Research Article Physicochemical Characterization and Thermodynamic Studies of Nanoemulsion-Based Transdermal Delivery System for Fullerene Cheng Loong Ngan, 1 Mahiran Basri, 1,2 Minaketan Tripathy, 3,4 Roghayeh Abedi Karjiban, 1 and Emilia Abdul-Malek 1 1 Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia 2 Halal Products Research Institute, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia 3 Laboratory of Fundamentals of Pharmaceutics, Faculty of Pharmacy, Universiti Teknologi MARA (UiTM), Puncak Alam Campus, 42300 Selangor, Malaysia 4 Brain and Neuroscience Communities of Research, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor, Malaysia Correspondence should be addressed to Cheng Loong Ngan; clngan88@yahoo.com and Mahiran Basri; mahiran@upm.edu.my Received 24 March 2014; Accepted 25 June 2014; Published 3 August 2014 Academic Editor: Roberto Rivelino Copyright © 2014 Cheng Loong Ngan et al. his 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. Fullerene nanoemulsions were formulated in palm kernel oil esters stabilized by low amount of mixed nonionic surfactants. Pseudoternary phase diagrams were established in the colloidal system of PKOEs/Tween 80 : Span 80/water incorporated with fullerene as antioxidant. Preformulation was subjected to combination of high and low energy emulsiication methods and the physicochemical characteristics of fullerene nanoemulsions were analyzed using electroacoustic spectrometer. Oil-in-water (O/W) nanoemulsions with particle sizes in the range of 70–160 nm were formed. he rheological characteristics of colloidal systems exhibited shear thinning behavior which itted well into the power law model. he efect of xanthan gum (0.2–1.0%, w/w) and beeswax (1–3%,w/w) in the estimation of thermodynamics was further studied. From the energetic parameters calculated for the viscous low, a moderate energy barrier for transport process was observed. hermodynamic study showed that the enthalpy was positive in all xanthan gum and beeswax concentrations indicating that the formation of nanoemulsions could be endothermic in nature. Fullerene nanoemulsions with 0.6% or higher xanthan gum content were found to be stable against creaming and locculation when exposed to extreme environmental conditions. 1. Introduction Nanoemulsions are non-equilibrium colloidal systems formed by forcing two immiscible liquids into homogeneous state which is kinetically stable with particle size ranging from 20 to 200 nm [1]. Unlike microemulsions, both systems can be distinguished in terms of their thermodynamic stabilities where microemulsions are thermodynamically stable, whereas nanoemulsions are thermodynamically unstable. he use of nanoemulsions in eicient delivery of active ingredients or drugs into human body has been widely investigated. here are many areas such as pharmacy, cosmetics, and food technologies as well as non-medical- related products such as polymers and pesticides which utilize the concept of nanoemulsiication. In fact, most of the drugs are lipophilic in nature [2], and oil-in-water (O/W) type of emulsion is widely developed over the water-in-oil (W/O) emulsion where oil acts as carrier for drugs. In drug delivery system, toxicity of the inal product depends on the ingredients which constitute the emulsion system. Microemulsions have a presence of noxious cosur- factant and higher concentration of surfactant that leads to unwanted toxicity, whereas nanoemulsions are devoid of such disadvantage. Nonionic surfactants have prominent Hindawi Publishing Corporation e Scientific World Journal Volume 2014, Article ID 219035, 12 pages http://dx.doi.org/10.1155/2014/219035