<PAGE>   1
                                                                     EXHIBIT 2.6


                          REGISTRATION RIGHTS AGREEMENT
                          -----------------------------


         THIS REGISTRATION RIGHTS AGREEMENT (the "Agreement") is made and
entered into as of February 11, 1998 between KENDLE INTERNATIONAL INC., an Ohio
corporation (the "Company"), and TZUO-YAN LEE ("TYL"), JEAN C. LEE ("JCL"), and
MICHAEL MINOR ("Minor"), CONWAY LEE ("CL"), STEVEN LEE ("SL"), JCL as Trustee
under a Trust dated March 8, 1991 fbo JENNIFER LEE ("JL") and CITICORP
TRUST-SOUTH DAKOTA as trustee under an agreement dated May 15, 1997 made by TYL
(the "Trust") (TYL, JCL, Minor, CL, SL, JL and the Trust collectively, the
"Investors").


                                R E C I T A L S:
                                ----------------

         A. This Agreement is made pursuant to a Stock Purchase Agreement dated
as of February 11, 1998 (the "Purchase Agreement") among the Company, the
Investors and certain other shareholders of ACER/EXCEL, Inc. and pursuant to
which the Investors will acquire shares of common stock of the Company ("Common
Stock").

         B. The shares the Investors acquire will not be registered under the
Securities Act of 1933, as amended ("Securities Act").

         C. In order to induce the Investors to enter into the Purchase
Agreement, the Company has agreed to provide to the Investors the registration
rights set forth in this Agreement to enable the Investors to dispose of such
shares freely in the circumstances set forth below. The execution and delivery
of this Agreement is a condition to the Closing under the Purchase Agreement.

         IN WITNESS WHEREOF, in consideration of the premises and the mutual
covenants and agreements contained hereinafter, the parties hereby agree as
follows:

         1.       SECURITIES SUBJECT TO THIS AGREEMENT
                  ------------------------------------

                  (A)      DEFINITIONS.
                           -----------

                           (i)         The term "Registrable Securities" means
(x) Nine Hundred Eighty Seven Thousand Five Hundred Seventy Four (987,574)
shares of Common Stock issuable to the Investors pursuant to the Purchase
Agreement; and (y) any other securities of the Company issued in exchange for,
or in a distribution with respect to, the securities referred to in (x) above.

                           (ii)        The term "person" means a corporation, an
association, a limited liability company, a partnership, a trust, an
organization, a business, a government or political agency or other entity or an
individual.


<PAGE>   2


                                      - 2 -


                           (iii)       Capitalized terms not defined in this
Agreement shall have the respective meanings therefor set forth in the Purchase
Agreement.

                  (B) REGISTRABLE SECURITIES. For the purposes of this
Agreement, securities subject to this Agreement will cease to be Registrable
Securities when: (i) they have been effectively registered under the Securities
Act and disposed of pursuant to such effective registration statement; (ii) they
are sold pursuant to Rule 144 under the Securities Act or any similar rule then
in effect ("Rule 144"); or (iii) they have been otherwise transferred and new
certificates or other evidences of ownership for them (not bearing a legend to
the effect that such securities may not be sold or transferred in the absence of
registration or an exemption therefrom under the Securities Act, and not subject
to any stop transfer order or other restriction on transfer) have been delivered
by the Company.

         2.       PIGGYBACK REGISTRATION
                  ----------------------
                  (A) RIGHT TO PIGGYBACK. If at any time the Company proposes to
file a registration statement under the Securities Act (except with respect to
registration statements on Forms S-4 or S-8, or any other form not available for
registering the Registrable Securities for sale to the public generally) with
respect to an offering for its own account or for the account of another person
(other than the holders of Registrable Securities in their capacity as such) of
shares of Common Stock (a "Proposed Registration"), then the Company shall in
each case give written notice of such proposed filing to the Investors at least
forty five (45) days before the anticipated filing date, and shall, subject to
Section 2(b), include in such registration statement such amount of Registrable
Securities as the Investors may request within twenty (20) days of the receipt
of such notice. The Company shall register ("Piggyback Registration") such
Registrable Securities on the same terms and subject to the same conditions
applicable to the registration in the Proposed Registration of securities to be
sold by the Company or the persons selling under such Proposed Registration.

