Evaluation of dexamethasone acetate as a topical ophthalmic formulation

Penetration of an ophthalmic suspension of 0.1% dexamethasone acetate into the rabbit cornea and aqueous humor was unaffected by the status of the corneal epithelium or by the presence or absence of intraocular inflammation. However, the total quantity of this corticosteroid that could be measured in the cornea or aqueous humor was significantly less than that produced by either dexamethason alcohol or dexamethasone sodium phosphate. Despite this, dexamethasone acetate was the most effective of the three dexamethasone derivatives in suppressing inflammation in the cornea, which indicates that following topical administration to the eye it is the most potent of the dexamethasone derivatives studied. This greater therapeutic effect does not seem to be accompanied by a greater propensity to increase intraocular pressure. Comparison of the intraocular pressureincreasing effect in known corticosteroid responders of dexamethasone acetate with that of dexamethasone sodium phosphate, the least effective of the dexamethasone products studied, demonstrated no difference between the two drugs. These data support the conclusion that dexamethasone acetate is superior to the commercially available dexamethasone derivatives for use as a topical ocular anti-inflammatory agent.