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Control of microbial contamination of Franz diffusion cell receptor phase in the development of transcutaneous breast
Z Davison1, R I Nicholson, J-Y Maillard
1Welsh School of Pharmacy, Cardiff University, Cardiff, UK.
Aims:
To determine the micro-organism contamination of excised porcine (pig) ear, and evaluate the use of Cyclopore track-etched membranes (CTEM) for preventing ingress into Franz-type diffusion cells.
Methods:
Swabs were taken from four locations and used to inoculate Tryptone Soya Agar (TSA) and Sabouraud Dextrose Agar (SDA) plates. Diffusion cells were assembled to include porcine skin with and without CTEM, and the receptor phase sampled periodically and spread onto plates.
Results:
Five distinct colony types were isolated after incubation of all swabs on TSA plates at 37 degrees C; on SDA plates, one fungal colony was found at 30 degrees C and one at 37 degrees C. The SDA agar plate incubated at 30 degrees C resulted in the growth of a large diffused white fungal colony. No regional differences were observed. Without the CTEM, the receptor phase became contaminated within 6 h. With the CTEM present, microbial ingress was substantially retarded with visible presumptive fungal growth occurring at 24 h and detectable contamination on both microbiological media at 48 h.
Conclusions:
As expected, the native porcine ears were considerably contaminated. The ingress of contamination into the diffusion cell receptor phases can be largely, but not entirely, eliminated using CTEM. The addition of antimicrobial agents was necessary to eliminate micro-organisms that were observed at later time points.
Significance And Impact Of The Study:
This article, while highlighting the presence of a high number of micro-organisms on native porcine skin, presents a practical means to reduce the risk of microbial contamination in transdermal/transcutaneous permeation studies, particularly in the study of cell cultures grown within Franz diffusion cell receptor compartments.
Insights
Excised porcine ears are contaminated with microorganisms. Cyclopore track-etched membranes (CTEM) largely prevent microbial contamination in Franz diffusion cells, but antimicrobial agents may still be needed for complete elimination.
Area of Science:
- Microbiology
- Dermal Research
- Membrane Technology
Background:
- Excised porcine skin is frequently used in transdermal permeation studies.
- Microbial contamination poses a significant challenge in these studies, potentially affecting results.
- Franz-type diffusion cells are standard equipment for evaluating skin permeability.
Purpose of the Study:
- To quantify microbial contamination on excised porcine ear skin.
- To assess the efficacy of Cyclopore track-etched membranes (CTEM) in preventing microbial ingress into Franz diffusion cells.
- To provide insights for improving the reliability of transdermal and transcutaneous permeation studies.
Main Methods:
- Porcine ear swabs were cultured on Tryptone Soya Agar (TSA) and Sabouraud Dextrose Agar (SDA) plates.
- Franz-type diffusion cells were assembled with and without CTEM.
- Receptor phases were periodically sampled and cultured to monitor microbial contamination.
Main Results:
- Multiple distinct microbial colonies, including fungi, were isolated from porcine ear swabs.
- Without CTEM, Franz diffusion cell receptor phases became contaminated within 6 hours.
- CTEM significantly retarded microbial ingress, with detectable contamination occurring at 48 hours.
Conclusions:
- Native porcine skin harbors substantial microbial contamination.
- CTEM effectively reduces, but does not completely eliminate, microbial contamination in diffusion cells.
- Antimicrobial agents are necessary to fully prevent microbial contamination at later time points.
