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                                                                     EXHIBIT 2.1

TRANSLATION FROM FRENCH FOR INFORMATION ONLY

                            SHARE PURCHASE AGREEMENT
                             DATED DECEMBER 3, 2001


AMONG THE UNDERSIGNED

Mr. Francois Lafon, an individual born in Paris on October 27, 1944, residing at
41, avenue Foch - 75116 Paris, France

Ms. Andree Carpentier, widow (VEUVE) of Mr. Louis Lafon, an individual born in
Hanoi (Vietnam) on April 15, 1918, residing at 5, rue de l'Alboni - 75016 Paris,
France

                                       hereinafter together called the "Sellers"

                                                                ON THE ONE HAND,

AND

Cephalon , Inc. , an American company organized in the State of Delaware, with
its principal place of business located at 145 Brandywine Parkway, West Chester,
Pennsylvania 19380, United States, herein represented by Mr. Frank Baldino, Jr.,
Ph.D., Chairman and Chief Executive Officer, thereunto duly authorized by a
resolution of Cephalon's Board of Directors, dated 1st November 2001, a copy of
which is attached hereto as SCHEDULE A

                                              hereinafter called the "Purchaser"

                                                               ON THE OTHER HAND

                                         Hereinafter together called the Parties
                                                       and individually a Party.


WHEREAS

A.       Financiere Lafon (hereinafter called the "Company") is a corporation
         (SOCIETE ANONYME) with its registered office located at 12 rue Clement
         Marot - 75008 Paris and which is registered with the Registry of
         Commerce and Companies (REGISTRE DU COMMERCE ET DES SOCIETES) of Paris
         under number 340 102 391.

B.       The share capital of the Company is forty thousand euros ([EURO]
         40,000) divided into two thousand five hundred (2,500) shares, par
         value sixteen euros ([EURO] 16) per share (hereinafter


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         called the "Financiere Lafon Shares"). On the date of this Agreement
         (hereinafter called this "Agreement"), the Sellers own 2,495 Financiere
         Lafon Shares in the proportions set out in SCHEDULE B to this
         Agreement.

C.       The Company is a holding company.

D.       Organisation de Synthese Mondiale Orsymonde (hereinafter called
         "Orsymonde") is a corporation (SOCIETE ANONYME) with its registered
         office located at 12 rue Clement Marot - 75008 Paris and which is
         registered with the Registry of Commerce and Companies (REGISTRE DU
         COMMERCE ET DES SOCIETES) of Paris under number 582 079 711.

E.       The share capital of Orsymonde is one million eight hundred thirty six
         thousand euros ([EURO] 1,836,000) divided into twelve thousand (12,000)
         shares, par value one hundred and fifty three euros ([EURO] 153) per
         share (hereinafter called the "Orsymonde Shares"). On the date of this
         Agreement, the Sellers own 2,553 Orsymonde shares in the proportions
         set out in SCHEDULE E to this Agreement.

F.       The Company directly and indirectly owns the subsidiaries in France and
         abroad, including Orsymonde (hereinafter called the "Subsidiaries") a
         description of which, including the percentage of the share capital of
         the Subsidiaries directly and indirectly held by the Company and/or the
         Subsidiaries, is set out SCHEDULE F to this Agreement (the Company and
         the Subsidiaries are hereinafter together called the "Companies").

G.       The business of the Subsidiaries consists mainly of the manufacture,
         purchase, and sale of chemical and pharmaceutical products.

H.       The business of the Purchaser's group consists of the manufacture,
         purchase, and sale of pharmaceutical products, including, in
         particular, a product covered by a license granted by one of the
         Subsidiaries, the French corporation (SOCIETE ANONYME) Laboratoire L.
         Lafon.

I.       Prior to the date of this Agreement, (i) the Companies have delivered
         to the Purchaser their accounts (balance sheet, income statement and
         notes to the accounts (including, for the French companies, off-balance
         sheet commitments )) as of December 31, 1998, December 31, 1999, and
         December 31, 2000 (hereinafter together called the "1998, 1999, and
         2000 Company Accounts"), and (ii) the Company has delivered to the
         Purchaser its consolidated accounts (balance sheet, income statement
         and notes to the accounts (including off-balance sheet commitments)) as
         of December 31, 1998, December 31, 1999, and December 31, 2000
         (hereinafter called the "1998, 1999, and 2000 Consolidated Accounts").

J.       The Company has made available to the Purchaser the following documents
         on the dates hereinbelow set forth:


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         -        on November 6, 2001, the working papers supporting preparation
                  of the 1998, 1999, and 2000 Company Accounts;

         -        on November 13, 2001, the working papers supporting
                  preparation of the Interim Accounts, as defined hereinafter;

         -        on November 15, 2001, the working papers supporting
                  preparation of the 1998, 1999, and 2000 Consolidated Accounts;

         -        on November 15, 2001, the interim accounts (balance sheet,
                  income statement and notes to the accounts, including
                  off-balance sheet items and cash flow statements) of the
                  Company for the periods from January 1 to September 30, 2000
                  (hereinafter called the "2000 Interim Accounts"), and from
                  January 1 to September 30, 2001 (hereinafter called the "2001
                  Interim Accounts") (the 2000 Interim Accounts and the 2001
                  Interim Accounts are hereinafter together called the "Interim
                  Accounts"), prepared by the Company with the assistance of an
                  accounting firm agreed by the Parties, using the same methods
                  as those applied for the preparation of the 1998, 1999, and
                  2000 Consolidated Accounts, such methods to be in accordance
                  with the accounting principles issued in the NOUVEAU PLAN
                  COMPTABLE FRANCAIS ["New French Accounting Methods"] and
                  consistent with the recommendations of the ORDRE DES EXPERTS
                  COMPTABLES FRANCAIS [French Professional Accountants' Council]
                  and the CONSEIL NATIONAL DE LA COMPTABILITE [French National
                  Accounting Standards Board];

         -        on the day hereof, the 1998, 1999, and 2000 Consolidated
                  Accounts prepared by the Company with the assistance of an
                  accounting firm agreed by the Parties in accordance with
                  accounting principles generally accepted in France and
                  including disclosures relating to the reconciliation between
                  French generally accepted accounting principles and US
                  generally accepted accounting principles, I.E., (i) balance
                  sheet, income statement, cash flow statements and statements
                  of changes in shareholders' equity, such items complying with
                  French accounting principles, and presented according to an
                  American format, (ii) notes to the accounts prepared in
                  accordance with French generally accepted accounting
                  principles, (iii) reconciliation statements of net financial
                  condition and net income in accordance with French generally
                  accepted accounting principles showing the adjustments
                  required for conversion into U.S. generally accepted
                  accounting principles, (iv) statements of comprehensive
                  income, prepared in accordance with generally accepted
                  accounting principles in the United States (hereinafter called
                  the "1998, 1999, and 2000 US GAAP Consolidated Accounts").

K.       The Sellers have agreed to deliver to the firm of
         PriceWaterhouseCoopers (hereinafter called "PWC"), no later than
         December 10, 2001, the Interim Accounts prepared by the Company with
         the assistance of an accounting firm agreed by the Parties in
         accordance with French generally accepted accounting principles and
         including additional disclosures relating to the reconciliation between
         French generally accepted accounting principles and


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         U.S. generally accepted accounting principles, I.E., (i) balance sheet,
         income statement, cash flow statements, and statements of changes in
         shareholders' equity, such items complying with French accounting
         principles, and presented in according to an American format, (ii)
         notes to the accounts presented in accordance with French generally
         accepted accounting principles, (iii) reconciliation statements of net
         financial condition and net income in accordance with French generally
         accepted accounting principles showing the adjustments required for
         conversion into U.S. generally accepted accounting principles, (iv)
         statements of comprehensive income, prepared in accordance with
         generally accepted accounting principles in the United States
         (hereinafter called the "US GAAP Interim Accounts").

