WASHINGTON — The FDA has raised concerns about the manufacturing processes at Toronto-based Apotex, one of the largest Canadian-owned pharmaceutical companies. The FDA said that a December inspection of the company’s plant in Toronto found “significant deviations from U.S. current good manufacturing practice (CGMP) regulations.” In a warning letter to the company last month, the regulator acknowledged some changes had been made, but said problems remained. The FDA warned that until all the corrections have been completed and the company is compliant with the regulations, it could recommend withholding approval of any new applications or supplements listing Apotex as a drug product manufacturer. It also warned that failure to correct the violations may result in FDA denying entry of drugs manufactured at the company’s plant in Etobicoke, Ont., into the U.S.