Abstract:

This study develops a novel transdermal delivery vehicle for the enhanced delivery of sodium diclofenac (Na-DFC). The system utilizes the advantages of reversed hexagonal lyotropic liq. crystals (HIILC), combined with a peptide cell penetration enhancer (CPE), creating together an adaptable system that provides versatile options in the field of transdermal delivery. This enhancer peptide is based on a family of amphipathic peptides that exhibit improved membrane permeability. Franz permeation cell expts. revealed that the peptide enhancer (RALA) improved Na-DFC skin penetration of the liq. crystal 2.2-fold. The authors studied the structural effects of RALA solubilization on the HII mesophase. RALA acts as a chaotropic agent, interfering in the structure of the water, and causes a measurable swelling of the aq. cylinders by 5 \AA. Small angle x-ray scattering (SAXS) and attenuated total reflectance-Fourier transform IR (ATR-FTIR) measurements reveal enhanced hydration of the glycerol monooleate (GMO) headgroups and a 6.5% increase in the fraction of non-freezable water resulting from RALA incorporation. RALA caused a gradual increase in the GMO effective headgroup area due to the hydration, leading eventually to a transform of the hexagonal structure towards a lamellar one. CD and ATR-FTIR measurements showed a conservation of the peptide structure when incorporated into the HII mesophase. The combined HIILC-CPE systems can serve as high potential vehicles for a variety of drugs, as they can easily be modified by varying the compn. and temp., according to the required dose and delivery features. [on SciFinder(R)]