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Evidence-Based Complementary and Alternative Medicine
Volume 2016 (2016), Article ID 8175265, 7 pages
Research Article

Formulation of Propolis Phenolic Acids Containing Microemulsions and Their Biopharmaceutical Characterization

Department of Clinical Pharmacy, Lithuanian University of Health Sciences, Sukilėlių Street 13, LT-50161 Kaunas, Lithuania

Received 20 May 2016; Accepted 10 July 2016

Academic Editor: Vassya Bankova

Copyright © 2016 Modestas Žilius et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Microemulsions (MEs) were formulated using PEG-8 caprylic/capric glycerides and ethanolic propolis extracts. Characterization of MEs was performed by determining mean droplet size, polydispersity index, stability under varying external factors, and formulation effect on delivery of phenolic compounds into the skin ex vivo. Essential oils were included into the formulations of MEs and their influence on physical characteristics of the nanostructured systems as well as penetration into epidermis and dermis were evaluated. The droplet size, their distribution, and stability of the formulated MEs were not affected. Presence of essential oils in the formulation increased penetration of phenolic compounds in general, but only the amount of ferulic acid increased significantly. Mean droplet size increased with increase of oily phase amount, suggesting that phenolic compounds and components of essential oils were not modifying the formation of the interphase film composition and/or structure. Phenolic compounds were predominantly located in the lipid phase of the MEs thus minimizing their availability at the surface of the skin.