May 16, 2003

INCREASED SALES AND OPERATING PROFITS REPORTED IN FISCAL 2003

NON-OPERATING EXPENSES PRODUCES LOSS

Toronto, Ontario, May 16, 2003 -- Polydex Pharmaceuticals Limited (NASDAQ:POLXF) (BSE:PXL) said today that sales increased 5% or $618,813 to $12,786,343 in fiscal 2003, and the Company's gross profit increased 19% or $520,963 to $3,257,384 in fiscal 2003.

The Company reported a provision for income taxes in fiscal 2003 of $751,366, as compared to $168,982 in fiscal 2002. This principally represents a one-time write-off of future tax benefits previously recorded. Due primarily to this, the Company reported a net loss of $673,741 in fiscal 2003, as compared to $206,880 in fiscal 2002, an overall loss of $0.22 per share for the year.

Sales for the Company's products remain strong. With recent pressure on the U.S. dollar, Polydex is experiencing renewed interest from European distributors of its' dextran based products. Management is planning further refurbishment to its' Toronto facility which will streamline and increase production, reduce costs and further augment profit margins.

The Company continues to pursue its' research and development goals, with focus on the progress of Ushercell, a microbicidal gel anticipated for use as a contraceptive and for prevention of sexually transmitted diseases including HIV, Gonorrhea, Chlamydia Trachomatis, Herpes simplex virus 1 and 2, Bacterial Vaginosis and the Human Papilloma virus, a leading cause of cervical cancer. This research is being conducted through collaboration with scientists from the Program for the Topical Prevention of Conception and Disease (TOPCAD) and the Rush Institute at the University of Illinois in Chicago. Ushercell also continues to benefit from the continued research and funding support of CONRAD, formerly the Contraceptive Research and Development Program. Considering the extensive amount of funding it takes to bring a compound like Ushercell through the development process, this continued collaboration is key, and Management expects this support to continue through the international large-scale human clinical trials planned for this year in India, Uganda, Nigeria and the United States.

Polydex Pharmaceuticals Ltd., based in Toronto, Ontario, Canada, is engaged in the research, manufacture and marketing of biotechnology-based products. Polydex's business approach with respect to the development of the human pharmaceutical pipeline is to research and license out potential products to valued partners for development, thereby minimizing R&D expenditures while retaining a royalty revenue stream from successful products. This is the reason that the search for development partners is so important, and is an integral part of all of the potential human pharmaceutical products in the Polydex pipeline.

Note: This press release may contain forward-looking statements, within the meaning of the United States Securities Act of 1933, as amended, and the United States Securities Exchange Act of 1934, as amended, regarding Polydex Pharmaceuticals Limited. Actual events or results may differ materially from the Company's expectations, which are subject to a number of known and unknown risks and uncertainties including but not limited to changing market conditions, future actions by the U.S. Food and Drug Administration or equivalent foreign regulatory authorities as well as results of pending or future clinical trials. Other risk factors discussed in the Company's filings with the United States Securities and Exchange Commission may also affect the actual results achieved by the Company.

CONTACT:
Polydex Pharmaceuticals Limited
George G. Usher, President
(416) 755-2231
or e-mail: gu-dextran@rogers.com

Investor Relations
North Arm Capital Services
Linda Hughes, Toll-free 1-877-945-1621
or e-mail: Linda@northarm.com