TAX SHARING AGREEMENT

EXHIBIT 10.1

TAX SHARING AGREEMENT

     This Tax Sharing Agreement (this “ Agreement ”) is entered into as of June 13, 2008 between Bentley Pharmaceuticals, Inc., a Delaware corporation (“ Bentley ”), and CPEX Pharmaceuticals, Inc., a Delaware corporation and wholly owned subsidiary of Bentley (“ CPEX ” and together with Bentley, the “ Parties ”). Capitalized terms used in this Agreement and not otherwise defined herein shall have the meanings ascribed to such terms in the Separation and Distribution Agreement, dated as of the date hereof, by and between Bentley and CPEX (the “ Separation Agreement ”).

RECITALS

     Whereas, Bentley is the common parent corporation of an affiliated group of corporations within the meaning of Section 1504(a) of the Internal Revenue Code of 1986, as amended (the “ Code ”), that has filed consolidated federal income tax returns.

     Whereas, CPEX is a newly-formed, wholly owned subsidiary of Bentley.

     Whereas, pursuant to the Separation Agreement, among other things, Bentley will transfer to CPEX all of the CPEX Assets and CPEX will issue to Bentley shares of CPEX Common Stock and CPEX will contribute all of the CPEX Assets to CPEX Pharma, Inc., a Delaware corporation, newly-formed and wholly owned subsidiary of CPEX, in exchange for common stock (collectively, the “ Contribution ”);

     Whereas, on the Distribution Date, Bentley will distribute all of the issued and outstanding shares of CPEX Common Stock on a pro rata basis to holders of Bentley Common Stock (the “ Distribution ”);

     Whereas, the Parties intend that the Distribution shall not qualify as a distribution described in Section 355 of the Code (the “ Distribution Tax Treatment ”);

     Whereas, the Parties intend that after the Distribution none of CPEX or its Subsidiaries will be a member of the Bentley Group for federal income tax purposes;

     Whereas, the Parties intend that the Contribution, taking into account the Distribution, shall qualify as a series of transfers described in Section 351(a) of th eCode or otherwise as a transaction eligible for tax-free treatment under the Code (the “ Contribution Tax Treatment ”); and

     Whereas, the Parties desire to set forth their rights and obligations with respect to Taxes (as defined herein) due for periods before and after the Distribution Date;

     NOW, THEREFORE, for good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Parties hereto agree as follows:

ARTICLE I.

DEFINITIONS

     1.01 GENERAL. As used in this Agreement, the following terms shall have the following meanings:

“ Affiliate ” shall have the meaning set forth in the Separation Agreement.

“ Agreement ” shall have the meaning set forth in the preamble to this Agreement.

“ Ancillary Agreements ” shall mean the Ancillary Agreements as set forth in the Separation Agreement together with the Separation Agreement.

“ Bentley ” shall have the meaning set forth in the preamble to this Agreement.

“ Bentley Filed Tax Return ” shall have the meaning set forth in Section 2.01(a).

“ Bentley Group ” shall have the meaning set forth in the Separation Agreement.

“ Bentley Indemnitees ” shall have the meaning set forth in Section 4.01(b).

“ Bentley Taxes ” shall have the meaning set forth in Section 2.03(b).

“ Code ” shall have the meaning set forth in the recitals.

“ Contribution ” shall have the meaning set forth in the recitals.

“ Contribution Tax Treatment ” shall have the meaning set forth in the recitals.

“ CPEX ” shall have the meaning set forth in the preamble to this Agreement.

“ CPEX Assets ” shall have the meaning set forth in the Separation Agreement.

“ CPEX Business ” shall have the meaning set forth in the Separation Agreement.

“ CPEX Common Stock ” shall have the meaning set forth in the Separation Agreement.

“ CPEX Filed Tax Return ” shall have the meaning set forth in Section 2.01(b).

“ CPEX Group ” shall have the meaning set forth in the Separation Agreement.

“ CPEX Indemnitees ” shall have the meaning set forth in Section 4.01(a).

“ CPEX Taxes ” shall have the meaning set forth in Section 2.03(a).

