<PAGE>
                                                                   EXHIBIT 10.01

[***] indicates the omission of confidential portions for which confidential
treatment has been requested. Such confidential information has been filed
separately with the Securities and Exchange Commission.

                               AMENDMENT NO. 4 TO
                              AMENDED AND RESTATED
                         RECEIVABLES PURCHASE AGREEMENT

          This AMENDMENT NO. 4 TO AMENDED AND RESTATED RECEIVABLES PURCHASE
AGREEMENT(this "AMENDMENT"), dated as of February 3, 2005, by and among Cardinal
Health Funding, LLC, a Nevada limited liability company, as Seller ("SELLER"),
Griffin Capital, LLC, a Nevada limited liability company, as Servicer
("SERVICER"), each entity signatory hereto as a Conduit (each a "Conduit " and
collectively, the "CONDUITS"), each entity signatory hereto as a Financial
Institution (each a "FINANCIAL INSTITUTION" and, collectively with the Conduits,
the "PURCHASERS"), each entity signatory hereto as a Managing Agent (each a
"MANAGING AGENT" and collectively, the "MANAGING AGENTS") and JPMorgan Chase
Bank, N.A. (successor by merger to Bank One, NA (Main Office Chicago), as the
Agent (the "AGENT").

                                    RECITALS

          Seller, Servicer, the Purchasers, the Managing Agents and the Agent
have entered into that certain Amended and Restated Receivables Purchase
Agreement, dated as of May 21, 2004, as amended by the Omnibus Amendment, dated
as of August 18, 2004, as further amended by the Omnibus Limited Waiver and
Second Omnibus Amendment thereto, dated as of September 24, 2004, and as further
amended by the Amendment No. 3 thereto, dated as of September 30, 2004 (as
heretofore amended, the "PURCHASE AGREEMENT").

          Seller, Servicer, the Purchasers, the Managing Agents and the Agent
now desire to amend a certain provision of the Purchase Agreement upon the terms
and subject to the conditions set forth herein to provide for a Special
Concentration Limit for [***].

                                    AGREEMENT

          NOW, THEREFORE, in consideration of the premises herein contained and
for other good and valuable consideration, the receipt and adequacy of which are
hereby acknowledged by the parties hereto, the parties hereto agree as follows:

     SECTION 1. Definitions. Capitalized terms used herein and not defined
herein shall have the respective meanings assigned thereto in the Purchase
Agreement, as amended hereby.

     SECTION 2. Amendment to Purchase Agreement. Subject to the terms and
conditions set forth herein, the definition of "Concentration Limit" set forth
in Exhibit I to the Purchase Agreement is hereby amended by amending and
restating, in its entirety, such definition where it appears therein to read as
follows:

<PAGE>

          "Concentration Limit" means, at any time, for any Obligor, three
percent (3%) of the aggregate Outstanding Balance of all Receivables that are
Eligible Receivables, or such other amount (a "Special Concentration Limit") for
such Obligor designated by the Agent; provided, that the Rating Agencies then
rating the Commercial Paper notes of the Scotia Conduit shall have confirmed
that the ratings of the Commercial Paper notes of the Scotia Conduit will not be
downgraded or withdrawn as a result of any designation by the Agent of any new
Obligor subject to a Special Concentration Limit or any increase by the Agent of
an existing Special Concentration Limit percentage; and provided, further, that
in the case of an Obligor and any Affiliate of such Obligor, the Concentration
Limit shall be calculated as if such Obligor and such Affiliate are one Obligor;
and provided, further, that the Agent or any Managing Agent may, upon not less
than three Business Days' notice to Seller, cancel any Special Concentration
Limit; and provided, further, the Special Concentration Limit for the Obligor
[***] shall be automatically cancelled if, at any time, the senior unsecured
long-term debt rating of [***] shall fall below BBB- (or is withdrawn), as
determined by S&P, or shall fall below Baa3 (or is withdrawn), as determined by
Moody's. The following Special Concentration Limits have been established by the
Agent for the following Obligors:

<TABLE>
<CAPTION>
                                    SPECIAL CONCENTRATION LIMIT
                                  (% OF THE AGGREGATE OUTSTANDING
OBLIGOR                          BALANCE OF ELIGIBLE RECEIVABLES)
-------                          --------------------------------
<S>                              <C>
[***]                                            7%
[***]                                            4%
[***]                                            5%
[***]                                            4%
[***]                                           18%
</TABLE>

     SECTION 3. Conditions to Effectiveness of this Amendment. This Amendment
shall become effective as of the date hereof, subject to the satisfaction of the
following conditions:

          (a) Amendment. The Agent and each Managing Agent shall have received
executed counterparts of this Amendment, duly executed by each of the parties
hereto.



                                        2

<PAGE>

          (b) Confirmation. Either of Scotia or the Scotia Conduit shall have
received confirmation from each of the Rating Agencies then rating the
Commercial Paper notes of the Scotia Conduit that the ratings of the Commercial
Paper notes of the Scotia Conduit will not be downgraded or withdrawn as a
result of the designation of [***] being subject to a Special Concentration
Limit.

