title: Design and evaluation of a brinzolamide drug-resin in situ thermosensitive gelling system for sustained ophthalmic drug delivery.
abstract: In this study a brinzolamide drug-resin ophthalmic thermosensitive in situ gelling system was developed and evaluated. Brinzolamide was combined with ion exchange resins to prolong the retention time of drugs in the eye and to reduce ocular and systemic side effects. Poloxamer F127 was used as gelling vehicle in combination with carbopol 934P, which acted as a viscosity-enhancing agent. They were prepared using the cold method. The optimized formulation exhibited a sol-gel transition at 33.2±1.1°C with pseudoplastic flow behavior. This formulation was stable and nonirritant to rabbit eyes. In vitro release studies demonstrated diffusion-controlled release of brinzolamide from the combined solutions over a period of 8 h. In vivo evaluation (the elimination of brinzolamide through tears and absorption of brinzolamide in aqueous humor) indicated that the solution combination was better able to retain the drug than commercial preparations. Thus this formulation is safe for ophthalmic use and significantly increases brinzolamide bioavailability in aqueous humor.
authors.affiliation: Department of Pharmaceutics, School of Pharmaceutical Science, Zhengzhou University.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Hua
authors.initials: H
authors.lastname: Liu
authors.forename: Li-li
authors.initials: LL
authors.lastname: Liu
authors.forename: Chao-nan
authors.initials: CN
authors.lastname: Cai
authors.forename: Hong-xia
authors.initials: HX
authors.lastname: Xin
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
mesh_terms: D000179:Acrylates / Q000737:chemistry; D060433:Administration, Ophthalmic; D000818:Animals; D002626:Chemistry, Pharmaceutical; D004337:Drug Carriers / Q000737:chemistry*; D005123:Eye / Q000187:drug effects; D005782:Gels / Q000737:chemistry*; D006207:Half-Life; D007475:Ion Exchange Resins / Q000737:chemistry*; D020442:Poloxamer / Q000737:chemistry; D011817:Rabbits; D012212:Rheology; D013449:Sulfonamides / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics; D013696:Temperature; D013843:Thiazines / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics; D014783:Viscosity
chemical_list: D000179:Acrylates; D004337:Drug Carriers; D005782:Gels; D007475:Ion Exchange Resins; D013449:Sulfonamides; D013843:Thiazines; D020442:Poloxamer; C111827:brinzolamide; C453622:carbopol 934P