Document:

Exhibit 4.5

Exhibit 4.5

PRIVATE PLACEMENT SUBSCRIPTION AMENDING AGREEMENT

THIS AMENDING AGREEMENT dated for reference December 22, 2005 is made

AMONG:

UOB CAPITAL INVESTMENTS PTE LTD,
80 Raffles Place, UOB Plaza 2 #30-20 Singapore 048624

(the “Purchaser”)

OF THE FIRST PART

AND:

WEX PHARMACEUTICALS INC. (formerly known as INTERNATIONAL
WEX TECHNOLOGIES INC.), a corporation formed under the
Canada Business Corporations Act and having an office at
2100 – 1040 West Georgia Street, Vancouver, British Columbia
V6E 4H1

(the “Company”)

OF THE SECOND PART

AND:

WEX MEDICAL LIMITED, a corporation formed under the laws of
Hong Kong and having an office at Unit A, 34/F., Manulife
Tower, 169 Electric Road, North Point, Hong Kong

(the “Subsidiary”)

OF THE THIRD PART

WHEREAS:

	A.	 	On June 14, 2004, the Purchaser advanced to the Subsidiary $1,500,000 (the “Advanced
Funds”) pursuant to a subscription agreement among the Purchaser, the Subsidiary and
the Company dated May 18, 2004 (the “Original Subscription Agreement”);

	 
	B.	 	Pursuant to the Original Subscription Agreement, the Subsidiary and the Company issued
to the Purchaser a debenture dated June 14, 2004 relating to the Advanced Funds (the
“Debenture”);

 

 

 

	C.	 	The Purchaser, the Subsidiary and the Company wish to enter into this Amending
Agreement to amend certain provisions of the Original Subscription Agreement as hereinafter provided; and

	 
	D.	 	Concurrently with the execution of this Amending Agreement, the Purchaser, the
Subsidiary and the Company have agreed to amend the Debenture.

NOW THEREFORE in consideration of the mutual premises, covenants and agreements herein set forth,
and $1.00 now paid by each party to the others, and other good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, the parties hereto covenant and agree as
follows:

	1.	 	Definitions

In this Amending Agreement and the recitals hereto, unless the context otherwise requires,
any capitalized term not otherwise defined herein will have the meaning ascribed thereto
in the Original Subscription Agreement.

	2.	 	One Instrument

The parties hereto agree that the Original Subscription Agreement, as amended hereby,
shall continue to have full force and effect and this Amending Agreement shall have
effect, so far as practicable, as if all of the provisions of the Original Subscription
Agreement and this Amending Agreement were contained in the one instrument.

	3.	 	Amendments

	 	3.1	 	The definition of “Debentures” in section l.l(j) of the Original Subscription
Agreement is deleted and the following is substituted in its place:

	 	“(j)	 	 “Debentures” means the unsecured convertible debentures
originally due five years and one day from the date of issuance and bearing
interest at 51/2% per annum payable semi annually and otherwise
having the attributes and being in the form of Schedule “A” attached to this
Agreement, as amended from time to time;”

	 	3.2	 	Article 5 of the Original Subscription Agreement is deleted and the following
is substituted in its place:

	 	“5. 	 	COVENANTS OF THE COMPANIES

	 
	 	5.1	 	The Company and each of its subsidiaries shall deliver to the
Purchaser
such financial statements and other documents as required under the
Debentures.

	 
	 	5.2	 	So long as any Debentures are outstanding, the Companies agree to
appoint to the board of directors of Nanning Maple Leaf Pharmaceutical
Co. Ltd. (a limited liability company under the laws of China), one nominee
designated in writing by holders of Debentures.

 

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	 	5.3	 	So long as any Debentures are outstanding, the Purchaser shall
be entitled
to appoint an observer who shall have the right to attend all board
meetings of the Company, including committee meetings, either in person
or by phone. The observer will have the right to receive notice of all
meetings of the board of the Company, including committee meetings, and
the right to speak thereat and will receive all information and material
presented to the board as would a director. The Companies will pay all
reasonable expenses of the observer incurred in attending at meetings of
the board of directors, or any committees thereof. Such expenses will be
paid by the Companies in the same manner as the Companies pay the
expenses of their directors.

	 
	 	5.4	 	The covenants contained in this section 5 will survive Closing
and shall
terminate upon the conversion of the Debentures in accordance with the
terms thereof.”

	4.	 	Representation, Warranties and Covenants of the Companies

	 	4.1	 	The Companies, jointly and severally, represent, warrant and covenant
that, as of the date hereof:

	 	(a)	 	except as disclosed in Schedule A hereto, the
representations and
warranties in Section 4.1 of the Original Subscription Agreement are true
and correct;

	 
	 	(b)	 	each of the Companies has full corporate power and authority to
enter into
this Amending Agreement and perform its obligations hereunder;

	 
	 	(c)	 	the execution and delivery of this Amending Agreement will not
breach,
violate or conflict with any instrument or agreement governing any
Intellectual Property right owned, used by or licensed to the Company or
any of its subsidiaries, will not cause the forfeiture or termination of any
Intellectual Property right owned, used by or licensed to the Company or
any of its subsidiaries to use, sell, license or dispose of or to bring any
action for the infringement of any Intellectual Property right owned, used
by or licensed to the Company or any of its subsidiaries (or any portion
thereof);

	 
	 	(d)	 	the Company and its subsidiaries are not in default or breach
of, and the
execution and delivery of, and the performance of and compliance with
the terms of this Amending Agreement by the Company or any of the
transactions contemplated hereby does not and will not result in any
breach of, or constitute a default under, and does not and will not create a
state of facts which, after notice or lapse of time or both, would result in
a
breach or constitute a default under, any term or provision of the
constating documents or resolutions of shareholders or directors of the
Company or any of its subsidiaries, or any indenture, mortgage, note,
contract, agreement (written or oral), instrument, lease or other document
to which the Company or any of its subsidiaries is a party or by which it
is bound, or any judgment, decree, order, statute, rule or regulation
applicable to the Company or any of its subsidiaries, which default or
breach might reasonably be expected to materially adversely affect the
business, operations, capital or condition (financial or otherwise) of the
Company or any of its subsidiaries or their properties or assets;

 

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	 	(e)	 	this Amending Agreement has been duly authorized by all
necessary
corporate action on the part of the Companies;

	 
	 	(f)	 	the Company has obtained the approval from the Exchange in
respect of
the transactions contemplated by this Amending Agreement; and

	 
	 	(g)	 	to the best of the Company’s knowledge, the representations,
warranties
and statements of fact contained herein or otherwise furnished by or on
behalf of the Company or the subsidiaries to the Purchaser in connection
with the transactions contemplated by this Amending Agreement do not
omit to state any material fact necessary to make any such representation,
warranty or statement not misleading. The Company has no knowledge of
any facts relating to the Business which, if known to the Purchaser, might
reasonably be expected to deter the Purchaser from entering into this
Amending Agreement.

	 	4.2	 	The representations, warranties and covenants contained in this section
will survive the execution of this Amending Agreement.

	5.	 	Release

Upon timely payment being made in accordance with section 3.1(a) of each of the
Debentures, the Purchaser shall deliver to the Company a release in the form attached
hereto as Schedule B executed by the Purchaser.

	6.	 	Expenses

Upon execution of this Amending Agreement, the Company shall reimburse the Purchaser for
half of the legal fees and expenses (and taxes thereon) incurred by the Purchaser arising
out of the non-disclosure by the Company of the dispute relating to Chinese patent ZL
95190556.2, including the costs relating to the negotiation, preparation and execution of
this Amending Agreement.

	7.	 	Counterparts

This Agreement may be executed in any number of counterparts, each of which will be deemed
to be an original and all of which taken together will be deemed to constitute one and the
same instrument. Counterparts may be delivered either in original or faxed form
and the parties adopt any signatures received by a receiving fax machine as original
signatures of the parties; provided, however, that any party providing its signature in such
manner will promptly forward to the other party an original of the signed copy of this
Agreement which was so faxed.

 

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IN WITNESS WHEREOF the parties hereto have duly executed this Agreement as of the day and year
first above written.

	 	 	 	 	 	 	 
	For and on behalf of

UOB CAPITAL INVESTMENTS PTE LTD
	 	 	 	 	 	 
	 
	 	 	 	 	 	 
	/s/ “Terence Ong Sea Eng”
 

Signature

	 	 	 	 	 	 
	 
	 	 	 	 	 	 
	Terence Ong Sea Eng
	 	 	 	 	 	 
	 
	 	 	 	 	 	 
	Name
	 	 	 	 	 	 
	 
	 	 	 	 	 	 
	Authorised Signatory
	 	 	 	 	 	 
	 
	 	 	 	 	 	 
	Title
	 	 	 	 	 	 
	 
	 	 	 	 	 	 
	SIGNED, SEALED AND DELIVERED

	 	 	)	 	 	 
	BY WEX PHARMACEUTICALS INC.

	 	 	)	 	 	 
	in the presence of:

	 	 	)	 	 	 
	 

	 	 	)	 	 	 
	/s/ “Iain R. Mant”

	 	 	)	 	 	 
	 
	 	 	 	 	 	 
	Signature

	 	 	)	 	 	 
	 

	 	 	)	 	 	/s/ “Edge Wang”
	 

	 	 	 	 	 	 
	Iain R. Mant

	 	 	)	 	 	Edge Wang, President
	Barrister & Solicitor

	 	 	)	 	 	 
	 
	 	 	 	 	 	 
	Name

	 	 	)	 	 	 
	 

	 	 	)	 	 	 
	2100 – 1075 West Georgia Street

	 	 	)	 	 	 
	Vancouver, BC V6E 3G2

	 	 	)	 	 	 
	604 631 4734

	 	 	)	 	 	 
	 
	 	 	 	 	 	 
	Address

	 	 	)	 	 	 
	 

	 	 	)	 	 	 
	 

	 	 	)	 	 	 
	 
	 	 	 	 	 	 

 

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	SIGNED, SEALED AND DELIVERED

	 	 	)	 	 	 
	BY WEX MEDICAL LIMITED)
	 	 	 	 	 	 
	in the presence of:

	 	 	)	 	 	 
	 

	 	 	)	 	 	 
	/s/ “Iain Mant”
 

	 	) 
	 	 
	Signature

	 	 	)	 	 	 
	 

	 	 	)	 	 	/s/ “Edge Wang”
	 

	 	 	 	 	 	 
	Iain R. Mant

	 	 	)	 	 	Edge Wang, President
	Barrister & Solicitor

	 	 	)	 	 	 
	 
	 	 	 	 	 	 
	Name

	 	 	)	 	 	 
	 

	 	 	)	 	 	 
	2100 – 1075 West Georgia Street

	 	 	)	 	 	 
	Vancouver, BC V6E 3G2

	 	 	)	 	 	 
	604 631 4734

	 	 	)	 	 	 
	 
	 	 	 	 	 	 
	Address

	 	 	)	 	 	 
	 

	 	 	)	 	 	 
	 

	 	 	)	 	 	 
	 
	 	 	 	 	 	 

 

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SCHEDULE A

DISCLOSURE SCHEDULE TO

PRIVATE PLACEMENT SUBSCRIPTION AMENDING AGREEMENT

DATED FOR REFERENCE DECEMBER 22, 2005

The representations set forth in section 4.1 of the original Subscription Agreement are true and
correct except as set forth below. Paragraph numbers below correspond to paragraph references under
section 4.1 of the Original Subscription Agreement.

