Incorporation of Cordia glabrata (Mart.) A.DC. extract in microemulsions and their potential antioxidant, photoprotective and virucidal activities.

Extracts of species from the Cordia genus have been reported with potential biological activities, such as antioxidant, antimicrobial, antiviral, and antiparasitic. The aim of this study was to develop microemulsions containing ethanolic extracts of C. glabrata leaves and to evaluate their stability and biological activities. The five developed microemulsions presented physicochemical stability and presented Newtonian behavior when submitted to rheological analysis. The diameter values of the globules ranged between 225.74 and 273.33 nm and the zeta potential of the formulations remained between -22.40 and -25.08. All phenolic acids of the extract, quantified by HPLC, showed consistency after being microemulsified. The EC50 values for the antioxidant activity by the DPPH scavenging method ranged between 38.13 and 45.54 µgmL-1, and between 34.46 and 39.60 mM for the ABTS+ scavenging method. The virucidal activity presented a CV50 <0.195 µgmL-1 and a selectivity index greater than 20. The photoprotection results ranged between 2.14 to 2.84. The study revealed stable microemulsions and potentiation of the antioxidant effect in the microemulsified extracts.