Development and characterization of multiple emulsions for controlled release of Trichilia catigua (Catuaba) extract

Abstract

Considering the antioxidant activity of the Trichilia catigua extract (TCE), the aim of the current study was to develop and characterize W/O/W multiple emulsions containing different vegetable oils as a platform to deliver a TCE. The extract displayed antioxidant activity (IC₅₀) of 4.59 µg/mL and total phenol content (TPC) of 50.84%. Formulations were prepared by the phase-inversion emulsification method and analyzed for morphological appearance, pH, conductivity, droplet size and distribution, content of active, rheological properties, in vitro release, skin permeation, and stability. Formulations prepared with canola oil were selected and displayed regular morphology, mean diameter 2.77 µm (without TCE), 3.07 µm with 0.5% and 3.23 µm with 1.0% TCE. Rheometry (flow) showed pseudoplastic behavior with minimal thixotropy for both systems. TCE could be released from emulsions containing 1.0% and 0.5% TCE in a controlled manner for 16 and 23 h, respectively. The emulsions allowed good retention of TCE in the skin (stratum corneum, epidermis, and dermis). In a 180-d assessment of accelerated chemical stability, TPC was more reduced for the emulsions at 40 °C; other parameters remained stable. Multiple emulsions containing TCE were developed, exhibited good characteristics, and may be considered for future investigations as anti-aging formulations for the skin.

• Antioxidant activity
• drug delivery system
• drug release
• rheometry
• stability

Acknowledgements

The authors would like to thank the Brazilian agencies CNPq, CAPES, INCT_if, FINEP, COMCAP/UEM, and Fundação Araucária. The authors are grateful to BASF and Oxiteno for the donation of PEG 40 hydrogenated castor oil and Sorbitan monooleate, respectively. The technical assistance provided by A. Arantes and C. R. Novello is gratefully acknowledged. The authors are grateful to Dr. Janet W. Reid, JWR Associates, Trumansburg, New York, for the English language revision.

Declaration of interest

The authors report that they have no conflicts of interest.