	(d)	 	As of September 30, 2005 the Company had issued and outstanding 35,059,461 common
 shares.

	 
	(i)	 	The reference to March 31, 2003 should be changed to June 30, 2005.

	 
	(j)	 	Schedule D of the Original Subscription Agreement should include reference to the
following agreements:

A. Licensing and Collaboration Agreement and accompanying Supply Agreement
between the Company and Laboratories Del Dr. Esteve, S.A. dated November 27, 2002,
as amended by a Revised Collaboration Letter dated March 9, 2005.

B. Manufacturing and Option Agreement between the Company and Sabex 2002
Inc., dated March 17, 2004.

C. Letter of Understanding between the Company and Mr. Claude Cardinal dated
November 21, 2003 (7% royalty on certain topical formulations)

D. Licensing Agreement between the Company and Techpharm Inc., dated
November 21, 2003 (7% on certain topical formulations)

	(m)	 	As disclosed in the Company’s news release dated June 28, 2005 the Company has been notified
the Chinese Patent Office has changed registered ownership of the drug withdrawal patent ZL
95190556.2 “Use of Amino Quinazoline Hydride Compound and it Derivative for Abstaining from
Drug Dependence” in China from the Company’s subsidiary, Nanning Maple Leaf Pharmaceuticals
to one of two inventors and a third party who alleges to have been an employer of the other
inventor. The Company has decided to temporarily postpone development and testing of its
opiate addiction withdrawal drug in China. In August 2005, the Company was notified that an
earlier attempt by a third party to invalidate this patent had been withdrawn.

The Company has initiated re-examination proceedings for patent US 6,407,088 “Method of
Analgesia”.

During the preparation and prosecution of the Company’s patent applications a range of
documents have been identified. These include patents and applications directed to some
aspects of the chemistry and use of TTX.

 

 

 

There may be additional patent documents (including pending applications) in existence of
which the Company is unaware, including patent applications which have been filed but have
not yet been laid open to public inspection. To the best of the Company’s knowledge, there
are no existing patents of such a scope that they would preclude the Company from
conducting its Business. Nonetheless it is possible that some aspect of the Company’s
planned activities might at some point potentially infringe upon one or more existing
patents or patent applications in one or more jurisdictions.

Although not exhaustive it is believed that the results of the International Search
Reports that have issued in the Company’s PCT applications (including applications owned
by Nanning Maple Leaf Pharmaceutical Co. Ltd.) provide a reasonably comprehensive
representation of the relevant prior art patents and patent applications. The lists of
prior art cited in Search Reports already issued with respect to the Company’s PCT filings
are attached hereto. Additional documents may have been identified in individual national
or regional prosecutions.

	(n)	 	See paragraph (m) above.

	 
	(q)	 	See paragraph (j) above.

	 
	(t)	 	See paragraph (m) above.

	 
	(y)	 	The Company is the subject of an investigation by the British Columbia Securities
Commission with respect to the disclosure of certain clinical trial results.

	 
	(ii)	 	A. See paragraph (y) above.

B. The Company has received requisitions to call a meeting from two different shareholders.
The first requisition was received from Ms. Margaret Chow and the second from Mr. Arlyn Miller.

Ms. Chow’s request asks the Company to call a special meeting to remove all of the directors, to
fix the size of the board at six and to elect her nominees (which had not been specified). The
Company had considered Ms. Chow’s requisition and determined not to call a meeting of shareholders
to deal with her requisition. As a result, Ms. Chow was entitled to call a meeting, but took no
steps in furtherance thereof other than to issue a press release.

Mr. Miller’s subsequent requisition asks the Company to call a special meeting to remove Donna
Shum, Frank Shum and Kenneth Li as directors, and elect Dr. Benjamin Chen, Mr. Pierre Cantin and
Mr. Arlyn Miller as directors in their place. The Company has considered Mr. Miller’s requisition
and has called the Meeting to address his requisition. The Company recommends shareholders vote in
favour of this resolution.

Mr. Miller’s requisition also asks the Company to call a special meeting to ask shareholders of
the Company to approve the creation of a Royalty Trust. The Company is making no recommendation to
shareholders with respect to this resolution.

C. See paragraph (y) above.

 

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SCHEDULE B

RELEASE

 

 

 

MUTUAL RELEASE

This Agreement is made the 22nd  day of December, 2005.

BETWEEN:

WEX PHARMACEUTICALS INC.

(“Wex”)

AND:

WEX MEDICAL LIMITED

(“Wex HK”)

AND:

UOB CAPITAL INVESTMENTS PTE LTD

(“UOB”)

WHEREAS:

A. Wex, Wex HK and UOB entered into a Private Placement Subscription Agreement dated
May 18, 2004 and a Debenture dated June 14, 2004 (together the “Loan Agreement”) whereby
UOB advanced the sum of US $1,500,000 to Wex HK.

B. Nanning Maple Leaf Pharmaceuticals, a subsidiary of Wex, is and has been involved in a
dispute regarding the ownership of Chinese Patent No. ZL95190556.2 “Use of Quinazoline
Hydride Compound and its Derivative for Abstaining from Drug Dependence” (the “Dispute”).

C. UOB has asserted that the representations and warranties made by Wex and Wex HK to
UOB in the Loan Agreement were not accurate because of the existence of the Dispute at the
time the Loan Agreement was entered into (the “Disclosure Issue”).

D. Wex, Wex HK and UOB have entered into a Private Placement Subscription Amending
Agreement dated December 22, 2005 and a Debenture Amendment Agreement dated
December 22, 2005 (collectively the “New Agreements”) to amend the terms and
conditions of the Loan Agreement.

 

 

 

NOW THEREFORE THIS AGREEMENT WITNESSES that in consideration of the sum of $10.00 now paid by each
party to the other and in consideration of the mutual covenants and agreements herein contained,
and other good and valuable consideration, including the entering into of the New Agreements the
parties hereto agree as follows:

1. RELEASE BY WEX

Wex and Wex HK each hereby remises, releases and forever discharges UOB and its successors,
assigns, directors, officers, agents and employees (collectively, the “UOB Releasees”) of and from
any and all liabilities, causes of action, claims, proceedings, suits, costs, demands,
obligations, interest, debts, duties and damages of whatever nature or kind, whether at law or at
equity and whether known or unknown, suspected or unsuspected, which Wex or Wex HK has or
subsequently may have against the UOB Releasees or any of them, arising out of the Disclosure
Issue.

2. RELEASE BY UOB

UOB hereby remises, releases and forever discharges Wex and Wex HK and their successors, assigns,
directors, officers, agents and employees (collectively, the “Wex Releasees”) of and from any and
all liabilities, causes of action, claims, proceedings, suits, costs, demands, obligations,
interest, debts, duties and damages of whatever nature or kind, whether at law or at equity and
whether known or unknown, suspected or unsuspected, which UOB has or subsequently may have against
the Wex Releasees arising out of the Disclosure Issue.

3. AGREEMENT NOT TO SUE OTHERS WITH RESPECT TO SUBJECT MATTER OF RELEASE

The parties agree not to make any claim or take or continue any proceedings against any other
person or corporation who might claim contribution or indemnity from the other in connection with
the subject matter of this Mutual Release.

4. RELEASE DOES NOT AFFECT ANY OBLIGATIONS UNDER THE NEW AGREEMENT

For greater clarity, this Mutual Release does not affect any of the obligations of any party
pursuant to the New Agreements.

5. NOT AN ADMISSION OF LIABILTY

This Mutual Release does not constitute any admission of liability or wrongdoing by any party to
this Mutual Release.

6. CONFIDENTIALITY

The parties have agreed on the terms of a press release to be issued by Wex announcing the
entering into of the New Agreement, the form of which is attached as Schedule A to this agreement
(the “Press Release”). The parties agree that, except to the extent disclosed in the Press
Release, they shall keep the terms of this Mutual Release and the New Agreements confidential and
not disclose them to any person or entity, except that they shall be permitted to disclose the
terms as necessary to professional advisors and as required by law.

 

- 2- 

 

7. AGREEMENT NOT TO BE AFFECTED BY DIFFERENCE IN FACTS OR LAW

The parties acknowledge that the facts and law in respect of which this Mutual Release is given
may be different from the facts and law now known or believed to be true. The parties agree that
this release will in all respects be enforceable and not subject to termination, rescission, or
variation by discovery of any difference in facts or law.

8. GOVERNING LAW

This Mutual Release is governed by the laws in force in the Province of British Columbia. The
Courts of British Columbia shall have exclusive jurisdiction over this Mutual Release, including
without limitation the enforcement of this Mutual Release and any dispute regarding its
interpretation and application.

9. SUCCESSORS AND ASSIGNS

This Mutual Release is binding upon and for the benefit of the parties hereto and their respective
heirs, executors, administrators, successors, assigns, partners, agents and employees (in such
capacity).

10. COUNTERPARTS

This Mutual Release may be executed in one or more counterparts and such counterparts may be
transmitted by electronic facsimile, and each such counterpart shall be deemed to be an original
and together such counterparts shall constitute one document.

 

- 3- 

 

11. ENTIRE AGREEMENT

The provisions contained herein, together with the New Agreements, constitute the entire agreement
between the parties and supersede all previous communications, representations, understandings and
agreements, whether oral or written, between them with respect to the subject matter of this
Mutual Release and New Agreements.

IN WITNESS WHEREOF the parties have set their authorized signatures this 22 day
of December, 2005.

WEX PHARMACEUTICALS INC.

	 	 	 	 	 
	Per:
	 	/s/ “Edge Wang”
 

Authorized Signatory
	 	 
	 
	 	 	 	 
	WEX MEDICAL LIMITED	 	 
	 
	 	 	 	 
	Per:

	 	/s/ “Edge Wang”
 

Authorized Signatory
	 	 
	 
	 	 	 	 
	UOB CAPITAL INVESTMENTS PTE LTD	 	 
	 
	 	 	 	 
	Per:

	 	/s/ “Terence Ong Sea Eng”	 	 
	 

	 	 	 	 
	 

	 	Authorized Signatory	 	 

 

- 4- 

 

PRIVATE PLACEMENT SUBSCRIPTION AMENDING AGREEMENT

THIS AMENDING AGREEMENT dated for reference December 22, 2005 is made

AMONG:

UOB
VENTURE TECHNOLOGY INVESTMENTS LTD,

80 Raffles Place, UOB Plaza 2 #30-20, Singapore 048624

(the “Purchaser”)

OF THE FIRST PART

AND:

WEX PHARMACEUTICALS INC. (formerly known as INTERNATIONAL
WEX TECHNOLOGIES INC.), a corporation formed under the
Canada Business Corporations Act and having an office at
2100 — 1040 West Georgia Street, Vancouver, British
Columbia V6E 4H1

(the “Company”)

OF THE SECOND PART

AND:

WEX MEDICAL LIMITED, a corporation formed under the laws of
Hong Kong and having an office at Unit A, 34/F., Manulife
Tower, 169 Electric Road, North Point, Hong Kong

(the “Subsidiary”)

OF THE THIRD PART

WHEREAS:

	A.	 	On June 14, 2004, the Purchaser advanced to the Subsidiary $1,500,000 (the “Advanced Funds”)
pursuant to a subscription agreement among the Purchaser, the Subsidiary and the Company dated
May 18, 2004 (the “Original Subscription Agreement”);

	B.	 	Pursuant to the Original Subscription Agreement, the Subsidiary and the Company issued to the
Purchaser a debenture dated June 14, 2004 relating to the Advanced Funds (the “Debenture”);

 

 

 

	C.	 	The Purchaser, the Subsidiary and the Company wish to enter into this Amending Agreement to
amend certain provisions of the Original Subscription Agreement as hereinafter provided; and

	D.	 	Concurrently with the execution of this Amending Agreement, the Purchaser, the Subsidiary and
the Company have agreed to amend the Debenture.