“ Dispute ” shall have the meaning set forth in Article VIII.

“ Distribution ” shall have the meaning set forth in the recitals.

“ Distribution Date ” shall mean the date on which the Distribution shall become effective.

“ Distribution Tax Treatment ” shall have the meaning set forth in the recitals.

“ Final Determination ” shall mean a determination within the meaning of Section 1313 of the Code or any similar provision of state or local Tax law.

“ Governmental Authority ” shall have the meaning set forth in the Separation Agreement.

“ Group ” shall have the meaning set forth in the Separation Agreement.

“ Liabilities ” shall have the meaning set forth in the Separation Agreement.

“ Merger Date ” shall mean the Closing Date as set forth in the Agreement and Plan of Merger, dated as of the date hereof, by and among Teva Pharmaceutical Industries Limited, Beryllium Merger Corporation and Bentley.

“ Parties ” shall have the meaning set forth in the preamble to this Agreement.

“ Person ” shall have the meaning set forth in the Separation Agreement.

“ Post-Distribution Period ” shall mean any taxable year or other taxable period beginning after the Distribution Date and, in the case of any taxable year or other taxable period that begins before and ends after the Distribution Date, that part of the taxable year or other taxable period that begins at the beginning of the day after the Distribution Date.

“ Pre-Distribution Period ” shall mean any taxable year or other taxable period that ends on or before the Distribution Date and, in the case of any taxable year or other taxable period that begins before and ends after the Distribution Date, that part of the taxable year or other taxable period through the close of the Distribution Date.

“ Separation Agreement ” shall have the meaning set forth in the preamble to this Agreement.

“ Subsidiary ” shall have the meaning set forth in the Separation Agreement.

“ Taxes ” shall mean (i) all taxes, charges, fees, duties, levies, imposts, rates or other assessments or governmental charges of any kind imposed by any federal, state, local or foreign Governmental Authority, including, without limitation, income, gross receipts, employment, excise, severance, stamp, occupation, premium, windfall profits, environmental, custom duties, property, sales, use, license, capital stock, transfer, franchise, registration, payroll, withholding, social security, unemployment, disability, value added, alternative or add-on minimum or other taxes, whether disputed or not, and including any interest, penalties, charges or additions attributable thereto, (ii) liability for the payment of any amount of the type described in clause (i) above arising as a result of being (or having been) a member of any group or being (or having been) included or required to be included in any Tax Return related thereto, and (iii) liability for the payment of any amount of the type described in clauses (i) or (ii) above as a result of any express or implied obligation to indemnify or otherwise assume or succeed to the liability of any other Person.

“ Tax Advisor ” shall have the meaning set forth in Article VIII.

“ Tax Contest ” shall have the meaning set forth in Section 5.01.

“ Tax Information Packages ” shall mean any information required in order to prepare and file any Bentley Filed Tax Return.

“ Tax Materials ” shall have the meaning set forth in Section 3.01(a).

“ Tax Return ” shall mean any return, report, certificate, form or similar statement or document (including any related supporting information or schedule attached thereto and any information return, amended tax return, claim for refund or declaration of estimated tax) required to be supplied to, or filed with, a Governmental Authority or any bill for or notice related to ad valorem or other similar Taxes received from a Governmental Authority, in each case, in connection with the determination, assessment or collection of any Tax or the administration of any laws, regulations or administrative requirements relating to any Tax.

     1.02 REFERENCES; INTERPRETATION. References in this Agreement to the singular shall be held to include the plural and vice versa and words of one gender shall be held to include the other gender as the context requires. The terms “hereof,” “herein,” and “herewith” and words of similar import shall, unless otherwise stated, be construed to refer to this Agreement (or the applicable Ancillary Agreement) as a whole (including all of the Schedules and Exhibits hereto and thereto) and not to any particular provision of this Agreement (or such Ancillary Agreement). Article, Section, Exhibit, Schedule and Appendix references are to the Articles, Sections, Exhibits, Schedules and Appendices to this Agreement (or the applicable Ancillary Agreement) unless otherwise specified. The word “including” and words of similar import when used in this Agreement (or the applicable Ancillary Agreement) shall mean “including, without limitation,” unless the context otherwise requires or unless otherwise specified. The word “or” shall not be exclusive. Any definition of or reference to any statute shall be construed as referring also to any rules and regulations promulgated thereunder.

