UPDATE 2-Labopharm wins FDA approval for once-daily Ryzolt

* Wins approval for first product in the United States

* Sees U.S. launch of Ryzolt in 3 dosage strengths in Q2 (Adds stock price, analyst comment)

TORONTO, Dec 31 (Reuters) - Canadian drug maker Labopharm Inc (DDS.TO) said on Wednesday it has won its first U.S. regulatory approval for the pain drug Ryzolt, sending its stock as much as 63 percent higher.

Labopharm said its once-daily formulation of the analgesic tramadol, for adults who suffer moderate to moderately severe chronic pain and require around-the-clock treatment, has been approved by the U.S. Food and Drug Administration.

The drugmaker said its U.S. marketing partner, Purdue Pharma, plans to launch Ryzolt tablets in 100 mg, 200 mg and 300 mg dosages in the second quarter of 2009.

Labopharm's once-daily tramadol has been launched commercially in 14 countries.

Versant Partners raised its stock target to C$5 from C$3 on the news and Dundee Capital Markets hiked its 12-month price target to C$3.20 from C$2.30.

Versant analyst Douglas Loe, who projects Ryzolt royalty revenue of C$10.2 million from Purdue in 2009 on total sales of C$51 million, said the FDA approval was "unambiguously positive."

Share price momentum could be sustained in 2009 by a regulatory review of Labopharm's Phase 3 anti-depressant trazodone and Phase 3 pain data from its twice-daily tramadol-acetaminophen, he wrote.

Labopharm shares, which peaked at C$2.65 on the Toronto Stock Exchange, closed up 63 Canadian cents, or 38.7 percent percent, at C$2.26, a 10-month high. ($1=$1.22 Canadian) (Reporting by Susan Taylor and Ka Yan Ng; editing by Rob Wilson)