NOW THEREFORE in consideration of the mutual premises, covenants and agreements herein set forth,
and $1.00 now paid by each party to the others, and other good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, the parties hereto covenant and agree as
follows:

	1.	 	Definitions

In this Amending Agreement and the recitals hereto, unless the context otherwise requires,
any capitalized term not otherwise defined herein will have the meaning ascribed thereto in
the Original Subscription Agreement.

	2.	 	One Instrument

The parties hereto agree that the Original Subscription Agreement, as amended hereby, shall
continue to have full force and effect and this Amending Agreement shall have effect, so
far as practicable, as if all of the provisions of the Original Subscription Agreement and
this Amending Agreement were contained in the one instrument.

	3.	 	Amendments

	 	3.1	 	The definition of “Debentures” in section 1.1(j) of the Original Subscription
Agreement is deleted and the following is substituted in its place:

	 	“(j)	 	“Debentures” means the unsecured convertible debentures
originally due five years and one day from the date of issuance and bearing
interest at
51/2%
per annum payable semi annually and otherwise
having the attributes and being in the form of Schedule “A” attached to this
Agreement, as amended from time to time;”

	 	3.2	 	Article 5 of the Original Subscription Agreement is deleted and the following
is substituted in its place:

	 	“5.	 	COVENANTS OF THE COMPANIES

	 	5.1	 	The Company and each of its subsidiaries shall deliver to the
Purchaser such financial statements and other documents as required under the
Debentures.

	 
	 	5.2	 	So long as any Debentures are outstanding, the Companies agree to
appoint to the board of directors of Nanning Maple Leaf Pharmaceutical
Co. Ltd. (a limited liability company under the laws of China), one nominee
designated in writing by holders of Debentures.

 

 - 2 - 

 

	 	5.3	 	So long as any Debentures are outstanding, the Purchaser shall
be entitled to appoint an observer who shall have the right to attend all board
meetings of the Company, including committee meetings, either in person or by
phone. The observer will have the right to receive notice of all meetings of
the board of the Company, including committee meetings, and the right to speak
thereat and will receive all information and material presented to the board as
would a director. The Companies will pay all reasonable expenses of the
observer incurred in attending at meetings of the board of directors, or any
committees thereof. Such expenses will be paid by the Companies in the same
manner as the Companies pay the expenses of their directors.

	 
	 	5.4	 	The covenants contained in this section 5 will survive Closing
and shall terminate upon the conversion of the Debentures in accordance with
the terms thereof.”

	4.	 	Representation, Warranties and Covenants of the Companies

	 	4.1	 	The Companies, jointly and severally, represent, warrant and covenant
that, as of the date hereof:

	 	(a)	 	except as disclosed in Schedule A hereto, the representations
and warranties in Section 4.1 of the Original Subscription Agreement are true
and correct;

	 
	 	(b)	 	each of the Companies has full corporate power and authority to
enter into this Amending Agreement and perform its obligations hereunder;

	 
	 	(c)	 	the execution and delivery of this Amending Agreement will not
breach, violate or conflict with any instrument or agreement governing any
Intellectual Property right owned, used by or licensed to the Company or any of
its subsidiaries, will not cause the forfeiture or termination of any
Intellectual Property right owned, used by or licensed to the Company or any of
its subsidiaries to use, sell, license or dispose of or to bring any action for
the infringement of any Intellectual Property right owned, used by or licensed
to the Company or any of its subsidiaries (or any portion thereof);

	 
	 	(d)	 	the Company and its subsidiaries are not in default or breach of,
and the execution and delivery of, and the performance of and compliance with
the terms of this Amending Agreement by the Company or any of the transactions
contemplated hereby does not and will not result in any breach of, or constitute
a default under, and does not and will not create a state of facts which, after
notice or lapse of time or both, would result in a breach or constitute a
default under, any term or provision of the
constating documents or resolutions of shareholders or directors of the
Company or any of its subsidiaries, or any indenture, mortgage, note,
contract, agreement (written or oral), instrument, lease or other document
to which the Company or any of its subsidiaries is a party or by which it is
bound, or any judgment, decree, order, statute, rule or regulation
applicable to the Company or any of its subsidiaries, which default or
breach might reasonably be expected to materially adversely affect the
business, operations, capital or condition (financial or otherwise) of the
Company or any of its subsidiaries or their properties or assets;

 

 - 3 - 

 

	 	(e)	 	this Amending Agreement has been duly authorized by all
necessary corporate action on the part of the Companies;

	 
	 	(f)	 	the Company has obtained the approval from the Exchange in
respect of the transactions contemplated by this Amending Agreement; and

	 
	 	(g)	 	to the best of the Company’s knowledge, the representations,
warranties and statements of fact contained herein or otherwise furnished by or
on behalf of the Company or the subsidiaries to the Purchaser in connection
with the transactions contemplated by this Amending Agreement do not omit to
state any material fact necessary to make any such representation, warranty or
statement not misleading. The Company has no knowledge of any facts relating to
the Business which, if known to the Purchaser, might reasonably be expected to
deter the Purchaser from entering into this Amending Agreement.

	 	4.2	 	The representations, warranties and covenants contained in this section
will survive the execution of this Amending Agreement.

	5.	 	Release

Upon timely payment being made in accordance with section 3.1(a) of each of the
Debentures, the Purchaser shall deliver to the Company a release in the form attached
hereto as Schedule B executed by the Purchaser.

	6.	 	Expenses

Upon execution of this Amending Agreement, the Company shall reimburse the Purchaser for
half of the legal fees and expenses (and taxes thereon) incurred by the Purchaser arising
out of the non-disclosure by the Company of the dispute relating to Chinese patent ZL
95190556.2, including the costs relating to the negotiation, preparation and execution of
this Amending Agreement.

	7.	 	Counterparts

This Agreement may be executed in any number of counterparts, each of which will be deemed
to be an original and all of which taken together will be deemed to constitute one and the
same instrument. Counterparts may be delivered either in original or faxed form
and the parties adopt any signatures received by a receiving fax machine as original
signatures of the parties; provided, however, that any party providing its signature
in such manner will promptly forward to the other party an original of the signed
copy of this Agreement which was so faxed.

 

 - 4 - 

 

IN WITNESS WHEREOF the parties hereto have duly executed this Agreement as of the day and year
first above written.

For and on behalf of

UOB VENTURE TECHNOLOGY

INVESTMENTS LTD

	 	 	 
	/s/ “Seah Kian Wee”
 

Signature

	 	 

	 	 	 
	Seah Kian Wee
 

Name

	 	 

	 	 	 
	Managing Director of UOB Venture Management Pte Ltd
 

Title

	 	 

	 	 	 	 	 	 	 	 	 	 	 
	SIGNED, SEALED AND DELIVERED

	 	 	)	 	 	 	 	 	 	 
	BY WEX PHARMACEUTICALS INC.

	 	 	)	 	 	 	 	 	 	 
	in the presence of:

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 	 	 
	/s/ “Iain
R. Mant”
 

	 	 	)	 	 	 	 	 	 	 
	Signature

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	/s/ “Edge
Wang”
 

	 	 
	Iain R. Mant

	 	 	)	 	 	 	 	Edge Wane, President	 	 
	Barrister & Solicitor
 

	 	 	)	 	 	 	 	 	 	 
	Name

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 	 	 
	2100 — 1075 West Georgia Street

	 	 	)	 	 	 	 	 	 	 
	Vancouver, BC V6E 3G2

	 	 	)	 	 	 	 	 	 	 
	604 631 4734
 

Address

	 	 	)

)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	 	 	 

 

 - 5 - 

 

	 	 	 	 	 	 	 	 	 	 	 
	SIGNED, SEALED AND DELIVERED

	 	 	)	 	 	 	 	 	 	 
	BY WEX MEDICAL LIMITED )

	 	 		 	 	 	 	 	 	 
	in the presence of:

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 	 	 
	/s/ “ Iain R. Mant ”
 

	 	 	)	 	 	 	 	 	 	 
	Signature

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	/s/ “ Edge
Wang ”
 

	 	 
	Iain R. Mant

	 	 	)	 	 	 	 	Edge Wane, President	 	 
	Barrister & Solicitor
 

	 	 	)	 	 	 	 	 	 	 
	Name

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 	 	 
	2100 — 1075 West Georgia Street

	 	 	)	 	 	 	 	 	 	 
	Vancouver, BC V6E 3G2

	 	 	)	 	 	 	 	 	 	 
	604 631 4734
 

Address

	 	 	)

)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	 	 	 

 

 - 6 - 

 

SCHEDULE A

DISCLOSURE SCHEDULE TO

PRIVATE PLACEMENT SUBSCRIPTION AMENDING AGREEMENT

DATED FOR REFERENCE DECEMBER 22, 2005

The representations set forth in section 4.1 of the original Subscription Agreement are true and
correct except as set forth below. Paragraph numbers below correspond to paragraph references
under section 4.1 of the Original Subscription Agreement.

	(d)	 	As of September 30, 2005 the Company had issued and outstanding 35,059,461 common
 shares.

	(i)	 	The reference to March 31, 2003 should be changed to June 30, 2005.

	(j)	 	Schedule D of the Original Subscription Agreement should include reference to the
following agreements:

A. Licensing and Collaboration Agreement and accompanying Supply Agreement between the
Company and Laboratories Del Dr. Esteve, S.A. dated November 27, 2002, as amended by a
Revised Collaboration Letter dated March 9, 2005.

B. Manufacturing and Option Agreement between the Company and Sabex 2002 Inc., dated March
17, 2004.

C. Letter of Understanding between the Company and Mr. Claude Cardinal dated November 21,
2003 (7% royalty on certain topical formulations)

D. Licensing Agreement between the Company and Techpharm Inc., dated November 21,
2003 (7% on certain topical formulations)

	(m)	 	As disclosed in the Company’s news release dated June 28, 2005 the Company has been
notified the Chinese Patent Office has changed registered ownership of the drug withdrawal
patent ZL 95190556.2 “Use of Ammo Quinazoline Hydride Compound and it Derivative for
Abstaining from Drug Dependence” in China from the Company’s subsidiary, Nanning Maple Leaf
Pharmaceuticals to one of two inventors and a third party who alleges to have been an
employer of the other inventor. The Company has decided to temporarily postpone development
and testing of its opiate addiction withdrawal drug in China. In August 2005, the Company
was notified that an earlier attempt by a third party to invalidate this patent had been
withdrawn.