                  (B) PRIORITY ON PIGGYBACK REGISTRATIONS. If the managing
underwriter or underwriters of such offering delivers a written opinion to the
Investors that the total dollar amount which they and any other persons intend
to include in such offering is reasonably likely to materially and adversely
affect the success or offering price of such offering, then the amount of
securities to be offered for the accounts of holders of Registrable Securities
shall be reduced and the securities to be included in such Proposed Registration
shall be prioritized as follows: first, the securities which the Company
proposes to sell; and second, the Registrable Securities of the Investors and
the other securities requested to be included in such registration, pro rata in
accordance with the aggregate principal amount of such securities among the
holders of securities requested (including the Investors) to be included in such
registration.

                  (C) Nothing herein shall be construed as limiting or otherwise
interfering with the right of the Company to withdraw or abandon in its sole
discretion any registration statement filed by it in connection with a Piggyback
Registration notwithstanding the inclusion of Registrable Securities.



<PAGE>   3


                                      - 3 -

         3.       COVENANTS OF THE INVESTORS.
                  ---------------------------

                  Any request for registration made by the Investors pursuant to
this Agreement shall express the Investors' present intention to offer such
Registrable Securities for distribution and contain an undertaking to provide
all such information and materials and take all such actions and execute all
such documents as may be required in order to permit the Company to comply with
all applicable requirements of the Securities and Exchange Commission
("Commission") and to obtain acceleration of the effective date of the
Registration Statement.

         4.       COVENANTS OF THE COMPANY.
                  -------------------------

                  So long as the Company is under an obligation pursuant to the
provisions of this Agreement, the Company shall, upon a request by the Investors
to register any Registrable Securities under this Agreement, use its best
efforts to effect the registration and to further the sale of such Registrable
Securities in accordance with the intended method of disposition as quickly as
practicable, and in connection with any such request the Company shall, as
expeditiously as possible:

                  (a) prepare and file with the Commission such amendments and
supplements to such Registration Statement and the prospectus used in connection
therewith as may be necessary to keep such Registration Statement effective for
such period as shall be necessary to complete the marketing of the Registrable
Securities included therein, but in no event more than one hundred twenty (120)
days after the date the shares may first be sold;

                  (b) furnish to the Investors and the managing underwriter or
underwriters, if any, without charge such number of copies of a prospectus,
including, without limitation, a preliminary prospectus, in conformity with the
requirements of the Securities Act, and any amendment or supplement thereto and
such other documents as the Investors or the managing underwriter may reasonably
request in order to facilitate the public sale or other disposition of such
Registrable Securities;

                  (c) make every reasonable effort to obtain the withdrawal of
any order suspending the effectiveness of the Registration Statement at the
earliest possible moment;

                  (d) cooperate with the Investors and the managing underwriter
or underwriters, if any, to facilitate the timely preparation and delivery of
certificates (not bearing any restrictive legends) representing securities to be
sold under the registration statement, and enable such securities to be in such
denominations and registered in such names as the managing underwriter or
underwriters, if any, or the Investors may request;

                  (e) use its best efforts to register or qualify, not later
than the effective date of any Registration Statement filed pursuant to this
Agreement, the Registrable Securities covered by such Registration Statement
under the securities or Blue Sky laws of such jurisdictions within the United
States as the Investors or managing underwriter or underwriters may reasonably
request and do any and all other acts or things which may be necessary or
advisable to enable the Investors to consummate the public sale or other
disposition in such jurisdiction of such


<PAGE>   4


                                      - 4 -

Registrable Securities; PROVIDED, HOWEVER, that in connection with any such
registration or qualification, the Company shall not be obligated to file a
general consent to service of process to qualify to do business as a foreign
corporation or otherwise to subject itself to taxation in connection with such
qualification or compliance.

