Size-dependent skin penetration of silver nanoparticles: effect of penetration enhancers

Penetration enhancers are usually surfactants, and co-surfactants added to dermatological applications (creams) to solubilize lipophilic active principles. They have the potential to alter the lipid integrity within the stratum corneum. Transdermal preparations such as antibiotics are now gaining a lot of interest. The present study evaluates the effect of penetration enhancers and different nanoparticle sizes of silver nanoparticles with respect to their impact on nanoparticle-skin penetration, expressed as the flux (J), the Permeability Coefficient (PC) and Enhancement Ratio (ER). In this study, the modified Franz diffusion glass cell method was adapted to measure the primary skin permeability parameters. Drug delivery depends so much on the ability of vehicles to overcome the skin barrier and deliver their content deeply into tissue layers. Hence the need for the present studies which aims to evaluate the quantity of different sizes of silver nanoparticles permeating the skin per unit time in the presence of penetration enhancers. The observed flux for the different sizes was 26, 18, 30, and 4.2 µg/cm2/h, respectively, for 4.0% Tween 80; 28, 22, 34, and 8 µg/cm2/h, respectively, for 20% Propylene Glycol (PG); 18, 14, 24 and 2.8 µg/cm2/h, respectively, for 20.0% Poly Ethylene Glycol (PEG) and 34, 28, 46 and 12 µg/cm2/h, respectively, for 4.0% sodium lauryl sulfate when compared to an aqueous solution of AgNPs (22 NM). Considering the size of AgNPs and choice of penetration enhancers could pave way for developing an ideal dermatological preparation requiring the use of nanoparticles.