Antioxidant Activity Degradation, Formulation Optimization, Characterization, and Stability of Equisetum Arvense Extract Nanoemulsion

Abstract

Equisetum arvense supercritical CO₂ extracts (EAE) contained an initial antioxidant activity of 10.3 mM TEAC that suffered a sharp first order kinetics decay characterized by half-life time (t_1/2) of 1.05 ± 0.03 and 0.86 ± 0.03 weeks at 25 and 4°C, respectively. The aim of the present work was to develop a nanoemulsion formulation for providing EAE protection against deleterious environmental factors and extending its shelf-life functionality. The nanoemulsion area was identified by constructing pseudoternary phase diagrams and response surface methodology was used to optimize the preparation conditions. The best formulation achieved an EAE encapsulation efficiency of 97.5 ± 0.5% and antioxidant activity half-life time (t_1/2) was extended to 12.32 ± 0.40 and 14.56 ± 0.60 weeks at 25 and 4°C, respectively.

Keywords:

• Antioxidant activity
• decay kinetics
• Equisetum arvense extracts
• nanoemulsion formulation optimization

Acknowledgments

The authors thank the Consejo Nacional de Ciencia y Tecnología de México (CONACyT) for the partial financing of this work through grant 81157.

Notes

These formulations were made for TEmix ratios of 1:0, 1:0.2, 1:0.3 and 1:0.4.

The initial TEAC value was 10.30 ± 0.08 mM.