UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q/A

For the quarterly period ended December 31, 2011

For the transition period from              to             .

Commission File Number 333-153896

APTALIS PHARMA INC.

(Exact Name of Registrant as Specified in Its Charter)

(205) 991-8085

(Registrant’s telephone number, including area code)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  ¨    No  ¨

Registrant has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934, but is not required to file such reports under such sections.

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate website, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (paragraph 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  x    No  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See definitions of “large accelerated filer”, “accelerated filer” and “small reporting company” in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  x

As of April 27, 2012, there were 100 shares of common stock of the registrant outstanding, all of which were owned by Aptalis MidHoldings Inc.

EXPLANATORY NOTE

This Amendment No. 1 to Aptalis Pharma Inc.’s (the “Company”) Quarterly Report on Form 10-Q for the period ended December 31, 2011 (the “Form 10-Q”) is being filed for the sole purpose of re-filing Exhibit 10.30. No other changes have been made to the Form 10-Q.

This Amendment No. 1 to the Form 10-Q speaks as of the original filing date of the Form 10-Q, does not reflect events that may have occurred subsequent to the original filing date and does not modify or update in any way disclosures made in the original Form 10-Q.

PART II. OTHER INFORMATION

Item 6. Exhibits.

* Confidential treatment requested as to certain portions. Material has been omitted and separately filed with the Securities and Exchange Commission.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

EXHIBIT INDEX

* Confidential treatment requested as to certain portions. Material has been omitted and separately filed with the Securities and Exchange Commission.