REVOLVING CREDIT NOTE

$1,000,000.00 MINNEAPOLIS, MINNESOTA

Due: SEPTEMBER 1, 1998 AUGUST 22, 1997

1. LOAN AMOUNT AND INTEREST RATE. FOR VALUE RECEIVED, LECTEC
CORPORATION, a Minnesota corporation ("Maker") promises to pay to the order of
FIRST BANK NATIONAL ASSOCIATION, a national banking association ("Lender"), its
successors and assigns, at its office at 300 Prairie Center Drive, Eden Prairie,
Minnesota 55344, or such other place as the holder hereof may designate in
writing from time to time, the principal sum of One Million and No/100 Dollars
($1,000,000.00), or so much thereof as may be advanced from time to time
pursuant to that certain Credit Agreement dated of even date herewith between
the Maker and the Lender, as the same may be amended, modified, restated or
replaced from time to time as agreed upon in writing by the Lender ("Credit
Agreement"), in lawful money of the United States, together with interest from
the date hereof on the unpaid balance hereof from time to time outstanding at
one of the following rates to be selected from time to time by the Maker in
accordance with and subject to the terms of the Credit Agreement: (i) a variable
annual rate at all times equal to the prevailing Reference Rate of interest
established and announced by the Lender as the same may change from time to
time, as to all Reference Rate Advances; or (ii) the Resetting Eurodollar Rate,
as defined in the Credit Agreement, as to all Daily Eurodollar Advances; or
(iii) the Eurodollar Rate (Reserve Adjusted) as defined in the Credit Agreement,
plus 250 basis points, as to all Eurodollar Advances. The Lender may make loans
to its customers or any other person or entity at, above or below the Reference
Rate. In the event that the Lender ceases to establish and announce a Reference
Rate at any time during the term of this Note, the Lender shall be entitled to
designate a reasonably comparable substitute index for the calculation of the
interest rate hereon so long as any amount remains outstanding hereunder. All
changes in the rate of interest applicable hereto shall become effective on the
same day that the change in said Reference Rate is announced.

2. PAYMENT SCHEDULE. This Note shall be payable in the following
manner:

2.1 As to Reference Rate Advances and Daily Eurodollar Advances,
accrued interest shall be due and payable on the first day of
each month, beginning September 1, 1997, and at Maturity, and
as to Eurodollar Advances, accrued interest shall be due and
payable on the last day of each Interest Period, until all
indebtedness evidenced hereby is paid in full. All outstanding
principal and accrued and unpaid interest shall be due and
payable on September 1, 1998.

2.2 Each payment made under this Note shall be applied, first, to
the amount then due for any expenses, costs or other
expenditures incurred by the Lender in connection with this
Note and payable by the Maker, and then applied to any accrued
interest then due under this Note, and any balance thereafter
remaining shall be applied against principal outstanding under
this Note.

2.3 Any payment due on any non-business day of the Lender shall be
due upon (and interest shall accrue to) the next business day.

3. DEFAULT INTEREST RATE. Upon the occurrence and during the
continuation of an Event of Default as defined in the Credit Agreement, the
interest rate shall thereafter increase and shall be payable on the whole of the
unpaid principal balance, interest and other charges at a rate equal to the
greater of (i) two percent (2.00%) per annum in excess of the rate of interest
then in effect under the terms



of this Note or (ii) two percent (2.00%) per annum plus the Reference Rate (as
defined in the Credit Agreement) in effect from time to time. This provision
shall not be deemed to excuse an Event of Default not be deemed a waiver of any
other rights the Lender may have including the right to declare the entire
unpaid principal and interest under this Note immediately due and payable.

4. CREDIT AGREEMENT. This Note is the Revolving Credit Note issued
pursuant to the terms and provisions of the Credit Agreement and this Note and
the holder hereof are entitled to all of the benefits provided for in the Credit
Agreement, or referred to therein. Reference is made to the Credit Agreement for
a statement of the terms and conditions under which this indebtedness was
incurred and is to be repaid and under which the due date of this Note may be
accelerated. The provisions of the Credit Agreement are hereby incorporated by
reference with the same force and effect as if fully set forth herein.