L.       With the Sellers' agreement, the Purchaser has appointed PWC (i) to
         audit the 1998, 1999, and 2001 US GAAP Consolidated Accounts and (ii)
         to perform a review of the US GAAP Interim Accounts, in accordance with
         generally accepted auditing and review standards in the United States,
         as well as the applicable rules and regulations of the U.S. Securities
         and Exchange Commission (Regulation S-X).

M.       The Sellers wish to sell and the Purchaser wishes to purchase (i) 2,560
         Orsymonde Shares from Mr. Francois Lafon, and (ii) 1,260 Financiere
         Lafon Shares from Mr. Francois Lafon and 1,240 Financiere Lafon Shares
         from Ms. Andree Lafon , I.E., all of the Financiere Lafon Shares. The
         2,560 Orsymonde Shares and the Financiere Lafon Shares are hereinafter
         collectively referred to as the "Shares").

N.       The Purchaser has indicated to the Sellers:

         -        that it has available to it cash-flow in the amount of three
                  hundred million U.S. dollars ($ 300,000,000); and

         -        that it was in advanced negotiations to obtain, on a timely
                  basis, an additional one hundred fifty million U.S. dollars ($
                  150,000,000), representing the balance of the Price (as
                  defined in Article 2 hereinbelow). The Purchaser has delivered
                  to the Sellers, prior to the date of this Agreement, a comfort
                  letter (lettre de confort) issued by Credit Suisse First
                  Boston (Cayman Islands Branch) pursuant to which such
                  financial institution has confirmed that a bridge loan
                  (financement relais) of one hundred million U.S. dollars ($
                  100,000,000) is available, if the Purchaser is unable to raise
                  the above-described additional funds by the Closing Date (as
                  set forth in Article 4 hereinbelow)

O.       Attached as Schedule O to this Agreement are documents provided by PWC
         (two letters dated December 2, 2001, and a letter dated November 9,
         2001) in which such firm advises the Purchaser of the progress of its
         work as of the date of this Agreement, as set forth in paragraph L
         hereinabove, and the date for delivery of its opinions, as set forth in
         Article 4(f)(i) and (ii) hereinbelow. It is understood and agreed, to
         the extent necessary, that all of the Company's obligations in
         connection with the above-described letter have been undertaken only
         for purposes PWC's assignment in connection with such letter.


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NOW, THEREFORE, THE PARTIES HAVE AGREED TO THE FOLLOWING:

1.       SALE AND PURCHASE

(a)      On the Closing Date, subject to the terms and conditions set forth
         hereafter, the Sellers shall sell and the Purchaser shall purchase all,
         but not part only, of the Financiere Lafon Shares and at least 2,556
         Orsymonde Shares, together with all rights now or hereafter attached
         thereto, in accordance with the terms and conditions of this Agreement.

(b)      Each Seller agrees to cause the other Seller to sell his/her Financiere
         Lafon Shares and, as regards Mr. Francois Lafon, his Orsymonde Shares,
         their obligations being joint and several.

(c)      On the Closing Date the Sellers shall have used their best efforts to
         ensure that:

         (i)      Mr. Francois Lafon owns the four (4) Orsymonde Shares
                  presently owned by the individuals listed in Schedule1(c) to
                  this Agreement (hereinafter called the "Orsymonde Minority
                  Shares"), so that they can be sold by Mr. Francois Lafon to
                  the Purchaser on the Closing Date, and

         (ii)     the three (3) shares of Laboratoire L Lafon, presently owned
                  by the individual whose name is shown in SCHEDULE 1(C) of this
                  Agreement (hereinafter called the "Laboratoire L. Lafon
                  Minority Shares") be owned by Orsymonde or Mr. Francois Lafon
                  on the Closing Date, in which case he agrees to sell them to
                  the Purchaser for their par value on such Closing Date, it
                  being understood that the price at which Orsymonde acquires
                  the Laboratoire L. Lafon Minority Shares shall not exceed
                  their par value for each such share.

         (the Orsymonde Minority Shares and the Laboratoire L. Lafon Minority
Shares are hereinafter together called the "Minority Shares" and individually a
"Minority Share").

2.       PRICE

(a)      The total price for the Shares (hereinafter called the "Price") shall
         be four hundred fifty million US dollars ($450,000,000).

(b)      The total Price shall be divided between the Sellers as follows:

         (i)      two hundred seventy-four million four hundred sixteen thousand
                  U.S. dollars ($274,416,000) to Mr. Francois Lafon, divided as
                  follows:

                  -        one hundred seventy-eight million four hundred
                           sixteen thousand U.S. dollars ($178,416,000) for his
                           1,260 Financiere Lafon Shares;


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                  -        ninety-six million U.S. dollars ($96,000,000) for his
                           2,650 Orsymonde Shares; and

         (ii)     one hundred seventy-five million five hundred eighty-four
                  thousand U.S. dollars ($175,584,000) to Ms. Andree Lafon, for
                  her 1,240 Financiere Lafon Shares.

(c)      On the Closing Date the part of the Price paid to Mr. Francois Lafon
         shall be reduced by thirty-seven thousand five hundred US dollars
         (US$37,500) per Minority Share not sold to the Purchaser or not owned
         by Orsymonde (as the case may be) as provided in Article 1(c) hereof on
         the Closing Date.

(d)      If, on the Closing Date, the Minority Shares are not sold to the
         Purchaser or are not owned by Orsymonde (as the case may be) as
         provided in Article 1(c) hereof, Mr. Francois Lafon shall continue to
         use his best efforts (by negotiating for a period of eighteen months
         from the Closing Date) to make possible the sale of the Minority Shares
         to the Purchaser, or any Associated Company (as defined in Article 7(a)
         hereinbelow), for a maximum price per share of thirty-seven thousand
         five hundred U.S. dollars ($37,500). All expenses relating to such
         negotiation shall remain Mr. Francois Lafon's responsibility
         exclusively.

         If, between the Closing Date and the end of the above-described
         eighteen month period, the Purchaser, or any Associated Company, should
         acquire, or cause to be acquired, one or more of the Minority Shares at
         a price per share which is less than the one hereinabove provided,
         I.E., thirty-seven thousand five hundred U.S. dollars ($37,500), the
         Purchaser, within eight (8) business days following such acquisition,
         shall pay to Mr. Francois Lafon any such difference.

         To the extent the owners of the Minority Shares are willing to sell
         them during the above-described eighteen month period, the Purchaser
         hereby agrees as of the date hereof, both on its own behalf and on
         behalf of any Associated Company, to acquire, or cause to be acquired,
         any Minority Share for a maximum price per share of thirty-seven
         thousand five hundred U.S. dollars ($37,500).

         To make it possible for the Sellers to ensure the completion of such an
         acquisition, the Purchaser agrees, both on its own behalf and on behalf
         of the Companies:

         -        to deliver immediately a copy of any legal act or document
                  evidencing the acquisition of Minority Shares, together with a
                  certificate from the Purchaser certifying the price paid for
                  such acquisition as well as a copy certified true and correct
                  of the legal act, document, or form relating thereto, recorded
                  with the tax office having jurisdiction thereover;

         -        to allow the Sellers (or their advisors), upon request, to
                  review the share transfer and shareholder records of Orsymonde
                  and/or Laboratoire L. Lafon.