          (c) Representations and Warranties. As of the date hereof, both before
and after giving effect to this Amendment, all of the representations and
warranties of Seller and Servicer contained in the Purchase Agreement, as
amended hereby, and in each other Transaction Document (other than those that
speak expressly only as of a different date) shall be true and correct in all
material respects as though made on the date hereof (and by its execution
hereof, each of Seller and Servicer shall be deemed to have represented and
warranted such).

          (d) No Amortization Event. As of the date hereof, both before and
after giving effect to this Amendment, no Amortization Event or Potential
Amortization Event shall have occurred and be continuing (and by its execution
hereof, each of Seller and Servicer shall be deemed to have represented and
warranted such).

     SECTION 4. Miscellaneous.

          (a) Effect; Ratification. The amendments set forth herein are
effective solely for the purposes set forth herein and shall be limited
precisely as written, and shall not be deemed to (i) be a consent to any
amendment, waiver or modification of any other term or condition of the Purchase
Agreement or of any other instrument or agreement referred to therein; or (ii)
prejudice any right or remedy which any Purchaser, each Managing Agent or the
Agent may now have or may have in the future under or in connection with the
Purchase Agreement or any other instrument or agreement referred to therein.
Each reference in the Purchase Agreement to "this Agreement," "herein," "hereof"
and words of like import and each reference in the other Transaction Documents
to "Receivables Purchase Agreement," the "Purchase Agreement" or the Purchase
Agreement shall mean the Purchase Agreement, as amended hereby, as applicable.
This Amendment shall be construed in connection with and as part of the Purchase
Agreement and all terms, conditions, representations, warranties, covenants and
agreements set forth in the Purchase Agreement and each other instrument or
agreement referred to therein, except as herein amended, are hereby ratified and
confirmed and shall remain in full force and effect.

          (b) Transaction Documents. This Amendment is a Transaction Document
executed pursuant to the Purchase Agreement and shall be construed, administered
and applied in accordance with the terms and provisions thereof.


                                        3

<PAGE>
          (c) Costs, Fees and Expenses. Seller agrees to reimburse the Agent,
each Managing Agent and each Purchaser on demand for all costs, fees and
expenses incurred by the Agent, each Managing Agent and each Purchaser
(including, without limitation, the reasonable fees and expenses of counsels to
the Agent, each Managing Agent and each Purchaser) incurred in connection with
the preparation, execution and delivery of this Amendment.

          (d) Counterparts. This Amendment may be executed in any number of
counterparts, each such counterpart constituting an original and all of which
when taken together shall constitute one and the same instrument.

          (e) Severability. Any provision contained in this Amendment which is
held to be inoperative, unenforceable or invalid in any jurisdiction shall, as
to that jurisdiction, be inoperative, unenforceable or invalid without affecting
the remaining provisions of this Amendment in that jurisdiction or the
operation, enforceability or validity of such provision in any other
jurisdiction.

          (f) GOVERNING LAW. THIS AMENDMENT SHALL BE GOVERNED BY, AND CONSTRUED
AND INTERPRETED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF ILLINOIS.

          (g) WAIVER OF TRIAL BY JURY. TO THE EXTENT PERMITTED BY APPLICABLE
LAW, EACH OF THE PARTIES HERETO HEREBY IRREVOCABLY WAIVES ALL RIGHT OF TRIAL BY
JURY IN ANY ACTION, PROCEEDING OR COUNTERCLAIM ARISING OUT OF OR IN CONNECTION
WITH THIS AMENDMENT OR ANY MATTER ARISING HEREUNDER OR THEREUNDER.

                            (Signature Pages Follow)


                                        4

<PAGE>

          IN WITNESS WHEREOF, the undersigned have caused this Amendment to be
executed as of the date first above written.

                                        CARDINAL HEALTH FUNDING, LLC


                                        By: /s/: Ali Rizvi
                                            ------------------------------------
                                        Name: Ali Rizvi
                                        Title: President


                                        GRIFFIN CAPITAL, LLC


                                        By: /s/: Wayne Jeu
                                            ------------------------------------
                                        Name: Wayne Jeu
                                        Title: President


                                      S-1

<PAGE>

                                        PREFERRED RECEIVABLES FUNDING
                                        CORPORATION, as a Conduit


                                        By: /s/: Serri Gerner
                                            ------------------------------------
                                        Name: Sherri Gerner
                                        Title: Authorized Signer


                                        FALCON ASSET SECURITIZATION CORPORATION,
                                        as a Conduit


                                        By: /s/: Sherri Gerner
                                            ------------------------------------
                                        Name: Sherri Gerner
                                        Title: Authorized Signer


                                        JPMORGAN CHASE BANK, N.A. (successor by
                                        merger to Bank One, NA (Main Office
                                        Chicago)), as a Financial Institution
                                        and as Agent


                                        By: /s/: Sherri Gerner
                                            ------------------------------------
                                        Name: Sherri Gerner
                                        Title: Vice President



                                      S-2
<PAGE>

                                        LIBERTY STREET FUNDING CORP., as a
                                        Conduit


                                        By: /s/: Kevin Burns
                                            ------------------------------------
                                        Name:  Kevin Burns
                                        Title: Vice President



                                        THE BANK OF NOVA SCOTIA,
                                        as a Financial Institution and as a
                                        Managing Agent


                                        By: /s/: Michael Eden
                                            ------------------------------------
                                        Name:  Michael Eden
                                        Title: Director



                                      S-3