The
following is an internal report, which has not been reviewed. A verbatim transcript will be available in approximately
two weeks, sent to the Division and posted on the FDA website at http://www.fda.gov.dockets/ecomments. Slides shown at the meeting will be available
at the same website.
All external requests for the meeting transcripts should be submitted to the CDER Freedom of Information office.
_________________________________________________________________________________________
The
Advisory Committee for Pharmaceutical Science of the Food and Drug
Administration, Center for Drug Evaluation and Research met on
Advisory Committee for Pharmaceutical Members (voting):
Arthur H. Kibbe, Ph.D., Joseph Bloom, Ph.D., Patrick P. DeLuca, Ph.D., Robert Gary Hollenbeck, Ph.D., Michael S. Korczynski, Ph.D., Marvin C. Meyer, Ph.D., Lemuel A. Moye, M.D., Ph.D., Wolfgang Sadee, Dr.rer.nat., Cynthia R.D. Selassie, Ph.D.
Advisory Committee for Pharmaceutical Consultants(voting):
Judy Boehlert, Ph.D., Nozer Singpurwalla, Ph. D., Jürgen Venitz, M.D., Ph.D.
Acting Industry Representative (non-voting):
Efraim Shek, Ph.D.
Guest Speakers:
Annette L. Bunge, Ph.D., Michael Golden, John R. Murphy, Ph.D., Darlene Rosario
FDA Guest Speakers:
Wallace Adams, Ph.D., Lucinda Buhse, Ph.D., Yuan-Yuan Chiu, Ph.D., Frank Holcombe Jr., Ph.D., Ajaz Hussain, Ph.D., Moheb Nasr, Ph.D., Vilayat Sayeed, Ph.D., Jonathan Wilkin, M.D., Lawrence Yu, Ph.D.
FDA Participants:
Gary Buelher, R.Ph., Ph.D.
Open Public Hearing Speakers:
No speakers were signed-up to participate in the Open Public Hearing
These summary minutes for the October 21 and 22, 2003 of the Advisory Committee for Pharmaceutical Science of the Food and Drug Administration were approved on __11/05/03________.
I certify that I attended the
_____//S//_______________________ _______//S//_____________________
Hilda Scharen, M.S. Art Kibbe, Ph.D.
Executive Secretary Chair
The
Committee received an update from the subcommittee and discussed the following:
Parametric Tolerance Interval Test for Dose Content Uniformity; Risk-based CMC
Review Proposals; Nomenclature issues and challenges; Research Plan for
Generics –Bioequivalence of Topical Products.
The members and the invited consultants were provided the background
material from the FDA prior to the meeting.
Art
Kibbe, Ph.D. (Committee Chair), called the meeting to order at
Day 1:
Welcome and Introduction to the Meeting Ajaz Hussain, Ph.D., FDA
Subcommittee Reports
ACPS Manufacturing Subcommittee Update Judy Boehlert, Ph.D.
Clinical Pharmacology Subcommittee Report Jürgen Venitz, M.D., Ph.D.
Draft PAT Guidance
PAT – A Framework for Innovative Pharmaceutical Manufacturing Ajaz Hussain, Ph.D., FDA
and Quality Assurance
Questions/Discussion
Break
Parametric Tolerance Interval Test for Dose Content Uniformity
Dose Content Uniformity: Parametric Tolerance Interval Approach Ajaz Hussain, Ph.D., FDA
PTIT for DCU of OINDP: Approach to Resolution of Identified Issues Wallace Adams, Ph.D., FDA
Lunch
IPAC-RS Presentations
Pharmaceutical Product Quality Assurance Through CMC Drug Darlene Rosario, Aradigm
Development Process
Zero Tolerance Criteria Do Not Assure Product Quality John R. Murphy, Ph.D
Summary and Status of IPAC-RS Proposal for Improved Control of Delivered Michael Golden, GlaxoSmithKline
Dose Uniformity (DDU) of Orally Inhaled and Nasal Drug Products
Break
Committee Discussion and Recommendations
The meeting was
adjourned at approximately
Art Kibbe, Ph.D. (Committee Chair), called the
meeting to order at
Day 2:
Risk-based CMC Review Proposals
Risk-based CMC Review Yuan-yuan Ciu, Ph.D.
