<PAGE>



Exhibit 10.20(c-1)


                               AMENDMENT NO. 1 TO
                            KENDLE INTERNATIONAL INC.
                   1997 STOCK OPTION AND STOCK INCENTIVE PLAN



This Amendment No. 1 is made and effective as of March 23, 1999 to the
Kendle International Inc. 1997 Stock Option and Stock Incentive Plan (the
"Plan") under the following circumstances:

         A.   Kendle International Inc. (the "Company") desires to amend the
              Plan to clarify permitted tax withholding thereunder; and

         B.   On March 23, 1999, the Board of Directors approved amending the
              Plan, in accordance with the terms set forth below.


NOW, THEREFORE, the Plan shall be amended as follows:

1.       Definitions. All capitalized terms herein, unless specifically defined
         in this Amendment, shall have the meanings given to them in the Plan.

2.       Amendment. Section 13.3 is hereby amended by adding the following
         sentence to the end of such section: "Shares cannot be withheld in
         excess of the minimum number required for tax withholding."

3.       Affirmation. Except as amended hereby, the Plan remains unchanged and
         in full force and effect.


IN WITNESS WHEREOF, this Amendment has been executed as of March 23, 1999.



                                      KENDLE INTERNATIONAL INC.



                                      /s/ Paul F. Ritter
                                      ------------------------------
                                      Paul F. Ritter, Secretary



                                       1
<PAGE>














Exhibit 10.20(c-3)
                               AMENDMENT NO. 3 TO
                            KENDLE INTERNATIONAL INC.
                   1997 STOCK OPTION AND STOCK INCENTIVE PLAN



This Amendment No. 3 is made and effective as of February 22, 2001 to the Kendle
International Inc. 1997 Stock Option and Stock Incentive Plan, as amended, (the
"Plan") under the following circumstances:

         A.   Kendle International Inc. (the "Company") desires to amend the
              Plan to adjust the number of options awarded to non-employee
              directors thereunder; and

         B.   On February 22, 2001, the Board of Directors approved amending the
              Plan, in accordance with the terms set forth below.


NOW, THEREFORE, the Plan shall be amended as follows:

1.       Definitions. All capitalized terms used herein, unless specifically
         defined in this Amendment, shall have the meanings given to them in the
         Plan.

2.       Amendment. Section 6.4(a)(iv) is hereby amended and restated in its
         entirety to read as follows: "(iv) An Option for such number of Shares,
         if any, as determined annually by the Board upon each annual election
         as a director thereafter."

3.       Affirmation. Except as amended hereby, the Plan remains unchanged and
         in full force and effect.


IN WITNESS WHEREOF, this Amendment has been executed as of February 22, 2001.



                                     KENDLE INTERNATIONAL INC.



                                     /s/ Paul F. Ritter
                                     ---------------------------
                                     Paul F. Ritter, Secretary


                                       2
<PAGE>




Exhibit 10.20(e-1)

                            KENDLE INTERNATIONAL INC.
                        1998 EMPLOYEE STOCK PURCHASE PLAN
                               AMENDMENT NUMBER 1


         The Kendle International Inc. 1998 Employee Stock Purchase Plan (the
"Plan"), as adopted by the Board of Directors of Kendle International Inc.
("Kendle") on March 24, 1998 and by Kendle's shareholders on May 21, 1998 is
hereby amended in the following respects:

         1.   The reference to "24" contained in the first paragraph of Section
              2 of the Plan is corrected to refer to "20".

         2.   The second paragraph of Section 2 of the Plan is corrected in its
              entirety to read as follows:


              An Eligible Employee may not be granted the right to purchase
              Common Shares for any Purchase Period if, immediately after such
              right is granted, such employee would own 5% or more of the total
              combined voting power or value of all classes of stock of Kendle
              International Inc. or any subsidiary thereof (determined for
              purposes hereof after applying the rules of Section 424(d) of the
              Internal Revenue Code in calculating the employee's stock
              ownership and by treating stock which the employee may purchase
              under outstanding options or rights as stock owned by the
              employee). Also, an Eligible employee may not purchase Common
              Shares hereunder if and to the extent, for any calendar year, such
              employee's aggregate rights to purchase stock for such calendar
              year under all employee stock purchase plans of Kendle would
              exceed $25,000 of the fair market value of such stock (with such
              fair market value determined in the manner provided by Section
              423(b)(8) of the Internal Revenue Code).


         3.   Section 13.3 is added to the Plan, to immediately follow Section
              13.2 and shall read in its entirety as follows:

              Notwithstanding any other provision contained within this Plan,
              the maximum number of Common Shares which may be purchased by an
              Eligible employee during a Purchase Period shall be limited to not
              more than 5,000 shares.

         Except as modified in items 1, 2 and 3 above, all other provisions of
the Plan shall remain unchanged. This Amendment Number 1 to the Plan shall
become effective only upon the approval (by written consent or otherwise) of
Kendle's Board of Directors or an authorized subcommittee thereof.


                                       3
<PAGE>




Exhibit 10.20(e-2)


                            KENDLE INTERNATIONAL INC.
                        1998 EMPLOYEE STOCK PURCHASE PLAN
                               AMENDMENT NUMBER 2


         The Kendle International Inc. 1998 Employee Stock Purchase Plan (the
"Plan"), as adopted by the Board of Directors of Kendle International Inc.
("Kendle") on March 24, 1998 and by Kendle's shareholders on May 21, 1998, as
amended, is hereby amended further in the following respects:


         4.   The second sentence of the first paragraph of Section 2 is hereby
              amended in its entirety to read as follows:

              "An Eligible Employee is one who has been continuously employed
              by Kendle for at least one month."


