engleski

Micellar solutions of triblock copolymer surfactants with pilocarpine

Solutions of surface active triblock copolymer Pluronic F127 in the vicinity of the critical micellar concentraton (cmc) were prepared with or without pilocarpine (either as the hydrochloride salt or the free base) in water and phosphate buffer. The characteristics parameters of the surface activity (cmc gama and a) were determined for F127 solutions. Additionally, it was found that the pilocarpine solutions without F127 in water exhibits a certain surface activity. The solutions containing F127 (2 wt.%) well above the cmc and pilocarpine (2 wt.% for the salt, or equimolar 1.7 wt.% for the base) were further tessted in vivo (miotic response) on rabbit eye. Though the entrapment efficiency of the drug in the micelles was rather low (maximal 1.9%) the pharmacokinetic parameters (duration of miotic response and the area under miotic curve) were improved when compared to the standard pilocarpine solutions. The best results were obtained for the micellar pilocarpine base solution which exhibits significant prolongation of miotic activity and an increase of AUC for 64%.

pluronic F127 ; pilocarpine ; surface tension ; critical micellar concentration ; miosis

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