<PAGE>


                                                                    Exhibit 31.2
                                CERTIFICATION OF
                             CHIEF FINANCIAL OFFICER


I, Cornel C. Spiegler, CFO, certify that:


     1.  I have reviewed this report on Form 10-K for the year ended December
         31, 2003 of Impax Laboratories, Inc.

     2.  Based on my knowledge, this report does not contain any untrue
         statement of a material fact, or omit to state a material fact
         necessary to make the statements made, in light of the circumstances
         under which such statements were made, not misleading, with respect to
         the period covered by this report.

     3.  Based on my knowledge, the financial statements, and other financial
         information included in this report, fairly present, in all material
         respects, the financial condition, results of operations, and cash
         flows of the registrant as of, and for, the periods presented in this
         report.

     4.  The registrant's other certifying officers and I are responsible for
         establishing and maintaining disclosure controls and procedures (as
         defined in Exchange Act Rules 13a-15(e) and 15d-15(e) for the
         registrant, and have:

                  a)  Designed such disclosure controls and procedures, or
                      caused such disclosure controls and procedures to be
                      designed under our supervision to ensure that material
                      information relating to the registrant, including its
                      consolidated subsidiaries, is made known to us by others
                      within those entities, particularly during the period in
                      which this report is being prepared;

                  b)  (intentionally omitted)

                  c)  Evaluated the effectiveness of the registrant's disclosure
                      controls and procedures and presented in this report our
                      conclusions about the effectiveness of the disclosure
                      controls and procedures as of the end of the period
                      covered by this report based on such evaluation; and

                  d)  Disclosed in this report any change in the registrant's
                      internal control over financial reporting that occurred
                      during the registrant's most recent fiscal quarter that
                      has materially affected, or is reasonably likely to
                      materially affect, the registrant's internal control over
                      financial reporting.

     5.  The registrant's other certifying officers and I have disclosed, based
         on our most recent evaluation of internal control over financial
         reporting, to the registrant's auditors and the audit committee of
         registrant's board of directors (or persons performing the equivalent
         function):

                  a)  All significant deficiencies and material weaknesses in
                      the design or operation of internal controls over
                      financial reporting which are reasonably likely to
                      adversely affect the registrant's ability to record,
                      process, summarize, and report financial data; and

                  b)  Any fraud, whether or not material, that involves
                      management or other employees who have a significant role
                      in the registrant's internal controls.





                                                /s/ Cornel C. Spiegler
                                        ----------------------------------------
                                                  Cornel C. Spiegler
                                                Chief Financial Officer



                                                    March 12, 2004
                                        ----------------------------------------