Opportunities and challenges for the nasal administration of nanoemulsions

© 2015 Bentham Science Publishers. Nasal delivery has become a growing area of interest for drug administration as a consequence of several practical advantages, such as ease of administration and non-invasiveness. Moreover, the avoidance of hepatic first-pass metabolism and rapid and efficient absorption across the permeable nasal mucosa offer a promising alternative to other traditional administration routes, such as oral or parenteral delivery. In fact, nasal delivery has been proposed for a number of applications, including local, systemic, direct nose-to-brain and mucosal vaccine delivery. Nanoemulsions, due to their stability, small droplet size and optimal solubilization properties, represent a versatile formulation approach suitable for several administration routes. Nanoemulsions demonstrated great potential in nasal drug delivery, increasing the absorption and the bioavailability of many drugs for systemic and nose-tobrain delivery. Furthermore, they act as an active component, i.e. an adjuvant, in nasal mucosal vaccinations, displaying the ability to induce robust mucosal immunity, high serum antibodies titres and a cellular immune response avoiding inflammatory response. Interestingly, nanoemulsions have not been proposed for the treatment of local ailments of the nose. Despite the promising results in vitro and in vitro, the application of nanoemulsions for nasal delivery in humans appears mainly hindered by the lack of detailed toxicology studies to determine the effect of these formulations on the nasal mucosa and cilia and the lack of extensive clinical trials

Composição e estrutura do solo de parte das unidades de amostra de registro do inventário florestal de Santa Catarina.

Resumo

The nasal delivery of nanoencapsulated statins – An approach for brain delivery

© 2016 Clementino et al. Purpose: Along with their cholesterol-lowering effect, statins have shown a wide range of pleiotropic effects potentially beneficial to neurodegenerative diseases. However, such effects are extremely elusive via the conventional oral administration. The purpose of the present study was to prepare and characterize the physicochemical properties and the in vivo biodistribution of simvastatin-loaded lecithin/chitosan nanoparticles (SVT-LCNs) suitable for nasal administration in view of an improved delivery of the statins to the brain. Materials and methods: Chitosan, lecithin, and different oil excipients were used to prepare nanocapsules loaded with simvastatin. Particle size distribution, surface charge, structure, simvastatin loading and release, and interaction with mucus of nanoparticles were determined. The nanoparticle nasal toxicity was evaluated in vitro using RPMI 2651 nasal cell lines. Finally, in vivo biodistribution was assessed by gamma scintigraphy via Tc99m labeling of the particles. Results: Among the different types of nanoparticles produced, the SVT-LCN_MaiLab showed the most ideal physicochemical characteristics, with small diameter (200 nm), positive surface charge (+48 mV) and high encapsulation efficiency (EE; 98%). Size distribution was further confirmed by nanoparticle tracking analysis and electron microscopy. The particles showed a relatively fast release of simvastatin in vitro (35.6%±4.2% in 6 hours) in simulated nasal fluid. Blank nanoparticles did not show cytotoxicity, evidencing that the formulation is safe for nasal administration, while cytotoxicity of simvastatin-loaded nanoparticles (IC50) was found to be three times lower than the drug solution (9.92 vs 3.50 μM). In rats, a significantly higher radioactivity was evidenced in the brain after nasal delivery of simvastatin-loaded nanoparticles in comparison to the administration of a similar dose of simvastatin suspension. Conclusion: The SVT-LCNs developed presented some of the most desirable characteristics for mucosal delivery, that is, small particle size, positive surface charge, long-term stability, high EE, and mucoadhesion. In addition, they displayed two exciting features: First was their biodegradability by enzymes present in the mucus layer, such as lysozyme. This indicates a new Trojan-horse strategy which may enhance drug release in the proximity of the nasal mucosa. Second was their ability to enhance the nose-to-brain transport as evidenced by preliminary gamma scintigraphy studies

Brazilian national forest inventory: remote sensing and landscape analysis approaches for nationwide forest monitoring and assessment.

Edição dos abstracts do 24º IUFRO World Congress, 2014, Salt Lake City. Sustaining forests, sustaining people: the role of research

Zoneamento agroclimático para pereira no Rio Grande do Sul.

bitstream/CPACT/10925/1/documento_182.pdf; bitstream/item/33625/1/documento-182.pd

RapidEye object-based image classifi cation and landscape ecology analysis to support the geospatial component of the Brazilian National Forest Inventory.

Edição dos abstracts do 24º IUFRO World Congress, 2014, Salt Lake City. Sustaining forests, sustaining people: the role of research

Zoneamento agroclimático para produção de mudas de morangueiro no Rio Grande do Sul.

bitstream/item/33630/1/documento-187.pd

Conservação de frutíferas nativas: localização, fenologia e reprodução.

bitstream/item/33626/1/documento-183.pd