Pharmacopoeial media · Neutralising diluent
Fluid Casein Digest Soy Lecithin Polysorbate 20 Medium – diluent for preserved products
Fluid Casein Digest Soy Lecithin Polysorbate 20 Medium is a neutralising medium named in USP <61> for products that contain preservatives or antimicrobial substances, and for samples that do not mix well with water.
- Neutralising diluent named in USP <61>
- Lecithin and polysorbate 20
- For creams, ointments and preserved products
How Fluid Casein Digest Soy Lecithin Polysorbate 20 works
Soy lecithin and polysorbate 20 inactivate many preservatives and surfactant-type antimicrobials and help to disperse fatty samples, while the casein digest supports recovery of the micro-organisms released from the sample.
Applications and practical notes
Pharmacopoeial testing starts with sample preparation: the product is dissolved or suspended in a buffered diluent, and preservatives or antimicrobial residues are neutralised with lecithin and polysorbate so that surviving micro-organisms can grow (Ph. Eur. 2.6.12, USP <61>). Typical applications include:
- Preparation of initial suspensions and dilutions
- Neutralisation of preservatives and disinfectants
- Rinsing of membrane filters
- Pharmaceutical and cosmetic laboratories
Working with Fluid Casein Digest Soy Lecithin Polysorbate 20: Warm the medium before adding fatty samples and show the neutralising effect for each product in the method suitability test.
Good practice with dehydrated media: keep the bottle tightly closed in a cool, dry place, weigh the powder quickly to avoid moisture uptake, and use fresh distilled or deionised water. Check the pH of each new batch after preparation and before use, and label prepared media with the date. Performance of each lot can be verified with reference strains according to ISO 11133, the standard for the preparation, production, storage and performance testing of culture media.
About pharmacopoeial microbiological testing: the European Pharmacopoeia and the USP describe harmonised methods for non-sterile products – microbial enumeration (Ph. Eur. 2.6.12, USP <61>) and tests for specified micro-organisms (Ph. Eur. 2.6.13, USP <62>) – and the sterility test for sterile products (Ph. Eur. 2.6.1, USP <71>). The chapters define the media, incubation conditions and the growth promotion test that each batch of medium must pass with reference strains. COLO.Science offers the media, diluents, neutralisers and QC strains for these tests from one source.
Complete sets from one supplier: COLO.Science supplies culture media, supplements, rapid tests, identification kits and QC strains as complete sets for the method you follow. Send us your sample types and standards, and we will prepare an offer with the matching products and documentation.
Fluid Casein Digest Soy Lecithin Polysorbate 20 is supplied by COLO.Science in the pack sizes listed under Ordering information. For larger quantities, regular deliveries or method-specific sets that include Fluid Casein Digest Soy Lecithin Polysorbate 20, please send us a request. With every delivery of Fluid Casein Digest Soy Lecithin Polysorbate 20 you receive the lot number and expiry date, and on request we send the available documentation for Fluid Casein Digest Soy Lecithin Polysorbate 20.
Where Fluid Casein Digest Soy Lecithin Polysorbate 20 fits in pharmacopoeial testing
- Sample preparation – Buffered Sodium Chloride-Peptone Solution, Tryptic Soy Broth and neutralising diluents
- Microbial enumeration – Tryptic Soy Agar (TAMC) and Sabouraud Dextrose Agar (TYMC)
- Specified micro-organisms – enrichment in Tryptic Soy Broth, then MacConkey, Mannitol Salt, Cetrimide, XLD, VRBG, RCM and Columbia media
- Sterility test – Fluid Thioglycollate Medium and Tryptic Soy Broth, 14 days
See all pharmacopoeial media in the Microbiology Catalogue →
Ordering information
| Product | COLO code | Pack |
|---|---|---|
| Fluid Casein Digest Soy Lecithin Polysorbate 20 Medium | PRO7456 | 500 g |
Product notice: preparation, storage conditions and shelf life are given on the label. Technical data on this page are for orientation; the label and the lot documentation apply. B2B prices are quoted net, excluding VAT.
Sales and technical support
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Quotations and technical support for culture media and microbiology products across our international sales territory. B2B prices are net, excluding VAT.
COLO.SCIENCE | MICROBIOLOGY SUPPORT
Need the complete set for your method?
Send the sample type, target organism and the standard you follow. COLO.Science will put together the media, supplements, QC strains and confirmation tests for the whole procedure.
