title: A novel in situ gel base of deacetylase gellan gum for sustained ophthalmic drug delivery of ketotifen: in vitro and in vivo evaluation.
abstract: In this study, an ion-activated ketotifen ophthalmic delivery system was developed by using a natural polysaccharide, deacetylase gellan gum. Its rheological characteristics, stability, in vitro gelation, release in vitro, and pharmacodynamic activity in vivo were investigated. The formulation had an optimum viscosity that will allow easy drop as a liquid, which then underwent a rapid sol-gel transition due to ionic interaction. There were negligible alterations in the initial values of viscosity of the formulations over a storage period of 180 days. The in vitro release profiles indicated that the release of ketotifen from in situ gels exhibited a sustained feature. Scintigraphic studies indicated that deacetylase gellan gum could increase the residence time of the formulation. At the same dose, in situ gels demonstrated a typical sustained and prolonged drug-effects behavior compared with the common drops.
authors.affiliation: Department of Ophthalmology, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
authors.forename: Lina
authors.initials: L
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
authors.forename: Junping
authors.initials: J
authors.lastname: Ao
authors.affiliation: Department of Ophthalmology, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
authors.forename: Peiling
authors.initials: P
authors.lastname: Li
mesh_terms: D060433:Administration, Ophthalmic; D000818:Animals; D018926:Anti-Allergic Agents / Q000008:administration & dosage* / Q000737:chemistry; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D065546:Drug Liberation; D004355:Drug Stability; D004356:Drug Storage; D005260:Female; D007665:Ketotifen / Q000008:administration & dosage* / Q000737:chemistry; D008297:Male; D044367:Phase Transition; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D012212:Rheology; D014783:Viscosity
chemical_list: D018926:Anti-Allergic Agents; D003692:Delayed-Action Preparations; D011135:Polysaccharides, Bacterial; C048288:gellan gum; D007665:Ketotifen
keywords: deacetylase gellan gum; ophthalmic delivery; pharmacodynamic; scintigraphic studies; sol–gel transition