Abstract
Purpose:
To investigate the kinetics of nanoparticle γ-cyclodextrin dexamethasone eye drops in tear fluid in rabbits and humans.
Methods:
One drop of dexamethasone in γ-cyclodextrin nanoparticle suspension (DexNP) was instilled into both eyes of pigmented rabbits (n = 15). After a washout period of 72 hours, one drop of commercial dexamethasone eye drops (Maxidex®, Alcon) was instilled into both eyes as reference. Tear fluid was collected at 15, 30, 45, 60 and 120 minutes after drop instillation. The tear fluid was sampled with micro capillary pipettes. The quantification of dexamethasone was performed with a UPLC-MS/MS system. A similar study is currently underway in humans.
Results:
The concentration (µg/ml) of dexamethasone for DexNP and Maxidex® was 968.5 ± 754.6 and 6.9 ± 6.0 (mean ± SD) after 15 minutes, 192.3 ± 141.9 and 7.8 ± 4.4 after 30 minutes, 51.7 ± 37.5 and 3.4 ± 2.1 after 45 minutes, 46.3 ± 57.4 and 4.3 ± 6.6 after 60 minutes and 7.4 ± 5.4 and 2.2 ± 1.2 after 120 minutes after administration, respectively. The difference between DexNP and Maxidex® was highly significant at all time points (p < 0.001).
Conclusions:
There was a highly significant difference in concentration of dexamethasone in the tear fluid at all time points between DexNP and Maxidex®. The concentration was up to 140 fold higher in the DexNP eyes than the Maxidex® eyes. The results indicate a greater mucoadhesion of DexNP which can explain the more long lasting effect of the cyclodextrin nanoparticle drug delivery platform.
Keywords: 608 nanomedicine •
607 nanotechnology