Document:

<PAGE>
                                                                   Exhibit 10.28

                           PENWEST PHARMACEUTICALS CO.

                          Executive Retention Agreement

     THIS EXECUTIVE RETENTION AGREEMENT by and between Penwest Pharmaceuticals
Co., a Washington corporation (the "Company"), and [__________] (the
"Executive") is made as of December [__], 2005 (the "Effective Date").

     WHEREAS, the Company recognizes that, as is the case with many
publicly-held corporations, the possibility of a change in control of the
Company exists and that such possibility, and the uncertainty and questions
which it may raise among key personnel, may result in the departure or
distraction of key personnel to the detriment of the Company and its
stockholders, and

     WHEREAS, the Company desires to reinforce and encourage the continued
employment and dedication of the Company's key personnel without distraction
from the possibility of a change in control of the Company and related events
and circumstances.

     NOW, THEREFORE, as an inducement for and in consideration of the Executive
remaining in its employ, the Company agrees that the Executive shall receive the
severance benefits set forth in this Agreement in the event the Executive's
employment with the Company is terminated under the circumstances described
below in connection with or subsequent to a Change in Control (as defined
below).

     1. Key Definitions.

     As used herein, the following terms shall have the following respective
meanings:

        1.1 "Change in Control" means an event or occurrence set forth in any
one or more of subsections (a) through (d) below (including an event or
occurrence that constitutes a Change in Control under one of such subsections
but is specifically exempted from another such subsection):

             (a) the acquisition by an individual, entity or group (within the
meaning of Section 13(d)(3) or 14(d)(2) of the 1934 Securities Exchange Act, as
amended) (a "Person") of beneficial ownership of any capital stock of the
Company if, after such acquisition, such Person beneficially owns (within the
meaning of Rule 13d-3 promulgated under the 1934 Securities Exchange Act, as
amended) 50% or more of the combined voting power of the then-outstanding
securities of the Company entitled to vote generally in the election of
directors (the "Outstanding Company Voting Securities"); provided, however, that
for purposes of this subsection (a), the following acquisitions shall not
constitute a Change in Control Event: (i) any acquisition directly from the
Company, (ii) any acquisition by any employee benefit plan (or related trust)
sponsored or maintained by the Company or any corporation controlled by the
Company or (iii) any acquisition by any corporation pursuant to a Business
Combination (as defined below) which complies with clauses (i) and (ii) of
subsection (c) of this definition; or

<PAGE>

             (b) such time as the Continuing Directors (as defined below) do not
constitute a majority of the Board of Directors of the Company (or, if
applicable, the Board of Directors of a successor corporation to the Company),
where the term "Continuing Director" means at any date a member of the Board (i)
who was a member of the Board on the date of execution of this Agreement or (ii)
who was nominated or elected subsequent to such date by at least a majority of
the directors who were Continuing Directors at the time of such nomination or
election or whose election to the Board was recommended or endorsed by at least
a majority of the directors who were Continuing Directors at the time of such
nomination or election; provided, however, that there shall be excluded from
this clause (ii) any individual whose initial assumption of office occurred as a
result of an actual or threatened election contest with respect to the election
or removal of directors or other actual or threatened solicitation of proxies or
consents, by or on behalf of a person other than the Board; or

             (c) the consummation of a merger, consolidation, reorganization,
recapitalization or share exchange involving the Company or a sale or other
disposition of all or substantially all of the assets of the Company (a
"Business Combination"), unless, immediately following such Business
Combination, each of the following two conditions is satisfied: (i) all or
substantially all of the individuals and entities who were the beneficial owners
of the Outstanding Company Voting Securities immediately prior to such Business
Combination beneficially own, directly or indirectly, more than 60% the combined
voting power of the then-outstanding securities entitled to vote generally in
the election of directors, of the resulting or acquiring corporation in such
Business Combination (which shall include, without limitation, a corporation
which as a result of such transaction owns the Company or substantially all of
the Company's assets either directly or through one or more subsidiaries) (such
resulting or acquiring corporation is referred to herein as the "Acquiring
Corporation") in substantially the same proportions as their ownership of the
Outstanding Company Voting Securities immediately prior to such Business
Combination and (ii) no Person (excluding any employee benefit plan (or related
trust) maintained or sponsored by the Company or by the Acquiring Corporation)
beneficially owns, directly or indirectly, 50% of the combined voting power of
the then-outstanding securities of the Acquiring Corporation entitled to vote
generally in the election of directors (except to the extent that such ownership
existed prior to the Business Combination); or

             (d) the liquidation or dissolution of the Company.

