<PAGE>
 
                                                                   EXHIBIT 10.22



                        COMMON STOCK PURCHASE AGREEMENT
                        -------------------------------


          THIS COMMON STOCK PURCHASE AGREEMENT ("Agreement") is made and entered
into as of the 11th day of September 1998 by and between HARRIER, INC., a
Delaware corporation ("Harrier"), and NEW CAPITAL INVESTMENT FUND, a Cayman
Islands corporation ("NCIF").


                                R E C I T A L S
                                - - - - - - - -


          A.  Harrier currently owns 5,000,000 shares of the $.001 par value
common stock ("Common Stock") of Glycosyn Pharmaceuticals, Inc., a Delaware
corporation ("Glycosyn").

          B.  Harrier intends to undertake a reorganization which is conditioned
on Harrier selling 2,850,000 shares ("Shares") of Glycsoyn Common Stock prior to
consummation of the reorganization.

          C.  The principals of NCIF include certain current executive officers
and directors of Harrier and Glycosyn who are involved in the day-to-day
business activity of Glycosyn and are fully aware of all aspects of its
business.

          D.  NCIF wishes to acquire the Shares on the terms and conditions as
contained in this Agreement.

          E.  Prior to the transfer of the Shares, Harrier shall have received
from a qualified independent business appraiser an opinion to the effect that
the consideration to be received by Harrier in exchange for the Shares is fair
to the shareholders of Harrier from a financial point of view.

          NOW, THEREFORE, the parties agree as follows:


                               A G R E E M E N T
                               - - - - - - - - -


          1.  Incorporation of Recitals. The foregoing Recitals are herein
              -------------------------
incorporated by this reference.

          2.  Purchase and Sale of Shares.
              ---------------------------
<PAGE>
 
                2.1  Purchase and Sale of Stock. Subject to the terms and
                     --------------------------
conditions of this Agreement, at the Closing, Glycosyn will sell to NCIF, and
NCIF agrees to purchase from Glycosyn, the Shares in exchange for the
consideration as set forth in Section 2.2.

                2.2  Purchase Price. In consideration of its receipt of the
                     --------------
Shares, NCIF agrees:

                        2.2.1.  That concurrent with its receipt of the Shares
and without the need for any further action on the part of NCIF, all of the
indebtedness owing to NCIF by Harrier pursuant to that certain Loan Agreement
between NCIF and Harrier dated June 9, 1996 shall be canceled; and

                        2.2.2.  Effective as of the Closing, agree to indemnify,
defend and hold harmless Harrier against and in respect of any and all claims,
demands, losses, costs, expenses, liabilities and damages, including interest,
penalties, and reasonable attorneys' fees, that Harrier shall incur or suffer
which arise, result from or relate to that certain Research and Development
Agreement dated as of May 1, 1993 between Harrier and American Diagnostica, Inc.
("ADI"). In the event Harrier receives a complaint, claim or other notice of any
loss, claim or damage, liability or action, giving rise to a claim for
indemnification under this Section 2.2.2, Harrier shall promptly notify NCIF of
such complaint, notice, claim or action, and NCIF shall have the right to
investigate and defend any such loss, claim, damage, liability or action.
Harrier shall have the right to employ separate counsel in any such action and
to participate in the defense thereof but the fees and expenses of such counsel
shall not be at the expense of NCIF, unless NCIF fails to promptly defend, in
which case the fees and expenses of such separate counsel shall be borne by
NCIF. In no event shall NCIF be obligated to indemnify Harrier for any
settlement of any claim or action effected without NCIF's prior written consent.

          3.  Closing. The purchase and sale of the Shares shall take place at
              -------
the offices of Harrier, at 2200 Pacific Coast Highway, Suite 301, Hermosa Beach,
California 90254 at 10:00 a.m., California time, on September 11, 1998, or at
such other time and place as Harrier and NCIF shall mutually agree (which time
and place are designated as the "Closing"). At the Closing, Harrier shall
deliver to NCIF a certificate representing the Shares that NCIF is purchasing
against delivery of an executed copy of this Agreement.