The Company has initiated re-examination proceedings for patent US 6,407,088 “Method of
Analgesia”.

During the preparation and prosecution of the Company’s patent applications a range of
documents have been identified. These include patents and applications directed to some
aspects of the chemistry and use of TTX.

 

 

 

There may be additional patent documents (including pending applications) in existence of
which the Company is unaware, including patent applications which have been filed but have
not yet been laid open to public inspection. To the best of the Company’s knowledge, there
are no existing patents of such a scope that they would preclude the Company from
conducting its Business. Nonetheless it is possible that some aspect of the Company’s
planned activities might at some point potentially infringe upon one or more existing
patents or patent applications in one or more jurisdictions.

Although not exhaustive it is believed that the results of the International Search
Reports that have issued in the Company’s PCT applications (including applications owned
by Nanning Maple Leaf Pharmaceutical Co. Ltd.) provide a reasonably comprehensive
representation of the relevant prior art patents and patent applications. The lists of
prior art cited in Search Reports already issued with respect to the Company’s PCT filings
are attached hereto. Additional documents may have been identified in individual national
or regional prosecutions.

	(n)	 	See paragraph (m) above.

	 
	(q)	 	See paragraph (j) above.

	 
	(t)	 	See paragraph (m) above.

	 
	(y)	 	The Company is the subject of an investigation by the British Columbia Securities Commission
with respect to the disclosure of certain clinical trial results.

	 
	(ii)	 	A. See paragraph (y) above.

B. The Company has received requisitions to call a meeting from two different shareholders.
The first requisition was received from Ms. Margaret Chow and the second from Mr. Arlyn Miller.

Ms. Chow’s request asks the Company to call a special meeting to remove all of the directors, to
fix the size of the board at six and to elect her nominees (which had not been specified). The
Company had considered Ms. Chow’s requisition and determined not to call a meeting of
shareholders to deal with her requisition. As a result, Ms. Chow was entitled to call a meeting,
but took no steps in furtherance thereof other than to issue a press release.

Mr. Miller’s subsequent requisition asks the Company to call a special meeting to remove Donna
Shum, Frank Shum and Kenneth Li as directors, and elect Dr. Benjamin Chen, Mr. Pierre Cantin and
Mr. Arlyn Miller as directors in their place. The Company has considered Mr. Miller’s requisition
and has called the Meeting to address his requisition. The Company recommends shareholders vote
in favour of this resolution.

Mr. Miller’s requisition also asks the Company to call a special meeting to ask shareholders of
the Company to approve the creation of a Royalty Trust. The Company is making no recommendation
to shareholders with respect to this resolution.

	 	C.	 	See paragraph (y) above.

 

 

 

SCHEDULE B

RELEASE

 

 

 

MUTUAL RELEASE

This
Agreement is made the
22nd day of December, 2005.

BETWEEN:

WEX PHARMACEUTICALS INC.

(“Wex”)

AND:

WEX MEDICAL LIMITED

(“Wex HK”)

AND:

UOB VENTURE TECHNOLOGY INVESTMENTS LTD

(“UOB”) 

WHEREAS:

A. Wex, Wex HK and UOB entered into a Private Placement Subscription Agreement dated May 18, 2004
and a Debenture dated June 14, 2004 (together the “Loan Agreement”) whereby UOB advanced the sum of
US $1,500,000 to Wex HK.

B. Nanning Maple Leaf Pharmaceuticals, a subsidiary of Wex, is and has been involved in a dispute
regarding the ownership of Chinese Patent No. ZL95190556.2 “Use of Quinazoline Hydride Compound and
its Derivative for Abstaining from Drug Dependence” (the “Dispute”).

C. UOB has asserted that the representations and warranties made by Wex and Wex HK to UOB in the
Loan Agreement were not accurate because of the existence of the Dispute at the time the Loan
Agreement was entered into (the “Disclosure Issue”).

D. Wex, Wex HK and UOB have entered into a Private Placement Subscription Amending Agreement dated
December 22, 2005 and a Debenture Amendment
Agreement dated December 22, 2005
(collectively the “New Agreements”) to amend the terms and conditions of the Loan Agreement.

 

 

 

NOW THEREFORE THIS AGREEMENT WITNESSES that in consideration of the sum of $10.00 now paid by each
party to the other and in consideration of the mutual covenants and agreements herein contained,
and other good and valuable consideration, including the entering into of the New Agreements the
parties hereto agree as follows:

1. RELEASE BY WEX

Wex and Wex HK each hereby remises, releases and forever discharges UOB and its successors,
assigns, directors, officers, agents and employees (collectively, the “UOB Releasees”) of and from
any and all liabilities, causes of action, claims, proceedings, suits, costs, demands,
obligations, interest, debts, duties and damages of whatever nature or kind, whether at law or at
equity and whether known or unknown, suspected or unsuspected, which Wex or Wex HK has or
subsequently may have against the UOB Releasees or any of them, arising out of the Disclosure
Issue.

2. RELEASE BY UOB

UOB hereby remises, releases and forever discharges Wex and Wex HK and their successors, assigns,
directors, officers, agents and employees (collectively, the “Wex Releasees”) of and from any and
all liabilities, causes of action, claims, proceedings, suits, costs, demands, obligations,
interest, debts, duties and damages of whatever nature or kind, whether at law or at equity and
whether known or unknown, suspected or unsuspected, which UOB has or subsequently may have
against the Wex Releasees arising out of the Disclosure Issue.

3. AGREEMENT NOT TO SUE OTHERS WITH RESPECT TO SUBJECT MATTER OF RELEASE

The parties agree not to make any claim or take or continue any proceedings against any other
person or corporation who might claim contribution or indemnity from the other in connection with
the subject matter of this Mutual Release.

4. RELEASE DOES NOT AFFECT ANY OBLIGATIONS UNDER THE NEW AGREEMENT

For greater clarity, this Mutual Release does not affect any of the obligations of any party
pursuant to the New Agreements.

5. NOT AN ADMISSION OF LIABILTY

This Mutual Release does not constitute any admission of liability or wrongdoing by any party to
this Mutual Release.

6. CONFIDENTIALITY

The parties have agreed on the terms of a press release to be issued by Wex announcing the
entering into of the New Agreement, the form of which is attached as Schedule A to this agreement
(the “Press Release”). The parties agree that, except to the extent disclosed in the Press
Release, they shall keep the terms of this Mutual Release and the New Agreements confidential and
not disclose them to any person or entity, except that they shall be permitted to disclose the
terms as necessary to professional advisors and as required by law.

 

 - 2 - 

 

7. AGREEMENT NOT TO BE AFFECTED BY DIFFERENCE IN FACTS OR LAW

The parties acknowledge that the facts and law in respect of which this Mutual Release is given
may be different from the facts and law now known or believed to be true. The parties agree that
this release will in all respects be enforceable and not subject to termination, rescission, or
variation by discovery of any difference in facts or law.

8. GOVERNING LAW

This Mutual Release is governed by the laws in force in the Province of British Columbia. The
Courts of British Columbia shall have exclusive jurisdiction over this Mutual Release, including
without limitation the enforcement of this Mutual Release and any dispute regarding its
interpretation and application.

9. SUCCESSORS AND ASSIGNS

This Mutual Release is binding upon and for the benefit of the parties hereto and their respective
heirs, executors, administrators, successors, assigns, partners, agents and employees (in such
capacity).

10. COUNTERPARTS

This Mutual Release may be executed in one or more counterparts and such counterparts may be
transmitted by electronic facsimile, and each such counterpart shall be deemed to be an original
and together such counterparts shall constitute one document.

 

 - 3 - 

 

11. ENTIRE AGREEMENT

The provisions contained herein, together with the New Agreements, constitute the entire agreement
between the parties and supersede all previous communications, representations, understandings and
agreements, whether oral or written, between them with respect to the subject matter of this
Mutual Release and New Agreements.

IN WITNESS WHEREOF the parties have set their authorized signatures this 22 day of
December, 2005.

	 	 	 

WEX PHARMACEUTICALS INC.

	 	 	 	 	 
	Per:

	 	/s/ “Edge Wang”
 

Authorized Signatory
	 	 

WEX MEDICAL LIMITED

	 	 	 	 	 
	Per:

	 	/s/ “Edge Wang”
 

Authorized Signatory
	 	 

UOB VENTURE TECHNOLOGY INVESTMENTS LTD

	 	 	 	 	 
	Per:

	 	/s/ “Seah Kian Wee”
 

Authorized Signatory
	 	 

 

 - 4 - 

 

PRIVATE PLACEMENT SUBSCRIPTION AMENDING AGREEMENT

THIS AMENDING AGREEMENT dated for reference December 22, 2005 is made

AMONG:

UOB VENTURE (SHENZHEN) LIMITED,

608, St James Court, St Denis Street, Port Louis, Mauritius

(the “Purchaser”)

OF THE FIRST PART

AND:

WEX PHARMACEUTICALS INC. (formerly known as INTERNATIONAL
WEX TECHNOLOGIES INC.), a corporation formed under the
Canada Business Corporations Act and having an office at
2100 — 1040 West Georgia Street, Vancouver, British Columbia
V6E 4H1

(the “Company”)

OF THE SECOND PART

AND:

WEX MEDICAL LIMITED, a corporation formed under the laws of
Hong Kong and having an office at Unit A, 34/F., Manulife
Tower, 169 Electric Road, North Point, Hong Kong

(the “Subsidiary”)

OF THE THIRD PART

WHEREAS:

	A.	 	On June 14, 2004, the Purchaser advanced to the Subsidiary $2,100,000 (the “Advanced
Funds”) pursuant to a subscription agreement among the Purchaser, the Subsidiary and
the Company dated May 18, 2004 (the “Original Subscription Agreement”);

	B.	 	Pursuant to the Original Subscription Agreement, the Subsidiary and the Company issued
to the Purchaser a debenture dated June 14, 2004 relating to the Advanced Funds (the
“Debenture”);

 

 

 

	C.	 	The Purchaser, the Subsidiary and the Company wish to enter into this Amending
Agreement to amend certain provisions of the Original Subscription Agreement as
hereinafter provided; and

	D.	 	Concurrently with the execution of this Amending Agreement, the Purchaser, the
Subsidiary and the Company have agreed to amend the Debenture.

NOW THEREFORE in consideration of the mutual premises, covenants and agreements herein set forth,
and $1.00 now paid by each party to the others, and other good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, the parties hereto covenant and agree as
follows:

	1.	 	Definitions

In this Amending Agreement and the recitals hereto, unless the context otherwise requires,
any capitalized term not otherwise defined herein will have the meaning ascribed thereto in
the Original Subscription Agreement.

	2.	 	One Instrument

The parties hereto agree that the Original Subscription Agreement, as amended hereby, shall
continue to have full force and effect and this Amending Agreement shall have effect, so
far as practicable, as if all of the provisions of the Original Subscription Agreement and
this Amending Agreement were contained in the one instrument.