                  (f) promptly notify the Investors at any time when a
prospectus relating to the Registrable Securities being distributed is required
to be delivered under the Securities Act, of the happening of any event as a
result of which the prospectus included in such Registration Statement, as then
in effect, includes an untrue statement of material fact or omits to state a
material fact required to be stated therein or necessary to make the statements
therein not misleading in the light of the circumstances then existing and, at
the request of the Investors, promptly prepare, file with the Commission and
furnish to the Investors a reasonable number of copies of a supplement to, or an
amendment of, such prospectus as may be necessary so that, as thereafter
delivered to the purchasers of such Registrable Securities, such prospectus
shall not include an untrue statement of a material fact or omit to state a
material fact required to be stated therein or necessary to make the statements
therein not misleading in light of the circumstances then existing;

                  (g) make available for inspection, during normal business
hours, by the Investors, the managing underwriter or underwriters, if any, and
any attorney, accountant, or other agent retained by the Investors or managing
underwriter or underwriters (collectively, the "Inspectors"), all financial and
other records, pertinent corporate documents, and properties of the Company and
its subsidiaries (collectively, the "Records") as shall be reasonably necessary
to enable them to exercise their due diligence responsibility, and cause the
Company's officers, directors, and employees to supply all information
reasonably requested by any such Inspector in connection with such registration
statement;

                  (h) use its best efforts to furnish, at the request of the
Investors or any managing underwriter or underwriters of any distribution of the
Registrable Securities, (i) an opinion of legal counsel to the Company, covering
such matters as are typically covered by opinions of issuer's counsel in
underwritten offerings under the Securities Act; and (ii) a letter dated such
date from the independent public accountants retained by the Company, addressed
to the underwriters, if any, and to the Company in such form and covering such
matters of the type customarily covered by "cold comfort" letters delivered by
such public accountants;

                  (i) Further, at any time after the Investors has held
Registrable Securities for two (2) years, upon written request by the Investors,
Company shall remove from the Certificates of Registrable Securities held by the
Investors any legends referencing to compliance with the 1933 Act or regulations
thereunder and attach an opinion letter from U.S. counsel selected by the
Investors prepared at the expense of the Company (not to exceed $1,000.00) to
the effect that the legends can be removed from such certificate.

                  (j) The Company covenants that it will file the reports
required to be filed by it under the 1933 Act and the Securities Exchange Act of
1934 and the rules and regulations adopted by the SEC thereunder (or, if Company
is not required to file such reports, it will, upon the request of the Investors
of Registrable Securities, make publicly available other


<PAGE>   5


                                      - 5 -

nonconfidential information so long as necessary to permit sales under Rule 144
under the 1933 Act), and it will take such other action as any Investor of
Registrable Securities may reasonably request, all to the extent required from
time to time to enable such Investor to sell Registrable Securities without
registration under the 1933 Act within the limitation of the exemptions provided
by (a) Rule 144 under the 1933 Act, as such Rule may be amended from time to
time, or (b) any similar rule or regulation hereafter adopted by the SEC. Upon
the request of any Investor of Registrable Securities, Company will deliver to
such Investor a written statement as to whether it has complied with such
requirements.

                  (k) The Company agrees to cooperate fully with the Investors
in connection with a proposed sale by either such Investors under Rule 144 or
any other exemption under the United States securities laws or the securities
laws of any state thereof, including, without limitation, providing a letter of
instruction to its transfer agent and registrar authorizing the same to accept
(i) an opinion letter from counsel to the Company prepared at the expense of the
Company (not to exceed $1,000.00) to the effect that such exemption is available
and the shares are transferable without legends or, (ii) in the absence of such
opinion being delivered on a timely basis, to accept an opinion to the same
effect of U.S. counsel selected by the Investors. Delivery of such letter of
instruction shall be a condition to the closing of the transaction contemplated
hereby; and

                  (l) enter into an agreement with the underwriters for such
offering in which the Company shall provide indemnities similar to those
described in Section 6 hereof to the underwriters and in which the Company shall
make the usual representations and warranties made by issuers of equity
securities to underwriters in secondary distributions.

