THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER
THE SECURITIES ACT OF 1933 OR THE SECURITIES ACT OF ANY STATE. THE SECURITIES
HAVE BEEN ACQUIRED FOR INVESTMENT AND MAY NOT BE SOLD, TRANSFERRED FOR VALUE,
PLEDGED, HYPOTHECATED OR OTHERWISE ENCUMBERED IN THE ABSENCE OF AN EFFECTIVE
REGISTRATION OF THEM UNDER THE SECURITIES ACT OF 1933 AND/OR THE SECURITIES ACT
OF ANY STATE OR IN THE ABSENCE OF AN OPINION OF COUNSEL ACCEPTABLE TO THE ISSUER
THAT SUCH REGISTRATION UNDER SUCH ACT OR ACTS IS NOT REQUIRED.

THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE UNITED STATES OF SECURITIES
ACT OF 1933, AS AMENDED (THE "SECURITIES ACT"), THE SECURITIES LAWS OF ANY STATE
OF THE UNITED STATES ("STATE ACT"), OR THE SECURITIES LAWS OF CANADA OR ANY
PROVINCE THEREOF ("CANADIAN ACT"). SUCH SECURITIES MAY NOT BE OFFERED, SOLD OR
TRANSFERRED, DIRECTLY OR INDIRECTLY, IN THE UNITED STATES OF AMERICA ("UNITED
STATES") OR IN CANADA, OR IN THEIR JURISDICTION (COLLECTIVELY "NORTH AMERICA"),
OR TO OR FOR THE BENEFIT OF ANY PERSON WHO IS A NATIONAL, CITIZEN, OR RESIDENT,
OR NORMALLY A RESIDENT, THEREOF, THE ESTATE OF SUCH PERSON, OR ANY CORPORATION
OR OTHER ENTITY CREATED OR ORGANIZED UNDER ANY LAW OF THE UNITED STATES OR
CANADA OR ANY POLITICAL SUBDIVISION THEREOF (COLLECTIVELY REFERRED TO AS "NORTH
AMERICAN PERSONS") AT ANY TIME PRIOR TO THE EARLIER OF (i) THAT DATE ON WHICH
THE SECURITIES BECOME REGISTERED UNDER THE SECURITIES ACT, ANY APPLICABLE STATE
ACT, AND ANY APPLICABLE CANADIAN ACT; OR (ii) 40 DAYS AFTER TERMINATION OF THIS
OFFERING PROVIDED THAT AS OF THE DATE OF TRANSFER, THE SECURITIES ARE DULY
REGISTERED UNDER THE SECURITIES ACT, ANY APPLICABLE STATE ACT, AND ANY
APPLICABLE CANADIAN ACT, OR AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES
ACT, ANY APPLICABLE STATE ACT, AND ANY APPLICABLE CANADIAN ACT IS AVAILABLE, AND
THE COMPANY HAS RECEIVED AN OPINION OF COUNSEL TO SUCH EFFECT REASONABLY
SATISFACTORY TO IT.

                            NOCOPI TECHNOLOGIES, INC.

                            SERIES B PROMISSORY NOTE

                               Due March 31, 2000


No. 52                                                                $50,000.00

     FOR VALUE RECEIVED, the undersigned, Nocopi Technologies, Inc., a Maryland
corporation (hereinafter "Maker"), promises to pay to Egger & Co. or order
(hereinafter "Payee"), at Chase Manhattan Bank, 4 New York Plaza-11th Floor, New
York, NY 10004 or at such other place as the holder of this Note may from time

<PAGE>

to time designate, the principal sum of Fifty Thousand Dollars ($50,000.00),
payable as hereinafter provided, in such coin or currency of the United States
of America as at the time of payment shall be legal tender for the payment of
public and private debts.

     This Note is one of two Notes, designated the Series B Extended Notes,
aggregating One Hundred and Twenty-Five Thousand Dollars ($125,000), issued by
the Maker. All Series B Extended Notes shall rank pari passu in respect of
payment of principal and interest and upon any dissolution, liquidation or
winding-up of the Maker.

     The principal sum hereof shall be payable on March 31, 2000 (the "Maturity
Date"), when all unpaid principal and interest shall become due and payable.

     Interest at the rate of Nine Percent (9%) per annum on the outstanding
balance shall be payable semi-annually on September 30 and March 31 of each
year, commencing on September 30, 1998, to the person in whose name this Note is
registered at the close of business on the preceding August 15 or February 15,
as the case may be. Interest shall accrue from the most recent date to which
interest has been paid or duly provided for, or, if no interest has been paid or
duly provided for, from the date of issuance of this Note. Interest hereon shall
be computed on the basis of a 365-day year.