	3.	 	Amendments

	 	3.1	 	The definition of “Debentures” in section l.l(j) of the Original Subscription
Agreement is deleted and the following is substituted in its place:

	 	“(j)	 	 “Debentures” means the unsecured convertible debentures
originally due five years and one day from the date of issuance and bearing
interest at 51/2% per annum payable semi annually and otherwise having the
attributes and being in the form of Schedule “A” attached to this Agreement,
as amended from time to time;”

	 	3.2	 	Article 5 of the Original Subscription Agreement is deleted and the following
is substituted in its place:

	 	“5.	 	 COVENANTS OF THE COMPANIES

	 
	 	5.1	 	The Company and each of its
subsidiaries shall deliver to the Purchaser such financial statements
and other documents as required under the Debentures.

	 
	 	5.2	 	So long as any Debentures are outstanding, the Companies agree to
appoint to the board of directors of Nanning Maple Leaf Pharmaceutical
Co. Ltd. (a limited liability company under the laws of China), one nominee
designated in writing by holders of Debentures.

 

 - 2 - 

 

	 	5.3	 	So long as any Debentures are outstanding, the Purchaser shall
be entitled
to appoint an observer who shall have the right to attend all board
meetings of the Company, including committee meetings, either in person
or by phone. The observer will have the right to receive notice of all
meetings of the board of the Company, including committee meetings, and
the right to speak thereat and will receive all information and material
presented to the board as would a director. The Companies will pay all
reasonable expenses of the observer incurred in attending at meetings of
the board of directors, or any committees thereof. Such expenses will be
paid by the Companies in the same manner as the Companies pay the
expenses of their directors.

	 
	 	5.4	 	The covenants contained in this section 5 will survive Closing and shall
terminate upon the conversion of the Debentures in accordance with the
terms thereof.”

	4.	 	Representation, Warranties and Covenants of the Companies

	 	4.1	 	The Companies, jointly and severally, represent, warrant and covenant
that, as of the date hereof:

	 	(a)	 	except as disclosed in Schedule A hereto, the
representations and
warranties in Section 4.1 of the Original Subscription Agreement are true
and correct;

	 
	 	(b)	 	each of the Companies has full corporate power and authority to
enter into
this Amending Agreement and perform its obligations hereunder;

	 
	 	(c)	 	the execution and delivery of this Amending Agreement will not
breach,
violate or conflict with any instrument or agreement governing any
Intellectual Property right owned, used by or licensed to the Company or
any of its subsidiaries, will not cause the forfeiture or termination of any
Intellectual Property right owned, used by or licensed to the Company or
any of its subsidiaries to use, sell, license or dispose of or to bring any
action for the infringement of any Intellectual Property right owned, used
by or licensed to the Company or any of its subsidiaries (or any portion
thereof);

 

 - 3 - 

 

	 	(d)	 	the Company and its subsidiaries are not in default or breach
of, and the
execution and delivery of, and the performance of and compliance with
the terms of this Amending Agreement by the Company or any of the
transactions contemplated hereby does not and will not result in any
breach of, or constitute a default under, and does not and will not create a
state of facts which, after notice or lapse of time or both, would result in
a
breach or constitute a default under, any term or provision of the
constating documents or resolutions of shareholders or directors of the
Company or any of its subsidiaries, or any indenture, mortgage, note,
contract, agreement (written or oral), instrument, lease or other document
to which the Company or any of its subsidiaries is a party or by which it is
bound, or any judgment, decree, order, statute, rule or regulation
applicable to the Company or any of its subsidiaries, which default or
breach might reasonably be expected to materially adversely affect the
business, operations, capital or condition (financial or otherwise) of the
Company or any of its subsidiaries or their properties or assets;

	 
	 	(e)	 	this Amending Agreement has been duly authorized by all
necessary
corporate action on the part of the Companies;

	 
	 	(f)	 	the Company has obtained the approval from the Exchange in
respect of
the transactions contemplated by this Amending Agreement; and

	 
	 	(g)	 	to the best of the Company’s knowledge, the representations,
warranties
and statements of fact contained herein or otherwise furnished by or on
behalf of the Company or the subsidiaries to the Purchaser in connection
with the transactions contemplated by this Amending Agreement do not
omit to state any material fact necessary to make any such representation,
warranty or statement not misleading. The Company has no knowledge of
any facts relating to the Business which, if known to the Purchaser, might
reasonably be expected to deter the Purchaser from entering into this
Amending Agreement.

	 	4.2	 	The representations, warranties and covenants contained in this section
will survive the execution of this Amending Agreement.

	5.	 	Release

Upon timely payment being made in accordance with section 3.1(a) of each of the
Debentures, the Purchaser shall deliver to the Company a release in the form attached
hereto as Schedule B executed by the Purchaser.

	6.	 	Expenses

Upon execution of this Amending Agreement, the Company shall reimburse the Purchaser for
half of the legal fees and expenses (and taxes thereon) incurred by the Purchaser arising
out of the non-disclosure by the Company of the dispute relating to Chinese patent ZL
95190556.2, including the costs relating to the negotiation, preparation and execution of
this Amending Agreement.

	7.	 	Counterparts

This Agreement may be executed in any number of counterparts, each of which will be deemed
to be an original and all of which taken together will be deemed to constitute one and the
same instrument. Counterparts may be delivered either in original or faxed form
and the parties adopt any signatures received by a receiving fax machine as
original signatures of the parties; provided, however, that any party providing its
signature in such manner will promptly forward to the other party an original of
the signed copy of this Agreement which was so faxed.

 

 - 4 - 

 

IN WITNESS WHEREOF the parties hereto have duly executed this Agreement as of the day and
year first above written.

For and on behalf of

UOB VENTURE (SHENZHEN) LIMITED

	 	 	 
	/s/ “Seah Kian Wee”
 

Signature

	 	 

	 	 	 
	Seah Kian Wee
 

Name

	 	 

	 	 	 
	Director of SZVC UOB Venture Management Co Ltd
 

Title

	 	 

	 	 	 	 	 	 	 	 	 	 	 
	SIGNED, SEALED AND DELIVERED

	 	 	)	 	 	 	 	 	 	 
	BY WEX PHARMACEUTICALS INC.

	 	 	)	 	 	 	 	 	 	 
	in the presence of:

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 	 	 
	/s/ “Iain  Mant”
 

	 	 	)	 	 	 	 	 	 	 
	Signature

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	“/s/ Edge
Wang”	 	 
	 

	 	 	 	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	Edge Wang, President	 	 
	 

Name

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 	 	 
	 

Address

	 	 	)

)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	 	 	 

 

 - 5 - 

 

	 	 	 	 	 	 	 	 	 	 	 
	SIGNED, SEALED AND DELIVERED

	 	 	)	 	 	 	 	 	 	 
	BY
WEX MEDICAL LIMITED )

	 	 		 	 	 	 	 	 	 
	in the presence of:

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 	 	 
	/s/ “Iain  Mant”
 

	 	 	)	 	 	 	 	 	 	 
	Signature

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	/s/ “Edge
Wang”	 	 
	 

	 	 	 	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	Edge Wang, President	 	 
	 

Name

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 	 	 
	 

Address

	 	 	)

)	 	 	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	 	 	 

 

 - 6 - 

 

SCHEDULE A

DISCLOSURE SCHEDULE TO

PRIVATE PLACEMENT SUBSCRIPTION AMENDING AGREEMENT

DATED FOR REFERENCE DECEMBER 22, 2005

The representations set forth in section 4.1 of the original Subscription Agreement are true and
correct except as set forth below. Paragraph numbers below correspond to paragraph references under
section 4.1 of the Original Subscription Agreement.

	(d)	 	As of September 30, 2005 the Company had issued and outstanding 35,059,461 common
 shares.

	 
	(i)	 	The reference to March 31, 2003 should be changed to June 30, 2005.

	 
	(j)	 	Schedule D of the Original Subscription Agreement should include reference to the
following agreements:

	 
	 	 	A. Licensing and Collaboration Agreement and accompanying Supply Agreement between the
Company and Laboratorios Del Dr. Esteve, S.A. dated November 27, 2002, as amended by a
Revised Collaboration Letter dated March 9 2005.

	 
	 	 	B. Manufacturing and Option Agreement between the Company and Sabex 2002 Inc., dated March
17, 2004.

	 
	 	 	C. Letter of Understanding between the Company and Mr. Claude Cardinal dated November 21,
2003 (7% royalty on certain topical formulations)

	 
	 	 	D. Licensing Agreement between the Company and Techpharm Inc., dated November 21,
2003 (7% on certain topical formulations)

	 
	(m)	 	As disclosed in the Company’s news release dated June 28, 2005 the Company has been notified
the Chinese Patent Office has changed registered ownership of the drug withdrawal patent ZL
95190556.2 “Use of Amino Quinazoline Hydride Compound and it Derivative for Abstaining from
Drug Dependence” in China from the Company’s subsidiary, Nanning Maple Leaf Pharmaceuticals
to one of two inventors and a third party who alleges to have been an employer of the other
inventor. The Company has decided to temporarily postpone development and testing of its
opiate addiction withdrawal drug in China. In August 2005, the Company was notified that an
earlier attempt by a third party to invalidate this patent had been withdrawn.

	 
	 	 	The Company has initiated re-examination proceedings for patent US 6,407,088 “Method of
Analgesia”.

	 
	 	 	During the preparation and prosecution of the Company’s patent applications a range of
documents have been identified. These include patents and applications directed to some
aspects of the chemistry and use of TTX.

 

 

 

	 	 	There may be additional patent documents (including pending applications) in existence of
which the Company is unaware, including patent applications which have been filed but have
not yet been laid open to public inspection. To the best of the Company’s knowledge, there
are no existing patents of such a scope that they would preclude the Company from
conducting its Business. Nonetheless it is possible that some aspect of the Company’s
planned activities might at some point potentially infringe upon one or more existing
patents or patent applications in one or more jurisdictions.

	 
	 	 	Although not exhaustive it is believed that the results of the International Search
Reports that have issued in the Company’s PCT applications (including applications owned
by Nanning Maple Leaf Pharmaceutical Co. Ltd.) provide a reasonably comprehensive
representation of the relevant prior art patents and patent applications. The lists of
prior art cited in Search Reports already issued with respect to the Company’s PCT filings
are attached hereto. Additional documents may have been identified in individual national
or regional prosecutions.

	 
	(n)	 	See paragraph (m) above.

	 
	(q)	 	See paragraph (j) above.

	 
	(t)	 	See paragraph (m) above.

	 
	(y)	 	The Company is the subject of an investigation by the British Columbia Securities
Commission with respect to the disclosure of certain clinical trial results.

	 
	(ii)	 	A. See paragraph (y) above.

	 
	B. The Company has received requisitions to call a meeting from two different shareholders.
The first requisition was received from Ms. Margaret Chow and the second from Mr. Arlyn Miller.

