Specialty pharmaceutical company Alkermes PLC has reduced its reliance on one product and lowered its tax rate following the acquisition of Elan's drug technology business and Alkermes' move to Ireland, according to a Jefferies & Co. analyst.Analyst Graig Suvannavejh raised the company's stock to "buy" from "hold" and raised the price target on the shares to $21 from $19. He said in a Monday morning note the upgrade reflects his "enthusiasm" for the Elan deal, saying it improves Alkermes fundamentals in both the near and long term.Alkermes said earlier this month it had completed its acquisition of Irish drug maker Elan's drug technology business. Elan got $500 million in cash and 31.9 million Alkermes shares, representing a 25 percent stake in the company.Alkermes also reincorporated in Ireland as part of the deal. It is now headquartered in Dublin after being based in Waltham, Mass.Alkermes uses technology that improves the delivery of well-established drug compounds. Its products include Risperdal Consta, a schizophrenia treatment marketed by Johnson & Johnson that is delivered once every two weeks.The deal is expected to double Alkermes' annual revenue and make the company profitable, allowing it to make bigger investments in research.Suvannavejh said he thinks the Elan deal still remains under-appreciated. Risperdal Consta was Alkermes' main revenue source before the Elan deal, and the analyst expects its contribution to slide. The acquisition provides new products like the multiple sclerosis treatment Ampyra that have good patent protections.The analyst also noted that as a result of its reincorporation in Ireland, Alkermes will get a 12.5 percent tax rate on profits made in Ireland compared to a 38 percent rate in the United States.Alkermes shares have climbed more than 26 percent so far this year, after ending 2010 at $12.28. The stock closed at $15.55 on Friday.