Corticosteroids are thought to act by the induction of phospholipase A2 inhibitory proteins (lipocortins). It is postulated that these proteins control the biosynthesis of potent mediators of infammation such as prostaglandins and leukotrienes by inhibiting the release of their common precursor arachidonic acid. Arachidonic acid is released from membrane phospholipids by phospholipase A2.
Difluprednate is a corticosteroid used as an anti-inflammatory steroidal drug used primarily in ocular surgery.
Difluprednate is rapidly deacetylated in the aqueous humor to difluoroprednisolone butyrate (DFB), the drugês active metabolite. Endogenous tissue esterases then metabolize DFB to the inert metabolite hydroxyfluoroprednisolone butyrate (HFB), which limits systemic exposure to the active compound.
Preclinical pharmacokinetic and toxicity studies have established that difluprednate ophthalmic emulsion 0.05% given 4 times a day is not toxic to the eye.