	 
	Ms. Chow’s request asks the Company to call a special meeting to remove all of the directors, to
fix the size of the board at six and to elect her nominees (which had not been specified). The
Company had considered Ms. Chow’s requisition and determined not to call a meeting of shareholders
to deal with her requisition. As a result, Ms. Chow was entitled to call a meeting, but took no
steps in furtherance thereof other than to issue a press release.

	 
	Mr. Miller’s subsequent requisition asks the Company to call a special meeting to remove Donna
Shum, Frank Shum and Kenneth Li as directors, and elect Dr. Benjamin Chen, Mr. Pierre Cantin and
Mr. Arlyn Miller as directors in their place. The Company has considered Mr. Miller’s requisition
and has called the Meeting to address his requisition. The Company recommends shareholders vote
in favour of this resolution.

	 
	Mr. Miller’s requisition also asks the Company to call a special meeting to ask shareholders of
the Company to approve the creation of a Royalty Trust. The Company is making no recommendation to
shareholders with respect to this resolution.

C. See paragraph (y) above.

 

- 2 -

 

SCHEDULE B

RELEASE

 

 

 

MUTUAL RELEASE

This Agreement is made the 22nd day of December, 2005.

BETWEEN:

WEX PHARMACEUTICALS INC.

(“Wex”)

AND:

WEX MEDICAL LIMITED

(“Wex HK”)

AND:

UOB VENTURE (SHENZHEN) LIMITED

(“UOB”)

WHEREAS:

A. Wex, Wex HK and UOB entered into a Private Placement Subscription Agreement dated May 18, 2004
and a Debenture dated June 14, 2004 (together the “Loan Agreement”) whereby UOB advanced the sum of
US $2,100,000 to Wex HK.

B. Nanning Maple Leaf Pharmaceuticals, a subsidiary of Wex, is and has been involved in a dispute
regarding the ownership of Chinese Patent No. ZL95190556.2 “Use of Quinazoline Hydride Compound and
its Derivative for Abstaining from Drug Dependence” ( the “Dispute”).

C. UOB has asserted that the representations and warranties made by Wex and Wex HK to UOB in the
Loan Agreement were not accurate because of the existence of the Dispute at the time the Loan
Agreement was entered into (the “Disclosure Issue”).

D. Wex, Wex HK and UOB have entered into a Private Placement Subscription Amending Agreement dated
December 22, 2005 and a Debenture Amendment Agreement dated December 22, 2005
(collectively the “New Agreements”) to amend the terms and conditions of the Loan Agreement.

 

 

 

NOW THEREFORE THIS AGREEMENT WITNESSES that in consideration of the sum of $10.00 now paid by each
party to the other and in consideration of the mutual covenants and agreements herein contained,
and other good and valuable consideration, including the entering into of the New Agreements the
parties hereto agree as follows:

1. RELEASE BY WEX

Wex and Wex HK each hereby remises, releases and forever discharges UOB and its successors,
assigns, directors, officers, agents and employees (collectively, the “UOB Releasees”) of and from
any and all liabilities, causes of action, claims, proceedings, suits, costs, demands, obligations,
interest, debts, duties and damages of whatever nature or kind, whether at law or at equity and
whether known or unknown, suspected or unsuspected, which Wex or Wex HK has or subsequently may
have against the UOB Releasees or any of them, arising out of the Disclosure Issue.

2. RELEASE BY UOB

UOB hereby remises, releases and forever discharges Wex and Wex HK and their successors, assigns,
directors, officers, agents and employees (collectively, the “Wex Releasees”) of and from any and
all liabilities, causes of action, claims, proceedings, suits, costs, demands, obligations,
interest, debts, duties and damages of whatever nature or kind, whether at law or at equity and
whether known or unknown, suspected or unsuspected, which UOB has or subsequently may have against
the Wex Releasees arising out of the Disclosure Issue.

3. AGREEMENT NOT TO SUE OTHERS WITH RESPECT TO SUBJECT MATTER OF RELEASE

The parties agree not to make any claim or take or continue any proceedings against any other
person or corporation who might claim contribution or indemnity from the other in connection with
the subject matter of this Mutual Release.

4. RELEASE DOES NOT AFFECT ANY OBLIGATIONS UNDER THE NEW AGREEMENT

For greater clarity, this Mutual Release does not affect any of the obligations of any party
pursuant to the New Agreements.

5.
NOT AN ADMISSION OF LIABILITY

This Mutual Release does not constitute any admission of liability or wrongdoing by any party to
this Mutual Release.

6. CONFIDENTIALITY

The parties have agreed on the terms of a press release to be issued by Wex announcing the
entering into of the New Agreement, the form of which is attached as Schedule A to this agreement
(the “Press Release”). The parties agree that, except to the extent disclosed in the Press
Release, they shall keep the terms of this Mutual Release and the New Agreements confidential and
not disclose them to any person or entity, except that they shall be permitted to disclose the
terms as necessary to professional advisors and as required by law.

 

- 2 -

 

7. AGREEMENT NOT TO BE AFFECTED BY DIFFERENCE IN FACTS OR LAW

The parties acknowledge that the facts and law in respect of which this Mutual Release is given may
be different from the facts and law now known or believed to be true. The parties agree that this
release will in all respects be enforceable and not subject to termination, rescission, or
variation by discovery of any difference in facts or law.

8. GOVERNING LAW

This Mutual Release is governed by the laws in force in the Province of British Columbia. The
Courts of British Columbia shall have exclusive jurisdiction over this Mutual Release, including
without limitation the enforcement of this Mutual Release and any dispute regarding its
interpretation and application.

9. SUCCESSORS AND ASSIGNS

This Mutual Release is binding upon and for the benefit of the parties hereto and their respective
heirs, executors, administrators, successors, assigns, partners, agents and employees (in such
capacity).

10. COUNTERPARTS

This Mutual Release may be executed in one or more counterparts and such counterparts may be
transmitted by electronic facsimile, and each such counterpart shall be deemed to be an original
and together such counterparts shall constitute one document.

 

- 3 -

 

11. ENTIRE AGREEMENT

The provisions contained herein, together with the New Agreements, constitute the entire agreement
between the parties and supersede all previous communications, representations, understandings and
agreements, whether oral or written, between them with respect to the subject matter of this
Mutual Release and New Agreements.

IN WITNESS WHEREOF the parties have set their authorized signatures this 22 day of December,
2005.

WEX PHARMACEUTICALS INC.

	 	 	 	 	 
	Per:

	 	/s/ “Edge Wang”
 

Authorized Signatory
	 	 

WEX MEDICAL LIMITED

	 	 	 	 	 
	Per:

	 	/s/ “Edge Wang”
 

Authorized Signatory
	 	 

UOB VENTURE (SHENZEN) LIMITED

	 	 	 	 	 
	Per:

	 	/s/ “Seah Kian Wee”
 

Authorized Signatory
	 	 

 

- 4 -Exhibit 4.6

Exhibit 4.6

DEBENTURE AMENDMENT AGREEMENT

THIS AGREEMENT dated for reference December 22, 2005 is made

AMONG:

UOB CAPITAL INVESTMENTS PTE LTD

80 Raffles Place, UOB Plaza 2 #30-20 Singapore 048624

(the “Investor”)

OF THE FIRST PART

AND:

WEX PHARMACEUTICALS INC. (formerly known as INTERNATIONAL
WEX TECHNOLOGIES INC.), a corporation formed under the Canada
Business Corporations Act and having an office at 2100 –
1040 West Georgia Street, Vancouver, British Columbia V6E
4H1

(the “Company”)

OF THE SECOND PART

AND:

WEX MEDICAL LIMITED, a corporation formed under the laws of
Hong Kong and having an office at Unit A, 34/F., Manulife
Tower, 169 Electric Road, North Point, Hong Kong

(the “Subsidiary”)

OF THE THIRD PART

WHEREAS:

	A.	 	On June 14, 2004, the Investor advanced to the Subsidiary $1,500,000 (the “Advanced
Funds”) pursuant to a subscription agreement among the Investor, the Subsidiary and the
Company dated May 18, 2004 (the “Original Subscription Agreement”);

	 
	B.	 	Pursuant to the Original Subscription Agreement, the Subsidiary and the Company issued
to the Investor a debenture dated June 14, 2004 relating to the Advanced Funds (the
“Debenture”);

 

 

 

	C.	 	The Investor, the Subsidiary and the Company wish to enter into this Agreement to amend certain provisions of the Debenture as hereinafter provided; and

	 
	D.	 	Concurrently with the execution of this Agreement, the Investor, the Subsidiary and the
Company have agreed to amend the Original Subscription Agreement.

NOW THEREFORE in consideration of the mutual premises, covenants and agreements herein set forth,
and $1.00 now paid by each party to the others, and other good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, the parties hereto covenant and agree as
follows:

	1.	 	Definitions

	 
	 	 	In this Agreement and the recitals hereto, unless the context otherwise requires, any
capitalized term not otherwise defined herein will have the meaning ascribed thereto in the
Debenture.

	 
	2.	 	One Instrument

	 
	 	 	The parties hereto agree that the Debenture, as amended hereby, shall continue to have full
force and effect and this Agreement shall have effect, so far as practicable, as if all of
the provisions of the Debenture and this Agreement were contained in the one instrument.

	 
	3.	 	Amendments

	 	3.1	 	The definitions in section 1(l), (n) and (q) of the Debenture are deleted and
the following are substituted in their place:

	 	“(l) 	 	“Maturity Date” means December 31, 2007,”

	 
	 	“(n) 	 	“Subscription Agreement” means the subscription agreement among
the Investor, the Subsidiary and the Company dated May 18, 2004, as amended
December 22, 2005,”

	 
	 	“(q) 	 	“UOB Debentures” means this Debenture and the debentures issued
to each of UOB Venture (Shenzhen) Limited and UOB Venture Technology Investments
Ltd by the Companies and dated for reference June 14, 2004, each as amended
from time to time.”

 

 - 2 - 

 

	 	3.2	 	Article 3 of the Debenture is deleted and the following is substituted in its
place:

	 
	 	 	 	“THE ADVANCED FUNDS

	 	3.1	 	Repayment of the Advanced Funds

	 
	 	 	 	The Subsidiary promises to pay to the Investor the Advanced Funds
outstanding, less any amount already repaid by the Subsidiary to the Investor or converted into Common Shares in accordance with this Debenture, as follows
(the “Repayment Schedule”):

	 	(a)	 	$300,000 on or before December 31, 2005;

	 
	 	(b)	 	a further $112,500 on or before June 30, 2006;

	 
	 	(c)	 	a further $112,500 on or before September 30, 2006;

	 
	 	(d)	 	a further $225,000 on or before December 31, 2006;

	 
	 	(e)	 	a further $187,500 on or before March 31, 2007;

	 
	 	(f)	 	a further $187,500 on or before June 30, 2007;

	 
	 	(g)	 	a further $187,500 on or before September 30, 2007; and

	 
	 	(h)	 	a further $187,500 on or before December 31, 2007.

	 	 	 	Notwithstanding any other provision of this Debenture, in the event that the Subsidiary
fails to repay the Advanced Funds in accordance with the foregoing, the Company promises
to pay to the Investor on demand the Advanced Funds outstanding, less any amount already
repaid by the Subsidiary to the Investor or converted into Common Shares in accordance
with this Debenture, (together with accrued and unpaid interest).

