November 6, 2001







Shire Pharmaceuticals Group plc
Hampshire International Business Park
Chineham
Basingstoke RG24 8EP

Shire Finance Limited
c/o Maples and Calder
Ugland House
South Church Street
P.O. Box 304 George Town
Grand Cayman

                    Re: 2% Senior Guaranteed Convertible Notes due 2001
                        -----------------------------------------------

Ladies and Gentlemen:

     We have acted as special New York counsel to Shire Pharmaceuticals Group
plc, a public limited liability company organized under the laws of England and
Wales ("Shire"), and Shire Finance Limited, an exempted limited company
organized under the laws of the Cayman Islands (the "Company"), in connection
with the Registration Statement on Form S-3 (the "Registration Statement") filed
by Shire and the Company with the Securities and Exchange Commission (the "SEC")
for the registration under the Securities Act of 1933, as amended (the "Act"),
of the Company's 2% Senior Guaranteed Convertible Notes due 2011 (the "Notes").
The Notes are convertible into exchangeable redeemable preference shares of the
Company (the "Preference Shares") which will be immediately exchanged (unless
redeemed at the Company's option for cash) into Shire's ordinary shares, nominal
value (pound)0.05 per share (the "Ordinary Shares") or American depositary
shares representing the Ordinary Shares.




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     The Notes were issued under an Indenture dated as of August 21, 2001 (the
"Indenture") by and among the Company, Shire and The Bank of New York ("BONY"),
as trustee. The Notes and the Preference Shares are unconditionally guaranteed
by Shire pursuant to the Indenture and the Preference Shares Guarantee Agreement
dated as of August 21, 2001 between Shire and BONY, as trustee, respectively
(collectively, the "Guarantees").

     In connection with this opinion, we have examined such records of Shire and
the Company as we have deemed necessary. We have also examined certificates of
public officials and directors and officers of Shire and the Company, as to such
factual matters as we have deemed necessary or appropriate for the purpose of
this opinion, but have made no independent investigation regarding such factual
matters. In our examination, we have assumed (a) the due organization and valid
existence of Shire and the Company, (b) the due authorization, execution,
authentication and delivery by all persons of each of the Indenture, the Notes
and the Guarantees, (c) that each of such parties has the legal power to act in
the respective capacity or capacities in which it is to act thereunder, (d) the
authenticity of all documents submitted to us as originals, (e) the conformity
to the original documents of all documents submitted to us as copies and (f) the
genuineness of all signatures on all documents submitted to us.

     Based upon the foregoing, we are of the opinion that:

     1. Insofar as the laws of the State of New York are applicable thereto, the
Indenture constitutes a valid and legally binding agreement of each of Shire and
the Company, enforceable against each of Shire and the Company in accordance
with its terms, except that (a) the enforceability thereof may be subject to (i)
bankruptcy, insolvency, reorganization, moratorium, fraudulent conveyance or
other similar laws now or hereafter in effect relating to or affecting
creditors' rights or remedies generally and (ii) general principles of equity
and to the discretion of the court before which any proceedings therefor may be
brought (regardless of whether enforcement is sought in a proceeding at law or
in equity) and (b) the enforceability of provisions imposing liquidated damages,
penalties or an increase in interest rate upon the occurrence of certain events
may be limited in certain circumstances.

     2. Insofar as the laws of the State of New York are applicable thereto, the
Notes constitute valid and legally binding obligations of the Company, entitled
to the benefits of the Indenture and enforceable against the Company in
accordance with their terms, except that (a) the enforceability thereof may be
subject to (i) bankruptcy, insolvency, reorganization, moratorium, fraudulent
conveyance or other similar laws now or hereafter in effect relating to or
affecting




                                      -3-


creditors' rights or remedies generally and (ii) general principles of equity
and to the discretion of the court before which any proceedings therefor may be
brought (regardless of whether enforcement is sought in a proceeding at law or
in equity) and (b) the enforceability of provisions imposing liquidated damages,
penalties or an increase in interest rate upon the occurrence of certain events
may be limited in certain circumstances.

     3. Insofar as the laws of the State of New York are applicable thereto, the
Guarantees constitute valid and legally binding obligations of Shire,
enforceable against Shire in accordance with their terms, except that (a) the
enforceability thereof may be subject to (i) bankruptcy, insolvency,
reorganization, moratorium, fraudulent conveyance or other similar laws now or
hereafter in effect relating to or affecting creditors' rights or remedies
generally and (ii) general principles of equity and to the discretion of the
court before which any proceedings therefor may be brought (regardless of
whether enforcement is sought in a proceeding at law or in equity) and (b) the
enforceability of provisions imposing liquidated damages, penalties or an
increase in interest rate upon the occurrence of certain events may be limited
in certain circumstances.

     We are admitted to practice law only in the State of New York and, in
rendering the opinions set forth above, we express no opinion as to the laws of
any jurisdiction other than the laws of the State of New York.

     We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the use of our name in the Registration Statement.
In giving this consent, we do not admit that we are "experts" within the meaning
of Section 11 of the Act. Our consent does not constitute a consent under
Section 7 of the Act, as we have not certified any part of such Registration
Statement and do not otherwise come within the categories of persons whose
consent is required under Section 7 of the Act or under the rules and
regulations of the SEC thereunder.

                                           Very truly yours,

                                           /s/ Cahill Gordon & Reindel