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                                                                     Exhibit 4.4

                     UNSECURED SUBORDINATED PROMISSORY NOTE

                                (PHARMCHEM, INC.)


PAYOR'S OBLIGATIONS UNDER THIS NOTE ARE SUBORDINATE TO ALL INDEBTEDNESS AND
OBLIGATIONS OF PAYOR TO COMERICA BANK -- CALIFORNIA ("BANK") AND ARE SUBJECT TO
THE TERMS OF A SUBORDINATION AGREEMENT DATED AS OF SEPTEMBER , 2001 BETWEEN
PAYEE AND BANK.

$____________                                             SEPTEMBER ___  , 2001

FOR VALUE RECEIVED, PHARMCHEM, INC., a Delaware corporation (the "Payor" or the
"Company"), promises to pay to the order of ______________ ("Payee") the
principal amount of ________________ U.S. Dollars (U.S. $__________) (the
"Principal") with simple interest on the unpaid balance of the principal amount
at nine percent (9%) per annum (the "Interest") commencing on the date of this
Note. The Principal and Interest shall be collectively referred to herein as the
"Obligation."

1. Interest shall be payable annually during the term of this Note commencing on
September , 2002. This Note shall mature on September 30, 2003 (the "Maturity
Date"), and all unpaid Principal and accrued and unpaid Interest shall be due
and payable on the Maturity Date. All or any portion of the Principal owing
hereunder may be paid at any time without any premium or penalty. Any payment or
prepayment of this Note will be credited first to accrued and unpaid Interest
and second to the unpaid Principal.

2. The Obligation shall be subordinate in payment and priority to the
indebtedness of the Payor due and owing to Comerica Bank -- California ("Bank")
evidenced by that certain Amended and Restated Loan and Security Agreement dated
as of May 15, 2000, as amended, by and between the Payor and Bank and any other
instrument evidencing indebtedness or obligations of the Payor to Bank (the
"Senior Debt") as provided in that certain Subordination Agreement between Bank
and the Payor dated as of September , 2001.

3. At its option, Payee may declare a default on this Note and all liabilities
of the Payor to Payee under this Note will become due upon the occurrence of any
of the following (each, an "Event of Default") after not less than three (3)
days shall have passed following delivery of written notice by Payee to the
Payor of such Event of Default:

        (a) Failure to make any payment within ten (10) days after the date due;

        (b) Issuance against the Payor of a writ of attachment, order of
            garnishment, and/or execution;

        (c) The material breach of any representation or warranty of the Payor
            contained in this Note at the time when such representation or
            warranty is made;

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        (d) The material breach of any covenants of the Payor contained in this
            Note;

        (e) Acceleration of any of the Payor's indebtedness for borrowed money
            as a result of a default or breach of or under any agreement for
            such borrowed money which default or breach is not cured within the
            applicable provisions of the agreements or instruments evidencing
            such indebtedness, including but not limited to loan agreements,
            real property lease agreements and capital equipment lease
            agreements, by which the Payor is bound or obligated;

        (f) The dissolution, termination of existence or insolvency of the
            Payor; the appointment of a receiver of all or any part of the
            property of the Payor; or an assignment for the benefit of creditors
            by the Payor; or

        (g) The initiation of any bankruptcy, insolvency, moratorium,
            receivership or reorganization proceedings by or against the Payor
            or a general assignment of assets by the Payor for the benefit of
            creditors.

4. The Payor hereby represents and warrants to Payee as follows:

        (a) The Payor has all requisite corporate power to execute and deliver
this Note and to carry out and perform its obligations under the terms of this
Note.

        (b) All corporate action on the part of the Payor necessary for the
authorization, execution, delivery and performance of this Note by the Payor and
the performance of the Payor's obligations hereunder has been taken. This Note,
when executed and delivered by the Payor, shall constitute the valid and binding
obligation of the Payor enforceable in accordance with its terms, except as
enforceability may be limited by bankruptcy, insolvency, reorganization,
moratorium and other laws affecting creditors' rights generally, or by general
equitable principles.

        (c) Except as set forth in a Schedule of Exceptions delivered to Payee
by the Payor concurrently with the execution of this Note, (i) the Payor is not
in violation in any material respect of any term or provision of any charter,
bylaw, or any material term or provision of any indebtedness, mortgage,
indenture, contract, agreement, judgment, or, to the Payor's knowledge, any
decree, order, statute, rule, or regulation applicable to the Payor, and (ii)
the execution, delivery, and performance of and compliance with this Note, or
the consummation of any other transaction contemplated hereby, will not, with or
without the passage of time or giving of notice, result in any such material
violation, or be in conflict with or constitute a default under any such term,
or result in the creation of any mortgage, pledge, lien, encumbrance or charge
upon any of the properties or assets of the Payor or the suspension, revocation,
impairment, forfeiture or nonrenewal of any permit, license, authorization or
approval applicable to the Payor, its business or operations or any of its
assets or properties.

        (d) The Payor is a corporation duly organized and validly existing under
the laws of the State of Delaware and is in good standing under such laws. The
Payor has all requisite corporate power and authority to own its properties and
assets and to carry on its business as presently conducted. The Payor is
qualified to do business in each jurisdiction in which the


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failure to be so qualified would have a materially adverse impact on the
business or financial condition of the Payor.

5. No delay on the part of Payee in the exercise of any power or right under
this Note or under any other instrument executed pursuant hereto shall operate
as a waiver thereof, nor shall a single or partial exercise of any power or
right preclude other or further exercise thereof or the exercise of any other
power or right.

6. The Payor and all endorsers of this Note waive demand, presentment, protest,
notice of dishonor, notice of nonpayment, notice of intention to accelerate,
notice of acceleration, notice of protest and any and all lack of diligence or
delay in collection or the filing of suit hereon which may occur, and agree to
all extensions and partial payments, before or after maturity, without prejudice
to Payee.