          4.  Representations and Warranties of Harrier. Harrier hereby
              -----------------------------------------
represents and warrants to NCIF as follows.

                4.1  Organization: Good Standing: Qualification. Harrier is a
                     ------------------------------------------         
corporation duly organized, validly existing, and in good standing under the
laws of the State of Delaware, has all requisite corporate power and authority
to own and operate its properties and assets and to carry on its business as now
conducted and as proposed to be conducted, to execute and deliver this Agreement
and each other agreement executed concurrently herewith. Harrier is duly
qualified to transact business and is in good standing in each jurisdiction in
which the failure so to qualify would have a material adverse affect on its
business, properties, prospects or financial condition.
<PAGE>
 
                4.2  Authorization. All corporate action on the part of Harrier
                     -------------
necessary for the authorization, execution and delivery of this Agreement and
the performance of its obligations hereunder at the Closing has been taken or
will be taken prior to the Closing, and this Agreement shall constitute the
valid and legally binding obligation of Harrier, enforceable in accordance with
its terms except (i) as limited by applicable bankruptcy, insolvency,
reorganization, moratorium, and other laws of general application affecting
enforcement of creditors' rights generally; and (ii) as limited by laws relating
to the availability of specific performance, injunctive relief, or other
equitable remedies.

                4.3  Validity; Title. The Shares, when sold and delivered in
                     --------------- 
accordance with the terms of this Agreement for the consideration expressed
herein, will be duly and validly issued, fully paid, and nonassessable, and will
be free of restrictions on transfer other than restrictions on transfer under
this Agreement and under applicable state and federal securities laws. Harrier
shall deliver to NCIF at the Closing the original certificate(s) evidencing the
Shares with such endorsements, assignments and other instruments of transfer, in
form satisfactory to NCIF and its counsel, in order to effectively vest in NCIF
all of Harrier's right, title and interest in and to the Shares. From time to
time after the Closing, and without further consideration, Harrier will execute
and deliver such other instruments of transfer and take such other actions as
NCIF may reasonably request in order to more effectively transfer to NCIF the
securities intended to be transferred hereunder.

                4.4  Approval of Harrier Stockholders. Harrier will duly call
                     --------------------------------
and will promptly hold a meeting of its stockholders for the purpose of
approving, among other things, its sale of the Shares on the terms and
conditions set forth in this Agreement and in connection therewith will comply
fully with the applicable provisions of the Bylaws of Harrier and the Delaware
General Corporation Law relating to the calling and holding of a meeting of
stockholders for such purpose.

                4.5  Governmental Consents. All consents, approvals, orders,
                     ---------------------                                   
authorizations or registrations, qualifications, designations, declarations or
filings with any U.S., federal or state governmental authority on the part of
Harrier required in connection with the consummation of the transactions
contemplated herein shall have been obtained prior to and be effective as of the
Closing.

                4.6  No Further Representations. Except as expressly provided
                     --------------------------
herein, Harrier makes no representations or warranties concerning Glycosyn, its
assets, operations, contracts or affairs. Harrier states hereby its intent to
enter into this Agreement in strict reliance on NCIF's representations,
acknowledgements and agreements set forth in Section __ that it is intimately
familiar with all aspects of Glycosyn and that it is willing to acquire the
Shares on a "as is", "where is" and "with all faults basis."

          5.  Representations and Warranties of NCIF. NCIF hereby represents and
              --------------------------------------
warrants to Harrier as follows.
<PAGE>
 
                5.1  Organization; Good Standing; Qualification.  NCIF is a
                     ------------------------------------------            
corporation duly organized, validly existing, and in good standing under the
laws of the Cayman Islands. NCIF has all requisite corporate power and authority
to own and operate its properties and assets and to carry on its business as now
conducted and as proposed to be conducted, to execute and deliver this Agreement
and each other agreement executed concurrently herewith. NCIF is duly qualified
to transact business and is in good standing in each jurisdiction in which the
failure so to qualify would have a material adverse effect on its business,
properties, prospects or financial condition.