Current Thinking
Risk-based CMC Review Vilayet Sayeed, Ph.D.
An example of Process Understanding Directed Risk-Based CMC Ajaz Hussain, Ph.D., FDA
Review Proposals
Oversight of Post-Approved Change
Risk-Based CMC Review Proposals: Issues and challenges Moheb Nasr, Ph.D., FDA
Committee Discussion
Break
Nomenclature
Pharmaceutical Nomenclature: Issues and challenges Moheb Nasr, Ph.D., FDA
FDA Perspective on Dosage Form Nomenclature Dan Boring, R.Ph., Ph.D.
Defining Orally Disintegrating Tablets Frank Holcombe Jr., Ph.D.
Topical Dosage Form Classification – an Update Lucinda Buhse, Ph.D.
Committee Discussion
Lunch
Research Plan for Generics – Bioequivalence of Topical Products
Office of
Generic Drugs Research Programs
Dermatopharmacokinetics: Improvement of methodology Annette L. Bunge, Ph.D.
for
assessing bioequivalence of topical
products
The Pursuit of Alternative Methodologies For Demonstrating Bioequivalence Jonathan Wilkin, M.D., FDA
for Generic Topical Dermatologic Drug Products: DPK, Q3, Cakes and 2 PIs
Committee Discussion
Conclusion and Summary Remarks Ajaz Hussain, Ph.D., FDA
Adjourn
Questions to the Committee:
Topic #1: Nomenclature
1)
What are the
factors that the Agency should consider in determining (a) whether a new dosage
form name is warranted and (b) how such a dosage form should be defined?
The Committee agreed we are facing many
challenges with new dosage forms and new technologies by using older names and
terminology, which actually do not make sense. The committee discussed Orally Disintegrating Tablets (ODT) and that there are no
standards methods for disintegration testing of ODT if a product is substituted
with another.
The members emphasized the difference
between dissolution versus disintegration and that the intent of
disintegration, as a less restrictive term, is that the tablet does not stay in
mouth. In addition, the Committee agreed that the tablet is not intended to be
swallowed but rather absorbed in mouth or gastro-intestinal tract.
The committee recognized the clear need to
use naming, as a means, to distinguish between chewable versus OD tablets; i.e.
if a tablet doesn’t disintegrate rapidly you have to chew it.
The Committee felt that the focus should be
on the dosage form and not the name of the drug and concluded that a new name
for a dosage form is not necessary.
The Committee proposed that as soon as a new dosage form brings either
convenience or becomes a labeling aspect, the intended use for a particular
product really needs to be re-examined, as well as the relevant criteria for
classifying these products.
2)
Is it
reasonable or useful to include a quantifiable attribute when defining a dosage
form or distinguishing between closely related dosage forms where
appropriate? Can such an approach be
viewed as too arbitrary in some cases and too rigid in other cases?
The Committee discussed the necessity of having quantifiable attributes
outweigh the possible consequences of not having one. The Committee members
argued that if the dosage form is meant to define an attribute, then that
attribute should be included in the definition. In the context of Quality by
Design, the Committee argued that aspects of the naming or labeling of a
product is associated with the attributes, as it implies the intended use of
the drug or product.
The Committee emphasized that the name
definition should apply only to the mode of administration of the product, and
thus needs to be as simple as possible. The members recommended that the
labeling or guidance could be sufficient in addressing the intended use of the
product.
The Committee agreed the non-specific definition of ODT is confusing
and one has to be cautious when describing a disintegration time. Overall the
Committee agreed that nomenclature is complex, not a purely scientific issue,
and challenges remain in ensuring the intended use of the product is reflected
in the label.
