1 EXHIBIT 4.1 [FRONT OF STOCK CERTIFICATE] DEVELOPPEMENT CLINICHEM DEVELOPMENT CONSTITUEE EN VERTU DE LA LOI CANADIENNE SUR LES SOCIETES PAR ACTIONS INCORPORATED UNDER THE CANADA BUSINESS CORPORATIONS ACT LE CAPITAL-ACTIONS AUTORISE DE LA SOCIETE EST CONSTITUE D'UN NOMBRE LIMITE DE 1 000 ACTIONS ORDINAIRES, D'UN NOMBRE ILLIMITE D'ACTIONS ORDINAIRES DE CATEGORIE A ET D'UN NOMBRE LIMITE DE 1 000 ACTIONS ORDINAIRES DE CATEGORIE B. THE AUTHORIZED SHARE CAPITAL OF THE CORPORATION CONSISTS OF A LIMITED NUMBER OF 1,000 COMMON SHARES, AN UNLIMITED NUMBER OF CLASS A COMMON SHARES AND A LIMITED NUMBER OF 1,000 CLASS B COMMON SHARES. CUSIP 186906 10 3 NUMERO - NUMBER ACTIONS - SHARES Les presentes attestent que This certifies that est le detenteur enregistre de is the registered holder of ACTIONS ORDINAIRES DE CATEGORIE A SANS VALEUR NOMINALE ENTIEREMENT LIBEREES ET NON SUJETTES A APPELS DE VERSEMENTS DU CAPITAL-ACTIONS DE DEVELOPPEMENT CLINICHEM INC. L'inscription des transferts des actions representees par ce certificat ne peut etre faite aux livres de la Societe que par le detenteur inscrit en personne ou par son mandataire dument autorise par ecrit sur remise de ce certificat dument endosse, sous reserve des exigences des lois regissant la Societe. Ce certificat n'est valide que s'il est contresigne par l'agent des transferts et inscrit par l'agent charge de la tenue des registres de la Societe. EN FOI DE QUOI, la Societe a fait signer ce certificat par ses officiers dument autorises. CLASS A COMMON SHARES WITHOUT PAR VALUE, FULLY PAID AND NOT SUBJECT TO CALLS, OF THE SHARE CAPITAL OF CLINICHEM DEVELOPMENT INC. Entry of the transfers of the shares represented by this certificate may be made in the books of the Corporation only by the registered holder in person or by his attorney duly authorized in writing, upon surrender of this certificate properly endorsed, subject to compliance with the requirements of the laws governing the Corporation. This certificate shall not be valid unless countersigned by the Transfer Agent and registered by the Registrar of the Corporation. IN WITNESS WHEREOF, the Corporation has caused this certificate to be signed by its duly authorized officers. Date/Dated: CONTRESIGNE ET INSCRIT - COUNTERSIGNED AND REGISTERED TRUST GENERAL DU CANADA, Montreal, Toronto GENERAL TRUST OF CANADA, Montreal, Toronto AGENT DES TRANSFERTS ET AGENT CHARGE DE LA TENUE DES REGISTRES TRANSFER AGENT AND REGISTRAR PAR - PER: --------------------------------------------------- REPRESENTANT AUTORISE - AUTHORIZED REPRESENTATIVE LE PRESIDENT, LE CHEF DE LA DIRECTION FINANCIERE, PRESIDENT CHIEF FINANCIAL OFFICER L'INSCRIPTION DU TRANSFERT DES ACTIONS REPRESENTEES PAR CE CERTIFICAT PEUT ETRE FAITE AUX PRINCIPALES PLACES D'AFFAIRES DE TRUST GENERAL DU CANADA A MONTREAL ET A TORONTO. REGISTRATION OF THE TRANSFER OF THE SHARES REPRESENTED BY THIS CERTIFICATE MAY BE MADE AT THE PRINCIPAL OFFICES OF GENERAL TRUST OF CANADA IN MONTREAL AND TORONTO. 2 [BACK OF STOCK CERTIFICATE] LE TEXTE QUI SUIT EST UN SOMMAIRE DES DROITS, THE FOLLOWING IS A SUMMARY OF THE RIGHTS, PRIVILEGES, PRIVILEGES, CONDITIONS ET RESTRICTIONS AFFERENTS AUX CONDITIONS AND RESTRICTIONS ATTACHING TO THE CLASS A ACTIONS ORDINAIRES DE CATEGORIE A DU CAPITAL-ACTIONS COMMON SHARES OF THE SHARE CAPITAL OF THE DE LA SOCIETE DONT LE TEXTE COMPLET SERA FOURNI, SANS CORPORATION, THE FULL TEXT OF WHICH WILL BE PROVIDED FRAIS, SUR DEMANDE. WITHOUT CHARGE UPON REQUEST. ACTIONS ORDINAIRES DE CATEGORIE A CLASS A COMMON SHARES Les porteurs d'actions ordinaires de