* To market generic version of Warner Chilcott's Doryx
* Drug's 75mg and 100mg doses had US sales of $25 mln
* Impax shares up 1 pct, Warner Chilcott shares flat
Dec 29 (Reuters) - Impax Laboratories Inc (IPXL.O) said the U.S. health regulator approved its generic version of Warner Chilcott Ltd's WCRX.O acne drug Doryx.
Impax said it is preparing for the drug's launch through its generic unit Global Pharmaceuticals. The company got approval to market 75 mg and 100 mg tablets of the drug.
According to health information publisher Wolters Kluwer Health, the drug's 75 mg and 100 mg tablets fetched about $25 million in U.S. sales for the year ended October 2010.
In December 2008, Warner Chilcott had filed a lawsuit against Impax, alleging patent infringement for the filing of marketing application of generic Doryx. The lawsuit is ongoing, Impax said.
Warner Chilcott also has a more recently approved 150 mg version of the drug. It was approved in June, 2008.
Impax shares were up 1 percent at $20.71 in morning trade on Nasdaq, while Warner Chilcott shares were almost flat at $22.26. (Reporting by Esha Dey in Bangalore; Editing by Vinu Pilakkott)