Original Article DEVELOPMENT OF ELLAGIC ACID RICH POMEGRANATE PEEL EXTRACT LOADED NANOSTRUCTURED LIPID CARRIERS (NLCS) NUKANYA TOKTON a, b , ANAN OUNAROON c , PHARKPHOOM PANICHAYUPAKARANANT d ,AND WAREE TIYABOONCHAI a,b* a Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok 6500, Thailand, b The Center of Excellence for Innovation in Chemistry, Commission on Higher Education, Bangkok 10400, Thailand, c Department of Pharmaceutical Chemistry and Pharmacognosy, Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok 65000, Thailand, d Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Songkhla 90112, Thailand, Email: wareet@nu.ac.th Received: 04 Feb 2014 Revised and Accepted: 25 Feb 2014 ABSTRACT Objective: This study aimed to access the anti-tyrosinase activity of ellagic acid rich pomegranate peel extract (EPP) and to prepare the EPP loaded nanostructure lipid carriers (NLCs) for topical application to promote active compound penetration efficiency. Methods: EPP contained ellagic acid 12% (w/w) has been prepared and subjected to mushroom tyrosinase inhibitory assay. The EPP loaded NLCs have been developed using a warm microemulsion technique. The physicochemical properties, entrapment efficacy, in vitro release profile and ex vivo permeation study were investigated. Results: The EPP possessed a strong anti-tyrosinase activity with IC50 values of 28.54 ± 1.34 µg/ml. At optimal condition, lyophilized EPP loaded NLCs showed spherical particles with a mean particle size of ~200 nm, polydispersity index of ~0.2 and zeta potential of ~ -34 mV. The high incorporation efficiency of ellagic acid, ~90%, was achieved. The in vitro release study showed a prolonged release of ellagic acid from the NLCs up to 12 h following the Higuchi’s model. The ex vivo permeation study showed that the cream containing EPP loaded NLCs clearly promote the active compound penetration compare to EPP cream (control). Conclusion: The prepared EPP showed strong anti-tyrosinase activity that suitable for use in cosmetics. NLCs were shown to be a promising delivery system for EPP to improved bioavailability of active ingredients. The penetration enhancing effect of NLCs was dependent on the types of oil and surfactant used in formulation. Keywords: Pomegranate; Punica granatum; Ellagic acid; Nanostructured lipid carriers; Anti-tyrosinase INTRODUCTION Pomegranate (Punica granatum L.) is one of the ancient fruit that has been used in folk medicine, cosmetic and food supplement in many countries [1, 2]. The main compounds found in pomegranate peel are ellagitannins, gallotannins, gallic acid and ellagic acid [3-5] Ellagic acid (EA), Fig. 1, is one of the best investigated for variety of pharmacological activities [6-8]. It possessed antioxidant, anti- inflammatory, anti-tyrosinase, and anti-mutagenic activities. Fascinatingly, Yoshimura et al.. reported that EA effectively suppress UV-induced skin pigmentation in brownish guinea pig [5] suggesting that EA can prevent the build-up of skin pigmentation after sunburn. It can also be expected to improve the appearance of pigmented skin such as melasma, freckles or post-inflammatory pigmentation [9]. Therefore, EA is a promising skin-whitening active agent for cosmetics. Nevertheless, the use of botanical products is expanding rapidly worldwide. Recently, it has been reported that the pomegranate peel extracts containing 13% w/w ellagic acid possessed comparable antibacterial, anti-allergic and anti- inflammatory activities to the pure ellagic acid [10]. Comparing the manufacturing procedure of pure compound and crude extract, the latter is cheaper and easier to prepare and less time consuming. Moreover, a crude extract contains the original combination of active ingredients which is difficult to imitate in purified compounds. Thus, in this study, EPP was used instead of ellagic acid. In addition, the anti-tyrosinase activity of both ellagic acid and EPP was compared. The main barrier for topical delivery is stratum corneum (SC), the topmost skin layer. It comprises of a multi-layered “brick and mortar” like structure, where the bricks are composed of keratin- rich corneocytes and the mortar is an intercellular matrix of a unique composition of lipids [11]. Fig. 1: Chemical structure of ellagic acid. Thus, further investigation with a suitable cosmetic delivery system has to be carried out in order to enhance active compound penetration efficiency. Among modern drug delivery carriers, nanostructure lipid carriers (NLCs) are a promising colloidal carrier system. They made from biodegradable and biocompatible lipids that exist in the submicron size range and can be prepared by several methods. The advantages of NLCs are following; possibility of controlled drug release, protection of incorporated compound against chemical degradation, no toxicity of the carrier, avoidance of organic solvent and no problem with respect to large scale production [12-14]. In addition, NLCs possess occlusive property leading to skin hydration and subsequently enhance skin penetration of active ingredient [15, 16]. Pardeike et al.. reported that the NLCs containing cream significantly increased the skin hydration more than conventional cream with the same composition of cream [16]. Thus, in this study, we aimed to access the anti- tyrosinase activity of EPP and to prepare the EPP loaded NLCs for topical application to promote active compound penetration efficiency. The EPP loaded NLCs were prepared by a warm International Journal of Pharmacy and Pharmaceutical Sciences ISSN- 0975-1491 Vol 6, Issue 4, 2014 Innovare Innovare Innovare Innovare Academic Sciences Academic Sciences Academic Sciences Academic Sciences