چکیده (انگلیسی):

The purpose of the present research was to investigate the
mechanism for improved intercellular and intracellular drug
delivery from ethosomes using visualization techniques and
cell line study. Ethosomal formulations were prepared using
lamivudine as model drug and characterized in vitro, ex vivo
and in vivo. Transmission electron microscopy, scanning
electron microscopy, and fluorescence microscopy were employed
to determine the effect of ethosome on ultrastructure
of skin. Cytotoxicity and cellular uptake of ethosome were
determined using T-lymphoid cell line (MT-2). The optimized
ethosomal formulation showed 25 times higher transdermal
flux (68.4 ± 3.5 μg/cm2/h) across the rat skin as compared
with that of lamivudine solution (2.8 ± 0.2 μg/cm2/h).
Microscopic studies revealed that ethosomes influenced the
ultrastructure of stratum corneum. Distinct regions with lamellar
stacks derived from vesicles were observed in intercellular
region of deeper skin layers. Results of cellular uptake
study showed significantly higher intracellular uptake of
ethosomes (85.7% ± 4.5%) as compared with drug solution
(24.9% ± 1.9%). The results of the characterization studies
indicate that lipid perturbation along with elasticity of ethosomes
vesicles seems to be the main contributor for improved
skin permeation.