** Shares of Biocon fall as much as 6.1 pct to lowest since Jan. 23
** U.S. health regulator issues Form 483 to Biocon's Bangalore facility with 8 observations
** An FDA Form 483 is issued to companies when the investigator has observed conditions that may constitute violations of the U.S. Federal Food, Drug and Cosmetic Act, 1938
** Up to Tuesday's close, stock gained about 10 pct this year vs 13.8 pct rise in NSE index
