EXHIBIT 23.1 INDEPENDENT AUDITORS' CONSENT We consent to the incorporation by reference in this Registration Statement of Biovail Corporation International on Form S-8 of our reports dated May 14, 1999 appearing in Biovail Corporation International's Annual Report on Form 20-F for the year ended December 31, 1998 and to the reference to us under the heading "Experts" in the Prospectus, which is part of this Registration Statement. /s/ DELOITTE & TOUCHE LLP - -------------------------------- DELOITTE & TOUCHE LLP Toronto, Ontario December 6, 1999