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(e)      If, at the end of the above-described eighteen month period, all of the
         Minority Shares have not been sold to the Purchaser or any Associated
         Company for a maximum price per share of thirty-seven five hundred U.S.
         dollars ($37,500):

         -        the amount of thirty-seven thousand five hundred U.S. dollars
                  ($37,500) described in paragraph (c) hereinabove, per
                  non-transferred Minority Share, shall remain finally with the
                  Purchaser; and

         -        the Sellers agree to pay a new amount equal to thirty-seven
                  thousand five hundred U.S. dollars ($37,500) per
                  non-transferred Minority Share to the Purchaser as a penalty,
                  to be charged against the Escrowed Amount (as defined in
                  paragraph (f) hereinbelow).

(f)      On the Closing Date the Purchaser shall pay into an escrow account
         established with OBC Odier Bungener Courvoisier Bank (hereinafter
         called "OBC") a part of the Price due Ms. Andree Lafon, I.E., an amount
         of forty five million U.S. Dollars ($45,000,000) in cash (hereinafter
         called the "Escrowed Amount"). The Escrowed Amount shall secure the
         payment by each of the Sellers of all amounts which may be due to the
         Purchaser under this Agreement or the indemnification clause of the
         Representations and Warranty Agreement of even date herewith
         (hereinafter called the "Representations and Warranties Agreement").
         Such escrow shall be created pursuant to an Escrow Agreement
         (hereinafter called the "Escrow Agreement") which shall be made with
         the above-described banking firm in substantially the form annexed
         hereto as SCHEDULE 2(F). Even though the Escrowed Amount is being paid
         with respect to the portion of the price to which Ms. Andree Lafon is
         entitled, the Sellers expressly acknowledge that there shall be no
         limitation on the Purchaser's right to demand from Mr. Francois Lafon
         the payment due by him and secured by the Escrowed Amount.

3.       CONDITION PRECEDENT

         (a)      The obligations of the Parties under this Agreement are
                  subject to the satisfaction of the condition precedent of
                  obtaining any necessary authorization, express or implied,
                  required from French, European, or American governmental
                  authorities, including the clearance of the antitrust
                  authorities, if such clearance is necessary. Unless waived by
                  the Parties, if this condition precedent is not met by
                  December 24, 2001, at the latest, this Agreement shall be null
                  and void, without any obligation to pay any indemnity by any
                  Party to the others.

         (b)      In addition the Purchaser shall have the right to terminate
                  this Agreement, if it does not obtain, by December 24, 2001,
                  at the latest, the financing in the amount of one hundred
                  fifty million dollars ($150,000,000) described in paragraph N
                  of the preamble. However, notwithstanding any clause to the
                  contrary, and as an essential and determining condition of the
                  Sellers' agreement, if the Purchaser exercises its right to
                  terminate this Agreement, , the Purchaser shall pay to the
                  Sellers, no later


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                  than December 31, 2001, the amount of five million U.S.
                  dollars ($5,000,000) in compensation, among other things, for
                  freezing their Shares and the resulting inability to sell such
                  Shares to a third party from the date of this Agreement. It is
                  specifically provided hereby, for the sake of good order, that
                  the payment of such amount by the Purchaser will constitute
                  final and complete indemnification of the Sellers and will be
                  the only indemnification to which the Sellers shall be
                  entitled for, among other things, reimbursement of any
                  expenses of any kind they may have incurred for the
                  negotiation, signature and performance of this Agreement, in
                  particular the indemnification set forth in Article 4(h) of
                  this Agreement.

(c)      Each of the Parties agrees to take the necessary steps in a timely
         manner to ensure that the foregoing conditions precedent are promptly
         met.

4.       CLOSING

(a)      The Closing, defined as the performance by the Sellers and the
         Purchaser of their obligations set forth in this Article, shall take
         place at the offices of Dechert in Paris on December 28, 2001,
         (hereinafter called the "Closing Date"), subject to meeting (or waiver,
         as the case may be of) the condition precedent set forth in Article
         3(a) hereinabove.

(b)      On the Closing Date, subject to the proper performance of the
         Purchaser's obligations set forth in paragraphs (d) and (e)
         hereinbelow, the Sellers shall deliver to the Purchaser the following
         documents:

         (i)      share transfer forms (ORDRES DE MOUVEMENT) relating to the
                  Shares (subject to the Orsymonde Minority Shares as set forth
                  in Articles 1 and 2 hereinabove) duly executed in favor of the
                  Purchaser, or any other person designated thereby pursuant to
                  Article 7(c) hereof, together with two signed copies of the
                  simplified share purchase agreement (hereinafter called the
                  "Simplified Agreement") relating to the sale of the Shares
                  (subject to the Orsymonde Minority Shares), made on the
                  Closing Date between the Sellers and the Purchaser (or any
                  person designated thereby) for purposes of recording with the
                  French tax authorities;

         (ii)     a certified copy of the resolutions of the board of directors
                  of the Company approving the Purchaser (or any other person
                  that the Purchaser may substitute for it pursuant to Article
                  7(c) hereof) as a shareholder of the Company and, for the
                  purpose of serving as director, any other person or company
                  designated by it shown in the list attached to this Agreement
                  as SCHEDULE (B)(II);

         (iii)    the shareholders' accounts of the Company and of Orsymonde
                  together with the Share Transfer Registers in both cases up to
                  date, to record the transfers made pursuant to the share
                  transfer forms referred to in Article 4(b)(i) hereof;


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         (iv)     the minute books of board and shareholders' meetings of the
                  Company and of Orsymonde in both cases up to date together
                  with the attendance book in respect of board meetings and the
                  relevant attendance sheets and proxies in respect of
                  shareholders' meetings, and all corporate documents relating
                  to the Companies that are not kept at the Company's and
                  Orsymonde's registered offices, including the resolutions
                  adopted at the shareholders' meetings of the Company and
                  Orsymonde ratifying the capital increases which took place on
                  May 3, 2001;

         (v)      unconditional letters of resignation of any of the Directors
                  (ADMINISTRATEURS) and Officers (MANDATAIRES SOCIAUX) (also
                  acting as officers - responsible pharmacists, if applicable),
                  the list of whom is attached to this Agreement as SCHEDULE
                  4(B)(V);

         (vi)     if possible, unconditional letters of resignation of the
                  Statutory Auditors (COMMISSAIRES AUX COMPTES) of the Companies
                  and their alternates, the list of whom is attached to this
                  Agreement as SCHEDULE 4(B)(VI);

         (vii)    a certificate signed by all the Sellers confirming the
                  accuracy on the Closing Date of the Representations and
                  Warranties contained in the Representations and Warranties
                  Agreement, subject to (1) the Exceptions (as such term is
                  defined in Article 3.10 of the Representations and Warranties
                  Agreement) including those affecting materially and negatively
                  the business and/or financial condition of the Companies, (2)
                  matters not affecting materially and adversely the business
                  and/or financial condition of the Companies, (3) economic
                  and/or financial matters of general applicability, including
                  those materially and adversely affecting the Companies'
                  business and/or financial condition, or (4) events under the
                  control of any company of the Cephalon group, including those
                  affecting materially and adversely the Companies' business
                  and/or financial condition, which may occur between the date
                  of this Agreement and the Closing Date. Between the signature
                  of this Agreement and the Closing Date, the Sellers shall
                  promptly advise the Purchaser of any event (excluding general
                  economic and/or financial events) materially and adversely
                  affecting the business and/or financial condition of the
                  Companies. It is expressly understood and agreed that the
                  certificate required hereunder may be provided only if the
                  Sellers believe, in good faith after making due inquiries,
                  that it is true and correct;