                5.2  Authorization. All corporate action on the part of NCIF
                     -------------
necessary for the authorization, execution and delivery of this Agreement and
the performance of all obligations of NCIF hereunder at the Closing has been
taken or will be taken prior to the Closing, and this Agreement shall constitute
the valid and legally binding obligation of NCIF, enforceable in accordance with
its terms except (i) as limited by applicable bankruptcy, insolvency,
reorganization, moratorium, and other laws of general application affecting
enforcement of creditors' rights generally; and (ii) as limited by laws relating
to the availability of specific performance, injunctive relief, or other
equitable remedies.

                5.3  Investment and Related Representations.
                     --------------------------------------

                        5.3.1  Harrier Shares as "Restricted" Securities. NCIF
                               -----------------------------------------
is aware that neither the Shares nor the offer or sale thereof to the NCIF has
been registered under the Securities Act of 1933, as amended ("Securities Act"),
or under any foreign or state securities law. NCIF further understands that no
registration statement has been filed with the Securities and Exchange
Commission ("SEC"), nor with any other U.S. or foreign regulatory authority and
that, as a result, any benefit which might normally accrue to an investor such
as NCIF by an impartial review of such a registration statement by the SEC or
other regulatory commission will not be forthcoming. NCIF acknowledges that the
Shares are being offered pursuant to certain exemptions from Section 5 of the
Securities Act for offers and sale of securities not involving and issuer,
underwriter or dealer. NCIF understands that Shares are "restricted" securities
under U.S. federal securities laws inasmuch as they are being acquired from an
affiliate of the issuer and that under such laws and applicable regulations such
securities may be resold without registration under the Securities Act only in
certain limited circumstances. NCIF represents that it is familiar in general
with Rule 144 under the Securities Act (which provides generally for a one year
holding period and limitations on the amount of "restricted" securities that can
be sold in compliance with the rule upon completion of the holding period), and
understands the resale limitations imposed thereby and by the Securities Act.
NCIF understands that each certificate representing the Shares and any other
securities issued in respect of the Shares upon any stock split, stock dividend,
recapitalization, merger or similar event (unless no longer required in the
opinion of counsel for Glycosyn) shall be stamped or otherwise imprinted with
legends substantially in the following forms (in addition to any legend that may
now or hereafter be required by applicable state law):

          "THE SHARES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED
UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY STATE 
<PAGE>
 
SECURITIES LAWS. THEY MAY NOT BE OFFERED, SOLD OR OTHERWISE TRANSFERRED, PLEDGED
OR HYPOTHECATED IN THE ABSENCE OF A REGISTRATION STATEMENT IN EFFECT WITH
RESPECT TO SUCH SECURITIES, OR DELIVERY OF AN OPINION OF COUNSEL SATISFACTORY TO
THE ISSUER OF SUCH SECURITIES THAT SUCH OFFER, SALE, TRANSFER, PLEDGE OR
HYPOTHECATION IS IN FULL COMPLIANCE WITH THE SECURITIES ACT OF 1933, AS AMENDED,
OR UNLESS SOLD IN COMPLIANCE WITH RULE 144 UNDER SUCH ACT."

NCIF agrees that the it will not sell any portion of Shares except pursuant to
registration under the Securities Act or pursuant to an available exemption from
registration under the Securities Act.  NCIF understands that Glycosyn shall
refuse to transfer the Shares except in accordance with the restrictions and
agreements of NCIF set forth in this Section 5.3.

                        5.3.2  Investment Representation. The Shares are being
                               -------------------------
acquired by NCIF pursuant to this Agreement for investment and not with a view
to the public resale or distribution thereof unless pursuant to an effective
registration statement or exemption under the Securities Act.

                        5.3.3  No Public Solicitation. NCIF is acquiring the
                               ----------------------
Shares after private negotiation and has not been attracted to the acquisition
of the Shares by any press release, advertising or publication.

