ISSN: 2232-8232 Volume 02, Issue 02, February,2020 21 Development, evaluation and application of Transfersomal Green tea extract (Camellia sinensis) formulations Omnia Sarhan 1* , Mahmoud Abdel-Ghany 2 , Mohamed Abdel-Hamid 1 Department of pharmaceutics, faculty of pharmacy, Badr University in Cairo, Egypt 1 Department of pharmaceutics, faculty of pharmacy, Zagazig University, Egypt 2 Postal address: Egypt, Cairo, El-Obour, 9th district, Naguib Mahfouz street, block 18045, villa 19 . Abstract Many studies have shown the beneficial health effects of green tea extract in treatment and protection from many diseases. However, inconsistent results were observed; mainly due to poor absorption and low bioavailability associated with oral administration of green tea extract formulations. Conventional alternative route of administration such as transdermal route is proceeded with an advanced nanoparticle delivery system known as transfersomes. Different formulations of transfersomes are prepared with different types and percentages of edge activators in relation to phospholipid content. This review is intended to evaluate and discuss in-vitro and in-vivo behavior of the prepared transfersomal formulations of green tea extract; which in turn would result in enhancing their therapeutic efficacy. Keywords— Bioavailability; edge activator; Green tea extract; transdermal and transfersome. 1. Introduction Since prehistoric times (i.e., for more than 60,000 years) natural products, such as plants, animals, microorganisms, and marine organisms, have been used to alleviate and treat many diseases in medicines [1]. The replacement of normally used drugs with natural products, must of course, have presented a tremendous challenge to humans all over ages. Green tea (Camellia sinensis) (fam. Theaceae) is one of the most important natural products that has been used since a long time ago and has been proven safe with many benefits as a source of medicine [2]. The main effective compound in green tea that is responsible for many beneficial effects is a catechin-derived compound, namely, epigallocatechin gallate (EGCG). EGCG has a high antioxidant activity that can provide protection to the body from the risk of cardiovascular diseases, diabetes mellitus, cancer, neurodegenerative disorders, obesity and also exhibits anti-inflammatory effects [3,4]. EGCG is found to be associated with low absorption rate in the alkaline medium as in the small intestine, only less than 5% of EGCG enters the systemic circulation [5]. The unabsorbed EGCG, which does not enter the systemic circulation; will be thrown away to the colon and degraded by intestinal microflora [6]. To overcome these problems, an alternative drug administration route such as transdermal drug delivery system is used, which have the ability to deliver drugs through the skin up to the systemic circulation [7]. This route is characterized by avoidance of gastrointestinal degradation, first pass effect, and drug fluctuations in the blood [8]. To provide optimal antioxidant effects, the bioactive component of green tea (i.e., EGCG) should penetrate into the skin. Furthermore, EGCG is poorly absorbed when administered orally. It is a hydrophilic molecule with a high polarity value (log p=0.48) and a considerable molecular weight (458.37 Da) that becomes an issue in skin penetration [9,10]. In addition, EGCG is known to have high affinity to interact chemically with skin lipid bilayers [11]. In overcoming this, green tea leaves extract can be formulated into a vesicle system or a carrier based lipid (i.e., Transfersomes) to enhance its penetration through skin.