Aim: One major challenge associated with the design of transdermal drug delivery
systems is to overcome the barrier of the skin. Hence, current study aimed at hydrogel
based nanoemulsion (HNE) of lercanidipine for enhanced transdermal delivery and investigation
for its rheology, bioadhesion, droplet size, transmission electron microscopy
(TEM), and skin permeation mechanism.
Main Methods: Flow behavior of HNE was studied by conducting the controlled stress
rate study using R/S CPS plus Rheometer and Bio-adhesive strength was measured by texture
analyzer. Skin permeation mechanism across rat skin was determined by differential
scanning calorimeter (DSC) study, activation energy (Ea) determination, histopathological
examination, confocal laser scanning microscopy (CLSM). Moreover, we have used TEM
and Biovis IP2000 software for microscopic analysis.
Key Finding: The formulation exhibited HershelBulkley flow with good bioadhesion
(43N/mm). A uniform droplets distribution under TEM image with size of
80.18±0.315nm inside gel network was found. DSC, Ea and histopathological examination
revealed that HNE might have dissolved intercellular lipid and separated corneocytes
from each other to weaken the barrier function of SC for enhancing the skin permeation.
CLSM result dictated a distributed droplets throughout the skin layers with high depth of
penetration (>150.0 μm).
Significance: The formulation has a good perspective to safe and effective delivery of lercanidipine
for enhanced transdermal application.