The U.S. Food and Drug Administration (FDA) has approved Perrigo’s generic version of Topicort (desoximetasone topical spray, 0.25%) to treat plaque psoriasis, the company announced.

Topicort, owned by Taro Pharmaceuticals US, is a topical corticosteroid intended for patients 18 and older. It had estimated sales of $24 million for the twelve months that ended in November, the company said in a press release. The spray helps reduce redness, itching, and irritation.

“The ability to develop and bring to market difficult formulations such as this one is what differentiates Perrigo’s Rx employees and portfolio and furthers our offerings to customers around the globe.” John T. Hendrickson, Perrigo’s chief executive officer, said in the release.

Patent litigation between the companies was settled on confidential terms.

The approval means Perrigo was able to demonstrate that its generic was comparable to Topicort in dosage form, strength, route of administration, quality, performance characteristics, and intended use.

According to the FDA, generic-drug applications are generally not required to include preclinical and clinical data to establish safety and effectiveness. Instead, companies must demonstrate the bioequivalence of their product to the marketed drug. (Bioequivalence means the active ingredient of two drug products has the same rate and extent of absorption.)

Plaque psoriasis is the most common type of psoriasis, a chronic autoimmune skin disease that speeds up skin cells’ growth cycle.

The disease causes patches of thick, red skin and silvery scales. Patches are typically found on the elbows, knees, scalp, lower back, face, palms, and soles of feet, but can affect other places (fingernails, toenails, and mouth). According to estimations from an analysis by Centers of Disease Control and Prevention’s National Health and Nutrition Examination Survey (NHANES), about 6.7 million adults older than 20 have psoriasis.