	 
	 	3.2	 	Evidence of Advanced Funds

	 
	 	 	 	The indebtedness of the Subsidiary to the Investor in respect of the Advanced Funds
outstanding will be evidenced by this Debenture.

	 
	 	3.3	 	Interest

	 
	 	 	 	The Subsidiary will pay interest to the Investor both before as well as after default and
maturity on the Advanced Funds from the date of disbursement, at the rate of 5.5% per
annum calculated semi-annually not in advance and payable semi-annually. Interest will be
paid in United States currency.

	 
	 	3.4	 	Timing of Interest Payments

	 
	 	 	 	The first semi-annual interest payment will be due and payable on the first day of
October, 2004 and thereafter interest payments will be due and payable on the first day
of each April and October (unless that day is not a Business Day in which case the
payment will be made on the Business Day immediately preceding it) until all principal
and interest has been repaid in full. Any accrued and unpaid interest existing on the
Maturity Date shall be paid on the Maturity Date.

 

 - 3 - 

 

	 	3.5	 	Net Interest

	 
	 	 	 	It is intended that all payments of the Advanced Funds, interest and all
other monies required to be paid to the Investor pursuant to this Debenture
shall be made without deduction or withholding for any taxes. If under
applicable law the payor of any such amounts is required to deduct or
withhold any amount in respect of taxes, the Companies will gross-up the
amount of each such payment so that the Investor will be in the same
position had no amount in respect of taxes been withheld or deducted.”

	4.	 	Counterparts

	 
	 	 	This Agreement may be executed in any number of counterparts, each of which will be deemed
to be an original and all of which taken together will be deemed to constitute one and the
same instrument. Counterparts may be delivered either in original or faxed form and the
parties adopt any signatures received by a receiving fax machine as original signatures of
the parties; provided, however, that any party providing its signature in such manner will
promptly forward to the other party an original of the signed copy of this Agreement which
was so faxed.

IN WITNESS WHEREOF the parties hereto have duly executed this Agreement as of the day and year
first above written.

For and on behalf of

UOB CAPITAL INVESTMENTS PTE LTD

	 	 	 
	 /s/ “Terence Ong Sea Eng”
 

Signature

	 	 
	 
	 	 
	Terence Ong Sea Eng
 

Name

	 	 
	 
	 	 
	Authorized Signatory
 

Title

	 	 

 

 - 4 - 

 

	 	 	 	 	 	 	 
	SIGNED, SEALED AND DELIVERED

	 	 	)	 	 	 
	BY WEX PHARMACEUTICALS INC.

	 	 	)	 	 	 
	in the presence of:

	 	 	)	 	 	 
	 

	 	 	)	 	 	 
	/s/ “Iain R. Mant”

	 	 	)	 	 	 
	 

Signature

	
)	 	 	 
	 

	 	 	)	 	 	/s/ “Edge Wang”
	 

	 	 	 	 	 	 
	Iain R. Mant

	 	 	)	 	 	EDGE WANG, PRESIDENT
	Barrister & Solicitor

	 	 	)	 	 	 
	 

Name

	
)	 	 	 
	 

	 	 	)	 	 	 
	2100 — 1075 West Georgia Street

	 	 	)	 	 	 
	Vancouver, BC V6E 3G2

	 	 	)	 	 	 
	604 631 4734

	 	 	)	 	 	 
	 

Address

	)	 	 	 
	 

	 	 	)	 	 	 
	 

	)	 	 	 
	 
	 	 	 	 	 	 
	SIGNED, SEALED AND DELIVERED

	 	 	)	 	 	 
	BY WEX MEDICAL LIMITED

	 	 	)	 	 	 
	in the presence of:

	 	 	)	 	 	 
	 

	 	 	)	 	 	 
	/s/ “Iain R. Mant”

	 	 	)	 	 	 
	 

Signature

	
)	 	 	 
	 

	 	 	)	 	 	/s/ “Edge Wang”
	 

	 	 	 	 	 	 
	Iain R. Mant

	 	 	)	 	 	EDGE WANG, PRESIDENT
	Barrister & Solicitor

	 	 	)	 	 	 
	 

Name

	
)	 	 	 
	 

	 	 	)	 	 	 
	2100 — 1075 West Georgia Street

	 	 	)	 	 	 
	Vancouver, BC V6E 3G2

	 	 	)	 	 	 
	604 631 4734

	 	 	)	 	 	 
	 

Address

	
)	 	 	 
	 

	 	 	)	 	 	 
	 

	)	 	 	 

 

 - 5 - 

 

DEBENTURE AMENDMENT AGREEMENT

THIS AGREEMENT dated for reference December 22, 2005 is made

AMONG:

UOB VENTURE TECHNOLOGY INVESTMENTS LTD 
80 Raffles Place, UOB Plaza 2 #30-20, Singapore 048624

(the “Investor”)

OF THE FIRST PART

AND:

WEX PHARMACEUTICALS INC. (formerly known as
INTERNATIONAL WEX TECHNOLOGIES INC.), a corporation formed under
the Canada Business Corporations Act and having an office at
2100 — 1040 West Georgia Street, Vancouver, British Columbia V6E
4H1

(the “Company”)

OF THE SECOND PART

AND:

WEX MEDICAL LIMITED, a corporation formed under the laws of Hong
Kong and having an office at Unit A, 34/F., Manulife Tower, 169
Electric Road, North Point, Hong Kong

(the “Subsidiary”)

OF THE THIRD PART

WHEREAS:

	A.	 	On June 14, 2004, the Investor advanced to the Subsidiary $1,500,000 (the “Advanced
Funds”) pursuant to a subscription agreement among the Investor, the Subsidiary and the
Company dated May 18, 2004 (the “Original Subscription Agreement”);

	 
	B.	 	Pursuant to the Original Subscription Agreement, the Subsidiary and the Company issued
to the Investor a debenture dated June 14, 2004 relating to the Advanced Funds (the
“Debenture”);

	 
	C.	 	The Investor, the Subsidiary and the Company wish to enter into this Agreement to
amend certain provisions of the Debenture as hereinafter provided; and

 

 

 

	D.	 	Concurrently with the execution of this Agreement, the Investor, the Subsidiary
and the Company have agreed to amend the Original Subscription Agreement.

NOW THEREFORE in consideration of the mutual premises, covenants and agreements herein set forth,
and $1.00 now paid by each party to the others, and other good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, the parties hereto covenant and agree as
follows:

	1.	 	Definitions

	 
	 	 	In this Agreement and the recitals hereto, unless the context otherwise requires, any
capitalized term not otherwise defined herein will have the meaning ascribed thereto in the
Debenture.

	 
	2.	 	One Instrument

	 
	 	 	The parties hereto agree that the Debenture, as amended hereby, shall continue to have full
force and effect and this Agreement shall have effect, so far as practicable, as if all of
the provisions of the Debenture and this Agreement were contained in the one instrument.

	 
	3.	 	Amendments

	 	3.1	 	The definitions in section 1(l), (n) and (q) of the Debenture are deleted and
the following are substituted in their place:

	 	“(l)	 	“Maturity Date” means December 31, 2007,”

	 
	 	“(n)	 	 “Subscription Agreement” means the subscription agreement among
the Investor, the Subsidiary and the Company dated May 18, 2004, as amended
December 22, 2005,”

	 
	 	“(q)	 	 “UOB Debentures” means this Debenture and the debentures issued
to each of UOB Venture (Shenzhen) Limited and UOB Venture Technology
Investments Ltd by the Companies and dated for reference June 14, 2004, each
as amended from time to time.”

	 	3.2	 	Article 3 of the Debenture is deleted and the following is substituted in its
place:

	 
	 	 	 	 “THE ADVANCED FUNDS

	 	3.1	 	Repayment of the Advanced Funds

The Subsidiary promises to pay to the Investor the Advanced Funds
outstanding, less any amount already repaid by the Subsidiary to the
Investor or converted into Common Shares in accordance with this
Debenture, as follows (the “Repayment Schedule”):

	 	(a)	 	$300,000 on or before December 31, 2005;

 

 - 2 - 

 

	 	(b)	 	a further $112,500 on or before June 30, 2006;

	 
	 	(c)	 	a further $112,500 on or before September 30, 2006;

	 
	 	(d)	 	a further $225,000 on or before December 31, 2006;

	 
	 	(e)	 	a further $187,500 on or before March 31, 2007;

	 
	 	(f)	 	a further $187,500 on or before June 30, 2007;

	 
	 	(g)	 	a further $187,500 on or before September 30, 2007; and

	 
	 	(h)	 	a further $187,500 on or before December 31, 2007.

	 	 	 	Notwithstanding any other provision of this Debenture, in the event that the Subsidiary
fails to repay the Advanced Funds in accordance with the foregoing, the Company promises
to pay to the Investor on demand the Advanced Funds outstanding, less any amount already
repaid by the Subsidiary to the Investor or converted into Common Shares in accordance
with this Debenture, (together with accrued and unpaid interest).

	 
	 	3.2	 	Evidence of Advanced Funds

	 
	 	 	 	The indebtedness of the Subsidiary to the Investor in respect of the Advanced Funds
outstanding will be evidenced by this Debenture.

	 
	 	3.3	 	Interest

	 
	 	 	 	The Subsidiary will pay interest to the Investor both before as well as after default and
maturity on the Advanced Funds from the date of disbursement, at the rate of 5.5% per
annum calculated semi-annually not in advance and payable semi-annually. Interest will be
paid in United States currency.

	 
	 	3.4	 	Timing of Interest Payments

	 
	 	 	 	The first semi-annual interest payment will be due and payable on the first day of
October, 2004 and thereafter interest payments will be due and payable on the first day
of each April and October (unless that day is not a Business Day in which case the
payment will be made on the Business Day immediately preceding it) until all principal and
interest has been repaid in full. Any accrued and unpaid interest existing on the Maturity
Date shall be paid on the Maturity Date.

 

 - 3 - 

 

	 	3.5	 	Net Interest

	 
	 	 	 	It is intended that all payments of the Advanced Funds, interest and all
other monies required to be paid to the Investor pursuant to this Debenture
shall be made without deduction or withholding for any taxes. If under
applicable law the payor of any such amounts is required to deduct or
withhold any amount in respect of taxes, the Companies will gross-up the
amount of each such payment so that the Investor will be in the same
position had no amount in respect of taxes been withheld or deducted.”

	4.	 	Counterparts

	 
	 	 	This Agreement may be executed in any number of counterparts, each of which will be deemed
to be an original and all of which taken together will be deemed to constitute one and the
same instrument. Counterparts may be delivered either in original or faxed form and the
parties adopt any signatures received by a receiving fax machine as original signatures of
the parties; provided, however, that any party providing its signature in such manner will
promptly forward to the other party an original of the signed copy of this Agreement which
was so faxed.

IN WITNESS WHEREOF the parties hereto have duly executed this Agreement as of the day and year
first above written.