         (viii)   a certificate signed by the Sellers confirming that there has
                  not been, between the date of this Agreement and the Closing
                  Date, any event having a material and adverse effect on the
                  Companies' business and/or financial condition, subject to (1)
                  the Exceptions (as such term is defined in Article 3.10 of the
                  Representations and Warranties Agreement), including those
                  affecting materially and adversely the business and/or
                  financial condition of the Companies, (2) economic and/or
                  financial matters of general applicability,


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                  including those materially and adversely affecting the
                  Companies' business and/or financial condition, or (3) events
                  under the control of any company of the Cephalon group,
                  including those having a material adverse effect on the
                  Companies' business and/or financial condition, which may
                  occur between the date of this Agreement and the Closing Date.
                  It is expressly understood and agreed that the certificate
                  required hereunder may be provided only if the Sellers
                  believe, in good faith after making due inquiries, that it is
                  true and correct;

         (ix)     the Escrow Agreement duly signed;

         (x)      a certified excerpt from the minutes of the meeting of the
                  workers' committee of Laboratoire L. Lafon certifying that it
                  was duly consulted and informed concerning the planned sale of
                  the Shares prior to the signature of this Agreement;

         (xi)     certificates issued, respectively, by Bank OBC, Baxter, and
                  Laboratoires Maphar, each indicating that the signatory
                  thereof has been informed of the proposed change of control in
                  favor of the Purchaser, and that it will not exercise its
                  rights, as far as OBC may be concerned, under the acceleration
                  clauses and, as far as Baxter and Maphar may be concerned, the
                  termination clauses provided in the agreements listed in
                  SCHEDULE 4(B)(XI) hereof;

         (xii)    a certificate or certificates signed, respectively, by BNP and
                  Natexis stating that the loan taken out by Laboratoire L.
                  Lafon on 26 June 1992 in the amount of FRF 42,000,000 has been
                  repaid in full at the Closing Date, and that Laboratoire L.
                  Lafon has met its obligations under such loan agreement;

         (xiii)   a certificate signed by Natexis Bail stating that the
                  signatory thereof has been advised that Laboratoire L. Lafon
                  has entered into the loans listed in SCHEDULE 4 (b)(xiii)
                  hereof and that it will not, as a result thereof, exercise its
                  rights under the termination clause provided in the agreement
                  listed in SCHEDULE 4(b)(xiii) to the Agreement;

         (xiv)    a firm offer by which Ms. Andree Lafon undertakes to sell the
                  land and rights relating thereto (including the vacation
                  facility) located in Marseillan to Laboratoire L. Lafon;

         (xv)     a transfer deed by which the ownership of the trademarks
                  Idrocol, Troizel and Troisel 3L is transferred by Ms. Andree
                  Lafon to Laboratoire L. Lafon;

(c)      The Sellers shall cause to be held, prior to or on the Closing Date (at
         their convenience and as required by applicable law), any required
         board and/or shareholders' meetings of the Companies to effect the
         appointment of such persons as the Purchaser may designate as Directors
         (ADMINISTRATEURS), Officers (MANDATAIRES SOCIAUX), and Statutory
         Auditors


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         (COMMISSAIRES AUX COMPTES) of the Companies, the list of whom is
         attached to this Agreement as SCHEDULE 4(C).

(d)      On the Closing Date, subject to the due performance by the Sellers of
         their obligations set forth hereinabove, the Purchaser shall pay:

         (i)      to each of the Sellers by bank transfer to the bank accounts
                  for which information shall have been provided eight (8) days
                  prior to the Closing Date, its part of the Price reduced by
                  (a) for Ms. Andree Lafon, the Escrowed Amount and (b) for Mr.
                  Francois Lafon, thirty-seven thousand five hundred U.S.
                  dollars ($37,500) per Minority Share not transferred on the
                  Closing Date, and each Seller shall give to the Purchaser a
                  receipt for that part of the Price received by him/her;

         (ii)     to the escrow account, the Escrowed Amount as provided in the
                  Escrow Agreement.

(e)      On the Closing Date, subject to the due performance by the Sellers of
         their obligations set forth hereinabove, the Purchaser shall deliver to
         the Sellers:

         (i)      a certificate confirming, as of the Closing Date, the accuracy
                  of the Beneficiary's Representations and Warranties set forth
                  in the Representations and Warranties Agreement;

         (ii)     two signed copies of the Simplified Agreement;

         (iii)    a duly signed copy of the Escrow Agreement.

(f)      On the Closing Date PWC, acting at the Purchaser's request, will
         deliver to the Purchaser and the Sellers:

         (i)      an opinion in which, pursuant to its audit assignment
                  performed at the Purchaser's request and covering the 1998,
                  1999, and 2000 US GAAP Consolidated Accounts and prepared in
                  compliance with the applicable rules and regulations of the
                  U.S. Securities and Exchange Commission (Regulation S-X) and
                  conducted in accordance with United States generally accepted
                  auditing standards, in which it certifies without
                  qualification such 1998, 1999, and 2000 US GAAP Consolidated
                  Accounts, in compliance with applicable rules and regulations
                  of the U.S. Securities and Exchange Commission (Regulation
                  S-X) and in accordance with United States generally accepted
                  auditing standards;

         (ii)     an opinion in which, pursuant to its review assignment
                  performed at the Purchaser's request and covering the US GAAP
                  Interim Accounts prepared in compliance with the applicable
                  rules and regulations of the U.S. Securities and Exchange
                  Commission (Regulation S-X) and conducted in accordance with
                  United States generally accepted auditing standards, it gives
                  an unqualified review


                                       11
<Page>

                  report on the 2001 US GAAP Interim Accounts in accordance with
                  the rules and regulations of the U.S. Securities and Exchange
                  Commission (Regulation S-X) and generally accepted auditing
                  standards in the United States.

         The Sellers agree, on their own behalf and on the Company's behalf, to
         continue to co-operate fully with PWC in connection with its
         assignments of auditing the 1998, 1999, and 2000 US GAAP Consolidated
         Accounts and reviewing the 2001 US GAAP Interim Accounts. Thus, the
         Sellers shall cause PWC to continue to have access, until the Closing
         Date, to the offices, records, and personnel of the Companies so as to
         allow PWC to perform its audit and review assignments.

         The Purchaser agrees to pay the fees of PWC within the time period
         agreed with it and not to impede PWC's performance of its review work
         and to co-operate fully with PWC, so that it is able to complete its
         audit and review assignments within the agreed time periods, I.E.,
         prior to the Closing Date.

         It is expressly understood and agreed by the Parties that the failure
         of PWC to deliver one or more of the opinions described in paragraphs
         (i) and (ii) hereinabove shall not be deemed to be a failure to meet
         the condition precedent described in this Article, if such failure
         results from failure of the Purchaser to comply with its obligations
         under the foregoing paragraph.

         For the avoidance of doubt, it is understood and agreed that the
         delivery of the opinions described in this Article, prepared to satisfy
         the rules and regulations of the U.S. Securities and Exchange
         Commission (Regulation S-X) is an essential and determining condition
         of the Purchaser's agreements. However, the Parties' obligations under
         this Agreement, shall not be affected by the contents of the financial
         documents described in this Article or any adjustments which may be
         made in connection with PWC's review, as set forth in paragraph L of
         the Recitals hereto.

(g)      If the Closing does not occur by December 28, 2001, at the latest for
         any reason other than one relating to the failure of the Purchaser to
         meet its obligations under this Agreement, the Purchaser may terminate
         this Agreement without there being any obligation by any Party to pay
         any indemnity to any other.