7. This Note shall be governed by and construed in accordance with the laws of
the State of Delaware without regard to the principles of conflicts of laws
thereof.

8. The provisions of this Note shall inure to the benefit of and shall be
binding on the heirs, personal representatives and successors in interest of the
parties hereto. Any amendment to this Note shall be in writing executed by the
Payor and Payee. The Payor shall pay all reasonable costs of collection,
including reasonable attorneys' fees, incurred in the event that all amounts
owing hereunder are not paid in accordance with the terms hereof. The Payor
shall have no right to set off from amounts due to Payee hereunder any amount
due or claimed to be due from Payee to the Payor.

9. All agreements between the Payor and Payee, whether now existing or hereafter
arising and whether written or oral, are expressly limited so that in no
contingency or event whatsoever, whether by acceleration of the maturity of this
Note or otherwise, shall the amount paid, or agreed to be paid, to Payee for the
use, forbearance or detention of the money to be loaned hereunder or otherwise,
exceed the maximum amount permissible under applicable law. If, from any
circumstances whatsoever, fulfillment of any provision of this Note, at the time
performance of such provision shall be due, shall involve transcending the limit
of validity prescribed by law, then ipso facto the obligation to be fulfilled
shall be reduced to the limit of such validity, and if from any such
circumstances Payee shall ever receive anything of value as interest or deemed
interest by applicable law under this Note an amount that would exceed the
highest lawful rate, such amount that would be excessive interest shall be
applied to the reduction of the principal amount owing under this Note or on
account of any other indebtedness of the Payor to Payee relating to this Note,
and not to the payment of interest, or if such excessive interest exceeds the
unpaid balance of principal of this Note, such excess shall be refunded to the
Payor. In determining whether or not the interest paid or payable with respect
to any indebtedness of the Payor to Payee, under any specific contingency,
exceeds the highest lawful rate, the Payor and Payee shall, to the maximum
extent permitted by applicable law, (i) characterize any nonprincipal payment as
an expense, fee or premium rather than as interest, (ii) amortize, prorate,
allocate and spread the total amount of interest throughout the full term of
such indebtedness so that the actual rate of interest on account of such
indebtedness is uniform throughout the term thereof, and/or (iii) allocate
interest between portions of such indebtedness, to the end that no such portion
shall bear interest at a rate greater than that permitted by law. The


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terms and provisions of this paragraph shall control and supersede every other
conflicting provision of all agreements between the Payor and Payee.

10. The Payor shall not assign or delegate its obligations hereunder without the
prior written consent of Payee; provided that the Payor may, without the consent
of Payee, assign or delegate its obligations hereunder to an affiliate of the
Payor or to a successor to the Payor as a result of a merger, consolidation,
corporate reorganization, sale of substantially all of its assets or similar
transaction. To the extent permitted hereunder, all of the stipulations,
promises and agreements in this Note contained by or on behalf of the Payor
shall bind the successors and assigns of the Payor and Payee, whether so
expressed or not, and inure to the benefit of the successors and assigns of the
Payor and Payee. Any permitted assignee of the Payor shall agree in writing
prior to the effectiveness of such assignment to be bound by the provisions
hereof. Payee may sell, transfer, assign, pledge or hypothecate all or any
portion of this Note.

11. This Note contains the entire agreement between the parties relating to the
subject matter hereof and supercedes any and all prior or contemporaneous
written or oral agreements, understandings, negotiations, correspondence or
discussions between the parties relating to the subject matter hereof. This Note
does not impose on Payee any obligations to contribute, lend or invest any
further sums of money or property to or in the Payor.

12. In the event any one or more of the provisions contained in this Note shall
for any reason be held to be invalid, illegal or unenforceable in any respect,
such invalidity, illegality or unenforceability shall not affect any other
provision hereof, and this Note shall be construed as if such invalid, illegal
or unenforceable provision had never been contained herein.

13. Any and all notices or other communications or deliveries hereunder shall be
in writing and shall be deemed given and effective on the earliest of (a) the
date of transmission, if such notice or communication is delivered via facsimile
at the facsimile telephone number specified in this Section prior to 4:30 p.m.
(Eastern Time) in the case of notices to Payee or 4:30 p.m. (Central time) in
the case of notices to the Payor, in each case on a business day, (b) the
business day after the date of transmission, if such notice or communication is
delivered via facsimile at the facsimile telephone number specified in this
Section later than 4:30 p.m. (Eastern Time) in the case of notices to Payee or
4:30 p.m. (Central time) in the case of notices to the Payor, in each case on
any date and earlier than 11:59 p.m. (Eastern Time) in the case of notices to
Payee or 11:59 p.m. (Central time) in the case of notices to the Payor on such
date, (c) the business day following the date of mailing, if sent by nationally
recognized overnight courier service, or (d) upon actual receipt by the party to
whom such notice is required to be given. The addresses for such communications
shall be:

If to the Payor:

PharmChem, Inc.
4600 Beach Street
Haltom City, Texas  76137
Attention:  Chief Financial Officer
Facsimile:  817-581-2049


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with a copy to:

Robin M. Edwards
Sonnenschein Nath & Rosenthal
685 Market Street, Sixth Floor
San Francisco, California  94105
Facsimile:  (415) 543-5472

If to Payee:

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with a copy to:

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or to such other address or facsimile number as one party may provide to the
other in accordance with this Section 13.


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IN WITNESS WHEREOF, the Payor has caused this Note to be signed by its duly
authorized officer as of the above date.

                                            PHARMCHEM, INC.

                                            By _________________________________

                                            Its:________________________________