Mucoadhesive liposomes as ocular delivery system: physical, microbiological, and in vivo assessment

Abstract

The results obtained pointed out that liposome coating process resulted in entrapment efficiency reduction and higher chitosan concentration, and molecular weight showed a more pronounced effect. No morphological differences between coated and uncoated liposomes were observed. Diffusion was the drug release mechanism from chitosomes. Concerning rheological behavior, pseudoplastic flow was characteristic to the prepared chitosomal dispersions. In addition, chitosan coating improved the ocular permeation of ciprofloxacin HCl. Microbiologically; this formulated system enhanced antimicrobial activity of ciprofloxacin HCl against both Gram-positive and Gram-negative bacteria. Moreover, this mucoadhesive system was able to inhibit the growth of Pseudomonas aeruginosa in rabbits' eyes for 24 hours when compared to the marketed preparation. In vivo bacterial conjunctivitis model elucidated that symptoms were controlled by the prolonged release formulation such as that done by the marketed product.

Recent advances in non-ionic surfactant vesicles (niosomes): self-assembly, fabrication, characterization, drug delivery applications and limitations

“…Dispersing liposomes in a viscous gel has been used either to reduce the rapid leakage of the encapsulated drug from liposomes (Meisnera & Mezeib, 1995) or to minimize the burst release effect observed with liposomes (Mehanna et al, 2009(Mehanna et al, , 2010. This approach may be extrapolated to improve the physical stability of ocular niosomes.…”

Low molecular weight chitosan-coated liposomes for ocular drug delivery:In vitroandin vivostudies

“…The rapid development of nano-technology of pharmaceutics brings new hope to resolve the difficulties in the ocular delivery. Such technologies include liposomes (Alsarra et al, 2008;Shehata et al, 2008;Pukanud et al, 2009;Mehanna et al, 2010), polymer nanoparticles (Oyarzun-Ampuero et al, 2009), lipid nanoparticles (Gokce et al, 2008), microemulsions (Chan et al, 2007), etc. Such formulations are suitable to be applied to a topical instillation for treatment of local ophthalmic diseases, and meanwhile the systematic adverse effects and clinical inconvenience during the treatment can be minimized.…”

Liposomes in topical ophthalmic drug delivery: an update

“…Chitosan, a biodegradable and nontoxic mucoadhesive substance, has been used to coat liposomes. Mehanna et al (2010) showed that coating liposomes with high molecular weight chitosan inhibits their aggregation, increases the viscosity and hence the corneal residence time. The chitosan coating slowed the rate of drug release and provided 1.74-fold higher corneal permeation due to absorption enhancing nature of chitosan.…”