For the purposes of acquiring, constructing, installing and equipping public health facilities, the authority is hereby authorized to issue and sell from time to time its bonds, which bonds may be in the form of interest-bearing bonds or noninterest-bearing bonds. Other than refunding bonds, the aggregate principal amount of bonds issued under this chapter shall not exceed $45,000,000.00; provided, however, that, if the authority determines that the total net amount of bond proceeds available to provide funds for paying the costs of acquiring, constructing, improving, and equipping public health facilities (excluding underwriting discount, other issuance expenses and 10 percent of the principal amount of such bonds to be used to capitalize or fund a debt service reserve fund as authorized by Section 22-3A-16(b)), plus the interest income, not exceeding $2,000,000.00, earned on such net amount of bond proceeds pending expenditure thereof, will be less than $45,000,000.00, the aggregate principal amount of bonds issued under this chapter may be increased by the authority to such amount as will permit the authority to receive such net bond proceeds and such interest income (not exceeding $2,000,000.00) thereon totaling $45,000,000.00. The determination of the estimated issuance expenses, underwriting discount and projected expenditure schedule necessary to calculate the additional principal amount of bonds (if any) to be issued under this section shall be made by the authority.