Effect of liposomal fluidity on skin permeation of sodium fluorescein entrapped in liposomes

Abstract

The purpose of this study was to investigate the effect of ultradeformable liposome components, Tween 20 and terpenes, on vesicle fluidity. The fluidity was evaluated by electron spin resonance spectroscopy using 5-doxyl stearic acid and 16-doxyl stearic acid as spin labels for phospholipid bilayer fluidity at the C5 atom of the acyl chain near the polar head group (hydrophilic region) and the C16 atom of the acyl chain (lipophilic region), respectively. The electron spin resonance study revealed that Tween 20 increased the fluidity at the C5 atom of the acyl chain, whereas terpenes increased the fluidity at the C16 atom of the acyl chain of the phospholipid bilayer. The increase in liposomal fluidity resulted in the increased skin penetration of sodium fluorescein. Confocal laser scanning microscopy showed that ultradeformable liposomes with terpenes increase the skin penetration of sodium fluorescein by enhancing hair follicle penetration.

Keywords:

• ultradeformable liposomes
• terpenes
• fluidity
• electron spin resonance spectroscopy
• confocal laser scanning microscopy

Acknowledgments

The authors gratefully acknowledge the Thailand Research Funds through the Basic Research Grant (Grant No 5680016), and the Faculty of Pharmacy, Silpakorn University, Nakhon Pathom, Thailand for facilities and financial support.

Disclosure

The authors report no conflicts of interest in this work.