     IT IS FURTHER AGREED:

     1. Conversion Privilege.

        (a) The holder of this Note shall have the right, at such holder's
option (but if such Note is called for redemption at the election of the Maker,
then in respect of such amount called for redemption or exchange, only to and
including but not after the close of business on (i) the fifth calendar day
before the date fixed for such redemption, provided that no default by the Maker
in payment of the applicable Redemption Price) (including any accrued and unpaid
dividends) or in the exchange of such Note, as the case may be, shall have
occurred and be continuing) to convert this Note, or any portion of the
principal amount thereof which is $25,000 or an integral multiple thereof, and
accrued but unpaid interest thereon, into that number of fully paid and
non-assessable shares of Common Stock (calculated as to each conversion to the
nearest 1/100th of a share) obtained by dividing the amount of principal and
accrued interest being converted by the Conversion Price then in effect. The
Conversion Price shall initially be equal to Twenty Cents ($0.20) per share.

        (b) In order to exercise the conversion privilege, the holder shall
surrender this Note, accompanied by a proper assignment thereof to the Maker or
in blank, at any of the offices or agencies maintained for such other purpose by
the Maker ("Conversion Agent") and shall give written notice to the Maker at
such Conversion Agent that the holder elects to convert this Note or a specified
portion thereof. Such notice shall also state the name(s), together with
address(es), in which the certificate(s) for shares of Common Stock which shall
be issuable on such conversion shall be issued. As promptly as practicable after



                                       2
<PAGE>

the surrender of this Note as aforesaid, the Maker shall issue and shall deliver
at such Conversion Agent to such holder, or on his written order, a
certificate(s) for the number of full shares of Common Stock issuable upon such
conversion in accordance with the provisions hereof and any fractional interest
in respect of a share of Common Stock arising upon such conversion shall be
settled as provided in subparagraph (c) below. Such conversion shall be deemed
to have been effected immediately prior to the close of business on the date on
which this Note shall have been so surrendered and such notice received by the
Maker as aforesaid, and the person(s) in whose name(s) any certificate(s) for
shares of Common Stock shall be issuable upon such conversion shall be deemed to
have become the holder(s) of record of the Common Stock represented thereby at
such time, unless the stock transfer books of the Maker shall be closed on the
date on which this Note is so surrendered for conversion, in which event such
conversion shall be deemed to have been effective immediately prior to the close
of business on the next succeeding day on which such stock at the close of
business on such later day. In either circumstance, such conversion shall be at
the Conversion Price in effect on the date upon which this Note shall have been
surrendered and such notice received by the Maker.

        (c) In case this Note shall be surrendered for conversion of only a
portion of the principal amount thereof, the Maker shall execute and deliver to
the holder of this Note, at the expense of the Maker, a new Note in the
denomination or denominations ($50,000 and integral multiples thereof, plus one
Note in a lesser denomination, if required) as such holder may request in an
aggregate principal amount equal to the unconverted portion of this Note.

     In the event the holder of this Note shall be entitled to receive a
fractional interest in a share of Common Stock, except as otherwise provided
herein the Maker shall either, in the sole discretion of its Board of Directors,
(i) round such fractional interest up to the next whole share of common stock,
or (ii) deliver cash in the amount of the fair market value of such fractional
interest.

     If, in lieu of fractional interest in a share of Common Stock which would
otherwise be deliverable upon the conversion of this Note, or any portion
thereof, the Maker, pursuant to the terms of this subparagraph (c), shall
deliver cash, the fair market value of a share of Common Stock shall be as
determined by the Board of Directors of the Maker. The determination of the
Board of Directors shall be conclusive and not subject to challenge by the
holder of this Note. If more than one Series B Note shall be surrendered for
conversion at one time by the same holder, the number of full shares issuable
upon conversion thereof shall be computed on the basis of the aggregate
principal and/or interest amount to be converted pursuant to all Series B
Extended Notes so surrendered by such holder.

        (d) The Conversion Price shall not be adjusted for (i) the grant or
exercise of any stock option under either the Maker's Incentive Stock Option
Plan or Stock Incentive Plan as in effect on May 15, 1998, or as thereafter
amended, or (ii) the exercise of any other options, warrants or rights to
acquire Common Stock granted by the Maker on or prior to May 15, 1998; provided
that the Conversion Price shall be adjusted in other cases from time to time as
follows:

                                       3
<PAGE>



            (i) In case the Maker shall pay or make a dividend or other
distribution on any class of capital stock of the Maker in Common Stock, the
Conversion Price in effect at the opening of business on the day following the
date fixed for the determination of stockholders entitled to receive such
dividend or other distribution shall be reduced by multiplying such Conversion
Price by a fraction of which the numerator shall be the number of shares of
Common Stock outstanding at the close of business on the date fixed for such
determination and the denominator shall be the sum of such number of shares and
the total number of shares constituting such dividend or other distribution,
such reduction to become effective immediately after the opening of business on
the day following the date fixed for such determination. For the purposes of
this subparagraph (i), the number of shares of Common Stock at any time
outstanding shall not include shares held in the treasury of the Maker but shall
include all shares issuable in respect of scrip certificates issued in lieu of
fractions of shares of Common Stock. The Maker will not pay any dividend or make
any distribution on shares of Common Stock held in the treasury of the Maker.

