Liofilchem® Buffered NaCl Peptone Solution pH 7.0

Liofilchem® Buffered NaCl Peptone Solution pH 7.0 is a non-nutritive, isotonic diluent designed for the dissolution, suspension, and dilution of test samples prior to microbiological examination. Its composition complies with Harmonized Pharmacopoeia (USP/EP/JP) requirements and ISO 21149, ensuring suitability for the microbiological testing of non-sterile pharmaceutical, cosmetic, and food products.

This solution maintains microbial viability during sample preparation without promoting growth, providing accurate enumeration and detection results in accordance with international standards.

Key Features

• Pharmacopoeia compliant: Formulated according to USP, EP, and JP harmonized methods.
• ISO 21149 compliant: Suitable for microbiological examination of cosmetics.
• Buffered at pH 7.0 ± 0.2 to preserve physiological conditions for microorganisms.
• Non-growth promoting: Maintains viability without supporting microbial multiplication.
• Versatile use: Suitable for diluting, rinsing, and suspending test materials.
• Compatible with enrichment or enumeration media: Ideal for use prior to plating on TSA, PCA, or other agar media.

Typical Formula (per litre)

Principle of the Method

• Phosphates act as buffering agents to maintain neutral pH conditions.
• Sodium chloride ensures osmotic balance, maintaining microbial cell integrity.
• Peptone provides minimal nutrients (amino acids, minerals, and vitamins) to sustain viability without allowing proliferation.
• The solution can be supplemented with inactivators or surfactants, such as Polysorbate 80 (ref. 80031), to neutralize antimicrobial residues when required.

Note: Buffered NaCl Peptone Solution pH 7.0 is not a culture medium; its composition prevents microbial growth while maintaining cell viability for accurate enumeration.

Preparation

1. Suspend 16.1 g of powder in 1 L of distilled or deionized water.
2. Mix well and heat to dissolve completely.
3. Sterilize by autoclaving at 121°C for 15 minutes.
4. Cool to room temperature before use.

Test Procedure

1. Prepare a 1:10 sample dilution in Buffered NaCl Peptone Solution.
2. Use suspensions within 2 hours, or store at 2–8°C for up to 24 hours.
3. Subculture onto the appropriate non-selective medium (e.g. TSA) by pour plate, spread plate, or membrane filtration.
4. Incubate according to the test organism and relevant pharmacopeial or ISO standard.

Interpretation of Results

As a diluent, this solution does not generate growth. Enumeration should be conducted using the target culture medium.

• No change in colony count compared to the original inoculum confirms neutrality and viability preservation.

Quality Control

Dehydrated medium: free-flowing beige powder

Prepared medium: clear, colorless solution

Storage and Stability

• Store dehydrated powder at 10–30°C, tightly closed and dry.
• Store bottles or bags at 10–25°C, away from light.
• Shelf life:
  • Dehydrated medium – 4 years
  • Ready-to-use bottles/bags – 2 years
• Discard if contaminated, discolored, or beyond expiry.

Safety and Handling

• For professional laboratory use only.
• Handle according to good microbiological practices.
• Consult the Safety Data Sheet (SDS) before use.
• Dispose of waste according to local regulations.

Ordering Information

Liofilchem® Buffered NaCl Peptone Solution pH 7.0 is a pharmacopoeia-compliant diluent designed for accurate microbiological analysis of non-sterile pharmaceuticals, cosmetics, and food products. By maintaining microorganism viability without supporting growth, it ensures precision and reproducibility in sample preparation and enumeration workflows. Its reliability, compliance with USP/EP/JP and ISO 21149, and multiple formats make it an essential component for quality control and laboratory testing environments worldwide.