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                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                  SCHEDULE 13G


                    Under the Securities Exchange Act of 1934
                               (Amendment No. _)*


                           INTERPHARM HOLDINGS, INC.
                                (Name of Issuer)


                     COMMON STOCK, PAR VALUE $0.01 PER SHARE
                         (Title of Class of Securities)


                                   460588106
                                 (CUSIP Number)

                                 SEPTEMBER 11, 2006
             (Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

             [_]  Rule 13d-1(b)
             [X]  Rule 13d-1(c)
             [_]  Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting  person's
initial  filing on this form with respect to the subject  class of  securities,
and for any  subsequent  amendment  containing  information  which  would alter
disclosures provided in a prior cover page.

The information required on the reminder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).

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CUSIP NO. 460588106               Schedule 13G                     Page 2 of 15
---------------------                                         ------------------

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1.   Name of Reporting Person:          Aisling Capital II, LP
     S.S. or I.R.S. Identifica-
     tion No. of Above Person

--------------------------------------------------------------------------------
2.   Check the Appropriate Box                                       (a)  [_]
     if a Member of a Group                                          (b)  [X]

--------------------------------------------------------------------------------
3.  SEC Use Only

--------------------------------------------------------------------------------
4.   Citizenship or Place of Organization      Delaware

--------------------------------------------------------------------------------
           Number of            5.  Sole Voting Power:         7,330,617*
            Shares              ------------------------------------------------
         Beneficially           6.  Shared Voting Power:       -0-
           Owned By             ------------------------------------------------
            Each                7.  Sole Dispositive Power:    7,330,617*
          Reporting             ------------------------------------------------
           Person               8.  Shared Dispositive Power:  -0-
--------------------------------------------------------------------------------
9.   Aggregate Amount Beneficially Owned by Each Reporting Person

     7,330,617*
--------------------------------------------------------------------------------
10.  Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares

                                                                          [_]
--------------------------------------------------------------------------------
11.  Percent of Class Represented by Amount in Row (9)         9.99%*

--------------------------------------------------------------------------------
12.  Type of Reporting Person                                  PN
--------------------------------------------------------------------------------

--------------------

*     This amount is an approximation, which includes 2,281,914 shares of
common stock issuable upon the exercise of warrants and approximately 5,048,703
shares of common stock issuable upon the initial conversion of 10,000 shares of
Series C-1 Convertible Preferred Stock (the "Preferred Shares"). See Item 4(a).


---------------------                                         ------------------
CUSIP NO. 460588106               Schedule 13G                     Page 3 of 15
---------------------                                         ------------------

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1.   Name of Reporting Person:          Aisling Capital Partners, LP
     S.S. or I.R.S. Identifica-
     tion No. of Above Person

--------------------------------------------------------------------------------
2.   Check the Appropriate Box                                       (a)  [_]
     if a Member of a Group                                          (b)  [X]

--------------------------------------------------------------------------------
3.  SEC Use Only

--------------------------------------------------------------------------------
4.   Citizenship or Place of Organization      Delaware

--------------------------------------------------------------------------------
           Number of            5.  Sole Voting Power:         7,330,617*
            Shares              ------------------------------------------------
         Beneficially           6.  Shared Voting Power:       -0-
           Owned By             ------------------------------------------------
            Each                7.  Sole Dispositive Power:    7,330,617*
          Reporting             ------------------------------------------------
           Person               8.  Shared Dispositive Power:  -0-
--------------------------------------------------------------------------------
9.   Aggregate Amount Beneficially Owned by Each Reporting Person

     7,330,617*
--------------------------------------------------------------------------------
10.  Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares

                                                                          [_]
--------------------------------------------------------------------------------
11.  Percent of Class Represented by Amount in Row (9)         9.99%

--------------------------------------------------------------------------------
12.  Type of Reporting Person                                  PN
--------------------------------------------------------------------------------

--------------------

*     This amount is an approximation, which includes 2,281,914 shares of
common stock issuable upon the exercise of warrants and approximately 5,048,703
shares of common stock issuable upon the initial conversion of the Preferred
Shares. See Item 4(a).