        1.2 "Change in Control Date" means the first date during the Term (as
defined in Section 2) on which a Change in Control occurs.

        1.3 "Cause" means willful misconduct by the Executive or willful failure
by the Executive to perform his/her responsibilities to the Company (including,
without limitation, breach by the Executive of any provision of any employment,
consulting, advisory, nondisclosure, non-competition or other similar agreement
between the Executive and the Company), as determined by the Company, which
determination shall be conclusive.

        1.4 "Good Reason" means the occurrence, without the Executive's written
consent, of any of the following events or circumstances:

                                       -2-

<PAGE>

             (a) the assignment to the Executive of duties inconsistent in any
material respect with the Executive's position (including status, offices,
titles and reporting requirements), authority or responsibilities in effect
immediately prior to the earliest to occur of (i) the Change in Control Date,
(ii) the date of the execution by the Company of the initial written agreement
or instrument providing for the Change in Control or (iii) the date of the
adoption by the Board of a resolution providing for the Change in Control (with
the earliest to occur of such dates referred to herein as the "Measurement
Date"), or any other action or omission by the Company which results in a
material diminution in such position, authority or responsibilities; or

             (b) a change by the Company in the location at which the Executive
performs his/her principal duties for the Company to a new location that is
outside a radius of 35 miles from the City of Danbury, Connecticut.

Notwithstanding the occurrence of any event or circumstance set forth in clauses
(a) or (b) above, such occurrence shall not be deemed to constitute Good Reason
if, prior to the Date of Termination specified in the Notice of Termination
(each as defined in Section 3.2(a)) given by the Executive in respect thereof,
such event or circumstance has been fully corrected and the Executive has been
reasonably compensated for any losses or damages resulting therefrom (provided
that such right of correction by the Company shall only apply to the first
Notice of Termination for Good Reason given by the Executive).

        1.5 "Disability" means a condition causing the Executive to be disabled
within the meaning of Section 22(e)(3) of the Internal Revenue Code of 1986, as
amended, and any regulations promulgated thereunder.

     2. Term of Agreement. This Agreement, and all rights and obligations of the
parties hereunder, shall take effect upon the Effective Date and shall expire
upon the first to occur of (a) the expiration of the Term (as defined below) if
a Change in Control has not occurred during the Term, (b) the termination of the
Executive's employment with the Company prior to the Change in Control Date, (c)
the date 12 months after the Change in Control Date, if the Executive is still
employed by the Company as of such later date, or (d) the fulfillment by the
Company of all of its obligations under this Agreement if the Executive's
employment with the Company terminates within 12 months following the Change in
Control Date. "Term" shall mean the period commencing as of the Effective Date
and continuing in effect through December 31, 2008.

     3. Employment Status; Termination Following Change in Control.

        3.1 Not an Employment Contract. The Executive acknowledges that this
Agreement does not constitute a contract of employment or impose on the Company
any obligation to retain the Executive as an employee and that this Agreement
does not prevent the Executive from terminating employment at any time. If the
Executive's employment with the Company terminates for any reason and
subsequently a Change in Control shall occur, the Executive shall not be
entitled to any benefits hereunder.

                                      -3-

<PAGE>

        3.2 Notice of Termination of Employment.

             (a) If the Change in Control Date occurs during the Term, any
termination of the Executive's employment by the Company or by the Executive
within 12 months following the Change in Control Date shall be communicated by a
written notice to the other party hereto (the "Notice of Termination"), given in
accordance with Section 7. Any Notice of Termination shall specify the effective
date of the employment termination (the "Date of Termination").

