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Rita Muzzalupo, Lorena Tavano Department of Pharmacy and Health and Nutrition Science, University of Calabria, Edificio Polifunzionale, Cosenza, Italy Abstract: Niosomes are vesicular nanocarriers and are receiving much attention as potential transdermal drug delivery systems due to properties such as enhanced drug penetration, local depot for sustained drug release, and a rate-limiting membrane for modulation of systemic absorption of drugs via the skin. Several mechanisms have been proposed to explain the ability of niosomes to increase drug transfer through the skin. Niosomal carriers are suitable for the transdermal delivery of numerous pharmacological agents, including antioxidant, anticancer, anti-inflammatory, antimicrobial, and antibacterial molecules, and this review attempts to provide an exhaustive collection of recent investigations in this interesting field, with special emphasis on the strategies used to enhance the potential of niosomes. Keywords: niosomes, transdermal, permeation, enhancer, drug delivery

In recent years, significant efforts have been devoted to the application of nanotechnology for the development of devices to be employed as drug delivery systems. The synergic combination of polymeric science, drug delivery concepts and material technology offers challenging and precious opportunities for the achievement of new useful materials. In particular surfactants, lipids and polymeric systems play an important role in modern drug delivery, where they may allow control of the drug release rate, enhance effective drug solubility, minimize its degradation, contribute to reduced its toxicity and facilitate control of its uptake. In all, they contribute significantly to therapeutic efficiency. Dottorato di ricerca in Methodologies for the Development of Molecules of pharmacological Interest XXII Ciclo,2006-2009 Università della Calabria

In the present work, we report the synthesis of cellulose hydrogel containing ferulic moieties and the evaluation of its antioxidant and scavenger activity. Acrylic groups were inserted onto cellulose backbone by a heterogeneous synthesis to produce two cellulose monomers with different degree of substitution (DS). The radical copolymerization of acrylcellulose (AcrC) with N,N-dimethylacrylamide (DMAA) was carried out in NH3/Urea aqueous solution, in a range of composition between 24 and 60 wt% of AcrC. The obtained hydrogels were characterized by infrared spectroscopy (FT-IR). Their equilibrium swelling degree (α%) was evaluated. They showed good swelling behavior in simulating gastric, intracellular and intestinal fluids and no more different at various pH. The ferulic moieties were directly grafted on the free hydroxylic groups of cellulose hydrogel by acylation, using dicyclohexylcarbodiimide (DCC) and 4-hydroxybenzotriazole (HBT) as condensation agents. Finally, the antioxidant activity in inhibiting the lipid peroxidation, in rat-liver microsomal membranes, induced in vitro by two different sources of free radicals, 2,2′-azobis (2-amidinopropane) (AAPH) and tert-butyl hydroperoxide (tert-BOOH), was evaluated. The effects of scavenging DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals were also investigated. Hydrogel was found to be very efficient scavengers of DPPH radicals. The results strongly suggested that the antioxidant hydrogel neutralize free radicals. This biomaterial could be successfully applied in pharmaceutical field both as prodrug of trans-ferulic acid than as carrier for photo and thermo-degradable drugs to improve their stability.