The nasal delivery of nanoencapsulated statins - an approach for brain delivery.

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.

Expanding the therapeutic potential of statins by means of nanotechnology enabled drug delivery systems.

Statins are effective lipid lowering agents traditionally used for the primary and secondary prevention of cardiovascular disease. Statins also exert a range of pleiotropic effects that make them attractive candidates for use in a wide range of disorders, in particular inflammatory and immune mediated conditions. However, the exploitation of such pleiotropic effects has been greatly hindered by poor bioavailability and adverse effects on muscles and the liver at higher doses. Nanotechnology is often suggested as the solution to this problem, as it enables an increased bioavailability of statins. Moreover, colloidal carriers can offer targeted drug delivery approaches that enable localised biological effects of statins, further reducing their potential for unwanted toxicity and adverse effects. This article reviews the available evidences for the increased potential of statin therapy when administered in nano-formulations such as nanocrystals, nanoparticles, liposomes, micelles and various nano-enabled devices.