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:
Bob Friedel <[log in to unmask]>
Reply To:
The Pharmaceutical Microbiology Forum Email List <[log in to unmask]>
Date:
Mon, 24 Oct 2005 09:47:55 -0400
Content-Type:
text/plain
Parts/Attachments:
text/plain (103 lines)
You need to incorporate the enzymatic neutralizers in the rinse medium.  These references should give you the information you need:

Negretti, F. (1989) "Experimental Observations on the Bacteriological Controls of the Antibiotics--I. Antibacterial Activity of Membranes Employed in Bacteriological Assays", J. Pharma. & Biomed. Anal., Vol. 7, No. 12, p.
1861.

Negretti, F., Casetta, P. (1991) "Research on the chemical inactivation of antibiotic activity in assays of sterility and contamination of pharmaceuticals," J Chemother., Jan., Vol. 3, Suppl. 1, p.76.

Russell, A.D., and Rogers, D.T. (1984) "Laboratory Uses of Antibiotic-Inactivating Enzymes", J. Antimicrob. Chemother., Vol. 14, p. 567.

Bob Friedel
[log in to unmask]



-----Original Message-----
From: The Pharmaceutical Microbiology Forum Email List [mailto:[log in to unmask]] On Behalf Of Manasith
Sent: Monday, October 24, 2005 6:25 AM
To: [log in to unmask]
Subject: [PMFLIST] PVDF for membrane filtration

Dear Colleague!

I have a question to the forum.

We use the membrane filtration method (EP 5th Edition) for the microbial limit testing of antibiotics.

We use the PVDF filters (0.45 Ám pore size), which have low-binding effect to proteins and other substances.

Unfortunately, we don't have recovery of test microorganisms (E. coli, St. aureus and B. subtilis) during the validation study, even after rinsing with 10x 100 ml of Peptone broth. I am not so happy with this filters, as they have promised.

 

Can some one please tell me, weather we have to go further with the rinsing, or use of new membrane or use of neutralizers?

Using of neutralizers is a problematic for us, since we have different kinds of antibiotics. Which neutralizers and which concentrations we should use for Amoxicillin 500mg, Cefalexin 500mg, Refampicin 300mg and Tetracycline 250mg.

 

Thanks you for your input.

 

Manasith Phithak

Microbiology laboratory

 

 


------------------
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.

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