             (b) If the Executive seeks to terminate his/her employment with the
Company for Good Reason, then the Notice of Termination shall set forth in
reasonable detail the facts and circumstances claimed to provide a basis for
termination of the Executive's employment. The Date of Termination set forth in
such Notice of Termination shall not be less than 30 days or more than 60 days
after the date of delivery of such Notice of Termination. Any Notice of
Termination for Good Reason given by the Executive must be given within 30 days
of the occurrence of the event(s) or circumstance(s) which constitute(s) Good
Reason.

     4. Benefits to Executive. If the Change in Control Date occurs during the
Term and the Executive's employment is terminated by the Company (other than for
Cause, Disability or death) or by the Executive for Good Reason within 12 months
following the Change in Control Date, then the Executive shall be entitled to
the following benefits:

             (a) Compensation.

                     (i) The Company shall pay to the Executive in a lump sum in
cash within 30 days after the Date of Termination (A) the Executive's base
salary through the Date of Termination and (B) the amount of any compensation
previously deferred by the Executive (together with any accrued interest or
earnings thereon) and any accrued vacation pay, in each case to the extent not
previously paid (the sum of the amounts described in this subsection (i) shall
be hereinafter referred to as the "Accrued Obligations");

                     (ii) for a period (the "Payment Period") that is equal in
length to the sum of (A) 12 months and (B) two weeks for each full year during
which the Executive has been employed by the Company (which for this purpose
shall include employment at Penford Corporation or any subsidiary of Penford
Corporation [or at Edward Mendell and Co.] prior to the Executive's employment
with the Company) prior to the Date of Termination and that commences on the
Date of Termination, the Company shall continue to pay to the Executive, in
accordance with the Company's regular payroll practices, the Executive's base
salary, which base salary shall be deemed for this purpose to be the greater of
(1) the Executive's base salary as in effect on the Date of Termination and (2)
the Executive's base salary as in effect immediately prior to the Measurement
Date;

                     (iii) for the Payment Period, or for such longer period as
may be provided by the terms of the appropriate plan, program, practice or
policy, the Company shall continue to provide benefits to the Executive and the
Executive's family at least equal to those which would have been provided to
them if the Executive's employment had not been terminated, in accordance with
the applicable benefit plans and programs in which the Executive

                                      -4-

<PAGE>

participated immediately prior to the Measurement Date (e.g., life insurance or
medical, health and accident or disability plan) or, if more favorable to the
Executive and his/her family, in effect generally at any time thereafter with
respect to other peer executives of the Company and its affiliated companies;
provided, however, that if the Executive becomes reemployed with another
employer and is eligible to receive a particular type of benefits (e.g., health
insurance benefits) from such employer on terms at least as favorable to the
Executive and his/her family as those being provided by the Company, then the
Company shall no longer be required to provide those particular benefits to the
Executive and his/her family;

                     (iv) on or before January 15 of the calendar year following
the calendar year during which the Date of Termination occurs, the Company shall
pay to the Executive in a lump sum in cash an amount equal to the target bonus
for the Executive established in writing by the Board of Directors of the
Company for the calendar year in which the Change in Control occurs; and

                     (v) to the extent not previously paid or provided, the
Company shall timely pay or provide to the Executive any other amounts or
benefits required to be paid or provided or which the Executive is eligible to
receive following the Executive's termination of employment under any plan,
program, policy, practice, contract or agreement of the Company and its
affiliated companies.

             (b) Stock Acceleration. Each outstanding option to purchase shares
of Common Stock of the Company held by the Executive shall become immediately
exercisable in full and shares of Common Stock of the Company received upon
exercise of any options will no longer be subject to a right of repurchase by
the Company, and each outstanding restricted stock award shall be deemed to be
fully vested and will no longer be subject to a right of repurchase by the
Company.

     5. Tax Limitations. Notwithstanding anything in Section 4 to the contrary,

             (a) to the extent that (i) any amount to be paid or provided to the
Executive under Section 4 of this Agreement is subject to Section 409A of the
Internal Revenue Code of 1986, as amended (the "Code"), and (ii) upon the Date
of Termination the Executive is considered a specified employee within the
meaning of Section 409A of the Code, then such payment shall not be made until
the date (the "Payment Date") that is six months and one day after the Date of
Termination (the "Six Month Period"). All amounts which would otherwise have
been paid during the Six Month Period will be paid in a lump sum on the Payment
Date; and

             (b) to the extent that any amount to be paid or provided to the
Executive under Section 4 of this Agreement may be deemed to constitute "excess
parachute payments" (as defined in Section 280G(b)(i) of the Code) for the
Executive, such payments may be subject to reduction as provided by, and as
calculated in accordance with, the provisions set forth on Exhibit A hereto,
which provisions are incorporated herein by reference.

