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