Document:

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                                                                    EXHIBIT 4.28

                          LEINER HEALTH PRODUCTS INC.
                             901 EAST 233RD STREET
                            CARSON, CALIFORNIA 90745

                                                               February 23, 2001

The Bank Of Nova Scotia,
 as the U.S. Agent
One Liberty Plaza
New York, New York 10006

The Bank of Nova Scotia,
 as the Canadian Agent
44 King Street West -- 14th Floor
Toronto, Ontario
Canada, M5H 1H1

Each of the Lenders party to the
 Credit Agreement referred to below

                           AMENDMENT TO WAIVER LETTER

Gentlemen and Ladies:

         We refer to (a) the Amended and Restated Credit Agreement, dated as of
May 15, 1998 (as further amended, supplemented, amended and restated or
otherwise modified prior to the date hereof, the "CREDIT AGREEMENT"), among
Leiner Health Products Inc., a Delaware corporation (the "U.S. BORROWER"), Vita
Health Products Inc., a Manitoba corporation (the "CANADIAN BORROWER", and
together with the U.S. Borrower, the "BORROWERS"), the various financial
institutions as are or may become parties thereto which extend a Commitment
under the U.S. Facility (collectively, the "U.S. LENDERS"), the various
financial institutions as are or may become parties thereto which extend a
Commitment under the Canadian Facility (collectively, the "CANADIAN LENDERS"),
and together with the U.S. Lenders, the "LENDERS"), The Bank of Nova Scotia
("SCOTIABANK") as agent for the U.S. Lenders under the U.S. Facility (in such
capacity, the "U.S. AGENT"), Scotiabank, as agent for the Canadian Lenders under
the Canadian Facility (in such capacity, the "CANADIAN AGENT", and together with
the U.S. Agent, collectively, the "AGENTS"), Merrill Lynch Capital Corporation,
as Documentation Agent, and Salomon Brothers Holding Company Inc., as
Syndication Agent, and (b) the Waiver Letter, dated February 13, 2001 (the
"WAIVER LETTER"), from the Borrowers to the Agents and the Lenders. Unless
otherwise defined in this amendment letter (this "AMENDMENT") or the context
otherwise requires, terms

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used in this Amendment have the meanings provided in the Credit Agreement or
the Waiver Letter, as applicable.

         The Borrowers hereby request that the Lenders amend the Waiver Letter
by inserting the following at the end of the first sentence in the second
paragraph of the Waiver Letter:

         " as well as any Default or Event of Default under clause (b) of
         Section 9.2.13 of the Credit Agreement (referred to as the "FEE
         DEFAULT") resulting from the payment to North Castle and/or its
         Affiliates on January 2, 2001 of a fee pursuant to the terms of the
         Management Services Agreement in the amount of $750,000 and the
         subsequent expense reimbursement in the amount of $35,000, and any
         Default or Event of Default under Section 9.1.7 of the Credit
         Agreement or under any other Loan Document (referred to collectively
         as the "COLLATERAL DEFAULTS") resulting from the failure of the
         Borrowers to deliver, or cause to be delivered, to the Agents any
         Guaranties, Pledge Agreements, Security Agreements and/or any other
         documents, certificates or instruments, or do any other act,
         required under such Section or under such Loan Documents with
         respect to the acquisition of additional Subsidiaries and additional
         personal property, in each case to the extent such Subsidiaries and
         personal property are set forth in the perfection certificate to be
         delivered to the Agents on February 16, 2001 pursuant to this Waiver
         Letter".

         The Lenders also hereby waive, for so long as the Waiver Letter is in
effect, any breach of the representation and warranty made by the Borrowers in
the Waiver Letter that no Default (other than those specifically referenced in
the Waiver Letter) had occurred and was continuing, insofar as such statement is
untrue with respect to the Fee Default and the Collateral Defaults.

         In consideration of this Amendment, the Borrowers agree that they shall
(a) on the date hereof, make, or cause to be made, a voluntary prepayment of the
outstanding Revolving Loans in an amount equal to $785,000 in accordance with
clause (a) of Section 5.1.1 of the Credit Agreement, to be applied PRO RATA
among outstanding U.S. Revolving Loans and outstanding Canadian Revolving Loans
(it being understood that no reduction in either the U.S. Revolving Loan
Commitment or the Canadian Revolving Loan Commitment shall result from such
prepayment), and (b) no later than February 28, 2001, deliver to the Agents all
documents and instruments necessary to comply with the provisions of Section
9.1.7 of the Credit Agreement and with each other Loan Document with respect to
the Collateral Defaults. Failure to comply with each of these covenants shall
constitute an immediate Event of Default.