                                      -5-
<PAGE>

     6. Successors.

        6.1 Successor to Company. The Company shall require any successor
(whether direct or indirect, by purchase, merger, consolidation or otherwise) to
all or substantially all of the business or assets of the Company expressly to
assume and agree to perform this Agreement to the same extent that the Company
would be required to perform it if no such succession had taken place. Failure
of the Company to obtain an assumption of this Agreement at or prior to the
effectiveness of any succession shall be a breach of this Agreement and shall
constitute Good Reason if the Executive elects to terminate employment, except
that for purposes of implementing the foregoing, the date on which any such
succession becomes effective shall be deemed the Date of Termination. As used in
this Agreement, "Company" shall mean the Company as defined above and any
successor to its business or assets as aforesaid which assumes and agrees to
perform this Agreement, by operation of law or otherwise.

        6.2 Successor to Executive. This Agreement shall inure to the benefit of
and be enforceable by the Executive's personal or legal representatives,
executors, administrators, successors, heirs, distributees, devisees and
legatees. If the Executive should die while any amount would still be payable to
the Executive or his/her family hereunder if the Executive had continued to
live, all such amounts, unless otherwise provided herein, shall be paid in
accordance with the terms of this Agreement to the executors, personal
representatives or administrators of the Executive's estate.

     7. Notice. All notices, instructions and other communications given
hereunder or in connection herewith shall be in writing. Any such notice,
instruction or communication shall be sent either (i) by registered or certified
mail, return receipt requested, postage prepaid, or (ii) prepaid via a reputable
nationwide overnight courier service, in each case addressed to the Company, at
39 Old Ridgebury Road, Suite 11, Danbury, Connecticut 06810, and to the
Executive at the Executive's address indicated on the signature page of this
Agreement (or to such other address as either the Company or the Executive may
have furnished to the other in writing in accordance herewith). Any such notice,
instruction or communication shall be deemed to have been delivered five
business days after it is sent by registered or certified mail, return receipt
requested, postage prepaid, or one business day after it is sent via a reputable
nationwide overnight courier service. Either party may give any notice,
instruction or other communication hereunder using any other means, but no such
notice, instruction or other communication shall be deemed to have been duly
delivered unless and until it actually is received by the party for whom it is
intended.

     8. Miscellaneous.

        8.1 Employment by Subsidiary. For purposes of this Agreement, the
Executive's employment with the Company shall not be deemed to have terminated
solely as a result of the Executive continuing to be employed by a wholly-owned
subsidiary of the Company.

        8.2 Severability. The invalidity or unenforceability of any provision of
this Agreement shall not affect the validity or enforceability of any other
provision of this Agreement, which shall remain in full force and effect.

                                      -6-

<PAGE>

        8.3 Injunctive Relief. The Company and the Executive agree that any
breach of this Agreement by the Company is likely to cause the Executive
substantial and irrevocable damage and therefore, in the event of any such
breach, in addition to such other remedies which may be available, the Executive
shall have the right to specific performance and injunctive relief.

        8.4 Governing Law. The validity, interpretation, construction and
performance of this Agreement shall be governed by the internal
laws of the State of Washington, without regard to conflicts of law principles.

        8.5 Waivers. No waiver by the Executive at any time of any breach of, or
compliance with, any provision of this Agreement to be performed by the Company
shall be deemed a waiver of that or any other provision at any subsequent time.

        8.6 Counterparts. This Agreement may be executed in counterparts, each
of which shall be deemed to be an original but both of which together shall
constitute one and the same instrument.

        8.7 Tax Withholding. Any payments provided for hereunder shall be paid
net of any applicable tax withholding required under federal, state or local
law.