            (ii) In case the Maker shall issue rights or warrants to all holders
of its Common Stock (not being available on an equivalent basis to holders of
the Series B Extended Notes upon conversion) entitling them to subscribe for or
purchase shares of Common Stock at a price per share less than the current
market price per share (determined as provided in subparagraph (vi) below) of
the Common Stock on the date fixed for the determination of stockholders
entitled to receive such rights or warrants (other than pursuant to a dividend
reinvestment plan), the Conversion Price in effect at the opening of business on
the day following the date fixed for such determination shall be reduced by
multiplying such Conversion Price by a fraction of which the numerator shall be
the number of shares of Common Stock outstanding at the close of business on the
date fixed for such determination plus the number of shares of Common Stock
which the aggregate of the offering price of the total number of shares of
Common Stock so offered for subscription or purchase would purchase at such
current market price and the denominator shall be the number of shares of Common
Stock outstanding at the close of business on the date fixed for such
determination plus the number of shares of Common Stock so offered for
subscription or purchase, such reduction to become effective immediately after
the opening of business on the day following the date fixed for such
determination. For the purposes of this subparagraph (ii), the number of shares
of Common Stock at any time outstanding shall not include shares held in the
treasury of the Maker but shall include shares issuable in respect of scrip
certificates issued in lieu of fractions of shares of Common Stock. The Maker
will not issue any rights or warrants in respect of shares of Common Stock held
in the treasury of the Maker.

            (iii) In case outstanding shares of Common Stock shall be subdivided
into a greater number of shares of Common Stock, the Conversion Price in effect
at the opening of business on the day following the day upon which such
subdivision becomes effective shall be proportionately reduced, and, conversely,
in case outstanding shares of Common Stock shall each be combined into a smaller
number of shares of Common Stock, the Conversion Price in effect at the opening
of business on the day following the day upon which such combination becomes
effective shall be proportionately increased, such reduction or increase, as the


                                       4
<PAGE>

case may be, to become effective immediately after the opening of business on
the day following the day upon which such subdivision or combination becomes
effective.

            (iv) In case the Maker shall, by dividend or otherwise, distribute
to all holders of its Common Stock evidences of its indebtedness or assets
(including securities, but excluding any rights or warrants referred to in
subparagraph (ii) above, any dividend or distribution paid in cash out of the
earned surplus of the Maker and any dividend or distribution referred to in
subparagraph (i) above), the Conversion Price shall be adjusted so that the same
shall equal the price determined by multiplying the Conversion Price in effect
immediately prior to the close of business on the date fixed for the
determination of stockholders entitled to receive such distribution by a
fraction of which the numerator shall be the current market price per share
(determined as provided in subparagraph (vi) below) of the Common Stock on the
date fixed for such determination less the fair market value (as determined by
the Board of Directors, whose determination shall be conclusive and shall be
described in a statement filed with any Conversion Agent) of the portion of the
assets or evidences of indebtedness so distributed applicable to one share of
Common Stock and the denominator shall be such current market price per share of
the Common Stock, such adjustment to become effective immediately prior to the
opening of business on the day following the date fixed for the determination of
stockholders entitled to receive such distribution. The foregoing provisions
shall also be applicable to any rights plan of the Maker. In any case in which
this subparagraph (iv) is applicable, subparagraph (ii) shall not be applicable.

            (v) The reclassification of Common Stock into securities including
securities other than Common Stock (other than any reclassification upon a
consolidation or merger to which subparagraph (ix) below applies) shall be
deemed to involve (A) a distribution of such securities other than Common Stock
to all holders of Common Stock (and the effective date of such reclassification
shall be deemed to be "the date fixed for the determination of stockholders
entitled to receive such distribution" and the "date fixed for such
determination" within the meaning of subparagraph (iv) above), and (B) a
subdivision or Common Stock outstanding immediately prior to such
reclassification shall be deemed to the "the day upon which such subdivision
becomes effective" or "the day upon which such combination becomes effective,"
as the case may be, and "the day upon which such subdivision or combination
becomes effective" within the meaning of subparagraph (iii) above).

            (vi) For the purpose of any computation under subparagraphs (ii) and
(iv) above, the current market price per share of Common Stock on any day shall
be deemed to be the average of the daily closing prices for the five consecutive
trading days selected by the Board of Directors commencing not more than twenty
trading days before, and ending not later than, the earlier of the day in
question and the day before the "ex" date with respect to the issuance or
distribution requiring such computation. For this purpose, the term "ex" date,
when used with respect to any issuance or distribution shall mean the first date
on which the Common Stock trades regular way on the applicable exchange or in
the applicable market without the right to receive such issuance or
distribution. The closing price for each day shall be the reported last sale
price regular way or, in case no such reported sale takes place on such day, the
average of the reported closing bid and asked prices regular way, in either case

                                       5
<PAGE>

on the New York Stock Exchange or, if the Common Stock is not listed or admitted
to trading on such Exchange, on the principal national securities exchange on
which the Common Stock is listed or admitted to trading or, if not listed or
admitted to trading on any national securities exchange, on the National
Association of Securities Dealers Automated Quotations National Market System
or, if the Common Stock is not listed or admitted to trading on any national
securities exchange or quoted on such National Market System, the average of the
closing bid and asked prices in the over-the-counter market as furnished by any
New York Stock Exchange member firm selected from time to time by the Board of
Directors for that purpose or, if the bid and asked prices in the
over-the-counter market are not reported, the current market price per share of
Common Stock shall be determined by the Board of Directors and such
determination shall be final and conclusive.

