Accused by the makers of Tylenol of stealing its process for coating pills with gelatin, the Bayer Corp. has responded to a patent suit by accusing its opponent, McNeill-PPC Inc., of filing false oaths before the U.S. Patent and Trademark Office and falsely marking its products with patent numbers that don’t cover them.

The new allegations were revealed yesterday when a formal answer and counterclaims were filed in U.S. District Court by Bayer’s lawyers, Robert M. Isackson, Peter Bucci, Charles W. Bradley and Rodger A. Sadler of Orrick Herrington & Sutcliffe in New York, along with Albert G. Bixler of Eckert Seamans Cherin & Mellott in Philadelphia.