---------------------                                         ------------------
CUSIP NO. 460588106               Schedule 13G                     Page 4 of 15
---------------------                                         ------------------

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1.   Name of Reporting Person:          Aisling Capital Partners LLC
     S.S. or I.R.S. Identifica-
     tion No. of Above Person

--------------------------------------------------------------------------------
2.   Check the Appropriate Box                                       (a)  [_]
     if a Member of a Group                                          (b)  [X]

--------------------------------------------------------------------------------
3.  SEC Use Only

--------------------------------------------------------------------------------
4.   Citizenship or Place of Organization      Delaware

--------------------------------------------------------------------------------
           Number of            5.  Sole Voting Power:         7,330,617*
            Shares              ------------------------------------------------
         Beneficially           6.  Shared Voting Power:       -0-
           Owned By             ------------------------------------------------
            Each                7.  Sole Dispositive Power:    7,330,617*
          Reporting             ------------------------------------------------
           Person               8.  Shared Dispositive Power:  -0-
--------------------------------------------------------------------------------
9.   Aggregate Amount Beneficially Owned by Each Reporting Person

     7,330,617*
--------------------------------------------------------------------------------
10.  Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares

                                                                          [_]
--------------------------------------------------------------------------------
11.  Percent of Class Represented by Amount in Row (9)         9.99%

--------------------------------------------------------------------------------
12.  Type of Reporting Person                                  OO
--------------------------------------------------------------------------------

--------------------
*     This amount is an approximation, which includes 2,281,914 shares of
common stock issuable upon the exercise of warrants and approximately 5,048,703
shares of common stock issuable upon the initial conversion of the Preferred
Shares. See Item 4(a).


---------------------                                         ------------------
CUSIP NO. 460588106               Schedule 13G                     Page 5 of 15
---------------------                                         ------------------

--------------------------------------------------------------------------------
1.   Name of Reporting Person:          Steve Elms
     S.S. or I.R.S. Identifica-
     tion No. of Above Person

--------------------------------------------------------------------------------
2.   Check the Appropriate Box                                       (a)  [_]
     if a Member of a Group                                          (b)  [X]

--------------------------------------------------------------------------------
3.  SEC Use Only

--------------------------------------------------------------------------------
4.   Citizenship or Place of Organization      United States

--------------------------------------------------------------------------------
           Number of            5.  Sole Voting Power:         -0-
            Shares              ------------------------------------------------
         Beneficially           6.  Shared Voting Power:       7,330,617*
           Owned By             ------------------------------------------------
            Each                7.  Sole Dispositive Power:    -0-
          Reporting             ------------------------------------------------
           Person               8.  Shared Dispositive Power:  7,330,617*
--------------------------------------------------------------------------------
9.   Aggregate Amount Beneficially Owned by Each Reporting Person

     7,330,617*
--------------------------------------------------------------------------------
10.  Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares

                                                                          [_]
--------------------------------------------------------------------------------
11.  Percent of Class Represented by Amount in Row (9)         9.99%

--------------------------------------------------------------------------------
12.  Type of Reporting Person                                  IN
--------------------------------------------------------------------------------

--------------------
*     This amount is an approximation, which includes 2,281,914 shares of
common stock issuable upon the exercise of warrants and approximately 5,048,703
shares of common stock issuable upon the initial conversion of the Preferred
Shares. See Item 4(a).


---------------------                                         ------------------
CUSIP NO. 460588106               Schedule 13G                     Page 6 of 15
---------------------                                         ------------------

--------------------------------------------------------------------------------
1.   Name of Reporting Person:          Dennis Purcell
     S.S. or I.R.S. Identifica-
     tion No. of Above Person

--------------------------------------------------------------------------------
2.   Check the Appropriate Box                                       (a)  [_]
     if a Member of a Group                                          (b)  [X]

--------------------------------------------------------------------------------
3.  SEC Use Only

--------------------------------------------------------------------------------
4.   Citizenship or Place of Organization      United States

--------------------------------------------------------------------------------
           Number of            5.  Sole Voting Power:         -0-
            Shares              ------------------------------------------------
         Beneficially           6.  Shared Voting Power:       7,330,617*
           Owned By             ------------------------------------------------
            Each                7.  Sole Dispositive Power:    -0-
          Reporting             ------------------------------------------------
           Person               8.  Shared Dispositive Power:  7,330,617*
--------------------------------------------------------------------------------
9.   Aggregate Amount Beneficially Owned by Each Reporting Person

     7,330,617*
--------------------------------------------------------------------------------
10.  Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares

                                                                          [_]
--------------------------------------------------------------------------------
11.  Percent of Class Represented by Amount in Row (9)         9.99%

--------------------------------------------------------------------------------
12.  Type of Reporting Person                                  IN
--------------------------------------------------------------------------------

--------------------
*     This amount is an approximation, which includes 2,281,914 shares of
common stock issuable upon the exercise of warrants and approximately 5,048,703
shares of common stock issuable upon the initial conversion of the Preferred
Shares. See Item 4(a).