            (vii) No adjustment in the Conversion Price shall be required unless
such adjustment would require an increase or decrease of at least 1% of such
price; provided, however, that any adjustments which by reason of this
subparagraph (vii) are not required to be made shall be carried forward and
taken into account in any subsequent adjustment, and provided further, that
adjustment shall be required and made in accordance with the provisions hereof
not later than such time as may be required in order to preserve the tax-free
nature (for purposes of United States Federal tax purposes) of a distribution to
the holder of this Note or the holders of the Common Stock. All calculations
shall be made to the nearest cent or to the nearest 1/100th of a share, as the
case may be. The Maker may make such reductions in the Conversion Price, in
addition to those required by subparagraphs (i), (ii), (iii) and (iv) above, as
it considers to be advisable in order to avoid or diminish any income tax (for
purposes of United States Federal Income Tax) to any holders of shares of Common
Stock resulting from any dividend or distribution of stock or issuance of rights
or warrants to purchase or subscribe for stock or from any event treated as such
for income tax purposes or for any other reasons. The Maker shall have the power
to resolve any ambiguity or correct any error with regard to the preceding
sentence and its actions in so doing shall be conclusive and binding.

            (viii) Whenever the Conversion Price is adjusted as herein provided,
(A) the Maker shall promptly file with any Conversion Agent a certificate of the
Maker's Chief Financial Officer setting forth the Conversion Price after such
adjustment and setting forth a brief statement of the facts requiring such
adjustment and the manner of computing the same, which certificate shall be
conclusive evidence of the correctness of such adjustment, and (B) a notice
stating that the Conversion Price has been adjusted and setting forth the
adjusted Conversion Price shall be given by the Maker to any Conversion Agent
and mailed by the Maker to the holder of this Note at his last address as the
same appears on the books of the Maker.

            (ix) In the case of any consolidation of the Maker with, or merger
of the Maker into, any other entity, any merger which does not result in any
reclassification, conversion, exchange, or cancellation of outstanding shares of
Common Stock of the Maker) or any sale or transfer of all or substantially all
of the assets of the Maker, the holder of this Note shall have the right
thereafter to convert this Note, or any portion of the principal thereof and
accrued interest thereon, only into the kind and amount of securities, cash and


                                       6
<PAGE>

other property receivable upon such consolidation, merger, sale or transfer by a
holder of the number of shares of Common Stock of the Maker into which this
Note, or portion thereof, might have been converted immediately prior to such
consolidation, merger, sale or transfer, assuming such holder of Common Stock of
the Maker is not an entity with which the Maker consolidated or into which the
Maker merged or which merged into the Maker or to which such sale or transfer
was made, as the case may be ("constituent entity"), or an affiliate of a
constituent entity, and failed to exercise his rights of election, if any, to
the kind or amount of securities, cash and other property receivable upon such
consolidation, merger, sale or transfer (provided that if the kind or amount of
securities, cash and other property receivable upon such consolidation, merger,
sale or transfer is not the same for each share of Common Stock of the Maker
held immediately prior to such consolidation, merger, sale or transfer by others
than a constituent entity or an affiliate thereof and in respect of which such
rights of election shall not have been exercised ("non-electing share"), then
for the purpose of this subparagraph (ix) the kind and amount of securities,
cash and other property receivable upon such consolidation, merger, sale or
transfer by each non-electing share shall be deemed to be the kind and amount so
receivable per share by a plurality of the non-electing shares). If necessary,
appropriate adjustment shall be made in application of the provisions set forth
herein with respect to the rights and interests thereafter of the holder of this
Note, to the end that the provisions set forth herein shall thereafter
correspondingly be made applicable, as nearly as may reasonably be, in relation
to any shares of stock or other securities or property thereafter deliverable on
the conversion of this Note. Any such adjustment shall be evidenced by a
certificate of the Chief Financial Officer of the Maker and a notice of such
adjustment filed and mailed in the manner set forth in subparagraph (viii)
above, and each containing the information set forth in such subparagraph
(viii); and any adjustment so certified shall for all purposes hereof
conclusively be deemed to be an appropriate adjustment. The above provisions
shall similarly apply to successive consolidations, mergers, sales or transfers.

        For purposes of this paragraph 2, "Common Stock" includes any stock of
any class of the Maker which has no preference in respect of dividends or of
amounts payable in the event of any voluntary or involuntary liquidation,
dissolution or winding-up of the Maker and which is not subject to redemption by
the Maker. However, subject to the provisions of subparagraph (ix) above, shares
issuable on conversion of this Note shall include only shares of the class
designated as Common Stock of the Maker at the date of issuance of this Note or
shares of any reclassifications thereof and which have no preference in respect
of dividends or of amounts payable in the event of any voluntary or involuntary
liquidation, dissolution or winding up of the Maker and which are not subject to
redemption by the Maker; provided that if at any time there shall be more than
one such resulting class, the shares of each such class then so issuable shall
be substantially in the proportion which the total number of shares of such
class resulting from all such classifications bears to the total number of
shares of all such classes resulting from all such reclassifications.

