Zinc Oxide Nanoparticles as Skin Permeation Enhancer for Solvents and Surfactants

Objective: Transdermal route of drug administration has absorbed largeinterests for its many advantages. Several materials, mainly different solvents and surfactants, have been used as excipients to enhance the skin permeation of drugs. Nanoparticles (NPs) also have been proved to affect the permeations of substances. ZnO-NPs, widely used in topical products, have been investigated in this study in terms of their effects on permeations of different substances (excipients) and therefore permeations of active ingredients.

Method: To determine the skin permeation of everysubstance, diffusion cell method and a cut of chicken skin were employed following by quantification of the substance concentration in the receiver medium after 1.5 hours.

Results: The substances showed different permeations. The ZnO-NPs increased the permeation of each substance. In the absence and also in the presence of the ZnO-NPs, the mean amounts permeated were respectively belonged to hydrophobic solvents, hydrophilic solvents, oily solvents and surfactants. The ZnO-NPs increased the permeation ofhydrophobic solvents, oily solvents, hydrophilic solvents and surfactants, with 31.33, 24, 20.33 and 5.34%, respectively. Such increases, were not dependent on the molecular weight (MW) of the oily and hydrophobic solvents but were dependent on the MW of the hydrophilic solvents and the surfactants.

Conclusion: The ZnO-NPs are suggested to be used for enhancing the skin permeations of solvents or surfactantsin topical products which potentially can improve absorption of active ingredients. Besides, such enhancing effect of the ZnO-NPs should be noticed in topical products where they may increase drug delivery dose and alsoincrease drug or excipient systemic toxicity.