(h)      In the event the Closing fails to take place by reason of the failure
         of the Sellers (on the one hand) or the Purchaser (on the other hand)
         to satisfy any of the obligations set forth in this Agreement between
         the date of this Agreement and the Closing Date (excluding the failure
         to close related to one of the conditions set forth in Article 3 of
         this Agreement), the non-defaulting Party may terminate this Agreement
         and shall be entitled to obtain from the defaulting Party, in addition
         to any other remedies to which it may be entitled by French courts, the
         immediate reimbursement of all reasonable costs and expenses (including
         fees of counsel and other advisors) incurred in connection with the
         negotiation, signature and performance of this Agreement. For the
         avoidance of doubt it is provided that the non-delivery by PWC of the
         opinions described in Articles 4(f)(i) to 4(f)(ii)


                                       12
<Page>

         hereinabove for reasons attributable to it shall not give rise to
         reimbursement of fees and expenses hereinabove provided.

(i)      The Parties agree to co-operate with each other so that the formalities
         required to create a tax consolidation group consisting of the
         Companies and any French subsidiary of the Purchaser which may control
         the Company following the Closing shall be completed by December 31,
         2001, so that a new tax consolidation group is in place by January 1,
         2002.

5.       SELLERS' OTHER OBLIGATIONS

(a)      As from the date of this Agreement and up to and including the Closing
         Date, the Sellers shall procure that the businesses of the Companies
         shall be carried on in the ordinary course and in a prudent and
         appropriate manner and consistent with the Companies' past practices.
         The Sellers shall comply with, and shall cause the Companies to comply
         with, the following commitments:

         (i)      not to change the normal terms and conditions of payment of
                  amounts which may be due to them and, especially, not to offer
                  incentives to third parties (other than normal discounts
                  offered to customers) for the purpose of accelerating
                  collection of the Companies' accounts receivable;

         (ii)     not to accept, with respect to accounts payable, payment terms
                  and conditions which vary from those customarily offered, or
                  postponing the payment of any accounts payable past the due
                  date hereof;

         (iii)    not to offer terms or discounts or take any other action which
                  results in customers increasing their inventory levels of the
                  Companies' products beyond what is customary with respect to
                  such products;

         (iv)     to comply with all applicable laws and regulations and, in
                  particular, but without limiting to the generality of the
                  foregoing, the requirements of all applicable employment laws
                  relating to the subject matter of this Agreement;

         (v)      without the prior written consent of the Purchaser, not amend
                  their articles of association (STATUTS), undertake any merger,
                  spin-off or other form of reorganisation, nor propose, declare
                  or pay any dividend or grant any mortgage, pledge or security,
                  or take any other step which may encumber or otherwise affect
                  the free disposition of their respective assets;

         (vi)     without the prior written consent of the Purchaser and except
                  for cost-of-living increases or increases which are mandatory
                  under applicable labor law or any relevant collective
                  bargaining agreement, or any other applicable labor agreement,
                  not to increase or undertake to increase the compensation
                  payable or other benefits due to any employees or of any
                  manager or officer (MANDATAIRE SOCIAL) (whether or not having
                  employee status) of the Companies


                                       13
<Page>

                  (such as bonuses, profit sharing, pension or retirement
                  benefits, or other similar benefits), nor hire or dismiss any
                  senior corporate managers (CADRES SUPERIEURS) or executive
                  employees (CADRES DIRIGEANTS), or increase the number of other
                  employees or personnel (temporary, under contract with
                  third-parties, or other);

         (vii)    without the prior written consent of the Purchaser, not to
                  enter into any contracts containing unusual or unduly onerous
                  terms, or which are outside the normal course of business of
                  the Companies;

         (viii)   not to terminate, or enter into, any business relationship ;

         (ix)     not to undertake any capital or non-routine expenditure, save
                  where such expenditure is essential to preserve the value of
                  an asset of the Companies or their business; and

         (x)      not to undertake or pursue any negotiation with a third-party
                  concerning a potential sale of the Financiere Lafon Shares or
                  the Orsymonde Shares, or any other acquisition of an interest
                  in the Companies.

(b)      Notwithstanding paragraph (a) hereinabove the Companies may undertake
         the transactions described hereinabove if

         (i)      they are necessary in the normal course of their businesses,
                  prudent and appropriate for their operations and consistent
                  with past practices, so long as the Purchaser is given prior
                  notice thereof; or

         (ii)     they appear in SCHEDULE 5(B) of the Agreement, such Schedule
                  to contain a list, among other things, of certain assets to be
                  sold by the Sellers, or acquired by the Companies from the
                  Sellers before the Closing Date, as well as the related sale
                  price thereof. The transfer of title to such assets shall be
                  for the price set forth in such SCHEDULE 5(B); or

         (iii)    they are contemplated by this Agreement and/or the
                  Representations and Warranties Agreement.

(c)      Between the date of this Agreement and the Closing Date the Sellers
         shall lend assistance to the Purchaser, and use their best efforts, to
         make it possible for Cephalon Group's senior managers (CADRES
         SUPERIEURS) to meet with the Companies' senior managers, advisors, or
         statutory auditors for the purpose of preparing for the transition and
         facilitate management of the Companies after completion of the
         transaction contemplated by this Agreement.

(d)      From the date of this Agreement until the Closing Date the Sellers
         agree to use their best efforts, in co-operation with the Purchaser, to
         obtain the consent of (i) other parties to


                                       14
<Page>

         contracts with Laboratoire L. Lafon, the list of which is set out in
         SCHEDULE 5(D)(I), to the transaction contemplated by this Agreement,
         and (ii) other parties which are parties to contracts with Laboratoire
         L. Lafon which are listed in SCHEDULE 5(D)(II) of the Agreement, to
         change the territories set forth in such agreements and exclude the
         territories listed in SCHEDULE 5(D)(II) hereof.

(e)      The Purchaser has had a Phase I environmental audit performed by the
         firm Duke Engineering on the Company's sites located at Mitry Mory,
         Maisons Alfort, Savigny-Le-Temple, and Nevers, which has disclosed
         potential problems, listed in paragraph (f) hereinbelow, along with a
         description of the sites involved.

(f)      From the date of this Agreement to the Closing Date the Sellers agree
         to continue to allow the environmental consulting firm chosen by the
         Purchasers, Duke Engineering, and any subcontractor it may use, to
         complete a Phase II environmental audit already begun and, if
         necessary, undertake detailed risk assessments for the risks relating
         to the following problems and facilities:

         -        the problem of fuel contamination identified at the office
                  facility located at 20 rue Charles Martigny in Maisons Alfort
                  site;

         -        the problem of potential contamination following a fire at the
                  research center located at 19 rue du Professeur Cadiot in
                  Maisons Alfort;

         -        the problem of possible pollution related to the coffee
                  business of the preceding users at the facility located at 5,
                  avenue Charles Martigny in Maisons-Alfort. For such facility,
                  the Phase II audit will not occur until the completion of an
                  historical study of the site;

         -        the required removal of asbestos at the Mitry Mory facility;

         -        the problem of possible contamination relating to the
                  accidental methyl chloride spill and the storage of products
                  hazardous to the environment and the past existence of PCB
                  transformers at the Mitry Mory site, ZI of Mitry Compans, rue
                  Gay Lussac.

         For this purpose, such consultants shall continue to have access to the
         documents and resources (electricity and water) they reasonably deem
         necessary to conduct their audit and to the above-described sites,
         after receiving agreement from the Companies involved, to undertake any
         sampling and analysis which they deem reasonably necessary.

