FORM OF COMMON STOCK CERTIFICATE COMMON STOCK NUMBER SHARES D DURA PHARMACEUTICALS [LOGO] Incorporated under the Laws of California SEE REVERSE FOR CERTAIN DEFINITIONS AND A STATEMENT AS TO THE RIGHTS, PREFERENCE, PRIVILEGES AND RESTRICTIONS OF SHARES CUSIP 26632S 10 9 THIS CERTIFIES THAT IS THE OWNER OF FULLY PAID AND NON-ASSESSABLE SHARE OF THE COMMON STOCK, WITHOUT PAR VALUE, OF DURA PHARMACEUTICALS, INC. transferable on the books of the Corporation by the holder hereof in person or by duly authorized attorney upon surrender of this certificate properly endorsed. This certificate is not valid until countersigned and registered by the Transfer Agent and Registrar. Witness the facsimile seal of the Corporation and the facsimile signatures of its duly authorized officer. NOW INCORPORATED IN THE STATE OF DELAWARE PAR VALUE $.001 Dated: [ Corporate Seal ] ---------------- --------------- --------------- Secretary President --------------- Transfer Agent REVERSE OF STOCK CERTIFICATE A Statement of the rights, preferences, privileges and restrictions granted to or imposed upon each class of shares authorized to be issued and upon the holders thereof may be obtained, upon request and without charge, from the corporation at its principal executive office or from the Transfer Agent. The following abbreviations, when used in the inscription on the face of this certificate, shall be construed as though they were written out in full according to applicable laws or regulations: TEN COM - as tenants in common TEN ENT - as tenants by the entireties JT TEN - as joint tenants with right of survivorship and not as tenants in common COM PROP - as community property UNIF GIFT MIN ACT - Uniform Gifts to Minors Act UNIF TRF MIN ACT - Uniform Transfers to Minors Act Additional Abbreviations may also be used though not in the above list. For Value Received, ______________ hereby sell(s), assign(s) and transfer(s) unto: ________________________________________________________________________________ Please insert Social Security or other Identifying Number of Assignee ________________________________________________________________________________ Name and Address Should Be Printed or Typewritten ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ shares of the capital stock represented by the within Certificate, and do hereby irrevocably constitute and appoint ____________________ Attorney-in-fact to transfer the said Stock on the books of the within named Corporation with full power of substitution in the premises. Dated: _____________________ ________________________________________ Signature Notice: The signature to this assignment must correspond with the name as written upon the face of the Certificate, in every particular, without alteration or enlargement, or any change whatever. Signature(s) Guaranteed By ___________________________________________