Electrically controlled transdermal delivery of naproxen and indomethacin from porous cis-1,4-polyisoprene matrix

This study is focused on the inquiry of using a porous polymeric structure to absorb
and release transdermally two drugs through a skin from deproteinized natural rubber
latex (DPNR). The porous DPNR films were fabricated from the internal formation of
surfactant micelles and their subsequent leaching out to generate porous structures.
The pore size of DPNR films increased with increasing surfactant amount. The model
drugs were naproxen and indomethacin; their releases and release-permeations were
investigated under the effects of surfactant amount, electrical potential, and drug
size. Without electric field, the drug release mechanism was mainly driven by concentration
gradient. The higher amount of drug released was obtained from the matrix
with a larger pore size. Under electric field, the higher amounts of drug release were
obtained in the shorter drug release durations, via the electrorepulsive force between
the negatively charged drugs and the cathode electrode. The molecular drug size was
a factor for the drug absorption, release rate and amount. For the drug releasepermeation
experiment through the pig skin, there were two release-permeation
periods as governed by the combination of concentration gradient and swelling in
the first period, and the matrix erosion in the second period. The fabricated porous
DPNR films have been shown here to be potential to be used as a transdermal patch
with electrically controllable drug release rate, amount and duration along with the
facile drug-matrix loading and absorption.