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Exhibit 31.1 

CERTIFICATION

I, George G. Usher, Chief Executive Officer ofPolydex Pharmaceuticals Limited (the "Company") certify that: 

1.

I have reviewed this quarterlyreport on Form 10–Q of the Company for the fiscal quarter ended July 31, 2008;
2.

Based on my knowledge, thisquarterly report does not contain any untrue statement of a material fact oromit to state a material fact necessary to make the statements made, in light ofthe circumstances under which such statements were made, not misleading withrespect to the period covered by this report; 
3.

Based on my knowledge, the financialstatements, and other financial information included in this report, fairlypresent in all material respects the financial condition, results of operationsand cash flows of the Company as of, and for, the period presented in thisreport; 
4.

The Company’s other certifying officer andI are responsible for establishing and maintaining disclosure controls andprocedures (as defined in Exchange Act Rules 13a–15(e) and 15d–15(e) )andinternal control over financial reporting (as defined in Exchange Act Rules13a-15(f)) and 15d-15(f)) for the Company and have: 

(a) 

designed such disclosure controls andprocedures, or caused such disclosure controls and procedures to be designedunder our supervision, to ensure that material information relating to theCompany, including its consolidated subsidiaries, is made known to us by otherswithin those entities, particularly during the period in which this report wasbeing prepared; 

(b) 

designed such internal control overfinancial reporting, or caused such internal control over financial reporting tobe designed under our supervision, to provide reasonable assurance regarding thereliability of financial reporting and the preparation of financial statementsfor external purposes in accordance with generally accepted accountingprincipals; 

(c) 

evaluated the effectiveness of theCompany’s disclosure controls and procedures and presented in this report ourconclusions about the effectiveness of the disclosure controls and procedures,as of the end of the period covered by this report based on such evaluation; and

(d) 

disclosed in this report any changein the Company’s internal control over financial reporting that occurred duringthe Company’s most recent fiscal quarter that has materially affected, or isreasonably likely to materially affect the Company’s internal control overfinancial reporting; and 
5.

The Company’s other certifyingofficer and I have disclosed, based on our most recent evaluation, to theCompany’s auditors and the audit committee of the Company’s board of directors:

(a) 

all significant deficiencies and materialweaknesses in the design or operation of internal control over financialreporting which are reasonably likely to adversely affect the Company’s abilityto record, process, summarize and report financial information; and 

(b) 

any fraud, whether or not material,that involves management or other employees who have a significant role in theCompany’s internal control over financial reporting. 
Dated: September 12, 2008 
/s/ George G. UsherChief Executive OfficerPolydex Pharmaceuticals Limited