The purpose of the study was to develop an optimized thermoreversible in situ gelling ophthalmic drug delivery system based on Pluronic F 127, containing moxifloxacin hydrochloride as a model drug. A 32 full factorial design was employed with two polymers Pluronic F 68 and Gelrite as independent variables used in combination with Pluronic F 127. Gelation temperature, gel strength, bioadhesion force, viscosity and in vitro drug release after 1 and 10 h were selected as dependent variables. Pluronic F 68 loading with Pluronic F 127 was found to have a significant effect on gelation temperature of the formulation and to be of importance for gel formation at temperatures 3336 ºC. Gelrite loading showed a positive effect on bioadhesion force and gel strength and was also found helpful in controling the release rate of the drug. The quadratic mathematical model developed is applicable to predicting formulations with desired gelation temperature, gel strength, bioadhesion force and drug release properties.Cilj rada bio je razvoj i optimizacija termoreverzibilnog sustava za isporuku lijekova koji gelira in situ. Sustav je napravljen na bazi Pluronic F 127, a sadrži moksifloksacin hidroklorid kao modelni lijek. U radu je primjenjeno 32 potpuno faktorijsko dizajniranje s dva polimera, Pluronic F 68 i Gelrite kao nezavisnim varijablama koji su kombinirani s Pluronic F 127. Kao zavisne varijable odabrane su temperatura geliranja, čvrstoća gela, jačina bioadhezije, viskoznost i in vitro oslobađanje lijeka nakon 1 i 10 h. Pronađeno je da Pluronic F 68 u kombinaciji s Pluronic F 127 ima značajan učinak na temperaturu geliranja u rasponu od 33 do 36 C. S druge strane, Gelrite ima povoljan učinak na jačinu bioadhezije, čvrstoću gela i oslobađanje lijeka. Razvijen je kvadratni matematički model pomoću kojeg se može predvidjeti temperatura geliranja, čvrstoća gela, jačina bioadhezije i oslobađanje ljekovite tvari