Liposomes in Pulmonary Applications: Physicochemical Considerations, Pulmonary Distribution and Antioxidant Delivery

Abstract

The application of liposomes for improved drug delivery to the lung is promising. Liposome-mediated pulmonary drug delivery promotes an increase in drug retention-time in the lung and more importantly, a reduction in extrapulmonary side-effects, invariably resulting in enhanced therapeutic efficacies. The engineering of an effective liposomal drug formulation for inhalation therapy must take into consideration the leakage problem associated with the nebulization process; vesicle stability and release kinetics within the pulmonary milieu; and, the altered pharmacokinetics of the entrapped drug. The delivery of liposome-entrapped antioxidants via the tracheobronchial route has been found to be very useful in increasing the half-times of the administered agents, thus providing a sustained release effect for prolonged drug action. The entrapment in liposomes of alpha-tocopherol, an extremely insoluble but highly effective antioxidant, has been shown to be very effective in ameliorating oxidant-induced injuries in the lung. The use of bifunctional liposomes containing two antioxidants have been determined to provide excellent resistance to an oxidative challenge and appears to hold promise for improved clinical applications in antioxidant therapy.

The antioxidant resveratrol down-regulates inflammation in an in-vitro model ofPseudomonas aeruginosainfection of lung epithelial cells

“…Composed of over 40 different cell types, the human lung is an organ responsible for respiration and is an active player in innate immunity and front-line defense against pathogens (Hippenstiel et al 2006;Shek et al 1994).The terminal ends of the respiratory tree are composed to alveolar epithelial cells, which are divided further into type I and type II cells (Evans et al 2010;Hippenstiel et al 2006 -Oliveira et al 2008;Shek et al 1994).…”

Targeting efficiency and biodistribution of biotinylated-EGF-conjugated gelatin nanoparticles administered via aerosol delivery in nude mice with lung cancer

“…However, its biodegradation rate is extremely slow, and it is therefore unsuitable for pulmonary drug delivery, especially in cases where frequent dosing is required [7]. Leakage has always been a limitation of liposome nanoparticles prepared by nebulization as aerosols for inhalation therapy [8].…”

Development of α-Tocopherol Acetate Nanoparticles: Influence of Preparative Processes

“…In fact, the specific delivery of particles to the alveoli level requires a size between 1.5 and 2 μm (Schreier, GonzalezRothi, & Stecenko, 1993;Shek, Suntres, & Brooks, 1994). Unquestionably, the aerosolization of nanoparticles suspensions would enhance their aggregation within the droplets, which is dependant on the nebulizer technology and on the nanoparticle characteristics (Dailey et al, 2003).…”