
[Federal Register Volume 77, Number 29 (Monday, February 13, 2012)]
[Notices]
[Pages 7585-7586]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-3234]


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DEPARTMENT OF HEALTH AND HUMAN SERVICES

Food and Drug Administration

[Docket No. FDA-2007-D-0369]


Draft Guidance for Industry on Bioequivalence Recommendations for 
Rifaximin Tablets; Availability

AGENCY: Food and Drug Administration, HHS.

ACTION: Notice.

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SUMMARY: The Food and Drug Administration (FDA) is announcing the 
availability of two draft guidances for industry entitled 
``Bioequivalence Recommendations for Rifaximin,'' one for the 200-
milligram (mg) strength (rifaximin-200) and one for the 550-mg strength 
(rifaximin-550). The recommendations provide specific guidance on the 
design of bioequivalence (BE) studies to support abbreviated new drug 
applications (ANDAs) for rifaximin tablets.

DATES: Although you can comment on any guidance at any time (see 21 CFR 
10.115(g)(5)), to ensure that the Agency considers your comment on the 
draft guidances before it begins work on the final versions of the 
guidances, submit either electronic or written comments on the draft 
guidances by April 13, 2012.

ADDRESSES: Submit written requests for single copies of the draft 
guidances to the Division of Drug Information, Center for Drug 
Evaluation and Research, Food and Drug Administration, 10903 New 
Hampshire Ave., Bldg. 51, rm. 2201, Silver Spring, MD 20993-0002. Send 
one self-addressed adhesive label to assist that office in processing 
your requests. See the SUPPLEMENTARY INFORMATION section for electronic 
access to the draft guidance documents.
    Submit electronic comments on the draft guidances to http://www.regulations.gov. Submit written comments to the Division of Dockets 
Management (HFA-305), Food and Drug Administration, 5630 Fishers Lane, 
rm. 1061, Rockville, MD 20852.

FOR FURTHER INFORMATION CONTACT: Doan T. Nguyen, Center for Drug 
Evaluation and Research (HFD-600), Food and Drug Administration, 7519 
Standish Pl., Rockville, MD 20855, 240-276-8608.

SUPPLEMENTARY INFORMATION: 

I. Background

    In the Federal Register of June 11, 2010 (75 FR 33311), FDA 
announced the availability of a guidance for industry entitled 
``Bioequivalence Recommendations for Specific Products,'' which 
explained the process that would be used to make product-specific BE 
recommendations available to the public on FDA's Web site at  http://www.fda.gov/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/default.htm. As described in that guidance, FDA adopted this process as 
a means to develop and disseminate product-specific BE recommendations 
and provide a meaningful opportunity for the public to consider and 
comment on those recommendations. This notice announces the 
availability of two draft BE recommendations, one for rifaximin-200 and 
one for rifaximin-550.
    Xifaxan (rifaximin) 200-mg tablets, approved by FDA in May 2004, 
are indicated for the treatment of patients (>= 12 years of age) with 
travelers' diarrhea caused by noninvasive strains of Escherichia coli. 
Xifaxan (rifaximin) 550-mg tablets, approved by FDA in March 2010, are 
indicated for reduction in risk of hepatic encephalopathy recurrence in 
patients >= 18 years of age. Xifaxan, 200 mg, and Xifaxan, 550 mg, are 
designated the reference listed drugs (RLDs) and therefore any ANDAs 
for generic rifaximin-200 or rifaximin-550 must demonstrate BE to the 
relevant RLD prior to approval. There are no approved ANDAs for these 
products.
    In November 2011, FDA posted on its Web site a draft guidance for 
industry on the Agency's recommendations for BE studies to support 
ANDAs for rifaximin-200 (Draft Rifaximin-200 BE Recommendations). FDA 
is now issuing a draft guidance for industry on BE recommendations for 
generic rifaximin-550 (Draft Rifaximin-550 BE Recommendations).
    In May 2008, Salix Pharmaceuticals, Inc. (Salix), manufacturer of 
the RLD, Xifaxan (200 mg), filed a citizen petition requesting that FDA 
refuse to receive for substantive review, or approve, ANDAs for generic 
rifaximin-200 unless the ANDAs contain certain data to demonstrate BE 
(Docket No. FDA-2008-P-0300). FDA is reviewing the issues raised in the 
petition and will consider any comments on the Draft Rifaximin-200 BE 
Recommendations before responding to Salix's citizen petition and 
finalizing its BE recommendations for rifaximin-200.
    These draft guidances are being issued consistent with FDA's good

[[Page 7586]]

guidance practices regulation (21 CFR 10.115). The draft guidances, 
when finalized, will represent the Agency's current thinking on the 
design of BE studies to support ANDAs for rifaximin-200 and rifaximin-
550. They do not create or confer any rights for or on any person and 
do not operate to bind FDA or the public. An alternative approach may 
be used if such approach satisfies the requirements of the applicable 
statutes and regulations.

II. Comments

    Interested persons may submit to the Division of Dockets Management 
(see ADDRESSES) either electronic or written comments regarding this 
document. It is only necessary to send one set of comments. It is no 
longer necessary to send two copies of mailed comments. Identify 
comments with the docket number found in brackets in the heading of 
this document. Received comments may be seen in the Division of Dockets 
Management between 9 a.m. and 4 p.m., Monday through Friday.

III. Electronic Access

    Persons with access to the Internet may obtain the documents at 
either http://www.fda.gov/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/default.htm or http://www.regulations.gov.

    Dated: February 7, 2012.
Leslie Kux,
Acting Assistant Commissioner for Policy.
[FR Doc. 2012-3234 Filed 2-10-12; 8:45 am]
BILLING CODE 4160-01-P


