# Steering the Clinical Translation of Delivery Systems for Drugs and Health Products
## 3 Poster Presentations
### Polysaccharide Hydrogels for the Stabilization and Controlled Release of Ionic Cargo
Solid Lipidic Nanoparticles Based on Naringentin and Linolenic Acid Viscosified with Biocompatible Polymers for The Transport and Release of Cyclosporine A  
[PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] *  
Department of Pharmacy and Health and Nutrition Sciences, University of Calabria, 87036 Arcavacata di Rende (CS), Italy  
* Correspondence: [EMAIL_ADDRESS]  
This work aimed to design, prepare and study gels containing SLNs, based on an ester of the naringenin and linolenic acid, useful as cyclosporin A release system (Figure 10) [28; 29; 30]. Figure 10: Schematic design of cyclosporin A-loaded SLN formulation. Figure 9: Residual concentration of native vancomycin within polysaccharide hydrogels as a function of time. The ester was characterized by FT-IR and 1H-NMR and the SLNs by Dynamic Light Scattering and Scanning Electronic Microscopy (Figure 11). Their capacity to inhibit the lipid peroxidation induced by a free radical generator, has been examined in rat liver microsomal membranes and compared to that of the free ester and various prepared gels, containing the empty lipid nanoparticles. All the materials were able to preserve the antioxidant capacity of the precursor (Figure 12) [31]. In particular, the major activity was exhibited by the free ester, the empty SLNs and the HA (hyaluronic acid)-based gel and Poloxamer 407 containing the empty SLNs [32]. This last result is due to the presence of the HA which also exerts an antioxidant action. However, even the other gels, despite being made up of non-antioxidant substances, show that they can preserve the microsomal membranes from lipid peroxidation due to the empty SLNs they contain. Nanoparticles have been shown also to possess excellent encapsulation efficiency, stability and size suitable for topical administration. This hypothesis was supported by the results obtained with the transdermal release studies, performed using Franz cells, which revealed that in the case in which the SLN are incorporated in gels containing promoters of absorption, such as Poloxamer 407 and Carbopol, the gels release a maximum of 5% of the loaded drug in contrast to free SLNs and colloidal silica gels. To validate this hypothesis and evaluate the amount of cyclospor A released in the stratum corneum and in the epidermis-dermis layer, the tape stripping method was used (Figure 13). The obtained data revealed that the amount of drug released by the colloidal silica-based gel was negligible in the stratum corneum (SC) and equal to 23% in the epidermis-dermis layer over 24 h. In contrast, the gel containing Poloxamer 407 at concentrations of 1.28% released about 79% of the drug over the 10 h in the SC and 15% in the epidermis-dermis layer. When the polymer changes, i.e., using Carbopol at 0.1%, the drug was more retained inside the gel than observed with the Poloxamer 407. In particular, the percentage of cyclospor A released within 24 h was equal to 36% in the SC and 28% in the epidermis-dermis layer. Figure 11: Photomicrography of empty SLN (Mag = 100 X) (**a**) and of gel based on HA and Poloxamer 407 containing empty SLN (Mag = 1.00 K X) (**b**). Figure 12: Inhibition of lipid peroxidation induced by _tert_-BOOH over 24 h.  
Furthermore, with the increase in the concentration of Poloxamer 407 in the gel, obtained using in addition also HA, the viscosity and strength of the gel increase and the drug was more retained inside the matrix but the release can be conditioned by the presence of ethanol which increase the permeation of cyclospor A by virtue of its solubility in this solvent.