categorie A, tout The holders of Class A Common shares, as for the holders comme les porteurs d'actions ordinaires ou d'actions of Common Shares or Class B Common Shares, are entitled ordinaires de categorie B, ont droit a un vote par to one vote per share except for the right of the holders action sous reserve du droit des porteurs d'actions of the Class B Common Shares to elect one of the directors ordinaires de categorie B d'elire un administrateur of the Corporation. Concurrently with the holders of Common de la Societe. Concurremment avec les porteurs Shares and Class B Common Shares, the holders of Class A d'actions ordinaires et d'actions ordinaires de Common Shares are entitled to receive such dividends as the categorie B, les porteurs d'actions ordinaires de Board of Directors of the Corporation may declare and in categorie A ont droit de recevoir les dividendes que event of the liquidation or dissolution of the Corporation, le conseil d'administration de la Societe peut to receive, after the holders of Class B Common Shares, declarer et de recevoir, apres les porteurs d'actions the remaining assets of the Corporation. ordinaires de categorie B, le reliquat des biens de la Societe en cas de dissolution ou de liquidation. Tel que plus amplement decrit aux status constitutifs As described in the Articles of Incorporation as amended of amendes de la Societe, les actions ordinaires de the Corporation, the Class A Common Shares evidenced hereby categorie A representees par les presentes sont are subject to an option to purchase in favour of the holder sujettes a une option d'achat en faveur du detenteur of the majority of the outstanding Class B Common Shares of de la majorite des actions ordinaires de categorie B the Corporation, such option is for a determined purchase en circulation de la Societe; cette option d'achat price and expires at a precise date. est pour un prix determine et se termine a une date precise. Pour valeur recue, le (la) soussigne(e) vend, For value received, the undersigned hereby sells, cede et transporte, par les presentes, a assigns and transfers unto INDIQUER LE NUMERO D'ASSURANCE (BOX)(BOX)(BOX)-(BOX)(BOX)(BOX)-(BOX)(BOX)(BOX) PLEASE INSERT SOCIAL INSURANCE SOCIALE DU CESSIONNAIRE NUMBER OF TRANSFEREE - ------------------------------------------------------------------------------------------------------------------- actions ordinaires de categorie A - ---------------------------------------------------------------------------------------------- Class A Common Shares du capital-actions representees par le present of the share capital represented by the within certificate, certificat et constitue par les presentes and does hereby irrevocably constitute and appoint - -------------------------------------------------------------------------------------------------------------------- son mandataire irrevocable, avec plein droit de his/her attorney to transfer the said shares on the securities delegation des pouvoirs conferes, pour le transfert registers of the within named Corporation with full power desdites actions dans les registres des valeurs of substitution. mobilieres de la Societe. Date------------------------------------------------ Signature---------------------------------------------------- Temoin Witness--------------------------------------------- AVIS: LA SIGNATURE A CETTE CESSION DOIT CORRESPONDRE, EN TOUS POINTS, AU NOM TEL QU'ECRIT AU RECTO OU CERTIFICAT, SANS AUCUNE ADDITION, ALTERATION OU MODIFICATION. 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.