(Reuters) - Specialty health care company Endo International PLC (ENDP.O) (ENL.TO) offered to buy Auxilium Pharmaceuticals Inc. (AUXL.O) for about $2.2 billion in cash and stock to expand its men's health care products business.

Auxilium, which said in June it would buy Canadian eye drug maker QLT Inc. in an all-stock deal to move its headquarters to lower-tax British Columbia, was not immediately available for comment.

Endo said it sent a proposal to Auxilium on Friday but had not received an official response.

Endo's offer of $28.10 per share represents a premium of 30.6 percent to Auxilium's Tuesday closing price of $21.52 on the Nasdaq.

Auxilium's shares rose 42 percent to $30.60 after the bell, indicating that some shareholders expected a higher offer.

Auxilium's Xiaflex is marketed in the United States to treat men with bothersome curvature of the penis, a condition known as Peyronie's disease.

"We expect that Endo's leading presence in men's health, combined with our R&D capabilities and considerable financial resources will accelerate the growth of Xiaflex and Auxilium's other products...," Endo's Chief Executive Rajiv De Silva said.

Xiaflex, which is also being evaluated for use in frozen shoulder syndrome, is approved to treat Dupuytren's contracture, a progressive hand disease that affects a person's ability to use his fingers.

Two doses of the drug were proved statistically significant in a mid-stage study to smoothen cellulite, the company said last month.

Dublin-based Endo, which makes branded men's health care products, including testosterone replacement therapy Aveed, said it intends to fund the transaction through cash on hand and debt financing.

Shares of Endo International, formerly known as Endo Health Solutions, were trading 5 percent higher at $68.50 after market.

Endo, which also makes generic pharmaceuticals and medical devices, bought privately owned DAVA Pharmaceuticals Inc. for $575 million in June.