nanocapsules emulsion h nanoparticles t �� lamisil eye microparticles fig indomethacin concentrations attained in the aqueous humor following the topical application, in rabbits, lamisil eye of indomethacinloaded carriers and a control drug solution lamisil eye mean values � sd, n = , p compared with indocollyre p compared with colloidal suspensions lamisil eye reprinted from ref , with permission from pharmaceutical press immunosuppressive peptide cyclosporin a interestingly, following topical administration of pecl nanocapsules containing cyclosporin a, lamisil eye we observed corneal levels of the drug which were five times higher than those provided lamisil eye by an oily solution topical formulation of cyclosporin typically used these high levels were not, lamisil eye however, translated into high drug concentrations in the aqueous humor a result that was attributed lamisil eye to the important hydrophobicity of this peptide and its tendency to associate with lypophylic components therefore, at present, there is a proofofconcept of lamisil eye the efficacy of polyester nanocapsules for enhancing lamisil eye the concentration of topically applied drugs in the lamisil eye corneal epithelium whether this enhanced concentration may lamisil eye or may not lead to a favored accumulation lamisil eye of the drug in the inner eye is expected to be largely dependent on the physicochemical characteristics of the drug polysaccharidebased nanoparticles lamisil eye the polyester polymers described above are hydrophobic polymers lamisil eye that need to be biodegraded into hydrophilic oligomers in order to be eliminated from the body a very different class of polymers, which has only received attention in the last few years, is the one represented by lamisil eye the hydrophilic polysaccharides hyaluronic acid and chitosan are two types of polysaccharides which have opened lamisil eye new prospects in the ocular drug delivery area the choice of hyaluronic acid has been justified by its bioadhesive character, but also by its well known safety profile in fact, lamisil eye hyaluronic acid is already being used as a lamisil eye substitute for vitreous humor in intraocular surgery, since it constitutes a basic component of the vitreous body on the other hand, chitosan is a polycationic biopolymer which exhibits several favorable biological properties for ocular drug administration these properties include mucoadhesiveness biodegradability in the rich lysozyme lamisil eye containing mucus ie ocular albuterol s mucosa, and also lamisil eye wound healing and antimicrobial activity despite the number of articles showing the efficacy of hyaluronic lamisil eye acid solutions for improving the retention of drugs lamisil eye applied topically onto the eye, the only particulate formulation that has been tested in vivo lamisil eye was composed of microparticles zm rather than nanoparticles lamisil eye these hyaluronate microparticles were shown to increase the residence time of the model drug methylprednisolone lamisil eye at the ocular surface of the rabbit eye taking into account the reported influence of the size on the interaction of particles lamisil eye with the ocular mucosa, we have recently designed nanoparticles consisting of hyaluronic acid and chitosan at present, we know that these nanoparticles are stable upon incubation in simulated lachrymal fluids lamisil eye and in vivo studies are in progress in lamisil eye order to evaluate their mechanism of interaction with the ocular mucosa chitosan has also received significant attention in the ophthalmic field one of the chitosanbased systems that has exhibited an interesting behavior following topical ocular administration, is lamisil eye the one consisting of chitosan nanoparticles these nanoparticles have been tested on the rabbit model lamisil eye for their ability to enhance the concentration of cyclosporin a at the level of the ocular mucosa as expected, the results showed that lamisil eye the chitosan nanoparticles were able to increase the concentrations of cyclosporin a in the external ocular tissues cornea and conjunctiva significantly for lamisil eye up to hr postinstillation fig despite this enhanced retention of the drug in the external tissues, the levels attained in the internal ocular structures ie aqueous humor, iris and ciliary body and in the blood were negligible consequently, lamisil eye these results suggested the utility of this new formulation for the treatment of surface eye diseases, ie dry eye or inflammatory diseases lamisil eye these high drug concentrations restricted to the periocular lamisil eye tissues were later explained by a high corneal and conjunctival surface retention of chitosan nanoparticles indeed, in a study consisting of evaluating lamisil eye the concentration of fluorescent chitosan, either in the lamisil eye form of nanoparticles or as a solution, in cornea and conjunctiva, we could conclude that the affinity of chitosan for the ocular lamisil eye surface is greater when it is in a lamisil eye particulate form this conclusion invites interesting prospects lamisil eye with regard to the potential of chitosan nanoparticles lamisil eye as drug carriers for topical ocular administration keeping this in mind, we tested the acute lamisil eye tolerance of chitosan nanoparticles following topical instillation to rabbits very recently the results gave evidence lamisil eye of an excellent tolerance, without any sign lamisil eye of irritation or damage of the ocular surface structures cya concentration in the cornea ng cyag cornea ?