         In order to induce the Lenders to enter into this Amendment, the
Borrowers hereby represent and warrant that, after giving effect to this
Amendment and the effectiveness of the Waiver Letter, all of the statements set
forth in Section 7.2.1 of the Credit Agreement are true and correct.

         This Amendment shall become effective upon the receipt by the U.S.
Agent of (i) executed counterparts hereof by the Borrowers and the Required
Lenders (ii) $785,000 to be

                                      -2-
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applied as a prepayment of the Revolving Loans as set forth above and (iii)
an agreement in form and substance satisfactory to it executed and delivered
by an authorized officer of North Castle pursuant to which North Castle will
irrevocably commit to return (or cause to be returned) to the U.S. Borrower
by no later than March 30, 2001 the $750,000 management fee paid by the U.S.
Borrower on January 2, 2001 and the subsequent $35,000 expense reimbursement,
in each case referred to above. This Amendment may be executed by the parties
hereto in several counterparts, each of which shall be an original and all of
which shall constitute together but one and the same agreement. Delivery of
an executed counterpart of a signature page to this Amendment by facsimile
shall be effective as delivery of a manually executed counterpart of this
Amendment.

         THIS AMENDMENT SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH,
THE INTERNAL LAWS OF THE STATE OF NEW YORK. Except as expressly waived by this
Amendment, all of the terms and provisions of the Waiver Letter, the Credit
Agreement and the other Loan Documents shall remain in full force and effect.
This Amendment is a Loan Document executed pursuant to the Credit Agreement and
shall be construed and administered in accordance with all of the terms and
provisions of the Credit Agreement.

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         If you are in agreement with the foregoing terms, kindly execute this
Amendment in the space provided below and deliver to the Agents an executed
counterpart of this Amendment.

                                               Very truly yours,

                                               LEINER HEALTH PRODUCTS INC.

                                               By:
                                                   -----------------------------
                                                   Title:

                                               VITA HEALTH PRODUCTS INC.

                                               By:
                                                   -----------------------------
                                                   Title:

                                      -4-
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AGREED TO AND ACCEPTED
AS OF THE DATE FIRST
ABOVE WRITTEN:

THE BANK OF NOVA SCOTIA,
as the U.S. Agent, the Canadian Agent
and a Lender

By:
    ---------------------------------
    Title

-------------------------------------
[NAME OF LENDER]

By:
    ---------------------------------
    Title

                                      -5-<PAGE>

                                                                     EXHIBIT 4.4

                             MODIFICATION AGREEMENT

         THIS MODIFICATION AGREEMENT made as of the 28th day of August, 2000 by
and among CHEQUEMATE INTERNATIONAL, INC., d/b/a C-3D DIGITAL, INC., a Utah
corporation (the "COMPANY"), and CROOKS HOLLOW ROAD, LLC, a Cayman Islands
limited liability company ("Purchaser").

                              W I T N E S S E T H:

         WHEREAS, the parties hereto have previously executed and delivered the
Transaction Documents, as more particularly defined in the Securities Purchase
Agreement dated May 10, 2000 (a copy of which has been filed with the Securities
and Exchange Commission as an Exhibit to the Company's Form 8-K dated May 26,
2000; and

         WHEREAS, the Purchaser desires to modify certain terms and provisions
of the Securities Purchase Agreement; and

         WHEREAS, the Company has determined that certain of the representations
made by the Company and set forth in the transaction documents were
inadvertently in error and did not fully set forth, and/or incorrectly set forth
certain facts about the Company and its outstanding contractual obligations,
including specifically, but not by way of limitation, representations as to the
number of options or warrants to acquire shares outstanding, the nature and
extent of contractual obligations to register shares of stock in the Company
either outstanding or which the Company is contractually obligated to issue,
under the Securities Act of 1933 (hereinafter collectively referred to as the
"inaccuracies"); and

