08) or selleck chemical the 180▒µm-thick membranes. Because of the ease of handling, the 180▒µm-thick membranes were considered worthy to predict the permeability of IB. Its versatility was further investigated using other two drugs, namely PR and TS. The permeation profiles of PR from both physiological solution and mineral oil were superimposable to those of human epidermis (Fig. 5 a and b) and the

FoD values were 0.56 and 0.51 for PR in physiological solution and mineral oil, respectively, demonstrating the membrane resistance in the presence of mineral oil. The only difference was represented by a slight delay in lag time ( Fig. 5 a and b). A different behavior was evidenced in the case of the permeation profile of TS from a water/ethanol solution. In this case, the diffusion patterns through human epidermis and Membrane 5 resulted similarly only in the early data points, namely 5▒h (Fig. 6). Afterwards the diffusion of TS increased since Membrane 5 did not maintain its integrity over a prolonged period of time. Indeed, at the end of the permeation experiment the intensity of the main ATR-FTIR bands in Membrane 5 decreased and their wavenumbers slightly shifted. It may be assumed that ethanol affected the biophysical properties of keratin membranes enhancing its fluidity followed by a detrimental

effect on its stability. Hence, the current membrane cannot be www.selleckchem.com/products/pifithrin-alpha.html used when organic solvents are selected as donor phase. The combination of regenerated keratin Farnesyltransferase and CERs permitted the development of simplified membranes of stratum corneum suitable to match the diffusion of small molecules through human epidermis as demonstrated by comparing the diffusion profiles of three model drugs. Nevertheless, the preparation method did not permit the production of membranes stable in presence of organic solvents, such as ethanol, over a prolonged period of time. However, the approach of using regenerated keratin to scaffold the lipid components of stratum corneum can permit the design of membranes with an environment closer to the outermost layer of the

epidermis with respect to other proposed systems. As a matter of fact the latter consist of porous substrates (i.e. filters) covered and/or embedded with lipid systems [31,32,12] and therefore cannot take into account possible interactions among the permeant and the protein domain of stratum corneum. “
“Nanoparticles can be used to design or even comprise excellent drug delivery systems [1,2]. For example, due to the enhanced permeability and retention (EPR) effect, nanoparticles can passively target tumors and accumulate in them [1,3]. Nanoparticles can increase the stability of drugs including proteins in blood, are secreted less readily by the kidney, which often results in increased therapeutic efficacy and can reduce side effects of other therapies. [1,[3], [4], [5], [6], [7] and [8]].