PMFLIST Archives

May 2011

PMFLIST@LISTS.MICROBIOLOGYNETWORK.COM

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Scott Sutton <[log in to unmask]>
Reply To:
The Pharmaceutical Microbiology Forum Email List <[log in to unmask]>
Date:
Tue, 24 May 2011 10:57:04 -0400
Content-Type:
text/plain
Parts/Attachments:
text/plain (148 lines)
Mike,

I have seen this done as well, but as Carole correctly notes you need to
understand the relationship of concentration to activity.  By the time you
figure this out you would have less work to just properly validate the test
for all formulations of interest.

The only time I might consider this approach was at Phase 1 clinical -
beyond that the risk, in my opinion, is too high if performed without a
proper understanding of the effect of concentration for the particular API
or excipient.  That is not to say I have not seen it done, only that it is a
poor idea (IMO).

Scott

-----Original Message-----
From: The Pharmaceutical Microbiology Forum Email List
[mailto:[log in to unmask]] On Behalf Of Carol Lampe
Sent: Monday, May 16, 2011 8:32 PM
To: [log in to unmask]
Subject: Re: [PMFLIST] Bracketing method suitability studies for sterility
testing

Michael,
I have seen concentration bracketing done in the past and it works well if
you have a good understanding of the effects increasing concentration has on
your panel of organisms.  As a basic example, if you were covering varying
concentrations of ethanol, and you tested the 90% and the 10%, you would
miss the most bacteriostatic concentration - 70%.  The 10% is too dilute to
be as effective as the  70%; and the 90% does not have the water activity
needed to be as effective bacteriostatic agent as the 70%.

You might try running some screening studies at each concentration, like a
mini sterility test, to determine which concentration poses the greatest
challenge to the bacterial panel you are using, and use that as the
justification for you choice of validation.  You will however, then be
forced to perform the most stringent neutralization on every product in that
line.  If that would not be cost or time prohibitive, then I think you would
have a logical approach for streamlining your validation.  Of course your
initial validation plan, with acceptance criteria, would need to be outlined
in a protocol or procedure prior to starting any formal studies.

Carol Lampe
Sr. Consultant, JMHAI

On Fri, May 13, 2011 at 2:01 PM, Dr. Michael J. Miller <
[log in to unmask]> wrote:

> Has anyone bracketed their method suitability 
> (bacteriostasis/fungistasis) testing for sterility testing? For 
> example, if a range of products only differ in their API concentration 
> and the API is the only ingredient in the formulation, have you 
> performed method suitability on the highest and the lowest API 
> concentrations instead of qualifying every concentration/formulation? I am
looking for current industry practices.
> Thanks, Michael
>
> Michael J. Miller, Ph.D.
> President
> Microbiology Consultants, LLC
> 19009 St. Laurent Drive, Lutz, FL 33558
> phone: 727-437-2743 (RAPID-RAPID)
> email: [log in to unmask]
> web: http://microbiologyconsultants.com
> linkedIn: http://www.linkedin.com/in/drmichaelmiller
>
> http://rapidmicromethods.com - advancing the science and 
> implementation of rapid microbiological methods.
>

--
Carol
"Life is not about waiting for the storms to pass - it is about learning to
dance in the rain."

------------------
The PMFList (http://microbiol.org/PMFList_info.htm) is operated from The
Microbiology Network (http://microbiol.org) and supported by our sponsors
(http://microbiol.org/sponsor.htm) as a service to the scientific community.

Please take a second to visit our sponsors' web sites and say thank you for
their support of this service.

Accugenix - http://www.accugenix.com

American Type Culture Collection - http://www.atcc.org

BD Diagnostic Systems - http://www.bd.com/ds/

Biolog - http://www.biolog.com

Biomerieux - http://industry.biomerieux-usa.com

Biotest - http://www.BiotestUSA.com/micro

MicroBioLogics, Inc. - http://www.microbiologics.com

MODA Technology Partners: now a LONZA company http://lonza.com/moda

Pall - http://www.pall.com

NovaTek International - http://www.ntint.com

Rapid Micro Biosystems - http://www.rapidmicrobio.com  (formerly GPS)

Veltek Associates, Inc - http://www.sterile.com

=================================
The nature of this service is to provide a medium for communication.  The
specific statements and endorsements of individuals participating in the
discussions are not necessarily those of The Microbiology Network, Inc., the
PMF, or the sponsors of the list.

------------------
The PMFList (http://microbiol.org/PMFList_info.htm) is operated from
The Microbiology Network (http://microbiol.org) and supported by
our sponsors (http://microbiol.org/sponsor.htm) as a service to
the scientific community.

Please take a second to visit our sponsors' web sites and say thank you for their support of this service.

Accugenix - http://www.accugenix.com

American Type Culture Collection - http://www.atcc.org

BD Diagnostic Systems - http://www.bd.com/ds/

Biolog - http://www.biolog.com

Biomerieux - http://industry.biomerieux-usa.com

Biotest - http://www.BiotestUSA.com/micro

MicroBioLogics, Inc. - http://www.microbiologics.com

MODA Technology Partners: now a LONZA company http://lonza.com/moda

Pall - http://www.pall.com

NovaTek International - http://www.ntint.com

Rapid Micro Biosystems - http://www.rapidmicrobio.com  (formerly GPS)

Veltek Associates, Inc - http://www.sterile.com

=================================
The nature of this service is to provide a medium for communication.  The specific statements and endorsements of individuals participating in the discussions are not necessarily those of The Microbiology Network, Inc., the PMF, or the sponsors of the list.

ATOM RSS1 RSS2