ARTICLE II.

TAX RETURNS AND TAX PAYMENTS

     2.01 OBLIGATIONS TO FILE TAX RETURNS.

          (a) Bentley shall have the sole and exclusive responsibility for the preparation and filing of each Tax Return that (x) includes any member of the Bentley Group or the CPEX Group and that is required to be filed on or before the Distribution Date or (y) includes any member of the Bentley Group and that is required to be filed after the Distribution Date (each, a “ Bentley Filed Tax Return ”); provided, however, that (1) all Bentley Filed Tax Returns shall be prepared on a basis that is consistent with both the Contribution Tax Treatment and the Distribution Tax Treatment, (2) CPEX shall promptly prepare and deliver to Bentley in a manner consistent with past practices pro forma Tax Returns and Tax Information Packages for any

taxable period in which any member of the CPEX Group is included in, or any portion of the CPEX Business is reflected on, a Bentley Filed Tax Return, (3) Bentley shall provide to CPEX sufficiently in advance of the due date for the filing thereof, and CPEX shall have a reasonable opportunity to review and comment on, any such Bentley Filed Tax Return (or the relevant portion thereof) to the extent that CPEX is responsible for any portion of the Taxes reported on such Bentley Filed Tax Return, and (4) in the case of any Bentley Filed Tax Return that includes any member of the CPEX Group or the CPEX Business only for the portion of the relevant taxable period that ends on the Distribution Date, Taxes shall be allocated to the portion of such taxable period that ends on the Distribution Date based on an actual or hypothetical closing of the books at the close of the Distribution Date. Each member of the CPEX Group hereby irrevocably authorizes and designates Bentley as its agent, coordinator and administrator for the purpose of taking any and all actions necessary or incidental to the filing of any such Bentley Filed Tax Returns and, except as otherwise provided herein, for the purpose of making payments to, or collecting refunds from, any Governmental Authority in respect of a Bentley Filed Tax Return. Except as otherwise provided herein, Bentley shall have the exclusive right to file, prosecute, compromise or settle any claim for, or refund of, Taxes in respect of a Bentley Filed Tax Return for which Bentley bears responsibility hereunder and to determine whether any refunds of Taxes to which the Bentley Group may be entitled shall be received by way of refund or credit against the Tax liability of the Bentley Group.

          (b) CPEX shall have the sole and exclusive responsibility for the preparation and filing of each Tax Return that is required to be filed after the Distribution Date that includes any member of the CPEX Group or otherwise relates to the CPEX Business that is not a Bentley Filed Tax Return (each, a “ CPEX Filed Tax Return ”); provided, however, that, except as otherwise required by law, (1) all CPEX Filed Tax Returns shall be prepared on a basis that is consistent with both the Contribution Tax Treatment and the Distribution Tax Treatment, (2) CPEX shall provide to Bentley sufficiently in advance of the due date for the filing thereof, and Bentley shall have a reasonable opportunity to review and comment on, any such CPEX Filed Tax Return (or the relevant portion thereof) to the extent that Bentley is responsible for any portion of the Taxes reported on such CPEX Filed Tax Return, and (3) in the case of any CPEX Filed Tax Return that includes any member of the CPEX Group or the CPEX Business only for the portion of the relevant taxable period that begins after the Distribution Date, Taxes shall be allocated to the portion of such taxable period that begins after the Distribution Date based on an actual or hypothetical closing of the books at the close of the Distribution Date.

     2.02 OBLIGATION TO REMIT TAXES. Subject to Section 2.01 and subject always to the ultimate division of responsibility for Taxes set out in Section 2.03, Bentley and CPEX shall each remit or cause to be remitted to the applicable Governmental Authority in a timely manner any Taxes due in respect of any Tax Return that such Party is required to file (or, in the case of a Tax for which no Tax Return is required to be filed, which is otherwise payable by such Party or a member of such Party’s Group to any Governmental Authority); pro