Microbiological control of pharmaceutical products containing preservatives: drawbacks of the method of membrane

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C Casetta1, F Negretti, C Trabattoni

  • 1Chair of Microbiology and Hygiene, Institute of Pharmacological Sciences, Milan.

Bollettino Chimico Farmaceutico
|July 1, 1992
PubMed

Insights

Filtration membranes used for pharmaceutical preservatives retain antimicrobial activity, even after washing. This residual activity can interfere with essential microbiological quality control testing of drug products.

Area of Science:

  • Pharmaceutical Science
  • Microbiology
  • Analytical Chemistry

Background:

  • Membranes are widely used for solution filtration in pharmaceutical manufacturing.
  • Preservatives are common excipients in pharmaceutical formulations.
  • Pharmacopoeial guidelines exist for membrane washing procedures.

Purpose of the Study:

  • To evaluate the residual antimicrobial activity of filtration membranes after washing.
  • To determine the impact of this residual activity on microbiological quality control.

Main Methods:

  • Microbiological assays were performed on filtration membranes.
  • Membranes were washed with peptone water as per Pharmacopoeial guidelines.
  • Antimicrobial activity was assessed by inhibition zones and colony-forming unit counts.

Main Results:

  • Washed membranes frequently exhibited significant antimicrobial activity.
  • Inhibition zones and reduced colony counts indicated residual activity.
  • This activity persisted despite adherence to standard washing protocols.

Conclusions:

  • Filtration membranes can retain significant antimicrobial activity post-washing.
  • This residual activity poses a challenge for accurate pharmaceutical microbiological testing.
  • Methods to mitigate membrane antimicrobial carryover may be necessary for reliable quality control.

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