Although the code contained in the target file is still subject to the loop, the require() itself happens only once.
If the require() ed file is called via HTTP using the fopen wrappers, and if the target server interprets the target file as PHP code, variables may be passed to the require() ed file using an URL request string as used with HTTP GET. This is not strictly speaking the same thing as require() ing the file and having it inherit the parent file's variable scope; the script is actually being run on the remote server and the result is then being included into the local script.