NEW YORK (AP) — Shares of Medicis Pharmaceutical Corp. advanced Tuesday after the company said regulators approved two new doses of its top drug, the acne treatment Solodyn. Medicis said the Food and Drug Administration approved 65 mg and 115 mg doses of acne drug Solodyn. The drug was first approved in May 2006, and doses of 45 mg, 90 mg and 135 mg were already on the market. In morning trading, Medicis shares gained $1.10, or 6.8 percent, to $17.24. Deutsche Bank analyst David Steinberg said Tuesday’s approvals could help the company protect the Solodyn franchise from generic competition. New low-cost versions of the drug could be approved as soon as September, he said, which would erode sales for Medicis. But the approvals would only cover generic versions of the older doses, not the new ones. He estimated that about 45 percent of Medicis’ revenue this year has come from Solodyn sales. Steinberg said Medicis could also choose to obtain legal settlements with Mylan Inc. and Sandoz, which are hoping to have their generics approved in the next few months. If it delays the launch of the generics through a settlement, he said, the Solodyn franchise could last another three or four years. The company reached similar settlements with Impax Laboratories Inc. and Teva Pharmaceutical Industries Ltd. earlier this year.