SECOND AMENDED AND RESTATED SECURED CONVERTIBLE MINIMUM BORROWING NOTE

Exhibit 10.2

THIS NOTE AND THE COMMON SHARES ISSUABLE UPON CONVERSION OF THIS NOTE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY STATE SECURITIES LAWS. THIS NOTE AND THE COMMON SHARES ISSUABLE UPON CONVERSION OF THIS NOTE MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR HYPOTHECATED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT AS TO THIS NOTE UNDER SAID ACT AND ANY APPLICABLE STATE SECURITIES LAWS OR AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO ACCENTIA BIOPHARMACEUTICALS, INC. THAT SUCH REGISTRATION IS NOT REQUIRED.

SECOND AMENDED AND RESTATED

SECURED CONVERTIBLE MINIMUM BORROWING NOTE

FOR VALUE RECEIVED, each of ACCENTIA BIOPHARMACEUTICALS, INC., a Florida corporation (the “ Parent ”), and the other companies listed on Exhibit A attached hereto (such other companies together with the Parent, each a “ Company ” and collectively, the “ Companies ”), jointly and severally, promises to pay to LAURUS MASTER FUND, LTD., c/o M&C Corporate Services Limited, P.O. Box 309 GT, Ugland House, South Church Street, George Town, Grand Cayman, Cayman Islands, Fax: 345-949-8080 (the “ Holder ”) or its registered assigns or successors in interest, the sum of Two Million Five Hundred Thousand Dollars ($2,500,000), or, if different, the aggregate principal amount of all Loans (as defined in the Security Agreement referred to below), together with any accrued and unpaid interest hereon, on April 29, 2006 (the “ Maturity Date ”) if not sooner indefeasibly paid in full; provided , however , if the Parent shall have consummated the initial public offering of Common Stock (as defined in the Security Agreement) on or prior to March 31, 2006, the Maturity Date shall be April 29, 2008. This Second Amended and Restated Secured Convertible Minimum Borrowing Note amends and restates in its entirety (and is given in substitution for and not in satisfaction of) that certain $2,500,000 Secured Convertible Minimum Borrowing Note made by the Companies in favor of the Holder on April 29, 2005 and amended and restated on or about September 13, 2005.

Capitalized terms used herein without definition shall have the meanings ascribed to such terms in the Security Agreement among the Companies and the Holder dated as of the date hereof (as amended and restated, further amended, modified and/or supplemented from time to time, the “ Security Agreement ”).

The following terms shall apply to this Second Amended and Restated Secured Convertible Minimum Borrowing Note (this “ Note ”):

ARTICLE I

CONTRACT RATE

1.1 Contract Rate . Subject to Sections 4.2 and 5.10, interest payable on the outstanding principal amount of this Note (the “ Principal Amount ”) shall accrue at a rate per annum equal to the “prime rate” published in The Wall Street Journal from time to time (the “ Prime Rate ”), plus two percent (2.0%) (the “ Contract Rate ”). The Contract Rate shall be

increased or decreased as the case may be for each increase or decrease in the Prime Rate in an amount equal to such increase or decrease in the Prime Rate; each change to be effective as of the day of the change in the Prime Rate. The Contract Rate shall not at any time be less than seven and three-quarters percent (7.75%). Interest shall be (i) calculated on the basis of a 360 day year, and (ii) payable monthly, in arrears, commencing on May 4, 2005 on the first business day of each consecutive calendar month thereafter through and including the Maturity Date and on the Maturity Date, whether by acceleration or otherwise.

1.2 Contract Rate Payments . The Contract Rate shall be calculated on the last business day of each calendar month hereafter (other than for increases or decreases in the Prime Rate which shall be calculated and become effective in accordance with the terms of Section 1.1) until the Maturity Date (each a “ Determination Date ”) and shall be subject to adjustment as set forth herein..

ARTICLE II

LOANS; PAYMENTS UNDER THIS NOTE

2.1 Loans . All Loans evidenced by this Note shall be made in accordance with the terms and provisions of the Security Agreement.

2.2 No Effective Registration . Notwithstanding anything to the contrary herein, the Holder shall not be required to accept shares of Common Stock as payment following a conversion by the Holder if there fails to exist an effective current Registration Statement (as defined in the Registration Rights Agreement) covering the shares of Common Stock to be issued, or if an Event of Default hereunder exists and is continuing, unless such requirement is otherwise waived in writing by the Holder in whole or in part at the Holder’s option.