         5.       COSTS AND EXPENSES.
                  -------------------

                  The Company will pay all expenses of any registrations made
pursuant to this Agreement (other than underwriting discounts and commissions
which shall be the responsibility of the selling Investors), including but not
limited to all registration and filing fees, transfer taxes, fees and expenses
of compliance with securities or blue sky laws (including reasonable fees and
disbursements of Company's counsel in connection with blue sky qualifications of
the Registrable Securities), rating agency fees, printing expenses, messenger
and delivery expenses, costs of insurance, fees of transfer agents and
registrars, internal expenses of the Company, the fees and expenses incurred in
connection with the listing of the securities to be registered in accordance
with Section 4, fees of the National Association of Securities Dealers, Inc.,
securities acts liability insurance (if the Company elects to obtain such
insurance), the fees and disbursements of counsel for the Company and all
independent certified public accountants (including the expenses of any annual
audit, special audit, or "cold comfort" and "bringdown" letters required by or
incident to such performance), the fees and expenses of any special experts
retained by the Company in connection with such registration and fees and
expenses of other persons retained by the Company, the reasonable and customary
fees and expenses of any underwriter (but not including any underwriting
discounts or commissions attributable to the sale of Registrable Securities by
the selling Investors), and the reasonable fees and disbursements of counsel
retained by the underwriter (all such expenses being herein called "Registration
Expenses"). The Investors shall


<PAGE>   6


                                      - 6 -

also be solely responsible for the reasonable fees and disbursements of counsel
retained by the Investors, and any reasonable out-of-pocket expenses of the
Investors.

         6.       INDEMNIFICATION
                  ---------------

                  (A) INDEMNIFICATION BY COMPANY. The Company agrees to
indemnify and to save and hold harmless, to the full extent permitted by law,
each holder of Registrable Securities, its officers, directors and partners and
partners of partners, and each person who controls such holder (within the
meaning of the Securities Act or the Securities Exchange Act of 1934, as amended
(the "Exchange Act")) from and against any and all losses, claims, damages,
liabilities, and expenses arising out of or based on any untrue or alleged
untrue statement of material fact contained in any registration statement or
prospectus relating to the Registrable Securities or in any amendment or
supplement thereto or in any preliminary prospectus, or arising out of or based
upon any omission or alleged omission to state therein a material fact required
to be stated therein or necessary to make the statements therein not misleading,
except insofar as the same arise out of reliance upon any untrue statement or
omission furnished to the Company by such holder expressly for use therein and
the Company shall not be required to indemnify any holder of Registrable
Securities for damages caused by such holder's continuing to use a prospectus or
any supplement or amendment thereto with respect to which such holder has
received a notice pursuant to Section 4(f) hereof and has not received a notice
of the amendment or supplementation of such prospectus, as contemplated in
Section 4(f).

                  (B) INDEMNIFICATION BY HOLDER OF REGISTRABLE SECURITIES. In
connection with any registration statement in which a holder of Registrable
Securities is participating, each such holder will furnish to the Company in
writing such information and affidavits with respect to such holder as the
Company reasonably requests for use in connection with any such registration
statement or prospectus and agrees to indemnify, to the extent permitted by law,
each of the Company and, if it is an underwritten offering, the underwriters,
the Company's directors and officers, and each person who controls the Company
(within the meaning of the Securities Act) against any losses, claims, damages,
liabilities, and expenses arising out of or based on any untrue or alleged
untrue statement of a material fact or any omission or alleged omission of a
material fact required to be stated in the registration statement or prospectus
or any amendment thereof or supplement thereto or necessary to make the
statements therein not misleading, to the extent, but only to the extent, that
such untrue statement, or omission is made in reliance upon and in conformity
with information with respect to such holder furnished in writing to the Company
by such holder specifically for use in such registration statement or prospectus
or amendment or supplement thereto; PROVIDED, HOWEVER, that the liability of any
such holder under this Section 6(b) shall be limited to the proportion of any
such losses, claims, damages, liabilities and expenses which is equal to the
proportion that the public offering price of securities sold by such holder
under such registration statement bears to the total public offering price of
all securities sold thereunder, and shall in no event exceed the net proceeds of
the sale of Registrable Securities being sold pursuant to said registration
statement or prospectus by such holder; and provided further that no such holder
shall be required to indemnify the Company for damages caused by any person,
including the Company, continuing to use a prospectus (prior to its amendment or
supplementation) more than three business days after the Company has received a
notice by such holder of any such untrue statement or omission contained in such
prospectus.


