used to prevent damage caused by UV radiation from the sun, thus protecting the skin from acute and chronic health effects. To promote broad spectrum protection, in most sunscreens, at least two organic filters are associated. The avobenzone is a chemical absorber for UVA and octyl methoxycinnamate are chemical absorbers for UVB. Rutin is a flavonoid used traditionally as a potent antioxidant and due to the similarity in the absorption spectrum in the UV rays presents the potential for protecting against radiation, and may provide a decrease in the concentration of chemical filters in formulations with this objective. The validation method uses quantitative 1H NMR spectroscopy for simultaneous quantification of avobenzone and octyl methoxycinnamate and observation of changes in molecular groups during the study of stability. The 1HNMR spectroscopy offers some advantages, among which we highlight the use of small volumes of solvents, and sample preparation is extremely simple.(AU)