2.3 Optional Redemption in Cash . The Companies will have the option of prepaying this Note (“ Optional Redemption ”) by paying to the Holder a sum of money equal to one hundred thirty percent (130%) of the principal amount of this Note together with accrued but unpaid interest thereon and any and all other sums due, accrued or payable to the Holder arising under this Note, the Security Agreement, or any other Ancillary Agreement (the “ Redemption Amount ”) outstanding on the Redemption Payment Date (as defined below). The Company shall deliver to the Holder a written notice of redemption (the “ Notice of Redemption ”) specifying the date for such Optional Redemption (the “ Redemption Payment Date ”), which date shall be seven (7) days after the date of the Notice of Redemption (the “ Redemption Period ”). A Notice of Redemption shall not be effective with respect to any portion of this Note for which the Holder has previously delivered a Notice of Conversion (defined below) pursuant to Section 3.1, or for conversions elected to be made by the Holder pursuant to Section 3.1 during the Redemption Period. The Redemption Amount shall be determined as if such Holder’s conversion elections had been completed immediately prior to the date of the Notice of Redemption. On the Redemption Payment Date, the Redemption Amount (plus any additional interest and fees accruing on the Notes during the Redemption Period) must be irrevocably paid in full in immediately available funds to the Holder. In the event the Companies fail to pay the Redemption Amount on the Redemption Payment Date, then such Redemption Notice shall be null and void.

ARTICLE III

CONVERSION RIGHTS AND FIXED CONVERSION PRICE

3.1 Optional Conversion . Subject to the terms of this Article III, the Holder shall have the right, but not the obligation, at any time until the Maturity Date, or during an Event of Default (as defined in Article IV), and, subject to the limitations set forth in Section 3.2 hereof, to convert all or any portion of the outstanding Principal Amount and/or accrued interest and fees due and payable into fully paid and nonassessable shares of the Common Stock at the Fixed Conversion Price. For purposes hereof, subject to Section 3.6 hereof, the initial “ Fixed Conversion Price ” shall be $6.80. The shares of Common Stock to be issued upon such conversion are herein referred to as the “ Conversion Shares. ”

3.2 Conversion Limitation . Notwithstanding anything contained herein to the contrary, the Holder shall not be entitled to convert pursuant to the terms of this Note an amount that would be convertible into that number of Conversion Shares which would exceed the difference between (i) 4.99% of the outstanding shares of Common Stock and (ii) the number of shares of Common Stock beneficially owned by the Holder. For purposes of the immediately preceding sentence, beneficial ownership shall be determined in accordance with Section 13(d) of the Exchange Act and Regulation 13d-3 thereunder. The Conversion Shares limitation described in this Section 3.2 shall automatically become null and void without any notice to any Company upon the occurrence and during the continuance of an Event of Default, or upon 75 days prior notice to the Parent. Notwithstanding anything contained herein to the contrary, the provisions of this Section 3.2 are irrevocable and may not be waived by the Holder or any Company.

3.3 Mechanics of Holder’s Conversion . In the event that the Holder elects to convert this Note into Common Stock, the Holder shall give notice of such election by delivering an executed and completed notice of conversion in substantially the form of Exhibit A hereto (appropriately completed) (“ Notice of Conversion ”) to the Parent and such Notice of Conversion shall provide a breakdown in reasonable detail of the Principal Amount, accrued interest and fees that are being converted. On each Conversion Date (as hereinafter defined) and in accordance with its Notice of Conversion, the Holder shall make the appropriate reduction to the Principal Amount, accrued interest and fees as entered in its records and shall provide written notice thereof to the Parent within two (2) Business Days after the Conversion Date. Each date on which a Notice of Conversion is delivered or telecopied to the Parent in accordance with the provisions hereof shall be deemed a Conversion Date (the “ Conversion Date ”). Pursuant to the terms of the Notice of Conversion, the Parent will issue instructions to the transfer agent accompanied by an opinion of counsel within one (1) Business Day of the date of the delivery to the Parent of the Notice of Conversion and shall cause the transfer agent to transmit the certificates representing the Conversion Shares to the Holder by crediting the account of the Holder’s designated broker with the Depository Trust Corporation (“ DTC ”) through its Deposit Withdrawal Agent Commission (“ DWAC ”) system within three (3) Business Days after receipt by the Parent of the Notice of Conversion (the “ Delivery Date ”). In the case of the exercise of the conversion rights set forth herein the conversion privilege shall be deemed to have been exercised and the Conversion Shares issuable upon such conversion shall be deemed to have been issued upon the date of receipt by the Parent of the Notice of Conversion. The Holder shall be treated for all purposes as the record holder of the Conversion Shares, unless the Holder provides the Parent written instructions to the contrary.

3.4 Late Payments . Each Company understands that a delay in the delivery of the Conversion Shares in the form required pursuant to this Article beyond the Delivery Date could result in economic loss to the Holder. As compensation to the Holder for such loss, in addition to all other rights and remedies which the Holder may have under this Note, applicable law or otherwise, the Companies shall, jointly and severally, pay late payments to the Holder for any late issuance of Conversion Shares in the form required pursuant to this Article III upon conversion of this Note, in the amount equal to $500 per Business Day after the Delivery Date. The Companies shall, jointly and severally, make any payments incurred under this Section in immediately available funds upon demand.

3.5 Conversion Mechanics . The number of shares of Common Stock to be issued upon each conversion of this Note shall be determined by dividing that portion of the principal and interest and fees to be converted, if any, by the then applicable Fixed Conversion Price.

3.6 Adjustment Provisions . The Fixed Conversion Price and number and kind of shares or other securities to be issued upon conversion determined pursuant to Section 3.1 shall be subject to adjustment from time to time upon the occurrence of certain eve