By Benjamin Horney ( August 20, 2014, 6:49 PM EDT) -- Generic-drug producer Mylan Inc., undisclosed Indian drugmakers, and private equity firms TPG Capital LLP, Advent International, KKR & Co. LP and Warburg Pincus LLC have made it to the second round of bidding for a mature drug portfolio being offered by GlaxoSmithKline PLC, The Wall Street Journal reported Wednesday. GSK's portfolio includes prescription medicine brands — such as the antidepressant drug Paxil and the hepatitis B drug Zeffix — that have annual sales of about $1.66 billion, according to WSJ. The sale price could end up being worth more than $3 billion, the report said....