<PAGE>   7


                                      - 7 -

                  (C) CONDUCT OF INDEMNIFICATION PROCEEDINGS. If any action or
proceeding (including any governmental investigation) is brought or asserted
against any selling holder of Registrable Securities (or its officers, directors
or agents) or any person controlling any such holder, in respect of which
indemnity now is sought from the Company, the Company shall assume the defense
thereof, including the employment of counsel reasonably satisfactory to such
holder, and shall pay all expenses in connection therewith. Such holder or any
controlling person of such holder shall have the right to employ separate
counsel in any such action and to participate in the defense thereof, but the
fees and expenses of such counsel shall be at the expense of such holder or such
controlling person, unless (i) the Company has agreed to pay such fees and
expenses or (ii) the named parties to any such action or proceeding (including
any impleaded parties) include both such holder or such controlling person and
the Company, and such holder or such controlling person shall have been advised
by counsel that there be one or more legal defenses available to such holder or
such controlling person which are different from or additional to those
available to the Company (in which case, if such holder or such controlling
person notifies the Company in writing that it elects to employ separate counsel
at the expense of the Company, the Company shall not have the right to assume
the defense of such action or proceeding on behalf of such holder or such
controlling person, being understood, however, that the Company shall not, in
connection with any one such action or proceeding or separate but substantially
similar or related actions or proceedings in the same jurisdiction arising out
of the same general allegations or circumstances, be liable for the fees and
expenses or more than one separate firm of attorneys (together with appropriate
local counsel) at any time for the holders and such controlling persons, which
firm shall be designated in writing by a majority of such holders). The Company
shall not be liable for any settlement of any such action or proceeding effected
without the Company's written consent (but such consent shall not be
unreasonably withheld), but if any action or proceeding is settled with the
Company's consent, or if there be a final judgment for the plaintiff in any such
action or proceeding, the Company agrees to indemnify and hold harmless such
holder and such controlling person from and against any loss or liability (to
the extent stated above) by reason of such settlement or judgment. The Company
will not consent to entry of any judgment or enter into any settlement which
does not include as an unconditional term thereof the giving by the claimant or
plaintiff to such indemnified party of a release from all liability in respect
of such action, claim or litigation.

                  (D) CONTRIBUTION. If the indemnification provided for in this
section is unavailable to the Company, the selling holder or holders of
Registrable Securities or the underwriters in an underwritten offering and such
underwriters' officers, directors and controlling persons (the "Securities
Professionals") in respect of any losses, claims, damages, liabilities, expenses
or judgments referred to herein, then each such indemnifying party, in lieu of
indemnifying such indemnified party, shall contribute the amount paid or payable
by such indemnified party as a result of such losses, claims, damages,
liabilities, expenses and judgments (i) as between the Company and such holders
on the one hand and the Securities Professionals on the other, in such
proportion as is appropriate to reflect the relative benefits received by the
Company and such holders on the one hand and the Securities Professionals on the
other from the offering of the Registrable Securities, or if such allocation is
not permitted by applicable law, in such proportion as is appropriate to reflect
not only such relative benefits but also the relative fault of the Company and
such holders on the one hand and of the Securities Professionals on the other in
connection with the statements or omissions which resulted in such losses,
claims,


<PAGE>   8


                                      - 8 -

damages, liabilities, expenses or judgment as well as any other relevant
equitable considerations; and (ii) as between the Company on the one hand and
each such holder on the other, in such proportion as is appropriate to reflect
the relative fault of the Company and of each such holder in connection with
such statements or omissions, as well as any other relevant equitable
considerations. The relative benefits received by the Company and such holders
on the one hand and the Securities Professionals on the other shall be deemed to
be in the same proportion as the total proceeds from the offering (net of
underwriting discounts and commissions but before deducting expenses) received
by the Company and such holders bear to the total underwriting discounts and
commissions received by the Securities Professionals, in each case as set forth
in the table on the cover page of the prospectus. The relative fault of the
Company on the one hand and of each such holder on the other shall be determined
by reference to, among other things, whether the untrue or alleged untrue
statement of a material fact or the omission or alleged omission to state a
material fact relates to information supplied by such party, and the parties'
relative intent, knowledge, access to information and opportunity to correct or
prevent such statement or omission.

