Barr Wins Tentative OK for Generic Zofran  NEW YORK (Reuters) - Barr Pharmaceuticals Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=BRL.N target=/stocks/quickinfo/fullquote"&gt;BRL.N&lt;/A&gt; on  Friday said U.S. regulators had granted tentative approval to  the company's quickly-dissolving generic form of  GlaxoSmithKline Plc's &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=GSK.L target=/stocks/quickinfo/fullquote"&gt;GSK.L&lt;/A&gt; Zofran antinausea tablet.