         WHEREAS, the Purchaser is willing to waive its rights with respect to
and as a result of the inaccuracies, in exchange for the Company's agreement to
the modifications to the transaction documents as set forth in this modification
agreement;

         NOW , THEREFORE, it is agreed by and between the parties as follows:

         1.       Section 1 of the Securities Purchase Agreement is hereby
amended to read as follows:

                  "1.      PURCHASE OF COMMON STOCK. Subject to the terms and
                           conditions of this Agreement, the Company agrees to
                           issue and sell, and Purchaser agrees to acquire,
                           seven hundred eighty-eight thousand seven hundred
                           thirty-two (788,732) fully paid and non-assessable
                           shares (the "INITIAL SHARES") at $3.55 per share, in
                           exchange for Purchaser's payment to

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                           the Company of aggregate consideration of Two
                           Million Eight Hundred Thousand Dollars
                           ($2,800,000) (the "PURCHASE PRICE")."

         2.       Section 2.2(c) of the Securities Purchase Agreement is hereby
amended to read as follows:

                           "(c) "INITIAL CLOSING PRICE" shall mean 80% of the
                           average Closing Bid Price for the ten (10)
                           consecutive Business Days immediately prior to the
                           date of the Initial Closing (i.e. $3.55).

         3.       Section 2.3 of the Securities Purchase Agreement is hereby
amended to read as follows:

                           "2.3 FIRST REPRICING PERIOD. The "FIRST REPRICING
                           PERIOD" shall commence on the later of (a) the day
                           that is sixty (60) days after the Closing Date, or
                           (b) the Effective Date, and end twenty (20) trading
                           days after such date. If the lowest average Closing
                           Bid Price for any five (5) Business Days (not
                           necessarily consecutive) during the First Repricing
                           Period (the "FIRST REPRICING PRICE"), is not equal to
                           or greater than 120% of the Initial Closing Price,
                           then one-third (1/3) of the Initial Shares shall be
                           repriced (the "FIRST REPRICED SHARES"). The Company
                           shall issue to Purchaser the number of additional
                           Shares as determined according to the following
                           formula:

((1.20 x Initial Closing Price) - First Repricing Price) x (# of the First
Repriced Shares) / First Repricing Price.

         4. The number of Warrants to be issued pursuant to the Securities
Purchase Agreement, as modified by this Modification Agreement is 157,746, and
the Warrants initially issued and the additional Warrants issuable pursuant to
this Modification Agreement, shall be deemed to be an exercise price of $5.32.

         5. Paragraph 5(b) of the Registration Rights Agreement is hereby
amended to read as follows:

                           "(b)     The Company shall not on or after the date
                                    of this Agreement, enter into any agreement
                                    with respect to its securities that is
                                    inconsistent with the rights granted to
                                    Investor in this Agreement or otherwise
                                    conflicts with the provisions hereof. Except
                                    as otherwise provided for in SCHEDULE 5(b),
                                    the Company has not previously entered into
                                    any agreement granting any registration
                                    rights with respect to any of its securities
                                    to any person. Except as otherwise provided
                                    for in this SECTION 5, and without limiting
                                    the generality of the foregoing, without the
                                    written consent of Investor, the Company
                                    shall not grant to any person the right to
                                    request the Company to

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                                    Register any securities of the Company
                                    under the Securities Act unless the
                                    rights so granted are subject in all
                                    respects to the prior rights in full of
                                    Investor set forth herein, and are not
                                    otherwise in conflict or inconsistent
                                    with the provisions of this Agreement and
                                    the other Transaction Documents. It shall
                                    be a condition of the inclusion of each
                                    of the existing registration rights set
                                    forth in items numbered 1 and 2 on
                                    Schedule 5(b) in the Registration
                                    Statement, that the Company use its best
                                    efforts to cause the holder of such
                                    securities to execute an agreement in
                                    form acceptable to counsel for the
                                    Investor, agreeing not to publicly sell
                                    or otherwise transfer any of their
                                    registrable securities until thirty (30)
                                    days after the conclusion of the Final
                                    Repricing Period pursuant to the
                                    Securities Purchase Agreement."

         6. Notwithstanding PARA 8.3 and 8.4 of the Securities Purchase
Agreement, the Company is granted the right to sell to one accredited
investor up to $15,000,000 of Common Stock during the next eighteen (18)
months at a price equal to or greater than 85% of the Market Price of the
Common Stock.