        In case:

        (A) the Maker shall declare a dividend (or any other distribution)
            on its Common Stock payable otherwise than in cash out of its
            earned surplus; or

                                       7
<PAGE>

        (B) the Maker shall authorize the granting to the holders of its
            Common Stock of rights or warrants to subscribe for or purchase
            any shares of capital stock of any class or of any other rights;
            or

        (C) of any reclassification of the Common Stock of the Maker (other
            than a subdivision or combination of its outstanding shares of
            Common Stock), or of any consolidation, merger or share exchange
            to which the Maker is a party and for which approval of any
            stockholders of the Maker is required, or of the sale or
            transfer of all or substantially all of the assets of the Maker;
            or

        (D) of the voluntary or involuntary dissolution, liquidation, or
            winding up of the Maker;

then the Maker shall cause to be filed with any Conversion Agent, and shall
cause to be mailed to the holder of this Note at such holder's last address as
the same appears on the books of the Maker, at least twenty (20) days (or at
least ten (10) days in any case specified in clause (A) or (B) above) prior to
the applicable record or effective date hereinafter specified, a notice stating
(A) the date on which a record is to be taken for the purpose of such dividend,
distribution, rights or warrants, or, if a record is not to be taken, the date
as of which the holders of Common Stock of record to be entitled to such
dividend, distribution, rights or warrants are to be determined, or (B) the date
on which such reclassification, consolidation, merger, share exchange, sale,
transfer, dissolution, liquidation or winding up is expected to become
effective, and the date as of which it is expected that holders of Common Stock
of record shall be entitled to exchange their shares of Common Stock for
securities cash or other property deliverable upon such reclassification,
consolidation, merger, share exchange, sale, transfer, dissolution, liquidation
or winding up. Neither the failure to give such notice nor any defect therein
shall affect the legality or validity of the proceedings described in clauses
(A) through (D) above.

        (e) Not less than seven (7) days prior to the Distribution Date, the
Maker shall cause to be filed with any Conversion Agent, and shall cause to be
mailed to the holder of this Note at such holder's last address as the same
appears on the books of the Maker, a notice stating the date on which the
Distribution Date is to occur, and briefly describing the import thereof.
Neither the failure to give such notice nor any defect therein shall affect the
legality or validity of the proceedings described herein.

        (f) The Maker will pay any and all documentary stamp or similar issue or
transfer taxes payable in respect of the issue or delivery of shares of Common
Stock on conversions of this Note or any portion thereof pursuant hereto;
provided, however, that the Maker shall not be required to pay any tax which may
be payable in respect of any transfer involved in the issue or delivery of
shares of Common Stock in a name other than that of the holder of this Note and
no such issue or delivery shall be made unless and until the person requesting
such issue or delivery has paid to the Maker the amount of any such tax has been
paid.

                                       8
<PAGE>

        (g) The Maker covenants that all shares of Common Stock which may be
delivered upon conversions of this Note or portions thereof will upon delivery
be duly and validly issued and fully paid and non-assessable, free of all liens
and charges and not subject to any preemptive rights.

        (h) The Maker covenants that it will at all times reserve and keep
available, free from preemptive rights, out of the aggregate of its authorized
but unissued shares of Common Stock, for the purpose of effecting conversions of
this Note, the full number of shares of Common Stock deliverable upon the
conversion of the total principal amount of this Note, plus accrued interest
thereon, not theretofore converted. The issuance of shares of Common Stock upon
conversion of this Note is authorized in all respects.

        (i) Prior to the conversion of this Note, the holder of this Note shall
not be entitled to any rights of a stockholder of the Maker, including without
limitation the right to vote, to receive dividends or other distributions or to
exercise any preemptive rights, and shall not be entitled to receive any notice
of any proceedings of the Maker, except as provided herein.

     2. Subordination.

        (a) The indebtedness evidenced by this Note, including the principal
hereof and interest thereon, shall be subordinate and subject in right of
payment, to the extent and in the manner hereinafter set forth, to the prior
payment in full of all Senior Debt of Maker as hereinafter defined, whether now
outstanding or hereafter incurred, and any holder of this Note, by acceptance
hereof, agrees to and shall be bound by the provisions of this paragraph. As
used in this Note, the term "Senior Debt" shall mean not more than $2,000,000 in
the aggregate of principal, premium if any, and interest on all indebtedness of
the Maker regardless of whether incurred on, before or after the date of
issuance of this Note (i) for money borrowed from any bank or similar financial
institution, and evidenced by notes, bonds, debentures or other written
obligations and such notes, bonds, debentures or other written obligations are
interest bearing securities only and are not convertible or issued in connection
with the issue of warrants or options, whether separate or attached, or some
other rights to receive stock or participate in the earnings of the Maker in any
form, including dividend distributions, and (ii) in connection with any renewals
or extensions of any indebtedness described in (i) above; provided, however,
that the terms does not include indebtedness which by the terms of the
instrument creating or evidencing it is subordinated to or on a parity with the
Series B Notes.

