Exhibit 10.9

[FORM OF LETTER AGREEMENT TO BE ENTERED INTO BY AND BETWEEN THE

REGISTRANT AND MEMBERS OF MANAGEMENT OTHER THAN THE INITIAL

STOCKHOLDERS]

                            , 2006

HEALTHCARE ACQUISITION PARTNERS CORP.

350 Madison Avenue

New York, NY 10017

Dear Ladies and Gentlemen:

This letter is being delivered to you in accordance with the Underwriting Agreement (the “Underwriting Agreement”) entered into by and between Healthcare Acquisition Partners Corp., a Delaware corporation (the “Company”), and FTN Midwest Securities Corp., as Representative (the “Representative”) of the Underwriters named in Schedule I thereto (the “Underwriters”), relating to an underwritten initial public offering (the “IPO”) of the Company’s units (the “Units”), each comprised of one share of the Company’s common stock, par value $0.0001 per share (the “Common Stock”), and two warrants, each being exercisable for one share of Common Stock (each, a “Warrant”). The capitalized terms set forth on Schedule 1 attached hereto are hereby incorporated by reference herein.

In order to induce the Company and the Underwriters to enter into the Underwriting Agreement and to proceed with the IPO and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the undersigned hereby agrees with the Company as follows:

1. The undersigned agrees not to acquire any IPO Shares prior to the completion of a Business Combination.

2. In the event that the Company fails to consummate a Business Combination within 18 months from the Effective Date of the registration statement relating to the IPO (or 24 months under the circumstances described in the prospectus relating to the IPO), the undersigned agrees to indemnify and hold harmless the Company against any and all loss, liability, claims, damage and expense whatsoever (including, but not limited to, any and all legal or other expenses reasonably incurred in investigating, preparing or defending against any litigation, whether pending or threatened, or any claim whatsoever) to which the Company may become subject as a result of any claim by any vendor that is owed money by the Company for services rendered or products sold but only to the extent necessary to ensure that such loss, liability, claim, damage or expense does not reduce the amount in the Trust Account.

3. The undersigned represents and warrants that (i) the biographical information furnished to the Company and the Representative and attached hereto as Exhibit A is true and accurate in all respects (other than de minimis errors or omissions), does not omit any material information with

respect to the undersigned’s background during the previous five years and contains all of the information required to be disclosed pursuant to Item 401 of Regulation S-K, promulgated under the Securities Act of 1933, as amended, (ii) the questionnaires furnished by the undersigned to the Company and the Representative are true and accurate in all respects (other than de minimis errors or omissions), and (ii) the undersigned has full right and power, without violating any agreement by which the undersigned is bound, to enter into this letter agreement and to serve as [            ][ and ][ a member of the Board of Directors] of the Company. The undersigned further represents and warrants that:

(a) The undersigned is not subject to or a respondent in any legal action for, any injunction, cease-and-desist order or order or stipulation to desist or refrain from any act or practice relating to the offering of securities in any jurisdiction;

(b) The undersigned has never been convicted of or pleaded guilty to any crime (i) involving any fraud or (ii) relating to any financial transaction or handling of funds of another person, or (iii) pertaining to any dealings in any securities and such person is not currently a defendant in any such criminal proceeding; and

(c) The undersigned has never been suspended or expelled from membership in any securities or commodities exchange or association or had a securities or commodities license or registration denied, suspended or revoked.

The undersigned acknowledges and understands that the Underwriters and the Company will rely upon the agreements, representations and warranties set forth herein in proceeding with the IPO.

This letter agreement shall be binding on the undersigned and such person’s respective successors, heirs, personal representatives and assigns. This letter agreement shall terminate on the earlier of (i) the Business Combination Date and (ii) the Termination Date.

This letter agreement shall be governed by and interpreted and construed in accordance with the laws of the State of New York applicable to contracts formed and to be performed entirely within the State of New York, without regard to the conflicts of law provisions thereof to the extent such principles or rules would require or permit the application of the laws of another jurisdiction.

No term or provision of this letter agreement may be amended, changed, waived, altered or modified except by written instrument executed and delivered by the party against whom such amendment, change, waiver, alteration or modification is to be enforced.

[The Remainder of this Page is Intentionally Left Blank]

Schedule 1

SUPPLEMENTAL COMMON DEFINITIONS

Unless the context shall otherwise require, the following terms shall have the following respective meanings for all purposes, and the following definitions are equally applicable to both the singular and the plural forms and the feminine, masculine and neuter forms of the terms defined.

“Business Combination” shall mean the acquisition by the Company, whether by merger, capital stock exchange, asset acquisition or other similar type of combination, of one or more operating businesses in the healthcare-related sector, having, collectively, a fair market value (as calculated in accordance with the Company’s Amended and Restated Certificate of Incorporation) of at least 80% of the Company’s net assets at the time of such merger, capital stock exchange, asset acquisition or other similar type of combination.

“Business Combination Date” shall mean the date upon which a Business Combination is consummated.

“Effective Date” shall mean the date upon which the Registration Statement is declared effective under the Securities Act of 1933, as amended, by the SEC.

“IPO Shares” shall mean all shares of Common Stock issued by the Company in its IPO, regardless of whether such shares were issued to an Insider or otherwise.

“Prospectus” shall mean the final prospectus filed pursuant to Rule 424(b) under the Securities Act of 1933, as amended, and included in the Registration Statement.

“Registration Statement” shall mean the registration statement filed by the Company on Form S-1 (No. 333-129035) with the SEC on October 14, 2005, and any amendment or supplement thereto, in connection with the Company’s IPO.

“SEC” shall mean the United States Securities and Exchange Commission.

“Termination Date” shall mean the date that is sixty (60) calendar days immediately following the Transaction Failure Date (inclusive thereof).

“Transaction Failure” shall mean the earlier of (i) the failure to enter into a definitive agreement with respect to a Business Combination on any day during the eighteen-month period immediately following the Effective Date, and (ii) the failure to consummate a Business Combination on any day during the twenty four-month period immediately following the Effective Date.

“Transaction Failure Date” shall mean the date upon which a Transaction Failure occurs, as conclusively established by a majority of the Independent Directors of the Company immediately following a Transaction Failure.

“Trust Account” shall mean that certain trust account established with JPMorgan Chase Bank, N.A. and in which the Company deposited the “offering proceeds to be held in trust”, as described in the Prospectus.

Exhibit A

BIOGRAPHY

[Insert Bio here]