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                                                                   Exhibit 10.37

                       SERVICE AGREEMENTS WITH THE COMPANY

                      Service Agreement dated June 30, 1997
                 between with the Company and Mr. A.J. Cataldo




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                          EXECUTIVE OFFICER'S AGREEMENT

AN AGREEMENT made the 30th day of June 1997.

                                     BETWEEN

SENETEK PLC ("the Company") whose registered office is situated at 23 Palace
        Street, London SW1E 5HW, and

ANTHONY J. CATALDO of 63 North East Village Road, Concord, New Hampshire, 03301,
        USA ("the Executive").

WHEREAS the Company employs the Executive and the Executive serves the Company
        as the Company's Chairman of the Board of Directors and Chief Executive
        Officer pursuant to an Employment Agreement dated September 1, 1996
        ("the Existing Agreement") the Company and the Executive have agreed
        that the Existing Agreement shall be superseded in its entirety by this
        present Agreement of June 30, 1997, save that the option entitlement
        referred to in Clause 4 of the Existing Agreement shall remain in full
        force and effect.

NOW IT IS HEREBY AGREED that the Company shall employ the Executive and the
        Executive shall serve the Company as its Chairman of the Board of
        Directors and Chief Executive Officer reporting to the Company's Board
        of Directors with effect from June 1, 1997, upon and subject to the
        following terms and conditions:

1.      In this Agreement:

        (a)     the expression "the Board" means the Board of Directors for the
                time being of the Company.

        (b)     the expression "Subsidiary" means a subsidiary (as defined by
                Section 736 of the United Kingdom Companies Act 1985) for the
                time being of the Company.

        (c)     the expression "associated Company" means in relation to a
                company, its holding company (as defined by Section 736 of the
                United Kingdom Companies Act 1985) or any subsidiary of such
                holding company.

        (d)     the expression "the Group" means the Company and any
                subsidiaries of the Company.

        (e)     any reference to a statutory provision shall be deemed to
                include a reference to any statutory modification or
                re-enactment of the same.

2.      The employment shall be for a fixed period from June 1, 1997 to December
        31, 1999, and shall be subject to termination as hereinafter provided.

3.      (a)     The remuneration of the Executive shall be a salary (which shall
                accrue from day to day) at a rate of U.S.$250,000 per annum.
                Such salary shall be payable by 



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                equal monthly installments on the last day of every month and
                the first of such payments shall be due with effect from June
                30, 1997. The over-all remuneration (which term shall also
                include the cost to the Company of the total benefits enjoyed by
                the Executive) of the Executive shall be subject to review by
                the Company's Compensation Committee during the first quarter of
                each of the Company's fiscal years and the Compensation
                Committee shall decide what, if any, increase in the said
                over-all remuneration shall apply to the fiscal year in
                question.

        (b)     The Executive shall be entitled to and the Company shall effect
                payment of a health insurance policy for the benefit of the
                Executive, his spouse and his immediate family with Blue
                Cross/BUPA or a similar organization offering equivalent
                benefits. Such policy to be reviewed and sanctioned by the
                Company prior to each renewal date.

        (c)     The Executive shall be entitled to participate in the Company's
                Number 1 Executive Share Option Scheme for Employees ("the
                Option Scheme") under the terms and conditions of that scheme
                and shall be granted Options to subscribe for shares of the
                Company in accordance with the Schedule attached hereto. The
                grant of options listed on the said Schedule shall be in
                addition to the Executive's existing option entitlements, the
                rights to which shall remain in full force and effect. The
                Company hereby confirms that the Board has undertaken to
                exercise its discretion in favor of the Executive under Clause
                4. (1), (2) (a) & (b), and (4)(a) & (b), of the Option Scheme in
                connection with the Executive's right of conversion of his
                option entitlements into shares and the subsequent sale of the
                said shares subject only to (i) the termination of this
                Executive Agreement for cause as provided in Clause 6(b) below,
                and (ii) compliance with the relevant provisions of Rule 144 of
                the U.S. Securities Act of 1933, as amended.

        (d)     During the period of his employment, the Company will effect
                insurance cover on the life of the Executive in the sum of
                U.S.$500,000, expressed in favor of the Executive's dependants
                or as he may direct, on a term basis only. Such cover to be
                reviewed and sanctioned by the Company prior to each renewal
                date.

        (e)     The Company shall be entitled to require the Executive to work
                at such locations or offices of the Company, its subsidiaries or
                associated companies as it may direct.

        (f)     There are no fixed hours of work.

4.      The Company will provide the Executive with a car allowance of
        U.S.$1,000 per month, from which the Executive shall meet all costs
        relating to his use of whatever vehicle he may decide to utilise.

5.      The Company shall reimburse the Executive all reasonable hotel and other
        expenses wholly and exclusively incurred by him in or about the
        performance of his duties.



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6.      (a)     In the case of illness of the Executive or other cause
                incapacitating him from attending to his duties, the Executive
                shall continue to be paid during such absence provided that if
                such absence shall aggregate in all thirteen weeks in any
                twenty-six consecutive weeks, the Company may terminate the
                employment of the Executive hereunder by notice given on the
                date not more than fourteen days after the end of the last of
                such thirteen weeks. In this event the Executive shall be paid 6
                months salary in lieu of notice.

        (b)     Termination for cause. The Company shall not be obligated to pay
                or provide for any compensation or other benefits to the
                Executive or give effect to any rights for the exercise of
                options for any period after termination for cause. For the
                purposes of this Agreement, "cause" shall mean termination for
                personal dishonesty, wilful misconduct, breach of fiduciary duty
                involving personal profit, wilful material violation of any law,
                rule or regulation or material breach of any provision of this
                Agreement.