---------------------                                         ------------------
CUSIP NO. 460588106               Schedule 13G                     Page 7 of 15
---------------------                                         ------------------

--------------------------------------------------------------------------------
1.   Name of Reporting Person:          Andrew Schiff
     S.S. or I.R.S. Identifica-
     tion No. of Above Person

--------------------------------------------------------------------------------
2.   Check the Appropriate Box                                       (a)  [_]
     if a Member of a Group                                          (b)  [X]

--------------------------------------------------------------------------------
3.  SEC Use Only

--------------------------------------------------------------------------------
4.   Citizenship or Place of Organization      United States

--------------------------------------------------------------------------------
           Number of            5.  Sole Voting Power:         -0-
            Shares              ------------------------------------------------
         Beneficially           6.  Shared Voting Power:       7,330,617*
           Owned By             ------------------------------------------------
            Each                7.  Sole Dispositive Power:    -0-
          Reporting             ------------------------------------------------
           Person               8.  Shared Dispositive Power:  7,330,617*
--------------------------------------------------------------------------------
9.   Aggregate Amount Beneficially Owned by Each Reporting Person

     7,330,617*
--------------------------------------------------------------------------------
10.  Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares

                                                                          [_]
--------------------------------------------------------------------------------
11.  Percent of Class Represented by Amount in Row (9)         9.99%

--------------------------------------------------------------------------------
12.  Type of Reporting Person                                  IN
--------------------------------------------------------------------------------

--------------------
*     This amount is an approximation, which includes 2,281,914 shares of
common stock issuable upon the exercise of warrants and approximately 5,048,703
shares of common stock issuable upon the initial conversion of the Preferred
Shares. See Item 4(a).


---------------------                                         ------------------
CUSIP NO. 460588106               Schedule 13G                     Page 8 of 15
---------------------                                         ------------------


Item 1.   (a)     NAME OF ISSUER

                  Interpharm Holdings, Inc. (the "Company").

          (b)     ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES

                  75 Adams Avenue
                  Hauppage, NY 11788

Item 2.   (a)     NAMES OF PERSONS FILING


                        This Statement is being filed on behalf of each of the
                  following persons (collectively, the "Reporting Persons")

                  (i)   Aisling Capital II, LP, a Delaware limited partnership
                        ("Aisling");

                  (ii)  Aisling Capital Partners, LP, a Delaware limited
                        partnership ("Aisling Partners" and general partner of
                        Aisling);

                  (iii) Aisling Capital Partners LLC, a Delaware limited
                        liability company ("Aisling Partners GP" and general
                        partner of Aisling Partners);

                  (iv)  Mr. Steve Elms ("Mr. Elms" and a managing member of
                        Aisling Partners GP);

                  (v)   Mr. Dennis Purcell ("Mr. Purcell" and a managing member
                        of Aisling Partners GP); and

                  (vi)  Mr. Andrew Schiff ("Mr. Schiff" and a managing member
                        of Aisling Partners GP);

          (b)     ADDRESS OF PRINCIPAL BUSINESS OFFICE


                  The address of the principal business offices of each of the
                  Reporting Persons is 888 Seventh Avenue, 30th Floor, New
                  York, NY 10106.

          (c)     CITIZENSHIP

                  (i)   Aisling - a Delaware limited partnership

                  (ii)  Aisling Partners - a Delaware limited partnership

                  (iii) Aisling Partners GP - a Delaware limited liability
                        company

                  (iv)  Mr. Elms - United States

                  (v)   Mr. Purcell - United States

                  (vi)  Mr. Schiff - United States


---------------------                                         ------------------
CUSIP NO. 460588106               Schedule 13G                     Page 9 of 15
---------------------                                         ------------------


          (d)     TITLE OF CLASS OF SECURITIES

                  Common Stock, par value $0.01 per share (the "Common Stock"
                  or "Shares")

          (e)     CUSIP NUMBER

                  460588106

Item 3.   This statement is not being filed pursuant to either Rule 13d-1(b) or
          13d-2(b) or (c).

Item 4.   OWNERSHIP.

          (a)     AMOUNT BENEFICIALLY OWNED:

                  Each of the Reporting  Persons may be deemed to  beneficially
                  own an aggregate of  approximately  7,330,617  Shares,  which
                  includes  2,281,914  Shares  issuable  upon the  exercise  of
                  warrants and approximately 5,048,703 Shares issuable upon the
                  initial  conversion of the Preferred Shares.  The certificate
                  of  designations  of the Preferred  Shares  provides that the
                  holder  of the  Preferred  Shares  does not have the right to
                  convert the  Preferred  Shares into Shares to the extent that
                  such conversion  would result in beneficial  ownership by the
                  holder of more than 9.99% of the number of Shares outstanding
                  immediately  after  giving  effect to such  conversion.  As a
                  result of this provision, the Reporting Persons are reporting
                  herein their beneficial  ownership of the Shares representing
                  9.99% of the current outstanding Shares. If there was no such
                  provision, as of the date hereof, the Reporting Persons would
                  be able to own an additional  1,449,867  Shares issuable upon
                  the initial  conversion of the Preferred  Shares held for the
                  account of Aisling.

