Essential oils in niosomes for enhanced transdermal delivery of felodipine

The fluidity of vesicular membrane affects vesicular transdermal drug delivery. Essential oils can be located in vesicular membrane imparting flexibility and influencing transdermal delivery. Accordingly, the objective was to investigate the effect of incorporation of essential oils in niosomes on felodipine transdermal delivery. Rigid niosomes comprising Span 60 with cholesterol (2:1, w/w) were used with clove, eucalyptus or lemon oils being incorporated in the vesicles at increasing concentrations. The vesicle size and shape was monitored using scanning electron microscopy. Thermal analysis was used to monitor the thermal behavior. Drug entrapment efficiency, release and skin permeation were monitored. Niosomes were spherical with size ranging from 279 to 345 nm. The drug entrapment ranged from 97.9 to 98.8%. Thermal analysis confirmed the existence of oils within vesicular membrane and highlighted the membrane fluidizing effect. Drug release depended on the oil with clove oil or eucalyptus oil showing a trend of increased drug release compared with plain niosomes. In contrast, lemon oil reduced drug release rate. Skin permeation study reflected the superiority of oil containing niosomes. The results correlated with the fluidizing and penetration enhancing effects of oils. The study introduced essential oils as potential niosomes fluidizing agents for enhanced transdermal drug delivery.