7.      The Executive shall (in addition to the usual public and bank holidays)
        be entitled to four weeks holiday in each year to be taken at a time or
        times convenient to the Company. Any vacation not taken during the 12
        month period to December 31 of each year shall lapse and shall not be
        carried forward. No payment shall be made in lieu of vacation time not
        taken.

8.      During the continuance of his employment hereunder, the Executive shall,
        unless prevented by ill health, do all in his power to promote, develop,
        and extend the business of the Group and shall at all times and in all
        respects conform to and comply with the directions and regulations made
        by the Board and also shall not, without the previous consent of the
        Board, engage in any other business of a similar nature to or
        competitive with that carried on by the Group.

9.      Any invention, discovery or improvement upon or in addition to any of
        the Company's inventions made by the Executive during the period of
        employment shall be forthwith communicated to the Company and shall be
        the absolute property of the Group and at the request of the Company the
        Executive shall give and supply all information, know-how and data as
        may be requisite to enable the Group to exploit such invention,
        discovery or improvement and shall execute and do all documents and
        things as may be necessary or desirable for obtaining patent or similar
        protection for the same in any parts of the world as may be specified by
        the Company and for vesting the same in the Group as it may direct.

10.     The Executive shall not (except in the proper course of his duties
        hereunder) either during or after the period of his employment
        hereunder, divulge to any person and shall use his best endeavors to
        prevent the publication or disclosure of any trade secret or
        manufacturing process or any information concerning the business or
        finances of the Group or any of its dealings, transactions or affairs or
        any trade secret or secret manufacturing process of any such
        confidential information governing the Group and all 




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        notes and memoranda of such trade secrets or information made or
        received by the Executive during the course of his employment hereunder
        shall be the property of the Company and shall be surrendered by the
        Executive or someone duly authorized in that behalf at the termination
        of his employment or at the request of the Board at any time during the
        course of his employment.

11.     The Executive hereby covenants with the Company that he will not, within
        2 years after ceasing to be employed hereunder, without the consent of
        the Company in writing under the hand of a Director duly authorized by a
        resolution of the Board, directly or indirectly seek to procure orders
        from or do business with any person, firm, or company who, on the date
        of the Executive ceasing to be employed hereunder or at any time in the
        twelve months prior to that date, was a client or customer of the Group
        and with whom in the course of his employment, the Executive shall have
        had dealings, provided always, that nothing in this clause contained
        shall be deemed to prohibit the seeking or procuring of orders or the
        doing of business not in direct or indirect competition with the
        business or businesses conducted by the Group.

12.     This Agreement shall not be terminated by any:

        (a)     merger or consolidation where the Company is not the
                consolidating or surviving entity; or

        (b)     transfer of all or a substantial majority of the assets of the
                Company.

        (c)     acquisition or control of 50 per cent or more of the Company's
                issued and voting equity share capital by any party, or by
                parties acting in concert or under common control.

        In the event of any such merger or consolidation or transfer of all or a
        substantial majority of the assets of the Company or acquisition or
        control of 50 per cent or more of the Company's issued and voting equity
        share capital by any party, or by parties acting in concert or under
        common control, the surviving or resulting entity or the transferee or
        transferees of the Company's assets or its issued and voting equity
        share capital shall be bound by, and shall have the benefit of, the
        provisions of this Agreement, and the Company shall endeavor to take all
        actions necessary to ensure that such entity or transferee or
        transferees is bound by the provisions of the Agreement. Moreover, in
        the event of such merger or consolidation, or transfer of all or a
        substantial majority of the assets of the Company or acquisition or
        control of 50 per cent or more of the Company's issued and voting equity
        share capital as aforesaid, the Executive may at his option at any time
        continue his employment under the terms and conditions of this
        Agreement, or upon giving not less than 28 days Notice at any time, by
        registered mail, to the registered office of the Company, require the
        Company to effect full settlement of all of the Executive's entitlements
        under the terms and conditions of this Agreement, which settlement shall
        also include the payment of his remuneration for the full term of the
        Agreement and the right to convert any and all Option entitlements,
        (whether such Options be vested or not) 



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        up to and including December 31, 1999 and the Company shall effect full
        and final settlement within 28 days of receiving the said Notice from
        the Executive.

13.     There is no pension payable, and there is no contracting out certificate
        in force in respect of the Executive's employment hereunder.

14.     There are no disciplinary rules or grievance procedures in place in
        relation to the Executive's employment hereunder. The Executive may
        raise any grievance or concern about any disciplinary matter with the
        Board.

15.     This Agreement shall be governed by and construed and enforced in
        accordance with the laws of the State of New York applicable to
        agreements made and to be performed in such State.

                              ********************

Signed by                       }                /s/ Paul A. Logan
for and on behalf of            }       ----------------------------------------
SENETEK PLC in the presence     }       PAUL A. LOGAN
of:

Witness
Signed by                       }               /s/ Anthony J. Cataldo  
ANTHONY J. CATALDO              }       ----------------------------------------
in the presence of:             }       ANTHONY J. CATALDO
Witness

                                    SCHEDULE



<TABLE>
<CAPTION>
 NO. OF OPTIONS GRANTED   CONVERSION SECURITY     CONVERSION PRICE         VESTING DATE
 ----------------------   -------------------     ----------------         ------------
<S>                       <C>                        <C>                <C>
        100,000           5p Ordinary shares     U.S.$1.50              December 31, 1997
                          of Senetek PLC
        100,000           5p Ordinary shares     U.S.$1.50              December 31, 1998
                          of Senetek PLC
        100,000           5p Ordinary shares     U.S.$1.50              December 31, 1999
                          of Senetek PLC
</TABLE>