['We have developed nanoparticle γ-cyclodextrin dexamethasone (DexNP) and dorzolamide (DorzNP) eye drops that provide sustained high drug concentrations on the eye surface. To test these characteristics, we measured dexamethasone and dorzolamide levels in tear fluid in humans following eye drop administration.', 'Concentration of dexamethasone was measured by mass spectrometry. One drop of DexNP was instilled into one eye. Tear fluid was sampled with microcapillary pipettes at seven time-points after drop instillation. Control eyes received Maxidex(®) (dexamethasone). The same procedure was performed for dorzolamide with DorzNP and Trusopt(®) .', 'Six subjects were included in each group. The peak concentration (μg/ml\xa0±\xa0standard deviation) of dexamethasone for DexNP eye drops (636.6\xa0±\xa0399.1) was up to 19-fold higher than with Maxidex(®) (39.3\xa0±\xa018.9) (p\xa0<\xa00.001). At 4\xa0hr, DexNP was still 10 times higher than Maxidex(®) . In addition, DexNP resulted in about 30-fold higher concentration of dissolved dexamethasone in the tear fluid of extended time period allowing more drug to partition into the eye tissue. The overall concentration of dorzolamide was about 50% higher for DorzNP (59.5\xa0±\xa076.9) than Trusopt(®) (40.0\xa0±\xa076.7) (p\xa0<\xa00.05).'] Does kinetics of γ-cyclodextrin nanoparticle suspension eye drop in tear fluid?