Photolysis study of octyl p-methoxycinnamate loaded microemulsion by molecular fluorescence and chemometric approach.

Octyl p-methoxycinnamate (OMC) is one of the most widely used sunscreen agents. However, the efficiency of OMC as UV filter over time is affected due to the formation of the cis-isomer which presents a markedly lower extinction coefficient (ε=12,600L molcm at 291nm) than the original trans-isomer (ε=24,000L molcm at 310nm). In this work, a novel carrier for OMC based on an oil-in-water microemulsion is proposed in order to improve the photostability of this sunscreen.

Selection of robust variables for transfer of classification models employing the successive projections algorithm.

Multivariate models have been widely used in analytical problems involving quantitative and qualitative analyzes. However, there are cases in which a model is not applicable to spectra of samples obtained under new experimental conditions or in an instrument not involved in the modeling step. A solution to this problem is the transfer of multivariate models, usually performed using standardization of the spectral responses or enhancement of the robustness of the model.