        8.8 Entire Agreement. This Agreement sets forth the entire agreement of
the parties hereto in respect of the subject matter contained herein and
supersedes all prior agreements, promises, covenants, arrangements,
communications, representations or warranties, whether oral or written, by any
officer, employee or representative of any party hereto in respect of the
subject matter contained herein; and any prior agreement of the parties hereto
in respect of the subject matter contained herein is hereby terminated and
cancelled.

        8.9 Amendments. This Agreement may be amended or modified only by a
written instrument executed by both the Company and the Executive.

        8.10 Executive's Acknowledgements. The Executive acknowledges that
he/she: (a) has read this Agreement; (b) has been represented in the
preparation, negotiation, and execution of this Agreement by legal counsel of
the Executive's own choice or has voluntarily declined to seek such counsel; (c)
understands the terms and consequences of this Agreement; and (d) understands
that the law firm of Wilmer Cutler Pickering Hale and Dorr LLP is acting as
counsel to the Company in connection with this Agreement and is not acting as
counsel for the Executive.

                                       -7-
<PAGE>

     IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of
the day and year first set forth above.

                                      PENWEST PHARMACEUTICALS CO.

                                      By:
                                         ---------------------------------------
                                      Name: Rolf H. Henel
                                      Title: Chairman of the Compensation
                                             Committee of the Board of Directors

                                      EXECUTIVE:

                                      ------------------------------------------
                                      Name:

                                      Address:

                                      ------------------------------------------

                                      ------------------------------------------

                                      -8-

<PAGE>

                                    EXHIBIT A

                    Adjustments to Payments for Section 280G

             (a) Notwithstanding any other provision of this Agreement, except
as set forth in paragraph (b) below, in the event that the Company undergoes a
"Change in Ownership or Control" (as defined below), the Company shall not be
obligated to provide to the Executive a portion of any "Contingent Compensation
Payments" (as defined below) that the Executive would otherwise be entitled to
receive under Section 4(a) of this Agreement to the extent necessary to
eliminate any "excess parachute payments" (as defined in Section 280G(b)(1) of
the Code) for the Executive; provided, however, if the complete elimination of
the payments the Executive is otherwise entitled to receive under Section 4(a)
is not sufficient to eliminate any "excess parachute payments", then no amount
shall be eliminated. For purposes of this Exhibit A, the Contingent Compensation
Payments so eliminated shall be referred to as the "Eliminated Payments" and the
aggregate amount of the Contingent Compensation Payments so eliminated shall be
referred to as the "Eliminated Amount."

             (b) Notwithstanding the provisions of paragraph (a), no such
reduction in Contingent Compensation Payments shall be made if (i) the
Eliminated Amount (computed without regard to this sentence) exceeds (ii) 110%
of the aggregate present value (determined in accordance with Treasury
Regulation Section 1.280G-1) of the amount of any additional taxes that would be
incurred by the Executive if the Eliminated Payments (determined without regard
to this sentence) were paid to his/her (including, state and federal income
taxes on the Eliminated Payments, the excise tax imposed by Section 4999 of the
Code payable with respect to the Contingent Compensation Payments). The override
of such reduction in Contingent Compensation Payments pursuant to this paragraph
(b) shall be referred to as an "Override." For purpose of this paragraph, if any
federal or state income taxes would be attributable to the receipt of any
Eliminated Payment, the amount of such taxes shall be computed by multiplying
the amount of the Eliminated Payment by the maximum combined federal and state
income tax rate provided by law.

             (c) For purposes of this Exhibit A the following terms shall have
the following respective meanings:

                     (i) "Change in Ownership or Control" shall mean a change in
the ownership or effective control of the Company or in the ownership of a
substantial portion of the assets of the Company determined in accordance with
Section 280G(b)(2) of the Code.

                     (ii) "Contingent Compensation Payment" shall mean any
payment (or benefit) in the nature of compensation that is made or made
available (under this Agreement or otherwise) to a "disqualified individual" (as
defined in Section 280G(c) of the Code) and that is contingent (within the
meaning of Section 280G(b)(2)(A)(i) of the Code) on a Change in Ownership or
Control of the Company.

