Difluprednate (Myser)(Durezol) is a corticosteroid, approved for the treatment of post-operative ocular inflammation and pain.

The difluprednate emulsion formulation begin by suspending DFBA in a variety of oils (castor, cottonseed, medium-chain fatty acid triglyceride, oleic, olive, peanut, and soybean). [1] Difluprednate ophthalmic emulsion's active metabolite, 6α,9-difluoroprednisolone 17-butyrate (DFB), has the lowest Ki value (611 nM) for the glucocorticoid receptor and is significantly more active than prednisolone, which has a Ki value of 3.4 nM. [2]

Difluprednate emulsion is rapidly deacetylated in the aqueous humor to difluoroprednisolone butyrate (DFB) in rats and rabbits, the drug's active metabolite, which has a similar corticosteroid activity profile. Radio-labeled difluprednate is instilled in the right eyes of pigmented rabbits in a separate study examining DFBA excretion. Difluprednate (0.05% emulsion) results in higher aqueous humor concentrations than the suspension form in the eyes of rabbits. Difluprednate concentrations ≥0.01% shows a statistically significant inhibition of inflammation compared to saline in a rabbit model, with the anti-inflammatory response proceeding in a dose-dependent manner. Difluprednate suppresses uveitis in all three concentration (0.002%, 0.01%, and 0.05%) in a dose-dependent manner in rats, and difluprednate 0.05% shows statistically superior anti-inflammatory activity compared to Betamethasone (0.1%). [1]