        (b) Upon any payment or distribution of assets of Maker of any kind or
character, whether in cash, property, or securities, to creditors upon any
dissolution or winding-up or total or partial liquidation or reorganization of
Maker whether voluntary or involuntary, or in bankruptcy, insolvency,
receivership or other proceedings, all principal, premium if any, and interest
due upon all Senior Debt shall first be paid in full, or payment thereof
provided for in money or money's worth, before the holder of this Note shall be
entitled to retain any assets so paid or distributed in respect thereof (for
principal or interest); and upon any such dissolution or winding-up or
liquidation or reorganization, any payment or distribution of assets of Maker of


                                       9
<PAGE>

any kind or character whether in cash, property, or securities, to which the
holder of this Note would be entitled, except for the provisions hereof, shall
be paid by Maker or by any receiver, trustee in bankruptcy, liquidating trustee,
agent or other person making such payment or distribution, or by the holder of
this Note, if received by such holder, direct to the holders of Senior Debt (pro
rata to each such holder on the basis of the respective amounts of Senior Debt
held by each such holder) or their representatives, to the extent necessary to
pay all Senior Debt in full, in money or money's worth, after giving effect to
any concurrent payment or distribution to or for the holders of Senior Debt,
before any payment or distribution is made to the holder of this Note.

        (c) Subject to the payment in full of all Senior Debt, the holder of
this Note shall be subrogated pro rata (based on respective amounts paid over
for the benefit of the holders of Senior Debt as provided in subparagraph (b),
above), with the holders of any other subordinated indebtedness of Maker that by
its terms ranks pari passu with this Note and is entitled to like rights of
subrogation, to the rights of holders of Senior Debt to receive payments or
distribution of assets of Maker applicable to the Senior Debt until the
principal of and interest on this Note shall be paid in full; and no payments or
distributions on the Senior Debt pursuant to this paragraph shall, as between
Maker, its creditors other than the holders of Senior Debt, and the holder this
Note, be deemed to be a payment by Maker to or on account of this Note, it being
understood that the provisions of this paragraph are and are intended solely for
the purpose of defining the relative rights of the holder of this Note and the
holders of the Senior Debt.

        (d) Nothing contained in this paragraph or elsewhere in this Note is
intended to or shall impair the obligation of Maker which is absolute and
unconditional, to pay to the holder of this Note the principal of and interest
on this Note, as and when the same shall become due and payable in accordance
with its terms, or to affect the relative rights of the holder of this Note and
creditors of Maker other than the holders of the Senior Debt, nor shall anything
herein or therein prevent the holder of this Note from exercising all remedies
otherwise permitted by applicable law upon default under this Note, subject to
the rights, if any, under this paragraph of the holders of Senior Debt in
respect of cash, property, or securities of Maker otherwise payable or delivered
to such holder upon the exercise of any such remedy.

        (e) No payments on account of the principal or interest on this Note, or
on account of the purchase or other acquisition of this Note if its maturity
shall have been accelerated, shall be made, and no holder of this Note shall be
entitled to receive any such payment, unless full payment of amounts then due
for principal, premium if any, and interest on Senior Debt has been made or duly
provided for in money or money's worth. No payment on account of principal or
interest on this Note, or on account of the purchase or other acquisition of
this Note if its maturity shall have been accelerated, shall be made, and no
holder of this Note shall be entitled to receive any such payment, if, at the
time of such payment or immediately after giving effect thereto, there shall
exist under any Senior Debt or any agreement pursuant to which any Senior Debt
is issued, any default or any condition, event or act, which, with notice or
lapse of time, or both, would constitute a default or any such default or
condition, event or act shall be the subject of a judicial proceeding, unless

                                       10
<PAGE>

and until such default or event of default shall have been cured or waived or
shall have ceased to exist, or such Senior Debt shall have been paid in full.

        (f) The provisions of this paragraph constitute a continuing offer to
all persons who, in reliance upon such provisions, become holders of Senior
Debt; and such provisions are made for the benefit of the holders of Senior Debt
and such holders are hereby made obligees hereunder to the same extent as if
their names were written herein as such, and they and/or each of them may
proceed to enforce such provisions. In furtherance of the foregoing, each holder
of Senior Debt (i) is hereby irrevocably authorized and empowered but shall not
be obligated to demand, sue for, collect, receive and receipt for such holder's
ratable share of all payments and distributions in respect of this Note which
are required to be paid or delivered to holders of Senior Debt as provided
herein, and to file and prove all such claims and take all such other action in
the name of the holder of this Note or otherwise, as such holder of Senior Debt
may determine to be necessary or appropriate for the enforcement of the rights
provided herein, and (ii) may require the delivery to him by the holder of this
Note of such other instruments conforming such authorizations and such powers of
attorney, proofs of claim, assignments of claim and other instruments, and the
taking of all such other action, as he may request in order to enable such
holder of Senior Debt to enforce such holder's ratable share of all payments and
distributions in respect to this Note. No present or future holder of Senior
Debt shall be prejudiced in any way in the rights of such holder to enforce
subordination of this Note by any act or failure to act on the part of Maker or
any such holder.