5. DEFAULT AND ACCELERATION. If an Event of Default, as defined in the
Credit Agreement or any other agreement made by any party in connection with
this Note, shall occur, and/or if any portion of the indebtedness evidenced
hereby is not paid when due, the Lender or other holder of this Note may,
without notice, demand, presentment for payment and/or notice of nonpayment, all
of which Maker hereby expressly waives, declare the indebtedness evidenced
hereby and all other indebtedness and obligations of the Maker to the Lender or
holder hereof immediately due and payable and the Lender or other holder hereof
may, without notice, immediately exercise any right of setoff and enforce any
lien or security interest securing payment hereof. The foregoing shall be in
addition to the rights of acceleration that may be provided in any loan
agreement, security agreement, mortgage and/or other writing relating to the
indebtedness evidenced hereby. If this Note is placed with any attorney(s) for
collection upon any default, the Maker agrees to pay to the Lender or holder,
its reasonable attorneys fees and all lawful costs and expenses of collection,
whether or not a suit is commenced.

6. WAIVER. Time is of the essence. No delay or omission on the part of
the Lender or other holder hereof in exercising any right or remedy hereunder
shall operate as a waiver of such right or of any other right or remedy under
this Note or any other document or agreement executed in connection herewith.
All waivers by the Lender must be in writing to be effective and a waiver on any
occasion shall not be construed as a bar to or a waiver of any similar right or
remedy on a future occasion. The makers, endorsers, sureties, guarantors and all
other persons liable for all or any part of the indebtedness evidenced by this
Note jointly and severally waive presentment for payment, protest and notice of
nonpayment. Such parties hereby consent without affecting their liability to any
extension or alteration of the time or terms of payment hereon, any renewal, any
release of all or any part of the security given for the payment hereof, any
acceptance of additional security of any kind, and any release of, or resort to
any party liable for payment hereof and such parties shall remain bound in the
same capacities as prior thereto upon each such event.

7. JURISDICTION. This Note represents a loan negotiated, executed and
to be performed in the State of Minnesota and shall be construed, interpreted
and governed by the law of said state. The Maker hereby consents to the personal
jurisdiction of the state and federal courts located in the State of Minnesota
in connection with any controversy related to this Note, waives any argument
that venue in such forums is not convenient and agrees that any litigation
instigated by the Maker against the Lender in connection with this Note shall be
venued in the federal or state court that has jurisdiction over matters arising
in Minneapolis, Minnesota.

8. INTEREST LIMITATION. All agreements between the Maker and the Lender
are hereby expressly limited so that in no contingency or event whatsoever,
whether by reason of acceleration of maturity of the indebtedness evidenced or
secured thereby or otherwise, shall the rate of interest charged or agreed to be
paid to the Lender for the use, forbearance, loaning or detention of such
indebtedness exceed the maximum permissible interest rate under applicable law
("Maximum Rate"). If for any reason or in any circumstance whatsoever
fulfillment of any provision of this Note, any document securing or executed in
connection with this Note, or any other agreement between the Maker and the
Lender, at any time shall require or permit the interest rate applied thereunder
to exceed the Maximum Rate, then the interest rate shall automatically be
reduced to the Maximum Rate, and if the Lender should ever receive



interest at a rate that would exceed the Maximum Rate, the amount of interest
received which would be in excess of the amount receivable after applying the
Maximum Rate to the balance of the outstanding obligation shall be applied to
the reduction of the principal balance of the outstanding obligation for which
the amount was paid and not to the payment of interest thereunder. This
provision shall control every other provision of any and all agreements between
the Maker and the Lender and shall also be binding upon and available to any
subsequent holder of this Note.

IN WITNESS WHEREOF, the Maker has executed and delivered this Note to
the Lender as of the day and year first above written.

LECTEC CORPORATION,
A MINNESOTA CORPORATION


By /s/Deborah L. Moore
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Its Chief Financial Officer
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