title: In situ gelling systems based on Pluronic F127/Pluronic F68 formulations for ocular drug delivery.
abstract: This study evaluated the use of Pluronic F127 and Pluronic F68 as excipients for formulating in situ gelling systems for ocular drug delivery. Thermal transitions have been studied in aqueous solutions of Pluronic F127, Pluronic F68 as well as their binary mixtures using differential scanning calorimetry, rheological measurements, and dynamic light scattering. It was established that the formation of transparent gels at physiologically relevant temperatures is observed only in the case of 20 wt% of Pluronic F127. The addition of Pluronic F68 to Pluronic F127 solutions increases the gelation temperature of binary formulation to above physiological range of temperatures. The biocompatibility evaluation of these formulations using slug mucosa irritation assay and bovine corneal erosion studies revealed that these polymers and their combinations do not cause significant irritation. In vitro drug retention study on glass surfaces and freshly excised bovine cornea showed superior performance of 20 wt% Pluronic F127 compared to other formulations. In addition, in vivo studies in rabbits demonstrated better retention performance of 20 wt% Pluronic F127 compared to Pluronic F68. These results confirmed that 20 wt% Pluronic F127 offers an attractive ocular formulation that can form a transparent gel in situ under physiological conditions with minimal irritation.
authors.affiliation: Reading School of Pharmacy, University of Reading, Whiteknights, PO Box 224, Reading RG6 6AD, United Kingdom.
authors.forename: Kosai
authors.initials: K
authors.lastname: Al Khateb
authors.affiliation: Semey State Medical University, 103 Abai Street, Semey 071400, Kazakhstan.
authors.forename: Elvira K
authors.initials: EK
authors.lastname: Ozhmukhametova
authors.affiliation: Semey State Medical University, 103 Abai Street, Semey 071400, Kazakhstan.
authors.forename: Marat N
authors.initials: MN
authors.lastname: Mussin
authors.affiliation: Semey State Medical University, 103 Abai Street, Semey 071400, Kazakhstan.
authors.forename: Serzhan K
authors.initials: SK
authors.lastname: Seilkhanov
authors.affiliation: Semey State Medical University, 103 Abai Street, Semey 071400, Kazakhstan.
authors.forename: Tolebai K
authors.initials: TK
authors.lastname: Rakhypbekov
authors.affiliation: Reading School of Pharmacy, University of Reading, Whiteknights, PO Box 224, Reading RG6 6AD, United Kingdom. Electronic address: w.lau@reading.ac.uk.
authors.forename: Wing Man
authors.initials: WM
authors.lastname: Lau
authors.affiliation: Reading School of Pharmacy, University of Reading, Whiteknights, PO Box 224, Reading RG6 6AD, United Kingdom. Electronic address: v.khutoryanskiy@reading.ac.uk.
authors.forename: Vitaliy V
authors.initials: VV
authors.lastname: Khutoryanskiy
mesh_terms: D060433:Administration, Ophthalmic; D000818:Animals; D002417:Cattle; D002626:Chemistry, Pharmaceutical; D016503:Drug Delivery Systems; D005079:Excipients / Q000737:chemistry / Q000494:pharmacology / Q000633:toxicity; D005123:Eye / Q000187:drug effects / Q000378:metabolism*; D049851:Gastropoda / Q000187:drug effects / Q000378:metabolism; D005782:Gels; D008823:Micelles; D009092:Mucous Membrane / Q000187:drug effects / Q000378:metabolism; D009093:Mucus / Q000378:metabolism; D020442:Poloxamer / Q000737:chemistry / Q000494:pharmacology / Q000633:toxicity; D011817:Rabbits; D012212:Rheology
chemical_list: D005079:Excipients; D005782:Gels; D008823:Micelles; D020442:Poloxamer
keywords: Gelation; In situ gelling systems; Mucoadhesion; Ocular drug delivery; Pluronics