     3. Redemption upon Change in Control.

        (a) In the event of any Change in Control, the holder of this Note shall
have the right, at such holder's option, to require the Maker to redeem, and
upon the exercise of such right the Maker shall redeem, all or any part of this
Note (in increments of Fifty Thousand Dollars ($50,000) principal amount) on the
date (the "Redemption Date") that is 100 calendar days after the date of such
Change in Control at a price equal to the principal amount purchased plus
accrued and unpaid interest to the Redemption Date.

        (b) On or before the 30th calendar day after any Change in Control, the
Maker shall give notice thereof and of the redemption right set forth herein
arising as a result thereof by first-class mail, postage pre-paid, to the holder
of this Note at such holder's address appearing in the books of the Maker.

            Each notice of a redemption right shall state:

                (i)   the Redemption Date,

                (ii)  the redemption price,

                (iii) the date by which the redemption right must be exercised,
                      and

                                       11
<PAGE>

                (iv)  a description of the procedure which the holder must 
                      follow to exercise a redemption right.

     No failure of the Maker to give the foregoing notice shall limit any
holder's right to exercise a redemption right.

        (c) To exercise a redemption right, the holder shall deliver to the
Maker (or an agent designated by the Maker for such purposes in the notice
referred to above) on or before the 90th calendar day after the Change in
Control (i) written notice of the holder's exercise of such right, which notice
shall set forth the name of the holder, the principal amount to be redeemed and
a statement that the option to exercise the redemption right is being made
thereby, and (ii) this Note, duly endorsed for transfer to the Maker. Such
written notice shall be irrevocable.

     In the event a redemption right shall be exercised in accordance with the
terms hereof, the Maker shall pay or cause to be paid the price payable with
respect to the principal amount as to which the redemption right has been
exercised in cash to the holder on the Redemption Date. In the event that a
redemption right is exercised with respect to less than the total principal
amount of this Note, the Maker shall cause to be issued a new Note representing
the principal amount of this Note which is not redeemed.

        (d) As used herein, (i) an "Affiliate" of or a Person "affiliated"
with, a specified Person, is a person that directly, or indirectly through one
or more intermediaries, controls, or is controlled by or is under common control
with, the Person specified; (ii) an "Associate" of, or a Person "associated"
with, any Person, means (1) any corporation or organization (other than the
Maker or a subsidiary of the Maker) of which such person is an officer, employee
or partner or is, directly or indirectly, the beneficial owner of 10% or more of
any class of equity securities, (2) any trust or other estate in which such
Person has substantial beneficial interest or as to which such Person serves as
trustee or in a similar fiduciary capacity, and (3) any relative or spouse of
such Person or who is a director or officer of such Person or any of its parents
or subsidiaries; (iii) the term "beneficial owner" shall be determined in
accordance with Rule 13d-3, as in effect on May 15, 1998, promulgated by the
Securities and Exchange Commission under the Securities and Exchange Act of
1934; (iv) a "Change in Control" of the Maker shall be deemed to have occurred
at such time as any Person, together with any Affiliates or Associates, (other
than Norman A. Gardner or entitles controlled by him, is or becomes the
beneficial owner, directly or indirectly, of shares of stock of the Maker
entitling such Person to exercise 55% or more of the total voting power of all
classes of stock or the Maker entitled generally to vote in elections of
directors; provided that such acquisition shall not be deemed to be a Change in
Control if such acquisition results from a business combination, including a
merger or consolidation or sale of all or substantially all assets, and
following such business combination this Note thereafter is convertible solely
into Common Stock (or like equity securities, exclusive of cash for fractional
shares) of the Maker, or of the then ultimate parent company of the Maker, which
Common Stock (or like equity securities) is publicly traded; and (v) "Person"
means any individual, corporation, partnership, joint venture, association,
join-stock company, trust, unincorporated organization or government or any


                                       12
<PAGE>

agency or political subdivision thereof. Notwithstanding the provisions
contained in this paragraph 3(d), the distribution, sale or exchange of shares
of Common Stock which, at the date of issuance of this Note, are owned by Norman
A. Gardner or entities controlled by him shall not constitute a "Change in
Control" as defined above.

     Except where inconsistent with the provisions of this paragraph 3, the
prepayment provisions of paragraph 1 shall be applicable to redemptions under
this paragraph 3.