         The Company and such holders agree that it would not be just and
equitable if contribution pursuant to this Section 6(d) were determined by pro
rata allocation (even if such holders were treated as one entity for such
purpose) or by any other method of allocation which does not take account of the
equitable considerations referred to in the immediately preceding paragraph. The
amount paid or payable by an indemnified party as a result of the losses,
claims, damages, liabilities, expenses or judgments referred to in the
immediately preceding paragraph shall be deemed to include, subject to the
limitations set forth above, any legal or other expenses reasonably incurred by
such indemnified party in connection with investigating or defending any such
action or claim. Notwithstanding the provisions of this Section 7(d), no
Securities Professional shall be required to contribute any amount in excess of
the amount by which the total price at which the Registrable Securities of such
holder were offered to the public exceeds the amount of any damages which such
holder has otherwise been required to pay by reason of such untrue or alleged
untrue statement or omission or alleged omission. No person guilty of fraudulent
misrepresentation (within the meaning of Section 11(f) of the Securities Act)
shall be entitled to contribution from any person who was not guilty of such
fraudulent misrepresentation.

         7.       MISCELLANEOUS
                  -------------

                  (A) RULE 144. The Company hereby agrees to maintain the
effectiveness of the registration statement of such Registrable Securities until
all Registrable Securities may be freely traded pursuant to the 1933 Act, any
applicable state securities laws or an exemption therefrom permitting
unrestricted resale. The Company further covenants that, after the Company shall
have filed an initial public offering, it will duly file in a timely manner any
and all reports required to be filed by it under the Securities Act and the
Exchange Act from time to time and that it will use its best efforts to continue
to satisfy the conditions set forth in Rule 144 and elsewhere under the
Securities Act all to the extent required from time to time to enable such
holders to sell Registrable Securities pursuant to the registration statement
referred to above (or without registration) under the Securities Act pursuant to
Rule 144.



<PAGE>   9


                                      - 9 -

                  (B) REPRESENTATIONS AND WARRANTIES OF THE COMPANY. The Company
represents and warrants to the Investors that the execution, delivery and
performance of this Agreement by the Company have been duly authorized by all
requisite corporate action and will not violate any provision of law, any order
of any court or other agency of government, the Charter or by-laws of the
Company, or any provision of any indenture, agreement or other instrument to
which it or any of its properties or assets is bound, or conflict with, result
in a breach of or constitute (with due notice or lapse of time or both) a
default under any such indenture, agreement or other instrument, or result in
the creation or imposition of any lien, charge or encumbrance of any nature
whatsoever upon any of the properties or assets of the Company. This Agreement
has been duly executed and delivered by the Company and constitutes the legal,
valid and binding obligation of the Company, enforceable in accordance with its
terms.

                  (C) REMEDIES. Each holder of Registrable Securities, in
addition to being entitled to specific performance of its rights under this
Agreement, shall be entitled to all other remedies available at law or in
equity. The Company agrees that monetary damages would not be adequate
compensation for any loss incurred by reason of a breach by it of the provisions
of this Agreement and hereby agrees to waive the defense in any action for
specific performance that a remedy at law would be adequate.

                  (D) AMENDMENTS AND WAIVERS. Except as otherwise provided
herein, the provisions of this Agreement may not be amended, restated, modified,
or supplemented, and waivers or consents to departures from the provisions
hereof may not be given, unless the Company has obtained the written consent of
the holders of a majority of the Registrable Securities then entitled to the
benefits of this Agreement.

                  (E) SUCCESSORS AND ASSIGNS. This Agreement shall inure to the
benefit of and be binding upon the successors and assigns of each of the
parties; PROVIDED, HOWEVER, that only in the event that the Investors transfer
any Registrable Securities by gift, bequest, transfer by intestacy or operation
of law to any person other than the Company shall such successor holder succeed
to all of the rights and obligations of the Investors hereunder.

                  (F) NOTICES. Any notice, request, instruction, or other
document to be given hereunder by any party to another shall be in writing,
shall be delivered personally or by overnight courier service or sent by
certified mail, postage prepaid and return receipt requested, or by facsimile
transmission (receipt confirmed) to the Company at Suite 700, Carew Tower,
Cincinnati, Ohio 45202, with a copy to Edward E. Steiner, Esq., Keating,
Muething & Klekamp, P.L.L., 1800 Provident Tower, One East Fourth Street,
Cincinnati, Ohio 45202 (Facsimile No. 513/579-6957) and to the Investors as set
forth in Schedule 1.1 (or to such other address as any subsequent holder of
Registrable Securities or any other party to whom notice is to be given may
provide in a written notice to the other parties) and (except when delivered
personally or by facsimile) shall be deemed received three days after such
notice is sent.