(g)      Promptly following the date of this Agreement and, in any event, prior
         to the Closing Date, the Purchaser will deliver one or more report(s)
         of its environmental consultants to the Sellers which will indicate:


                                       15
<Page>

         (i)      the type of pollution and/or fuel contamination found in the
                  soil, offices, or facilities of the office facility located at
                  20 rue Charles Martigny in Maisons Alfort; and

         (ii)     the type of pollution and/or contamination related to the fire
                  at the Maisons Alfort research center; and

         (iii)    the type of pollution and/or contamination related to the
                  coffee business of the preceding users at the facility located
                  at 5, avenue Charles Martigny in Maisons-Alfort

         (iv)     the type of pollution and/or contamination related to methyl
                  chloride, to storage of products hazardous to the environment
                  and/or the past existence of PCB transformers found in the
                  soil, offices, or facilities at Mitry Mory; and

         (v)      the type of pollution and/or contamination related to the
                  presence of asbestos at the Mitry Mory facility and taking
                  account of the contemplated asbestos removal; and

         (vi)     if applicable, the solutions proposed to remediate such
                  problems, with an estimate of the costs on a site-by-site
                  basis (each report being hereinafter called an "Environmental
                  Report").

         The Sellers shall have forty (40) days from the delivery of each
         Environmental Report to express in writing their objections with
         respect to such Environmental Report. The Sellers shall then be given
         access to the facilities to make any analysis and take any samples
         necessary and shall have access to any document used by the Purchaser's
         consultants during their audit. Should the Sellers send objections to
         the Purchaser, the Parties shall have thirty (30) days from receipt of
         such objections by the Purchaser to negotiate a solution.

         If they succeed, the Sellers agree to assume the cost, through a
         reduction of the Price, of the decontamination work involved, as
         determined by mutual agreement of the Parties, provided, however, that
         any amount assumed by the Sellers under this Article is understood to
         mean amounts excluding taxes (MONTANTS HORS TAXES), (i) net of the tax
         savings realized by the entity paying such costs to the extent such
         decontamination costs qualify as an accounting charge deductible from
         the taxable income of the Company involved, and (ii) exceeding any
         amount taken into consideration in the Closing Accounts (as defined in
         Article 6.1(a) hereinbelow) with respect to problems related to fuel
         and asbestos described in paragraphs (g)(i) and (v) hereinabove
         (hereinafter called the "Environmental Amount"). In the event the
         above-described costs should constitute depreciable fixed assets, the
         Parties agree to determine in good faith the amount of the tax saving
         realized in this respect.


                                       16
<Page>

         If they fail to agree, the Parties shall contact the office of the
         DIRECTION REGIONALE DE L'INDUSTRIE, DE LA RECHERCHE ET DE
         L'ENVIRONNEMENT (hereinafter called the "DRIRE" [French environmental
         protection agency] having jurisdiction and communicate to such
         authority and/or any expert expressly appointed by such authority the
         nature of the pollution problems found at the sites involved and
         request that it confirm the decontamination work required to be
         undertaken with respect thereto.

         If the DRIRE (or any expert appointed thereby) should refuse to take a
         position on the nature of the decontamination work required to be
         undertaken, such analysis shall be made by an expert appointed by the
         Presiding Judge of the [TRIBUNAL DE COMMERCE - Commercial Court] of
         Paris on the motion of the first of the Parties to act.

         The Sellers agree to assume the cost, through a reduction of the Price,
         of the decontamination work required by the DRIRE and/or any expert
         appointed on the terms and conditions hereinabove set forth, in the
         amount of the cost of such work as determined hereinabove on the basis
         of the estimate which will be prepared (at the Parties' request) by a
         decontamination firm chosen by the Parties, or recommended by the
         DRIRE, or, in the absence thereof, by such expert, applying the
         methodology nationally recognized in the area of managing contaminated
         soil and facilities. It is agreed that the cost of preparing such
         estimate shall be shared by the Parties in such a way that such costs
         borne by the Sellers are proportional to the relationship between (i)
         the disputed amounts identified by the Sellers in their Objections and
         finally confirmed by such firm or such expert and (ii) the total of the
         disputed amounts identified by the Sellers in their Objections. It is
         further understood that any amount borne by the Sellers, through a
         reduction of the price, under this Article shall be exclusive of taxes
         (HORS TAXES), net of the tax savings realized by the entity paying such
         costs to the extent such decontamination costs qualify as an accounting
         charge immediately deductible from the taxable income of the Company
         involved for the fiscal period in which it should be incurred.
         Likewise, should such costs constitute depreciable fixed assets, the
         Parties agree to determine in good faith the amount of the tax saving
         realized in this respect.

(h)      Subject to completion of the Closing, each Seller commits itself not to
         develop, exercise, be associated with, involved in, or interested in
         any activities in the European Union relating to products in the same
         therapeutic categories as those currently manufactured or sold by the
         Companies, or which are under development as of the Closing Date,
         whether alone or in collaboration with others, for a period of five (5)
         years from the date of this Agreement. In addition, the Sellers hereby
         agree not to engage, directly or indirectly, in any business
         relationship with any of the current legal representatives or employees
         of the Companies for a period of five (5) years from the Closing Date,
         except for the persons listed in SCHEDULE 5(H) of this Agreement. It is
         understood and agreed, to the extent necessary that this
         non-competition provision shall not apply to passive investments in
         publicly traded companies the business of which could fall within the
         scope of this paragraph, undertaken through the purchase of shares in
         mutual investment funds (SICAV or OPCVM), or by third parties managing
         the Sellers' assets.


                                       17
<Page>

(i)      According to the Sellers, Laboratoire L. Lafon has the right to use the
         names "Lafon", "L. Lafon" and "Louis Lafon" as a company name, trade
         name or, if applicable, as a trademark, in connection with all
         activities within their respective corporate purpose in perpetuity,
         with no payment other than those due to any governmental authority
         having jurisdiction under applicable company and/or, as the case may
         be, trademark law, or any advisor consulted in this connection. The
         Purchaser agrees not to use such names otherwise than as they are
         presently used in connection with the Companies' business activities.

(j)      The Sellers agree to deliver the 2001 US GAAP Interim Accounts to PWC
         no later than December 10, 2001.

6.       FINANCIAL MATTERS

6.1      Shareholders' Equity on the Closing Date

(a)      The Purchaser shall cause consolidated accounts (including a balance
         sheet, income statement, and notes to the consolidated accounts,
         including off-balance sheet items) of the Company to be prepared by the
         Company as of the Closing Date (hereinafter called the "Closing
         Accounts") as soon as possible after the Closing Date, using the same
         methods as those applied in the preparation of the 1998, 1999, and 2000
         Consolidated Accounts (it being understood that the amounts included in
         reserves for amortization of goodwill, shall be taken into
         consideration in the amount shown for fiscal year 2000, I.E., thirteen
         million five hundred ninety-four francs (FRF 13,594,999)), such
         accounting methods to comply with the accounting principles issued in
         the NOUVEAU PLAN COMPTABLE FRANCAIS and consistent with the
         recommendations of the ORDRE DES EXPERTS COMPTABLES FRANCAIS and the
         CONSEIL NATIONAL DE LA COMPTABILITE.

         The Purchaser has already decided to appoint PWC, to which it will
         deliver the Closing Accounts upon completion thereof, to audit the
         Closing Accounts. PWC shall submit the conclusions of its audit in a
         report (hereinafter called the "First PWC Report"), which will be
         delivered by the Purchaser to the Sellers, with the Closing Accounts,
         no later than ninety (90) days from the Closing Date. It is understood
         and agreed that PWC's fees and expenses shall be borne exclusively by
         the Purchaser.