                        5.3.4  Investor Sophistication and Ability to Bear Risk
                               ------------------------------------------------
of Loss. NCIF has not been organized for the purpose of acquiring the Shares.
-------
NCIF acknowledges that it is able to protect its interests in connection with
the acquisition of the Shares and can bear the economic risk of investment in
such securities without producing a material adverse change in NCIF's financial
condition. NCIF otherwise has such knowledge and experience in financial or
business matters that NCIF is capable of evaluating the merits and risks of the
investment in the Shares.

                5.4  Governmental Consents. All consents, approvals, orders,
                     ---------------------   
authorizations or registrations, qualifications, designations, declarations or
filings with any U.S., federal or state governmental authority on the part of
NCIF required in connection with the consummation of the transactions
contemplated herein shall have been obtained prior to and be effective as of the
Closing.

                5.5  Third Party Consents.  All third party consents, approvals,
                     --------------------                                       
orders or authorizations required to be obtained by NCIF in connection with the
consummation of the transactions contemplated herein have been obtained.

                5.6  Disclaimer of Warranty. NCIF acknowledges and agrees that
                     ----------------------
it is acquiring the Shares "AS-IS", "WHERE-IS" and "WITH ALL FAULTS" and subject
to any conditions which may exist, without any representations or warranties by
Harrier except as expressly provided herein. NCIF acknowledges that it is
relying solely upon its own inspections, examinations and evaluations of the
Shares and Glycosyn and is accepting assignment of the 
<PAGE>
 
Shares without the standard representations, warranties or covenants customarily
provided to the purchaser of a business.

          6.  Conditions of to the Parties' Obligations at Closing. The
              ----------------------------------------------------
obligations of the parties under Section 2 of this Agreement are subject to the
fulfillment on or before the Closing of each of the following conditions, the
waiver of which shall not be effective against any party unless such waiver is
in writing and signed by the party against whom the waiver is sought to be
enforced.

                6.1  Representations and Warranties. The representations and
                     ------------------------------       
warranties contained herein shall be true and correct on and as of the Closing
with the same effect as though such representations and warranties had been made
on and as of the date of such Closing.

                6.2  Performance. Each party shall have performed and complied
                     -----------       
with all agreements, obligations and conditions contained in this Agreement that
are required to be performed or complied with on or before the Closing.

                6.3  Qualifications. All authorizations, approvals, or permits,
                     --------------
if any, of any governmental authority or regulatory body of the United States or
of any state that are required to complete the purchase and sale described
herein shall be duly obtained and effective as of the Closing.

                6.4  Harrier Stockholder Approval. The holders of the
                     ----------------------------
outstanding shares of the Harrier Common Stock shall have approved, in
accordance with Delaware General Corporation Law, Harrier's sale of the Shares
pursuant to the terms and conditions of this Agreement.

                6.5  Fairness Opinion. Harrier shall have received the fairness
                     ----------------
opinion referred to in the recitals.

                6.6. Proceedings and Documents. All corporate and other
                     -------------------------
proceedings in connection with the transactions contemplated at the Closing and
all documents incident thereto shall be reasonably satisfactory in form and
substance to NCIF, which shall have received all such counterpart originals and
certified or other copies of such documents as it may reasonably request.

          7.  Termination.  This Agreement and each party's obligations
              -----------                                              
hereunder may be terminated at any time and for any reason, effective upon the
delivery of written notice by the terminating party, up to the time of the
Closing.

          8.  MISCELLANEOUS.
              ------------- 

                8.1  Cumulative Remedies. Any person having any rights under any
                     -------------------
provision of this Agreement will be entitled to enforce such rights
specifically, to recover damages by reason of any breach of any provision of
this Agreement, and to exercise all other rights granted by law, which rights
may be exercised cumulative and not alternatively.
<PAGE>
 
                8.2  Successors and Assigns.  The rights and obligations of the
                     ----------------------
parties under this Agreement shall not be assignable without the written consent
of COPE and Harrier and any such purported assignment with their written consent
shall be void ab initio.  Except as otherwise expressly provided herein, all
              -- ------                                                     
covenants and agreements contained in this Agreement by or on behalf of any of
the parties hereto will bind and inure to the benefit of the respective
successors and assigns of the parties hereto whether so expressed or not.