         Except as modified above, all other provisions of the Plan, as
previously amended, shall remain unchanged. This Amendment Number 2 to the Plan
shall become effective only upon the approval (by written consent or otherwise)
of Kendle's Board of Directors or an authorized subcommittee thereof.



                                       4
<PAGE>




Exhibit 10.20(e-3)
                            KENDLE INTERNATIONAL INC.
                        1998 EMPLOYEE STOCK PURCHASE PLAN
                               AMENDMENT NUMBER 3


         This Amendment No. 3 to the Kendle International Inc. 1998 Employee
Stock Purchase Plan (the "Plan"), as adopted by the Board of Directors of Kendle
International Inc. ("Kendle") on March 24, 1998 and by Kendle's shareholders on
May 21, 1998, as amended, is hereby amended further in the following respects:


         5.   Definitions. All capitalized terms herein, unless specifically
              defined in this Amendment No. 3, shall have the meanings given to
              them in the Plan.

         6.   Amendment. The second paragraph of Section 3 is hereby superseded
              and replaced in its entirety by the following new paragraph:

              "This Plan shall remain in effect until the later of: (a) the time
              when all Common Shares issuable under the Plan have been issued,
              or (b) June 30, 2007."


         7.   Condition. This Amendment No. 3 to the Plan shall become effective
              only upon the approval (by written consent or otherwise) of
              Kendle's Board of Directors or an authorized committee or
              subcommittee thereof.

         8.   Affirmation. Except as modified above, all other provisions of the
              Plan, as previously amended, shall remain unchanged and in full
              force and effect.


IN WITNESS WHEREOF, this Amendment No. 3 has been executed as of February 2003.




                                         KENDLE INTERNATIONAL INC.




                                         By: /s/ Paul F. Ritter
                                            ---------------------

                                         Paul F. Ritter, Secretary



                                       5
<PAGE>





Exhibit 10.20(f-1)
                               AMENDMENT NO. 1 TO
                            KENDLE INTERNATIONAL INC.
                        1997 DIRECTORS' COMPENSATION PLAN



This Amendment No. 1 is made and effective as of August 11, 2000 to the 1997
Directors' Compensation Plan (the "Plan") under the following circumstances:

         A.   Kendle International Inc. (the "Company") desires to amend the
              Plan to increase the compensation to be issued thereunder; and

         B.   On August 11, 2000, the Board of Directors of the Company approved
              amending the Plan as set forth below.

NOW, THEREFORE, the Plan is amended as follows:

1.       Definitions. All capitalized terms herein, unless specifically defined
         in this Amendment, shall have the meanings given to them in the Plan.

2.       Amendment. Section 1 is hereby amended and restated to read in its
         entirety as follows:

              1. Compensation of Non-Employee Directors.

              All directors who are not employees of the Company shall be paid
              the following fees as provided in Section 2 below:

              a. A retainer of $3,000 for each meeting of the Board of Directors
                 attended; and

              b. A retainer of $1500 for each committee meeting attended.

1.       Affirmation.  Except as amended hereby, the Plan remains unchanged
         and in full force and effect.


IN WITNESS WHEREOF, this Amendment has been executed as of August 11, 2000.



                                          KENDLE INTERNATIONAL INC.



                                          /s/ Paul F. Ritter
                                          ---------------------------
                                          Paul F. Ritter, Secretary





                                       6
<PAGE>






Exhibit 10.20(f-2)

                               AMENDMENT NO. 2 TO
                            KENDLE INTERNATIONAL INC.
                        1997 DIRECTORS' COMPENSATION PLAN

This Amendment No. 2 is made and effective as of November 8, 2001 to the 1997
Directors' Compensation Plan, as amended (the "Plan"), under the following
circumstances:

         A.   Kendle International Inc. (the "Company") desires to amend the
              Plan to provide that non-employee directors may elect to receive
              up to fifty percent (50%) of the compensation payable thereunder
              in the form of cash; and

         B.   On November 8, 2001, the Board of Directors of the Company
              approved amending the Plan as set forth below.

NOW, THEREFORE, the Plan is amended as follows:

1.       Definitions. All capitalized terms used herein, unless specifically
         defined in this Amendment, shall have the meanings given to them in the
         Plan.

2.       Amendment.

              2.1          The caption paragraph of the Plan is hereby amended
                           and restated to read in its entirety as follows:

                           "This Directors' Compensation Plan has been adopted
                           by the Board of Directors of Kendle International
                           Inc. in order to align further the interests of the
                           Company's non-employee Directors with the interests
                           of shareholders by providing that their compensation
                           be paid, at least in part, through the issuance of
                           Common Shares of the Company."

              2.2          Section 2 of the Plan is hereby amended and restated
                           to read in its entirety as follows:

                           "2. PAYMENT TERMS

                           The meeting fees set forth in Section 1 above shall
                           be paid by the Company quarterly, in arrears, as soon
                           as practicable following the end of each quarter in
                           the form of Company Common Shares. Notwithstanding
                           the foregoing, a Director may elect to receive not
                           more than fifty percent (50%) of his/her compensation
                           to be paid hereunder in the form of cash. Such
                           election may be made only once per year, in advance,
                           and will be effective for the entire ensuing calendar
                           year.

                           The number of Common Shares to be issued shall be
                           determined by dividing the dollar amount of the fee
                           by the average of the per share Fair Market Value of
                           the Common Shares, as defined in Section 3, for the
                           ten trading days prior to the end of each quarter.
                           The resulting number shall then be rounded up to the
                           nearest share."

3.       Affirmation. Except as amended hereby, the Plan remains unchanged and
         in full force and effect.


IN WITNESS WHEREOF, this Amendment has been executed as of November 8, 2001.


                                        KENDLE INTERNATIONAL INC.

                                        /s/ Paul F. Ritter
                                        ---------------------------
                                        Paul F. Ritter, Secretary


                                       7