         7. In consideration for the Company's execution of the Modification
Agreement, Purchaser hereby waives its rights with respect to, and as a result
of, the inaccuracies.

         8. Except as specifically set forth herein, nothing contained herein
shall in any way be deemed to effect or modify the warranties, rights and
obligations of the respective parties as set forth in the Transaction Documents.

         9. As hereby modified and amended, the Transaction Documents remain in
full force and effect.

         10. The Company undertakes, within ten (10) Business Days, to file any
necessary amendment to the Registration Statement currently filed with the
Securities and Exchange Commission in respect of the resale of the Shares.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]

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         IN WITNESS WHEREOF, the parties have executed this agreement as of the
date first above written.

                                  CHEQUEMATE INTERNATIONAL, INC.,
                                  d/b/a C-3D DIGITAL, INC.

                                  By: ________________________________
                                           Name: ________________________
                                           Title: _________________________

                                  CROOKS HOLLOW ROAD, LLC

                                  By: _________________________________
                                           Name: _________________________
                                           Title: _________________________

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                                  SCHEDULE 5(b)

         These are all the agreements which existed as of the execution of the
transaction documents in May, and all the agreement which exist today, whereby
the Company is contractually obligated to register shares of its stock.

         Crooks Hollow Road, LLC, by the modification agreement to which this is
attached, consents only to the registrations described in the sections below
numbered 1, 2, and 3.

         1. Issuance to United Business Systems (for purchase of hotel
pay-per-view manufacturer & patents) of $940,000 worth of stock, at the market,
to be registered. Recently renegotiated to 200,000 shares to be registered, and
440,000 restricted shares.

         2. Scott Applegate / CapitalPlus and Cinemaworks - $122,300 worth of
stock, recently agreed to be 61,150 shares, to be registered, for Scott
Applegate, and $236,000 worth of stock, recently agreed to be 55,000 registered
shares, and up to 40,000 restricted shares, for Cinema Internet Networks, Inc.,
issued as part of a transaction to acquire service rights over 2650
free-to-guest rooms (less those rooms in hotels in Canada) in various hotels.

         3. Duchess Capital Partners - 83,333 shares to be registered, for
investment banking services.

         4. Convertible line of credit promissory notes. $3,000,000 in debt is
to be converted into 1,300,000 shares of common stock at $1.00 per share, and
the other $1,700,000 to be converted to preferred stock, not convertible, after
shareholder approval of amendment to Articles to allow issuance of preferred
stock. The common stock has piggyback registration rights.

         5. Coast Communications (hotel movie business). Agreement to issue up
to 230,500 shares, with registration rights, in satisfaction of $461,000 in
debt.

         6. Trimark Pictures - 100,000 shares, to be issued as registered
shares, as part of a contract for motion picture digitization and conversion
from 2D to 3D.

         7. Hawatmeh, Iehab - 62,500 shares to be issued in settlement of claim
for breach of contract, with shares to be registered.

         8. i-O Display Systems, LLC - 105,263 shares (contract for $500,000
worth of viewing systems and 3D movies; shares to be issued and registered on an
S-3, and valued at $4.75) This is the company that makes the preferred wireless
shutter glasses, and also owns rights to a few low budget 3D movies.

         9. Full Moon Universe - 80,000 worth of common stock to be issued at
the market. (balance owed under last Summer's license fee for "Creeps", a 3D
movie.)

         10. James O'Brien / Optimum Source - 2,728 shares with registration
rights. (fee due

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from marketing / promotional services).

         11. Hudson Consulting Group - 25,000 shares with registration rights.
(amended fee due for consulting services).

         12. Academy Entertainment - $250,000 worth of restricted stock
w/piggyback registration rights. (contract for provision of public domain motion
pictures, for conversion to 3D).

         13. Hotel Movie Express (King Farms) - 31,250 (post-split) shares with
registration rights.

         14. Issuance of S-8 stock under the Company's current Consultant Stock
Compensation Plan, as per past issuances and future issuances under the plan.

         15. Stock options outstanding to ten key employees, plus directors and
former employees, for 1,534,334 shares, of which options for 910,000 shares will
require shareholder approval, together with registration rights.

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