3)
Is the
proposed criterion, i.e. an in-vitro disintegration time of less than 60
seconds, reasonable for defining an orally disintegrating tablet?.
The Committee members discussed whether a disintegrating tablet implies
it rapidly disintegrates or not. Although, the intended purpose of OD is for
the tablet not to be kept in the mouth for a long period of time i.e. oral
disintegration, the terminology of “ rapidly disintegrating” could have some
misleading implications from a therapeutic perspective. Also, it was felt that
OD describes the route of administration or the mechanism rather than the
release time.
The Committee agreed that 60 seconds was too long a time description for disintegration of an ODT. Although the Committee felt that it is not productive to include a time constraint, it was generally agreed that there is a need to have a requirement for disintegration time for each product but not to include it in the name of the product. The Committee felt that FDA should decide on the time description based on the different dosage forms developed.
4)
Has the
update on topical dosage forms presented today addressed the questions/comments
raised by the ACPS at the March 2003 meeting?
The Committee felt there was a dramatic
improvement in the presented flowchart and although there will always be a
“gray” area(lotion being an emulsion), it fit well
with classic expectations.
Topic #2: Bioequivalence of Topical Products
Dermatopharmacokinetics (DPK)
1)
What type of
studies should be conducted to validate the DPK method?
The Committee felt that the dissolution
isn’t going to give the same estimate on how well the drug gets out of the
delivery form, gets out of the dosage form, and is absorbed into the body as a
biostudy.
The Committee defined DPK as an in vitro
test and as one approach to assess the release rate of the drug from a complex
formulation. It was felt that DPK is a reasonable approach to look at that
aspect of drug release from the product. The Committee felt optimistic about
the reduction in variability presented but would like to see more reproducible
results in different labs. The members agreed that the key aspect of DPK is to
indicate the difference in the vehicle.
Q3: Structural Similarity
2)
What type of
data is needed to demonstrate that two products are Q3 equivalent?
The Committee felt that there are 2 aspects
to Q3: one as a simple solution to a system and another more complex and
unclear how it can serve as a support. The Committee agrees on predictability
of behavior of these systems in a complex environment and predictability
in-vivo, and generalizing capabilities by using fundamental attributes for
comparing different formulations.
3) How should the Q3 concept be validated or demonstrated
• Demonstration
that we can detect changes in manufacturing processes?
• Demonstration
that we can detect formulations with known differences?
• Demonstration
that drug release rates are identical?
The Committee felt that careful thought
needs to be placed into how we approach validation first principles and
identified variability in the substrate as a key aspect to be applied over time
and in the patient. The Committee agreed that as there is nothing similar to
first principles in a clinical trial assessment, how well can a product be
characterized and compared in a meaningful way.
The Committee concluded that because
dermatological products are for local effects, developing a system by product
could be a solution. Also, the Committee agreed that one is better off with comparing
two systems rather than just one. The Committee concluded that as we try to
equate it to bioquivalence, in a traditional way, it makes it more difficult to
come to a simple answer.
Bioequivalence for topical products
4) What
role should Q3 and DPK play in the demonstration of bioequivalence for topical
products?
• Under
what circumstances should Q3 equivalence be sufficient to justify a wavier of
in vivo bioequivalence tests?
• Under
what circumstances should Q3 equivalence and a DPK method in healthy subjects
be sufficient to determine bioequivalence?
The Committee discussed the goal is to find something to assess release of drugs at steady state and DPK indicates how fast the product comes out of the barrier. The Committee agreed that cadaver skin is as good a test method as DPK for in vitro diffusion and could be more controllable.
The Committee agreed that though there are theoretical shortfalls in analysis of any of these systems, the goal is to evaluate the behavior of the dosage form, the activity of the drugs and the related aspects.
The Committee concluded that the because there are different perspectives on each side it
is difficult finding a common ground. The agreement is to move toward
constructing a portfolio approach looking at a combination of tests or to test
different indications and be able to anticipate challenges.
The meeting was
adjourned at approximately