     4. Events of Default. If one or more of the following events of default
shall have occurred and be continuing,

        (a) default in the payment of any installment of interest or principal
as and when the same shall become due and payable, and continuation of such
default for a period of ninety (90) days; or

        (b) failure on the part of Maker duly to perform any other covenant or
agreement on the part of Maker contained in this Note for a period of sixty (60)
days after the date on which written notice of such failure, requiring the same
to be remedied, shall have been given to Maker by the holder of this Note; or

        (c) entry of a decree or order by a court having jurisdiction in the
premises adjudging Maker a bankrupt or insolvent, or approving as properly filed
a petition seeking a reorganization of Maker under any applicable federal or
state law relating to bankruptcy, and continuation of such decree or order
undischarged or unstayed for a period of ninety (90) days; or

        (d) entry of a decree or order by a court having jurisdiction in the
premises for the appointment of a receiver or trustee or assignee in insolvency,
bankruptcy or reorganization of Maker or of its property, or for the winding up
or liquidation of its affairs, and continuation of such decree or order in force
undischarged or unstayed for a period of ninety (90) days;

then, and in each and every such case, the holder of this Note may declare the
principal of this Note to be due and payable immediately, and payment of such
principal debt, or the unpaid principal balance thereof, and all accrued and
unpaid interest thereon, together with all other sums due under the terms
hereof, may be enforced and recovered at once.

     5. Payment of Expenses. Maker promises to pay all reasonable costs and
expenses (including reasonable attorneys' fees) incurred in connection with the
collection of this Note upon a default by Maker and declaration by the holder of
this Note that the principal balance hereof is immediately due and payable.

     6. Covenants of Maker.

        (a) Maker will pay all taxes, assessments and governmental charges
lawfully levied or assessed upon it or its property, or any part thereof, or
upon its


                                       13
<PAGE>

income or profits, or any part thereof, before the same shall become delinquent,
and will duly observe and conform to all lawful requirements of any government
authority relative to any of its property, and all covenants, terms and
conditions upon or under which any of its property is held; provided, however,
that Maker shall have the right to pay such taxes, assessments or charges under
protest and shall have the right to contest the amount of or validity of any
such tax, assessment or charge by appropriate legal proceeding.

        (b) Maker will maintain its corporate existence and right to carry on
its business and duly procure all necessary renewals and extensions thereof and
use its best efforts to maintain, preserve and renew all rights, powers,
privileges and franchises; provided, however, that nothing herein contained
shall be construed to prevent the Maker from ceasing or omitting to exercise any
rights, powers, privileges or franchises the continuing exercise of which in the
opinion of Maker is no longer in the best interest of Maker.

        (c) Maker will keep and maintain all buildings, plants, motor vehicles
and other property owned by it in such good condition, repair and working order
and supplied with all such necessary equipment as in the judgment of Maker may
be necessary, so that the business carried on in connection therewith may be
properly and advantageously conducted at all times; provided, however, that
nothing herein contained shall prevent Maker from selling, abandoning or
otherwise disposing of any building, plant, motor vehicle or other property
whenever in the opinion of Maker the retention thereof is inadvisable or not
necessary to the business of Maker.

        (d) Maker will insure and keep insured in a reasonable amount with
reputable insurance companies so much of its properties as companies engaged in
a similar business and to the extent such companies in accordance with good
business practice customarily insure properties of a similar character against
loss by fire or from other causes and, in addition, Maker will maintain in
effect such public liability and property damage insurance as is customarily
maintained in accordance with good business practice by companies engaged in
similar business; or, in lieu thereof, Maker may maintain a system or systems of
self-insurance which will accord with the approved practices of companies owning
or operating properties of a similar character and maintaining such systems.

        (e) Maker covenants and agrees to provide to the holder of this Note
copies of its annual financial statements, audited by independent certified
public accountants, no later than fifteen (15) days after such annual reports
are available for distribution.

        (f) Maker covenants and agrees to provide to the holder of this Note,
within fifty (50) days after the close of each of its interim fiscal quarters,
unaudited income statements and balance sheets relating to its operations during
the previous quarter.

     7. Restriction on Transfer. This Note has not been registered under the
Securities Act of 1933 and cannot be transferred without either registration or
exemption from registration under that act and regulations promulgated
thereunder.

                                       14
<PAGE>

     8. Waivers. Maker as maker of this Note waives presentment, demand, protest
and notice of dishonor and protest.

     9. Notice. Any notice required or permitted to be given hereunder shall be
deemed sufficiently given as of the date it is mailed, first-class mail, postage
prepaid, if to the Maker to Nocopi Technologies, Inc., 537 Apple Street, W.
Conshohocken, PA 19428-2903 with a copy to Jack H. Halperin, Esq. 317 Madison
Ave., Suite 1421, New York, NY 10017 and if to Payee, to such address as appears
in the Register of Series B Extended Notes maintained by the Maker. Notice of
any change in address shall be deemed sufficiently given if given in accordance
herewith.

     IN WITNESS WHEREOF, the undersigned has executed this Note as of the day of
May, 1998.

                                              NOCOPI TECHNOLOGIES, INC.
                                              a Maryland corporation


ATTEST:                                   By: 
                                              -------------------------
                                              Richard A. Check,
President


By: 
    ------------------------------
       Joel A. Pinsky, Secretary