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                                                                   Exhibit 10.13

              Employment Agreement with Christopher P. Schnittker

[LETTERHEAD OF MAGAININ PHARMACEUTICALS INC.]

May 22, 2000

Christopher P. Schnittker

Dear Chris:

I am pleased to offer you the position of Vice President & Chief Financial
Officer with Magainin Pharmaceuticals Inc., reporting to the Michael R.
Dougherty, President and Chief Executive Officer. Your base salary will be
$8,333.33 per month ($100,000/year). Contingent upon your acceptance of this
offer, it is expected that the Compensation Committee of the Board of Directors
will grant to you at its next meeting options to purchase 20,000 shares of
Magainin Common Stock, exercisable at the fair market value underlying common
stock on the date of such meeting. These options will have a term of 10 years
and vest at the rate of 25% per year. As with all Magainin options, the grant
will be subject to execution of a stock option agreement in the form specified
by the Compensation Committee.

Additionally, you will be eligible for merit increases, cash bonuses, and such
further stock options grants as may be awarded at the annual discretion of the
Company's Board of Directors.

Upon the commencement of your employment with the Company, you will be expected
to execute the Company's Drug Free Workplace Policy, Proprietary Information
Agreement, Policy Statement on Securities Trading by Magainin Personnel, and
Corporate Governance - Conflict of Interest Policy, each in the form previously
provided to you. Magainin may have already provided you with certain of its
confidential business or scientific information, which it expects you to keep
confidential, and to use only to further Magainin's legitimate business
interests. Just as Magainin expects you to keep confidential its business or
scientific information, Magainin also expects you to honor your obligations to
your former employers with respect to maintaining the confidentiality of their
business or scientific information.

You will be eligible for twenty (20) days vacation per year. Vacation accrues
proportionate to months employed. Employees are encouraged to take their
vacations yearly. However, up to five (5) days of unused vacation time can be
carried over into next year with supervisor approval. In addition, you will be
eligible for the benefits package available to all employees. Enclosed is a
summary of the benefits.

All the terms and conditions of this Agreement shall be binding upon and inure
to the benefit and be enforceable by the respective heirs, representatives,
successors (including any successor as a result of a merger or similar
reorganization) and assigns of the parties
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hereto, except that your duties and responsibilities hereunder are of a personal
nature and shall not be assignable in whole or in part by you.

We look forward to your joining us at Magainin Pharmaceuticals Inc. Please
indicate your acceptance of this offer, which is for at will employment, by your
signature below. This offer of employment will remain in effect until Friday,
June 1, 2000. We have agreed that your start date will be Monday, June 19, 2000,
at 8:30 AM, however, this is flexible. Please do not hesitate to speak with me
concerning any questions you may have.

                                        Sincerely,

                                        /s/ Michael R. Dougherty
                                        ------------------------
                                        Michael R. Dougherty
                                        President and Chief Executive Officer