                  (G) COUNTERPARTS. This Agreement may be executed in any number
of counterparts and by the parties hereto in separate counterparts, each of
which when so executed


<PAGE>   10


                                     - 10 -

shall be deemed to be an original and all of which taken together shall
constitute one and the same agreement.

                  (H) HEADINGS. The headings in this Agreement are for
convenience of reference only and shall not limit or otherwise affect the
meaning hereof.

                  (I) SEVERABILITY. In the event that any one or more of the
provisions contained herein, or any application of any provision contained
herein, shall be held invalid, illegal, or unenforceable, the validity,
legality, and enforceability of any such provision in every other respect and of
the remaining provisions contained herein shall not be affected or impaired
thereby.

                  (J) ENTIRE AGREEMENT; SUPERSESSION OF PRIOR AGREEMENTS. This
Agreement, together with the Purchase Agreement and the other agreements
contemplated thereby, are intended by the parties as a final expression of their
agreement and intended to be a complete and exclusive statement of the agreement
and understanding of the parties hereto in respect of the subject matter
contained herein and therein. There are no restrictions, promises, warranties,
or undertakings, other than those set forth or referred to herein and therein.
This Agreement, together with the Purchase Agreement and the other agreements
contemplated therein, supersede all prior agreements and understandings among
the parties with respect to such subject matter.

                  (K) ATTORNEYS' FEES. In any action or proceeding brought to
enforce any provision of this Agreement or where any provision hereof is validly
asserted as a defense, the successful party shall be entitled to recover
reasonable attorneys' fees and expenses in addition to any other available
remedy.

                  (L) GOVERNING LAW. This Agreement shall be governed by and
construed in accordance with the laws of the State of Ohio, U.S.A., applicable
to contracts made and to be performed wholly within that State without regard to
principles of conflicts of law.



                     (remainder of page intentionally blank)


<PAGE>   11


                                     - 11 -

         IN WITNESS WHEREOF, the parties have executed this Stock Registration
Rights Agreement as of the date first written above.

                                     KENDLE INTERNATIONAL INC.


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


                                     ------------------------------------------
                                     TZUO-YAN LEE


                                     ------------------------------------------
                                     JEAN C. LEE


                                     ------------------------------------------
                                     MICHAEL MINOR


                                     ------------------------------------------
                                     CONWAY LEE


                                     ------------------------------------------
                                     STEVEN LEE


                                     ------------------------------------------
                                     JEAN C. LEE as Trustee under a Trust dated
                                      March 8, 1991 fbo JENNIFER LEE



                                     ------------------------------------------
                                     CITICORP TRUST-SOUTH DAKOTA as Trustee
                                      under an agreement dated May 15, 1997




<PAGE>   12



                         SCHEDULE 1.1 - STOCK OWNERSHIP


                               NUMBER OF SHARES OF
INVESTORS                          COMMON STOCK            ADDRESS
---------                          ------------            -------

Tzuo-Yan Lee                           17,511        244 Ridgewood Avenue
                                                     Glen Ridge, NJ  07028

Jean C. Lee                            15,666        244 Ridgewood Avenue
                                                     Glen Ridge, NJ  07028


Michael Minor                           4,933        31 Mayflower Drive
                                                     Red Bank, NJ  07701

Conway Lee                              3,200        244 Ridgewood Avenue
                                                     Glen Ridge, NJ  07028

Steven Lee                              3,200        244 Ridgewood Avenue
                                                     Glen Ridge, NJ  07028

Jean C. Lee, as Trustee under           3,200        244 Ridgewood Avenue
a Trust dated March 8, 1991 fbo                      Glen Ridge, NJ  07028
Jennifer Lee

Citicorp Trust - South Dakota           1,666        701 East 60th Street North
as Trustee under an Agreement                        P.O. Box 6008
dated May 15, 1997                                   Sioux Falls, SD  57117
                                                     Attn: Robin Moug Stephens
                                                     Senior Trust Officer