         The Sellers shall have forty (40) days from the date on which the
         Closing Accounts and the First PWC Report are delivered to them to set
         forth in writing any objections, in a statement of objections
         (hereinafter called the "Objections Notice"), to the contents of such
         Closing Accounts and First PWC Report and, especially, the substance
         and amount of the shareholders' equity (including minority interests)
         set forth in the Closing Accounts (hereinafter called the "Closing
         Shareholders' Equity"), provided, however, that the Purchaser shall
         cause the accountants who prepared the Closing Accounts and PWC to
         co-operate with the Sellers and their respective advisors in connection
         with the procedure set forth in this Article and, especially, to
         disclose the documents prepared for the purpose of preparing the
         Closing Accounts.


                                       18
<Page>

(b)      Should the Sellers send the Purchaser an Objection Notice, the Parties
         shall have thirty (30) days from receipt of the Objection Notice by the
         Purchaser to negotiate a resolution of their disagreement.

         In the event of failure, the points in dispute shall be submitted to
         the firm of Deloitte & Touche or, if such firm is unable to accept such
         assignment, to the firm of Mazars et Guerard (hereinafter called the
         "Firm"), at the behest of either Party. The Firm shall have forty (40)
         days from the time it is contacted by the Party acting first to
         determine the contents of the Closing Accounts and, especially, to
         determine the amount of the Closing Shareholders' Equity and the Price
         Reduction (as such terms are hereinabove defined), if any.

         The Firm's conclusions, which shall only deal with the points as to
         which the Sellers and Purchaser have not reached agreement, shall be
         final and binding on the Parties, except in the case of manifest
         technical error.

         The Firm's fees and expenses shall be borne by the Purchaser, on the
         one hand, and the Sellers, on the other hand, so that the portion of
         such fees and expenses borne by the Sellers shall be proportional to
         the relationship between (i) the disputed amounts identified by the
         Sellers in the Objection Notice and finally determined by the Firm and
         (ii) the total of the disputed amounts identified in the Objection
         Notice by the Sellers. Such division shall be made by the Firm, whose
         determination shall be final and binding on the parties, except in the
         case of manifest technical error.

(c)      Should the Closing Shareholders' Equity be less than shareholders'
         equity (including minority interests and other items of shareholders'
         equity) as of December 31, 2000, as set forth in the 1998, 1999, and
         2000 Consolidated Accounts, I.E., four hundred seventy-nine million
         fifty-eight thousand French Francs (FRF 479,058,000) (i) increased by
         the Company's consolidated net income for the fiscal year 2001 (of a
         guaranteed minimum of ninety-one million four hundred six thousand
         French Francs (FRF 91,406,000)) taking into consideration the
         Purchaser's agreement to order eight (8) tons of the active ingredient
         of Modafinil during the period between January 1, 2000, and the Closing
         Date, and (ii) reduced by dividends paid by the Company and Orsymonde
         to their shareholders who are individuals during the 2001 fiscal year
         (of an amount of seventy-two million French Francs (FRF 72,000,000)),
         the Parties agree to reduce the Price in the amount of such difference
         (hereinafter called the "Price Reduction").

(d)      The Price Reduction shall be paid by the Sellers to the Purchaser no
         later than eight (8) business days from (i) the date on which the
         Parties reach agreement on the amount of the Price Reduction, or (ii)
         in the event of disagreement, the date of receipt by the Sellers of the
         Firm's determination.

         For purposes of effecting payment, the amount of the Price Reduction
         shall be converted into U.S. dollars on the basis of the five-day
         average of the mid-range rates published in


                                       19
<Page>

         the "U.S. Currency Trading, Dollar Exchange Rates" table of the
         European editions of THE WALL STREET JOURNAL preceding the Closing
         Date.

6.2      Cash-Flow, Borrowings, and Financial Obligations as of September 30,
         2001

(a)      On the Closing Date the 2001 Interim Accounts shall be available to the
         Purchaser, which it may review and correct. The Purchaser has already
         appointed PWC, to which it will deliver the 2001 Interim Accounts, to
         audit such 2001 Interim Accounts. The 2001 Interim Accounts, following
         review and correction, if any, by PWC, shall be hereinafter called the
         "Corrected 2001 Interim Accounts". PWC shall submit the conclusions of
         its assignment in a report (hereinafter called the "Second PWC
         Report"), which shall be delivered by the Purchaser to the Sellers,
         with the Corrected 2001 Interim Accounts, no later than ninety (90)
         days from the Closing Date. It is understood and agreed that PWC's fees
         and expenses shall be borne exclusively by the Purchaser.

         The Sellers shall have forty (40) days from the date on which the
         Corrected 2001 Interim Accounts and the Second PWC Report are delivered
         to them to set forth in writing any objections, in a statement of
         objections (hereinafter called the "Objections"), to the contents of
         such Corrected 2001 Interim Accounts and Second PWC Report and,
         especially (i) the substance and amount of the Cash-Flow (I.E., the
         amount of Cash Flow and Investment Securities set forth in the
         Corrected 2001 Interim Accounts), as set forth in the Corrected 2001
         Interim Accounts (hereinafter called the "Interim Cash-Flow"), and/or
         (ii) the substance and amount of the borrowings from, and obligations
         to, lending institutions and miscellaneous borrowings and financial
         obligations, as set forth in the Corrected 2001 Interim Accounts
         (hereinafter called "Interim Financial Obligations").

(b)      Should the Sellers send Objections to the Purchaser, the Parties shall
         have thirty (30) days from receipt of the Objections by the Purchaser
         to negotiate a resolution of their disagreement.

         In the event of failure, the points in dispute shall be submitted to
         the Firm at the behest of either Party. The Firm shall have forty (40)
         days from the time it is contacted by the Party acting first to
         determine the contents of the 2001 Interim Accounts and, especially, to
         determine the amount of (i) the Interim Cash Flow and/or the Interim
         Financial Obligations and (ii) the Difference in Cash-Flow and/or the
         Difference in Obligations and the Price Differential (as such terms are
         hereinbelow defined), if any.

         The Firm's conclusions, which shall only deal with the points as to
         which the Sellers and Purchaser have not reached agreement, shall be
         final and binding on the Parties, except in the case of manifest
         technical error.

         The Firm's fees and expenses shall be borne by the Purchaser, on the
         one hand, and the Sellers, on the other hand, so that the portion of
         such fees and expenses borne by the Sellers shall be proportional to
         the relationship between (i) the disputed amounts identified by the
         Sellers in the Objections and finally determined by the Firm and (ii)
         the


                                       20
<Page>

         total of the disputed amounts identified in the Objections by the
         Sellers. Such division shall be made by the Firm, whose determination
         shall be final and binding on the parties, except in the case of
         manifest technical error.

(c)      Should:

         (i)      the Interim Cash-Flow be less than seventy-five million four
                  hundred sixty-four thousand francs (FRF 75,464,000), the
                  Parties agree to reduce the Price by the amount of such
                  difference (hereinafter called the "Cash-Flow Difference");
                  and/or

         (ii)     the Interim Financial Obligations be greater than sixty-two
                  million eight hundred ninety-two thousand francs (FRF
                  62,892,000), the Parties agree to reduce the Price by the
                  amount of such difference (hereinafter called the "Difference
                  in Obligations").

         The amount of the Cash-Flow Difference and the Difference in
         Obligations shall hereinafter be called the "Price Differential".