             (d) Any payments or other benefits otherwise due to the Executive
following a Change in Ownership or Control that could reasonably be
characterized (as

                                      A-1

<PAGE>

determined by the Company) as Contingent Compensation Payments (the "Potential
Payments") shall not be made until the dates provided for in this paragraph (d).
Within 30 days after each date on which the Executive first becomes entitled to
receive (whether or not then due) a Contingent Compensation Payment relating to
such Change in Ownership or Control, the Company shall determine and notify the
Executive (with reasonable detail regarding the basis for its determinations)
(i) which Potential Payments constitute Contingent Compensation Payments, (ii)
the Eliminated Amount and (iii) whether the Override is applicable. Within 30
days after delivery of such notice to the Executive, the Executive shall deliver
a response to the Company (the "Executive Response") stating either (A) that
he/she agrees with the Company's determination pursuant to the preceding
sentence, in which case he/she shall indicate, if applicable, which Contingent
Compensation Payments, or portions thereof (the aggregate amount of which,
determined in accordance with Treasury Regulation Section 1.280G-1, shall be
equal to the Eliminated Amount), shall be treated as Eliminated Payments or (B)
that he/she disagrees with such determination, in which case he/she shall set
forth (i) which Potential Payments should be characterized as Contingent
Compensation Payments, (ii) the Eliminated Amount, (iii) whether the Override is
applicable, and (iv) which (if any) Contingent Compensation Payments, or
portions thereof (the aggregate amount of which, determined in accordance with
Treasury Regulation Section 1.280G-1, shall be equal to the Eliminated Amount,
if any), shall be treated as Eliminated Payments. In the event that the
Executive fails to deliver an Executive Response on or before the required date,
the Company's initial determination shall be final and the Contingent
Compensation Payments that shall be treated as Eliminated Payments shall be
determined by the Company in its absolute discretion. If the Executive states in
the Executive Response that he/she agrees with the Company's determination, the
Company shall make the Potential Payments to the Executive within three business
days following delivery to the Company of the Executive Response (except for any
Potential Payments which are not due to be made until after such date, which
Potential Payments shall be made on the date on which they are due). If the
Executive states in the Executive Response that he/she disagrees with the
Company's determination, then, for a period of 60 days following delivery of the
Executive Response, the Executive and the Company shall use good faith efforts
to resolve such dispute. If such dispute is not resolved within such 60-day
period, such dispute shall be settled exclusively by arbitration in Boston,
Massachusetts, in accordance with the rules of the American Arbitration
Association then in effect. Judgment may be entered on the arbitrator's award in
any court having jurisdiction. The Company shall, within three business days
following delivery to the Company of the Executive Response, make to the
Executive those Potential Payments as to which there is no dispute between the
Company and the Executive regarding whether they should be made (except for any
such Potential Payments which are not due to be made until after such date,
which Potential Payments shall be made on the date on which they are due). The
balance of the Potential Payments shall be made within three business days
following the resolution of such dispute.

             Subject to the limitations contained in paragraphs (a) and (b)
hereof, the amount of any payments to be made to the Executive following the
resolution of such dispute shall be increased by amount of the accrued interest
thereon computed at the prime rate announced from time to time by The Wall
Street Journal, compounded monthly from the date that such payments originally
were due.

                                      A-2<PAGE>
                                                                   EXHIBIT 10.29

                           PENWEST PHARMACEUTICALS CO.

                   Summary of Executive Officer Bonus Program

     Penwest Pharmaceuticals Co. ("the Company") maintains a bonus program for
its executive officers that is administered by the Compensation Committee (the
"Committee") of the Board of Directors of the Company. This program provides for
an annual cash payout dependent on achievement by both the executive and the
Company of predetermined short-term operating goals and longer-term strategic
objectives. These goals are weighted as follows: 75% of the target payout is
based upon achieving the Company goals, and 25% is based upon achieving
individual goals. Our President's target bonus is based 100% upon achieving
Company goals. Individual incentive compensation target awards are set annually
by the Compensation Committee. These target awards are determined by salary
grade and are subject to an adjustment based on individual performance, and
typically range from 25%-30% of the executive's salary.

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00099-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00099-of-00352.parquet"}]]