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J. Cosmet. Sci., 64, 341–353 (September/October 2013) 341 Formulation strategies to modulate the topical delivery of anti-infl ammatory compounds CARMELO PUGLIA, LUISA RIZZA, ALESSIA OFFERTA, FRANCO GASPARRI, VALENTINA GIANNINI, and FRANCESCO BONINA, Department of Drug Sciences, University of Catania, 95125 Catania (C.P., L.R., A.O., F.B.), and R&D, Rottapharm|Madaus, Monza (F.G., V.G.), Italy. Accepted for publication April 1, 2013. Synopsis The aim of this study was to assess the ability of some vehicles (emulsion and emulgel), containing hydroge- nated lecithin as penetration enhancer, in increasing the percutaneous absorption of the two model com- pounds dipotassium glycyrrhizinate (DG) and stearyl glycyrrhetinate (SG). Furthermore SG-loaded solid lipid nanoparticles (SLNs) were prepared and the effect of this vehicle on SG permeation profi le was evaluated as well. Percutaneous absorption has been studied in vitro, using excised human skin membranes (i.e., stratum corneum epidermis or [SCE]), and in vivo, determining their anti-infl ammatory activity. From the results obtained, the use of both penetration enhancers and SLNs resulted in being valid tools to optimize the topical delivery of DG and SG. Soy lecithin guaranteed an increase in the percutaneous absorption of the two actives and a rapid anti-infl ammatory effect in in vivo experiments, whereas SLNs produced an interesting delayed and sustained release of SG. INTRODUCTION During the recent decades, many cosmetic products with biologically active ingredients have been developed and marketed. This category of products showing medicinal or drug-like benefi ts is recognized with the term “cosmeceutical.” Cosmeceuticals are intended to carry out their function as protection, whitening, tan- ning, and antiaging. Like cosmetics, cosmeceuticals are applied topically but differ in that they contain potent ingredients that can infl uence the biological function of the skin and deliver nutrients to promote healthy skin. The extracts of Glycyrrhiza glabra roots contain interesting compounds that are among the most important ingredients used to formulate innovative cosmeceuticals (1). The biological properties of this plant are associated with the presence of glycyrrhizin, a 3-diglucuronide derivative and with its aglycone, glycyrrhetic acid. Some interesting derivatives of these active compounds, such as dipotassium glycyrrhizinate (DG) and Address all correspondence to Carmelo Puglia at capuglia@unict.it