(d)      The Price Differential shall be paid by the Sellers to the Purchaser no
         later than eight (8) business days from (i) the date on which the
         Parties reach agreement on the amount of the Price Differential, or
         (ii) in the event of disagreement, the date of receipt by the Sellers
         of the Firm's determination.

         For purposes of effecting payment, the amount of the Price Differential
         shall be converted into U.S. dollars on the basis of the mid-range
         exchange rates published in the "US Currency Trading Dollar Exchange
         Rates" table of the European editions of THE WALL STREET JOURNAL
         preceding the Closing Date.

6.3      For the avoidance of doubt, it is understood and agreed that:

(a)      Any new accounting entry (such as the creation or increase of a
         reserve) related to a risk disclosed as an Exception shall be
         eliminated for purposes of preparing the Closing Accounts (subject to
         the Environmental Amount, which will not be eliminated);

(b)      any fees paid by the Companies for preparation of the Interim Accounts
         shall also be eliminated for purposes of preparing the Closing
         Accounts; and

(c)      an event or fact giving rise to a Price Reduction cannot give rise to a
         Price Differential and VICE VERSA.

7.       ASSIGNMENT - SUBSTITUTION

(a)      This Agreement is personal to the Parties and may not be assigned by
         any of them save that the Purchaser may assign its rights under this
         Agreement to an Associated Company, as long as such assignment covers
         all of this Agreement and the Shares, and the Purchaser


                                       21
<Page>

         remains jointly liable for the Associated Company's performance of its
         obligations under this Agreement. For purposes of this Article 7 the
         term "Associated Company" shall mean any company which, directly or
         indirectly, controls or is controlled by or is under the control with
         the Purchaser, and the term "control" shall mean the ability to
         exercise, or to procure the exercise, directly or indirectly, of at
         least fifty per cent (50 %) of the voting rights of a company.

(b)      In the event of the death or permanent mental incapacity of one or more
         of the Sellers, this Agreement shall be binding on his/her/their heirs
         and successors or, as the case may be, legal guardian or trustee.

(c)      The Purchaser may, prior to the Closing Date, substitute for itself an
         Associated Company, provided that it give notice to the Sellers thereof
         not less than eight (8) days prior to the Closing. Such substitution
         shall automatically cause the substitution of the Associated Company to
         the terms and conditions of the Representations and Warranties
         Agreement and the Escrow Agreement.

8.       EXPENSES

         Except as otherwise expressly provided in this Agreement and/or the
         Representations and Warranties Agreement, each of the parties shall
         bear all the costs and expenses incurred by it in connection with this
         Agreement and its negotiation, signature and performance, including,
         but not limited to, the fees and disbursements of any professional
         advisor, attorney, accountant or any other person whose services may
         have been used by the said Party in relation hereto.

9.       CONFIDENTIALITY

(a)      Subject to the provisions of this Agreement, the Sellers and the
         Purchaser undertake to hold in confidence and not to disclose to third
         parties (except to their professional advisors and, in the case of the
         Purchaser, to any of its Associated Companies and, in the case of the
         Sellers, the managers and advisors of the Companies), without the prior
         written consent of the other Party, the terms and conditions of the
         transactions contemplated hereby.

(b)      All announcements or communications with governmental or administrative
         bodies, employee representatives or others, by or on behalf of the
         Parties, or on their behalf, relating to the transactions contemplated
         hereby, shall be made on terms agreed by the Parties, save that (i) the
         Purchaser shall be entitled to make such announcement as is required to
         comply with the regulations of any securities exchange on which the
         shares of the Purchaser or any Associated Company of the Purchaser may
         be traded and that (ii) the Sellers shall have the right to make
         statements and announcements required to the employee representation
         bodies of the Companies or French governmental or administrative
         bodies, after taking into consideration the reasonable comments of the
         other Party.


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(c)      If, for any reason, the transactions contemplated hereby are not
         completed, the obligations of the Parties pursuant to this Article 9
         will remain in force and effect for five (5) years from the date of
         this Agreement.

(d)      It is understood and agreed that, for the sake of good order, this
         confidentiality obligation shall not apply to the rights of the Parties
         to make disclosure of, or use, the contents of this Agreement to
         defend, or establish, their rights in connection with a legal
         proceeding, including, but not limited to, any proceeding before an
         administrative court or agency, or arbitration panel.

10.      NOTICES

(a)      Any notice hereunder shall be validly given, if sent by registered
         letter (with return receipt requested), by express delivery service
         with return receipt requested, or by personal delivery against
         handwritten receipt of such notice to the following addresses, or to
         such other address as may have been communicated by either of the
         Parties to the other at least five (5) business days prior to such
         notice:

                                    for notices to the Sellers:

                                    Mr. Francois Lafon
                                    c/o Maitre Joel Chevreau
                                    Bureau d'Etudes Juridiques Peyre
                                    174, rue de l'Universite
                                    75007 Paris

                                    for notices to the Purchaser:

                                    Cephalon Inc.
                                    145 Brandywine Parkway
                                    West Chester, Pennsylvania 19380
                                    United States
                                    to the attention of its General Counsel

                                    with a copy to:

                                    Dechert
                                    55, avenue Kleber
                                    75116 Paris
                                    To the attention of Jonathan Schur

         Notices shall be deemed received by the Party involved (i) three (3)
         days after the first attempt to deliver the registered letter with
         return receipt requested, or express delivery


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         service and (ii) the day of handwritten acknowledgement of receipt in
         the event of personal delivery.

(b)      The Sellers irrevocably confer on Mr. Francois Lafon, who accepts, the
         authority to accept notices on behalf of all of them. Any notice given
         to Mr. Francois Lafon as provided in paragraph (a) hereinabove shall be
         deemed to be valid notice to all the Sellers.

11.      GOVERNING LAW AND JURISDICTION

(a)      This Agreement shall be governed by and construed in accordance with
         French law.

(b)      Any dispute arising in relation to this Agreement, its interpretation
         or performance (including, without limitation, its validity,
         performance or interpretation) shall be submitted to the Commercial
         Court (TRIBUNAL DE COMMERCE) of Paris, including any demands for
         provisional or emergency remedies.

12.      WAIVERS

         The failure by any party hereto promptly to avail itself, in whole or
         in part, of any right, power or privilege to which such party is
         entitled pursuant to the terms of this Agreement shall not constitute a
         waiver of such right, power or privilege, which may be exercised at any
         time. To be valid, waiver by any party hereto of any such right, power
         or privilege must be in writing and notified to the other Parties as
         provided herein.

13.      HEADINGS

         The descriptive words or phrases at the head of the Articles are
         inserted only as a convenience and for reference purposes and are not
         intended in any way to define, limit, or describe the scope or intent
         of the Articles which they precede.

14.      ENTIRE AGREEMENT

         (a)      This Agreement constitutes the entire the agreement among the
                  Parties with regard to the subject matter hereof and
                  supersedes and replaces any previous agreement or agreements
                  whether oral or written with regard thereto.

         (b)      Each of the Schedules forms an integral part of this
                  Agreement.

SIGNED in Paris by the parties on the day and year first above written.


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CEPHALON , INC.


/s/ FRANK BALDINO, JR.
- -------------------------------------------
By:      Frank Baldino, Jr., Ph.D.
Title:   Chairman & Chief Executive Officer


Mr.Francois Lafon


/s/ FRANCOIS LAFON
- -------------------------------------------

Ms. Andree Carpentier, widow (VEUVE) of Mr. Louis Lafon


/s/  ANDREE CARPENTIER
- -------------------------------------------


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