title: Nanosuspension: a new vehicle for the improvement of the delivery of drugs to the ocular surface. Application to amphotericin B.
abstract: Present limitations in the management of ophthalmic fungal infections include the inability to provide long-term extraocular drug delivery without compromising intraocular structures and/or systemic drug exposure. In the present study, the potential of Eudragit RS 100 nanoparticles (NPs) as a new vehicle for the improvement of the delivery of drugs to the ocular mucosa was investigated. Amphotericin B (AmB) was chosen as a model compound because of its potential usefulness for the treatment of fungal diseases. A solvent displacement technique was used to produce AmB-loaded Eudragit NPs. These NPs had a mean size range of 150-290 nm and a zeta potential of +19-28 mV. Even after 6 months of stability study, results were unchanged, indicating the good potential for ocular application. In vitro release studies revealed that a maximum amount of drug was released within 24 hours (60%). The results obtained from microbial assay showed that the antifungal activity of drug-loaded NPs was equal to or slightly lower than that of free-AmB solution. In vivo experiments showed that, following topical instillation of nanosuspension to a rabbit's eye there was no irritation. From these results we can conclude that Eudragit RS 100 nanosuspension may represent an efficacious vehicle to deliver the drug into the eye.
  
  
  BACKGROUND
  Amphotericin B encapsulated into Eudragit, a mildly cationic nanoparticle, was shown to have 6 month stability, release 60% of its drug payload in dissolution within 24 hours, and elicited no irritation when instilled into rabbit eyes. The concept is being considered for local ophthalmologic therapy of fungal disease.
authors.affiliation: School of Pharmacy and Technology Management, NMIMS University, Mumbai, Maharastra, India. swarnali4u@rediffmail.com
authors.forename: Swarnali
authors.initials: S
authors.lastname: Das
authors.forename: Preeti K
authors.initials: PK
authors.lastname: Suresh
mesh_terms: D000180:Acrylic Resins / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use; D000666:Amphotericin B / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use; D000818:Animals; D000935:Antifungal Agents / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use; D004337:Drug Carriers / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use; D005123:Eye / Q000187:drug effects; D015821:Eye Infections, Fungal / Q000188:drug therapy*; D009092:Mucous Membrane / Q000187:drug effects; D053758:Nanoparticles / Q000008:administration & dosage* / Q000627:therapeutic use / Q000648:ultrastructure; D010316:Particle Size; D011817:Rabbits; D013535:Suspensions
chemical_list: D000180:Acrylic Resins; D000935:Antifungal Agents; D004337:Drug Carriers; D013535:Suspensions; C050528:Eudragit RS; D000666:Amphotericin B