An evaluation of tocotrienol ethosomes for transdermal delivery using Strat-M^® membrane and excised human skin

Abstract

Tocotrienol (TRF) ethosomes were developed and evaluated in vitro for potential transdermal delivery against melanoma. The optimised TRF ethosomal size ranged between 64.9 ± 2.2 nm to 79.6 ± 3.9 nm and zeta potential (ZP) between −53.3 mV to −62.0 ± 2.6 mV. Characterisation of the ethosomes by ATR-FTIR indicated the successful formation of TRF-ethosomes. Scanning electron microscopy (SEM) images demonstrated the spherical shape of ethosomes, and the entrapment efficiencies of all the formulations were above 66%. In vitro permeation studies using full-thickness human skin showed that the permeation of gamma-T3 from the TRF ethosomal formulations was significantly higher (p < 0.05) than from the control. The cumulative amount of gamma-T3 permeated from TRF ethosome after 48 hours was 1.03 ± 0.24 µg cm⁻² with a flux of 0.03 ± 0.01 µg cm⁻² h⁻¹. Furthermore, the flux of gamma-T3 across the Strat-M^® and the epidermal membrane was significantly higher than that across full-thickness human skin (p < 0.05). In vitro cytotoxicity studies on HaCat cells showed significantly higher cell viability than the pure drug solution (p < 0.05). The enhanced skin permeation and high cell viability associated with this formulation suggest a promising carrier for transdermal delivery.

Graphical Abstract

Keywords:

• Transdermal
• TRF
• ethosomes
• human skin
• permeation
• cell-viability

Acknowledgements

The authors are grateful to ExcelVite Sdn. Bhd. (Perak, Malaysia) for providing TRF and tocotrienol standards.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The present work was funded by the University of Nottingham Malaysia (UNM) and through the open access funding provided by the Qatar National Library.