For and on behalf of

UOB VENTURE TECHNOLOGY

INVESTMENTS LTD

	 	 	 
	 /s/ “Seah Kian Wee”
 

Signature

	 	 
	 
	 	 
	Seah Kian Wee
 

Name

	 	 
	 
	 	 
	Managing Director of UOB Venture Management Pte Ltd.
 

Title

	 	 

 

 - 4 - 

 

	 	 	 	 	 	 	 
	SIGNED, SEALED AND DELIVERED

	 	 	)	 	 	 
	BY WEX PHARMACEUTICALS INC.

	 	 	)	 	 	 
	in the presence of:

	 	 	)	 	 	 
	 

	 	 	)	 	 	 
	/s/ “Iain R. Mant”

	 	 	)	 	 	 
	 

Signature

	
)	 	 	 
	 

	 	 	)	 	 	/s/ “Edge Wang”
	 

	 	 	 	 	 	 
	Iain R. Mant

	 	 	)	 	 	EDGE WANG, PRESIDENT
	Barrister & Solicitor

	 	 	)	 	 	 
	 

Name

	
)	 	 	 
	 

	 	 	)	 	 	 
	2100 — 1075 West Georgia Street

	 	 	)	 	 	 
	Vancouver, BC V6E 3G2

	 	 	)	 	 	 
	604 631 4734

	 	 	)	 	 	 
	 

Address

	
)	 	 	 
	 

	 	 	)	 	 	 
	 

	)	 	 	 
	 
	 	 	 	 	 	 
	SIGNED, SEALED AND DELIVERED

	 	 	)	 	 	 
	BY WEX MEDICAL LIMITED

	 	 	)	 	 	 
	in the presence of:

	 	 	)	 	 	 
	 

	 	 	)	 	 	 
	/s/ “Iain R. Mant”

	 	 	)	 	 	 
	 

Signature

	
)	 	 	 
	 

	 	 	)	 	 	/s/ “Edge Wang”
	 

	 	 	 	 	 	 
	Iain R. Mant

	 	 	)	 	 	EDGE WANG, PRESIDENT
	Barrister & Solicitor

	 	 	)	 	 	 
	 

Name

	
)	 	 	 
	 

	 	 	)	 	 	 
	2100 — 1075 West Georgia Street

	 	 	)	 	 	 
	Vancouver, BC V6E 3G2

	 	 	)	 	 	 
	604 631 4734

	 	 	)	 	 	 
	 

Address

	
)	 	 	 
	 

	 	 	)	 	 	 
	 

	)	 	 	 

 

 

 

DEBENTURE AMENDMENT AGREEMENT

THIS AGREEMENT dated for reference December 22, 2005 is made

AMONG:

UOB VENTURE (SHENZHEN) LIMITED

608, St James Court, St. Denis Street, Port Louis, Mauritius

(the “Investor”)

OF THE FIRST PART

AND:

WEX
PHARMACEUTICALS INC. (formerly known as INTERNATIONAL
WEX TECHNOLOGIES INC.), a corporation formed under the
Canada Business Corporations Act and having an office at
2100 — 1040 West Georgia Street, Vancouver, British Columbia
V6E 4H1

(the “Company”)

OF THE SECOND PART

AND:

WEX
MEDICAL LIMITED, a corporation formed under the laws of
Hong Kong and having an office at Unit A, 34/F., Manulife
Tower, 169 Electric Road, North Point, Hong Kong

(the “Subsidiary”)

OF THE THIRD PART

WHEREAS:

	A.	 	On June 14, 2004, the Investor advanced to the Subsidiary $2,100,000 (the “Advanced
Funds”) pursuant to a subscription agreement among the Investor, the Subsidiary and the
Company dated May 18, 2004 (the “Original Subscription Agreement”);

	 
	B.	 	Pursuant to the Original Subscription Agreement, the Subsidiary and the Company issued
to the Investor a debenture dated June 14, 2004 relating to the Advanced Funds (the
“Debenture”);

 

 

 

	C.	 	The Investor, the Subsidiary and the Company wish to enter into this Agreement to
amend certain provisions of the Debenture as hereinafter provided; and

	 
	D.	 	Concurrently with the execution of this Agreement, the Investor, the Subsidiary and the
Company have agreed to amend the Original Subscription Agreement.

NOW THEREFORE in consideration of the mutual premises, covenants and agreements herein set forth,
and $1.00 now paid by each party to the others, and other good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, the parties hereto covenant and agree as
follows:

	1.	 	Definitions

	 
	 	 	In this Agreement and the recitals hereto, unless the context otherwise requires, any
capitalized term not otherwise defined herein will have the meaning ascribed thereto in the
Debenture.

	 
	2.	 	One Instrument

	 
	 	 	The parties hereto agree that the Debenture, as amended hereby, shall continue to have full
force and effect and this Agreement shall have effect, so far as practicable, as if all of
the provisions of the Debenture and this Agreement were contained in the one instrument.

	 
	3.	 	Amendments

	 	3.1	 	The definitions in section 1(l), (n) and (q) of the Debenture are deleted and
the following are substituted in their place:

	 	“(l)	 	 “Maturity Date” means December 31, 2007,”

	 
	 	“(n)	 	“Subscription Agreement” means the subscription agreement among
the Investor, the Subsidiary and the Company dated May 18, 2004, as amended
December 22, 2005,”

	 
	 	“(q)	 	“UOB Debentures” means this Debenture and the debentures issued
to each of UOB Venture (Shenzhen) Limited and UOB Venture Technology
Investments Ltd by the Companies and dated for reference June 14, 2004, each
as amended from time to time.”

	 	3.2	 	Article 3 of the Debenture is deleted and the following is substituted in its
place:

	 
	 	 	 	“THE ADVANCED FUNDS

 

- 2 -

 

	 	3.1	 	Repayment of the Advanced Funds

	 
	 	 	 	The Subsidiary promises to pay to the Investor the Advanced Funds outstanding,
less any amount already repaid by the Subsidiary to the
Investor or converted into Common Shares in accordance with this Debenture, as follows (the
“Repayment Schedule”):

	 	(a)	 	$420,000 on or before December 31, 2005;

	 
	 	(b)	 	a further $ 157,500 on or before June 30, 2006;

	 
	 	(c)	 	a further $ 157,500 on or before September 30, 2006;

	 
	 	(d)	 	a further $315,000 on or before December 31, 2006;

	 
	 	(e)	 	a further $262,500 on or before March 31, 2007;

	 
	 	(f)	 	a further $262,500 on or before June 30, 2007;

	 
	 	(g)	 	a further $262,500 on or before September 30, 2007; and

	 
	 	(h)	 	a further $262,500 on or before December 31, 2007.

	 	 	 	Notwithstanding any other provision of this Debenture, in the event that the Subsidiary
fails to repay the Advanced Funds in accordance with the foregoing, the Company promises to
pay to the Investor on demand the Advanced Funds outstanding, less any amount already
repaid by the Subsidiary to the Investor or converted into Common Shares in accordance with
this Debenture, (together with accrued and unpaid interest).

	 
	 	3.2	 	Evidence of Advanced Funds

	 
	 	 	 	The indebtedness of the Subsidiary to the Investor in respect of the Advanced Funds
outstanding will be evidenced by this Debenture.

	 
	 	3.3	 	Interest

	 
	 	 	 	The Subsidiary will pay interest to the Investor both before as well as after default and
maturity on the Advanced Funds from the date of disbursement, at the rate of 5.5% per
annum calculated semi-annually not in advance and payable semi-annually. Interest will be
paid in United States currency.

	 
	 	3.4	 	Timing of Interest Payments

	 
	 	 	 	The first semi-annual interest payment will be due and payable on the first day of October,
2004 and thereafter interest payments will be due and payable on the first day of each
April and October (unless that day is not a Business Day in which case the payment will be
made on the Business Day immediately preceding it) until all principal and interest has
been repaid in full. Any accrued and unpaid interest existing on the Maturity Date shall be
paid on the Maturity Date.

 

- 3 -

 

	 	3.5	 	Net Interest

	 
	 	 	 	It is intended that all payments of the Advanced Funds, interest and all
other monies required to be paid to the Investor pursuant to this Debenture
shall be made without deduction or withholding for any taxes. If under
applicable law the payor of any such amounts is required to deduct or
withhold any amount in respect of taxes, the Companies will gross-up the
amount of each such payment so that the Investor will be in the same
position had no amount in respect of taxes been withheld or deducted.”

	4.	 	Counterparts

	 
	 	 	This Agreement may be executed in any number of counterparts, each of which will be deemed
to be an original and all of which taken together will be deemed to constitute one and the
same instrument. Counterparts may be delivered either in original or faxed form and the
parties adopt any signatures received by a receiving fax machine as original signatures of
the parties; provided, however, that any party providing its signature in such manner will
promptly forward to the other party an original of the signed copy of this Agreement which
was so faxed.

IN WITNESS WHEREOF the parties hereto have duly executed this Agreement as of the day and year
first above written.

For and on behalf of

UOB VENTURE (SHENZHEN) LIMITED

	 	 	 
	/s/ “Seah Kian Wee”
 

Signature

	 	 
	 
	 	 
	Seah Kian Wee
 

Name

	 	 
	 
	 	 
	Director of SZVC UOB Venture Management Co Ltd
 

Title

	 	 

 

- 4 -

 

	 	 	 	 	 	 	 	 	 
	SIGNED, SEALED AND DELIVERED

	 	 	)	 	 	 	 	 
	BY
WEX PHARMACEUTICALS INC.

	 	 	)	 	 	 	 	 
	in the presence of:

	 	 	)	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 
	/s/ “Iain R. Mant”
 

Signature

	 	 	)

)	 	 	 	 	 
	 

	 	 	)	 	 	 	 	/s/ “Edge Wang”
	 

	 	 	 	 	 	 	 	 
	Iain R. Mant

	 	 	)	 	 	 	 	EDGE WANG, PRESIDENT
	Barrister & Solicitor
 

Name

	 	 	)

)	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 
	2100 — 1075 West Georgia Street

	 	 	)	 	 	 	 	 
	Vancouver, BC V6E 3G2

	 	 	)	 	 	 	 	 
	604 631 4734
 

Address

	 	 	)

)	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 
	 
	 	 	 	 	 	 	 	 
	SIGNED, SEALED AND DELIVERED

	 	 	)	 	 	 	 	 
	BY
WEX MEDICAL LIMITED

	 	 	)	 	 	 	 	 
	in the presence of:

	 	 	)	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 
	/s/ “Iain R. Mant”
 

Signature

	 	 	)

)	 	 	 	 	 
	 

	 	 	)	 	 	 	 	/s/ “Edge Wang”
	 

	 	 	 	 	 	 	 	 
	Iain R. Mant

	 	 	)	 	 	 	 	EDGE WANG, PRESIDENT
	Barrister & Solicitor
 

Name

	 	 	)

)	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 
	2100 — 1075 West Georgia Street

	 	 	)	 	 	 	 	 
	Vancouver, BC V6E 3G2

	 	 	)	 	 	 	 	 
	604 631 4734
 

Address

	 	 	)

)	 	 	 	 	 
	 

	 	 	)	 	 	 	 	 
	 

	 	 	)

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00159-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00159-of-00352.parquet"}]]