Allergan Inc. expects its ketorolac tromethamine ophthalmic solution 0.45% (Acuvail) to be available in the United States in September. The preservative-free formulation of ketorolac, a nonsteroidal anti-inflammatory drug (NSAID), is indicated for the treatment of pain and inflammation after cataract surgery and received FDA approval at the end of July, the company announced.

The new solution is formulated at pH 6.8 to enable deionized drug delivery on the corneal surface. It contains carboxymethylcellulose, a viscous molecule also found in one of the company's artificial tear formulations (Refresh Tears) and designed to enable the drug to adhere to the ocular surface and enhance patient comfort. Ketorolac tromethamine inhibits the cyclooxygenase (COX)-1 and COX-2 enzymes to hinder the development of prostaglandins, which are considered to be the primary sources of pain and inflammation following cataract surgery, the company said.

Patients administer one drop of the solution to the affected eye twice daily beginning the day before cataract surgery, then continue using the solution on the day of surgery and through the first 2 weeks of the postoperative period.

The efficacy of the solution was assessed in two multicentre, randomized, double-masked, parallel group comparison studies involving more than 500 patients receiving either ketorolac tromethamine or vehicle. Solution efficacy was defined as complete clearance of anterior chamber inflammation as measured by summed ocular inflammation score (SOIS) and ocular pain relief following cataract extraction with posterior chamber IOL implantation.

Results of these studies, according to the company, demonstrated that at day seven, 32% of patients receiving ketorolac tromethamine had an SOIS score of 0 compared with 17% of patients treated with vehicle. Also, according to Allergan, 53% of patients receiving the solution had clearing of anterior chamber inflammation at day 14 versus 26% of patients receiving vehicle. Additionally, on the first day after cataract surgery, the percentage of patients receiving ketorolac tromethamine who had a pain score of 0 was 72%, compared with 40% for patients in the vehicle group.

The most common adverse events, reported in 1% to 6% of patients, included increased IOP, conjunctival hyperemia and/or hemorrhage, corneal edema, ocular pain, headache, tearing, and blurred vision. Some of these events may have been the consequence of cataract surgery, according to Allergan.