Generic Tablet Manufacturers

Hello, I got my first fill of this med at WalMart at my Dr.s suggestion. Cost only $4 ! I wondered how they could sell so cheap, then saw they were made by "Lupin Limited" in INDIA!!! I want to know if these made offshore are safe and according to what they should be? I saw 4 mfgrs listed on another website, none was Lupin. Are there any American companies making these on US soil? Thanks. Henry