May 3, 2004

POLYDEX PHARMACEUTICALS LIMITED -
2004 FISCAL YEAR END RESULTS

Toronto, Ontario, May 3, 2004 -- Polydex Pharmaceuticals Limited (NASDAQ:POLXF) (BSE:PXL) has announced the results for its fiscal year ending January 31, 2004. All figures are reported in US dollars.

Sales of the Company increased 10% to $14,092,189 in fiscal 2004 from $12,786.343 in fiscal 2003. The Company's gross profit also increased by 3% to $3,349,496. However, the Company experienced a net loss of $5,999 or $0.00 per share due primarily to the significant increase in the value of the Canadian dollar relative to the United States dollar.

On March 5, 2004, the Company reported having completed the sale of its facility in Lenexa, Kansas, for $5.5 million in cash. Management expects that there will be changes in the results of operations, as sales of the Joint Venture accounted for 66% and 64% of the Company's total sales in fiscal 2004 and 2003 respectively. A significant gain in results will be recorded in fiscal 2005 and profit as a percentage of sales is expected to increase as a result of the sale of the lower margin finished product veterinary products business. Management anticipates using a portion of the proceeds from the sale for factory expansion in order to better meet the increasing worldwide demand for human and veterinary products.

Management's objectives for fiscal 2005 include utilizing a portion of the sale proceeds to fund a clinical trial to assess the Company's leading human pharmaceutical compound, known as Ushercell, as a potential treatment for Bacterial Vaginosis. If Ushercell, a cellulose sulphate gel, proves to be effective as a treatment for Bacterial Vaginosis, it may offer an opportunity to bring Ushercell to a commercial market in advance of the completion of contraceptive and HIV efficacy trials, which the product is undergoing.

Ushercell was recently recognized at the 'Microbicides 2004' conference as one of the leading candidates in the microbicide development field approaching late-stage, Phase III, human clinical trials, after having successfully completed a series of safety, tolerance and acceptability trials in India, Nigeria, Uganda, Cameroon, the Dominican Republic, and the United States. Ushercell is currently being assessed in a number of Phase II clinical trials for safety and efficacy as a contraceptive.

These trials have been conducted by CONRAD, leaders in reproductive health research and development, (www.Conrad.org) and funded with support garnered from the World Health Organization, Family Health International, and the HIV Prevention Trials Network. CONRAD has a projected start timeline of June of this year, for Phase III human clinical trials to assess efficacy in the prevention of HIV.

A copy of the Company's Annual Report on Form 10K, including its complete fiscal year end financial statements, is available at the company website at www.Polydex.com.

Polydex Pharmaceuticals Limited, based in Toronto, Ontario, Canada, is engaged in the research, development, manufacture and marketing of biotechnology-based products for the human pharmaceutical market, and also manufactures bulk pharmaceutical intermediates for the worldwide veterinary pharmaceutical industry.

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 United States 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:

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