PMFLIST Archives

October 2005

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:
Johan Bender <[log in to unmask]>
Reply To:
The Pharmaceutical Microbiology Forum Email List <[log in to unmask]>
Date:
Thu, 27 Oct 2005 10:21:47 +0200
Content-Type:
text/plain
Parts/Attachments:
text/plain (61 lines)
Lectori salutem,

I am looking for guidance on the interpretation of USP 788.  My
understanding is that the test is a measure of extraneous particles. I
am testing a powder product that I reconstitute for counting on an
automated particle counting system.  My product has multiple potencies
that are achieved by varying the reconstitution volume. I routinely
reconstitute to the highest prescribed volume and pool enough units to
achieve test volume.
* Given that the automated system will collect data on the number of
containers and total volume of solution to calculate the average number
of particles per container, does it matter what volume of diluent I use
in each container?
REPLY: mostly the counters have an automated dilution so most easy is to
dissolve worst case (i.e., resulting in the highest concentration of
active).

* Also does anyone tie dissolution of powder solution with the testing
described in <788>?
REPLY: it is evident that the counting should be done in reconstitution
fluid identical to the one described in the package insert. In most
cases the active(s) will dissolve rapidly - the 788 guidance gives some
room to use ultrasonification to get rid of air bubbles. My experience
is: always use a ultrasound step.

* Should undisolved product be considered particles for this test <788>?
REPLY: yes.

* Am I routinely swaying the test in my favor by using the highest
volume?
REPLY: it depends if your counter has an automated dilution.

Regards - Johan Bender
Bactimm - Farmalyse BV, The Netherlands

------------------
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/
ATS Laboratories - http://www.ats-labs.com
Biolog - http://www.biolog.com
Biomerieux - http://industry.biomerieux-usa.com/
Dupont Qualicon - http://www.qualicon.com
EMSL Analytical, Inc. - http://www.emsl.com
Genomic Profiling Systems, Inc. - http://www.genprosys.com
Microcheck Inc,  Microbial Analysis Laboratory - http://www.microcheck.com
MicroTest World Class Services - http://www.microtestlabs.com/
MIDI, Inc. - http://www.midi-inc.com/
Millipore - http://www.millipore.com/
NovaTek International - http://www.ntint.com
Raven Biological Labs - http://www.ravenlabs.com
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