title: Study of an alginate/HPMC-based in situ gelling ophthalmic delivery system for gatifloxacin.
abstract: The poor bioavailability and therapeutic response exhibited by conventional ophthalmic solutions due to rapid pre-corneal elimination of the drug may be overcome by the use of in situ gel-forming systems that are instilled as drops into the eye and then undergo a sol-gel transition in the cul-de-sac. The present work describes the formulation and evaluation of an ophthalmic delivery system of an antibacterial agent, gatifloxacin, based on the concept of ion-activated in situ gelation. Alginate (Kelton) was used as the gelling agent in combination with HPMC (Methocel E50Lv) which acted as a viscosity-enhancing agent. The rheological behaviors of all formulations were not affected by the incorporation of gatifloxacin. Both in vitro release studies and in vivo pre-corneal retention studies indicated that the alginate/HPMC solution retained the drug better than the alginate or HPMC E50Lv solutions alone. These results demonstrate that the alginate/HPMC mixture can be used as an in situ gelling vehicle to enhance ocular bioavailability and patient compliance.
authors.affiliation: Department of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China.
authors.forename: Zhidong
authors.initials: Z
authors.lastname: Liu
authors.forename: Jiawei
authors.initials: J
authors.lastname: Li
authors.forename: Shufang
authors.initials: S
authors.lastname: Nie
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.forename: Pingtian
authors.initials: P
authors.lastname: Ding
authors.forename: Weisan
authors.initials: W
authors.lastname: Pan
mesh_terms: D000464:Alginates / Q000627:therapeutic use; D000818:Animals; D001682:Biological Availability; D016503:Drug Delivery Systems / Q000379:methods*; D024841:Fluoroquinolones / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D000077734:Gatifloxacin; D005782:Gels / Q000737:chemistry / Q000627:therapeutic use; D020723:Glucuronic Acid / Q000627:therapeutic use; D006603:Hexuronic Acids / Q000627:therapeutic use; D065347:Hypromellose Derivatives; D007785:Lactose / Q000031:analogs & derivatives / Q000627:therapeutic use; D008747:Methylcellulose / Q000031:analogs & derivatives / Q000627:therapeutic use; D009883:Ophthalmic Solutions / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics; D044367:Phase Transition; D011817:Rabbits; D014783:Viscosity
chemical_list: D000464:Alginates; D024841:Fluoroquinolones; D005782:Gels; D006603:Hexuronic Acids; D009883:Ophthalmic Solutions; C509290:hydroxypropylmethylcellulose-lactose matrix; D065347:Hypromellose Derivatives; D020723:Glucuronic Acid; D008747:Methylcellulose; D007785:Lactose; D000077734:Gatifloxacin