                8.3  Severability. Whenever possible, each provision of this
                     ------------ 
Agreement will be interpreted in such manner as to be effective and valid under
applicable law, but if any provision of this Agreement is held to be prohibited
by or invalid under applicable law, such provision will be ineffective only to
the extent of such prohibition or invalidity, without invalidating the remainder
of this Agreement or the other documents.

                8.4  Counterparts. This Agreement may be executed in two or more
                     ------------
counterparts, any one of which need not contain the signatures of more than one
party, but all such counterparts when taken together will constitute one and the
same agreement.

                8.5  Notices.  Any approvals, consents or notices required or
                     ------- 
permitted to be sent or given shall be delivered in writing personally or
mailed, certified mail, return receipt requested, to the following addresses and
shall be deemed to have been received within five days after such mailing:

If to NCIF:                             New Capital Investment Fund
                               
                                        Georgetown, Grand Cayman
                                        Cayman Islands, British West Indies
                                        Attn: Jurg Kehrli, Director
<PAGE>
 
with a copy to:                         Raiskin and Ravitz
                                        10390 Santa Monica Boulevard
                                        Los Angeles, California  90254
                                        Attn: Daniel Raiskin, Esq.
If to Harrier:                          Harrier, Inc.
                                        2200 Pacific Coast Highway, Suite 301
                                        Hermosa Beach, California  90254
                                        Attn: Kevin DeVito, President

with a copy to:                         Oppenheimer Wolff & Donnelly
                                        A Professional Corporation
                                        500 Newport Center Drive, Suite 700
                                        Newport Beach, California  92660
                                        Attn:  Daniel K. Donahue, Esq.

                8.6  Governing Law; Arbitration. The validity, meaning and
                     --------------------------
effect of this Agreement shall be determined in accordance with the laws of the
State of California, applicable to contracts made and to be performed in that
state, without regard to its conflicts of laws rules; provided however that the
Federal Arbitration Act of the United States shall govern issues as to
arbitrability. If a dispute arises in connection with or relating to this
Agreement and the parties are unable to resolve it within forty-five (45) days
through direct negotiations, the dispute shall be referred to final and binding
arbitration to be held in Los Angeles, California in accordance with the rules
of the American Arbitration Association for Commercial Arbitration (as they may
be amended from time to time). The award of the arbitrator(s) shall be final and
binding upon the parties hereto and may be enforced by any court of competent
jurisdiction.

                8.7  Litigation Costs. If any legal action or any arbitration or
                     ----------------
other proceeding is brought for the enforcement of this Agreement, or because of
an alleged dispute, breach, default, or misrepresentation in connection with any
of the provisions thereof, the successful or prevailing party or parties shall
be entitled to recover reasonable attorneys' fees and other costs incurred in
that action or proceeding, in addition to any other relief to which it or they
may be entitled.

                8.8  Entire Agreement. This Agreement constitutes the entire
                     ----------------
agreement and understanding of the parties with respect to the subject matter
thereof, and supersedes all prior and contemporaneous agreements and
understandings.
<PAGE>
 
          IN WITNESS WHEREOF, each of the parties to this Agreement has executed
or caused this Agreement to be executed as of the date first above written.


                                         "HARRIER"
                                        
                                         Harrier, Inc.,
                                         a Delaware corporation
                                        
                                         By:/s/ Kevin DeVito
                                            ------------------------
                                            Kevin DeVito, President

                                         "NCIF"
                                        
                                         New Capital Investment Fund,
                                         a Cayman Islands corporation
                                        
                                        
                                         By:/s/ Jurg Kehrli
                                            ------------------------
                                            Jurg Kehrli, Director