Abstract
Abstract: :
Purpose: To assess the ocular bioavailability of a single dose of fluorescein from a novel water-free, freeze-dried ophthalmic drug delivery system compared to a single conventional eye drop. Method: Fluorescein methocel was deposited on sterilized flexible hydrophobic polytetrafluoroethylene (PTFE) carrier strips and freeze-dried under aseptic conditions. The fluorescein dose of the lyophilisate was 68 mg corresponding to a single preservative-free eye drop of 40 ml Fluorescein SETM 0.17% (Alcon). A: in a randomized, open-label study 10 healthy volunteers applied the lyophilisate to one eye and a preservative-free fluorescein eye drop to the fellow eye. Anterior segment fluorophotometry was performed (Fluorotron Master IITM, Ocumetrics, USA) before and every 2 minutes for 30 minutes after application. B: another 10 volunteers applied the lyophilisate to one eye and a preservative-free fluorescein eye drop to the fellow eye. Fluorophotometry was performed before, +2 minutes and +8;+10;+12 hours after application. The fluorescein concentration of cornea (C) and anterior chamber (AC) were analyzed by paired t-test (SPSS). Results: A: Cornea and AC mean values were significantly higher in eyes treated with the lyophilisate during 30 minutes. At +2 minutes the mean fluorescein concentration of C in the lyophilisate group was 3391 ng/ml compared to 839 ng/ml in eyes with the conventional eye drop. B: 8 to 12 hours after application the mean fluorescein concentration of C was significantly higher in the lyophilisate group. Eyes treated with conventional eye drops reached baseline values only. Conclusion: A significantly better bioavailability can be achieved with the lyophilisate. Our data confirm the findings of Dinslage et al. ( ARVO S766, 2000). Lyophilisates are a favourable alternative to conventional eye drops since they have no preservatives, no pH-adjustment and demonstrate easy handling. P B: Cornea: mean fluorescein conc. ng/ml
Keywords: 318 anterior segment • 357 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • 514 pharmacology