          (b)     PERCENTAGE OWNED:

                  Based on calculations  made in accordance with Rule 13d-3(d),
                  and there being 64,599,066 Shares outstanding as of September
                  11,  2006  each of the  Reporting  Persons  may be  deemed to
                  beneficially  own  approximately  9.99%  of  the  outstanding
                  Common Stock.

          (c)     NUMBER OF SHARES AS TO WHICH SUCH PERSON HAS:

                  (i) Each of Aisling, Aisling Partners and Aisling Partners GP
                  may be deemed to have sole  power to direct  the  voting  and
                  disposition  of the 7,330,617  Shares  beneficially  owned by
                  Aisling.

                  (ii) By virtue  of the  relationships  between  and among the
                  Reporting Persons as described in Item 2, each of the


---------------------                                         ------------------
CUSIP NO. 460588106               Schedule 13G                    Page 10 of 15
---------------------                                         ------------------


                  Reporting Persons,  other than Aisling,  Aisling Partners and
                  Aisling  Partners  GP,  may be  deemed  to share the power to
                  direct the voting and  disposition  of the  7,330,617  Shares
                  beneficially owned by Aisling.

Item 5.   OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS

          Not applicable.

Item 6.   OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON

          The partners of Aisling have the right to  participate in the receipt
          of dividends  from, or proceeds from the sale of, the securities held
          for the  account  of  Aisling  in  accordance  with  their  ownership
          interests in Aisling.

Item 7.   IDENTIFICATION AND CLASSIFICATION OF SUBSIDIARY WHICH ACQUIRED THE
          SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY

          Not applicable.

Item 8.   IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP

          Not applicable.

Item 9.   NOTICE OF DISSOLUTION OF GROUP

          Not applicable.

Item 10.  CERTIFICATION

          (b) The following certification shall be included if the statement is
          filed pursuant to ss.240.13d-1(c):

          By signing  below we certify  that,  to the best of our knowledge and
          belief,  the  securities  referred to above were not acquired and are
          not held  for the  purpose  of or with  the  effect  of  changing  or
          influencing  the control of the issuer of the securities and were not
          acquired and are not held in connection  with or as a participant  in
          any transaction having that purpose or effect.



                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]



---------------------                                         ------------------
CUSIP NO. 460588106               Schedule 13G                    Page 11 of 15
---------------------                                         ------------------


                                   SIGNATURES

         After reasonable inquiry and to the best of our knowledge and belief,
the undersigned certify that the information set forth in this statement is
true, complete and correct.

Dated as of September 21, 2006

                                        AISLING CAPITAL II, LP


                                        By:   Aisling Capital Partners, LP
                                              General Partner


                                        By:   Aisling Capital Partners LLC
                                              Managing Member


                                        By:   /s/ Adele Kittredge Murray
                                              -------------------------------
                                              Name:  Adele Kittredge Murray
                                              Title: Secretary


                                        AISLING CAPITAL PARTNERS, LP


                                        By:   Aisling Capital Partners LLC
                                              Managing Member


                                        By:   /s/ Adele Kittredge Murray
                                              -------------------------------
                                              Name:  Adele Kittredge Murray
                                              Title: Secretary


                                        AISLING CAPITAL PARTNERS LLC


                                        By:   /s/ Adele Kittredge Murray
                                              -------------------------------
                                              Name:  Adele Kittredge Murray
                                              Title: Secretary




---------------------                                         ------------------
CUSIP NO. 460588106               Schedule 13G                    Page 12 of 15
---------------------                                         ------------------




                                           /s/ Steve Elms
                                           ----------------------
                                           Steve Elms


                                           /s/ Dennis Purcell
                                           ----------------------
                                           Dennis Purcell


                                           /s/ Andrew Schiff
                                           ----------------------
                                           Andrew Schiff








---------------------                                         ------------------
CUSIP NO. 460588106               Schedule 13G                    Page 13 of 15
---------------------                                         ------------------


                                 EXHIBIT INDEX


Exhibit 1.      Joint Filing Agreement as required by Rule 13d-1(k)(1) under
                the Securities Exchange Act of 1934, as amended.