Preservative Efficacy Testing, Classical Microbiology & QC Testing Services

Classical Microbiology Testing for Cosmetic & Pharmaceutical Quality Control

The suite of classical microbiology testing services forms the cornerstone of a robust, GMP-compliant quality control (QC) program. These tests are essential for ensuring the microbiological safety and stability of the vast majority of cosmetic, personal care, and non-sterile pharmaceutical products. From evaluating raw materials to performing final batch release efficacy testing of preservatives on finished goods, these foundational services are critical for confirming that a product meets microbiological quality specifications before it is sold to consumers.

Our Complete QC Testing Capabilities

Our portfolio covers the essential microbiological tests required to support your entire quality control program, ensuring product integrity from development to distribution.

Preservative Efficacy Testing (PET/AET / Challenge Test)

Evaluates the ability of a product’s preservative system to resist microbial contamination throughout its shelf life and consumer use. Critical for water-based cosmetics, lotions, and pharmaceuticals. → USP, CTFA, AOAC compliant methods.

Microbial Limits Testing (MLT)

Quantifies the total bioburden and confirms the absence of specific objectionable organisms in finished goods. Ensures compliance with pharmacopeial microbiological quality standards. → Supports Manufacturing Batch Release Testing.

Standard Plate Counts

Determines the overall microbial load in raw materials and finished products, providing a foundational measure of microbiological quality.

Zone of Inhibition Testing

Assesses antimicrobial activity by measuring the inhibition zone created by active ingredients or formulations against targeted microorganisms.

Time-Kill & Rapid Germicidal Activity Studies (ASTM)

Evaluates how quickly and effectively antimicrobial agents kill or inhibit microorganisms—commonly used to substantiate rapid-kill or “kills 99.9% in seconds” claims.

Minimum Inhibitory Concentration (MIC) & Minimum Bactericidal Concentration (MBC)

Determines the lowest concentration of an antimicrobial that prevents visible growth or kills a specified organism—essential for research and product optimisation.

Surface Swab & Environmental Testing

Validates the cleanliness of manufacturing environments and surfaces to support GMP compliance and contamination control programs.

Water Testing

Assesses the microbiological quality of process and purified water used in manufacturing—ensuring compliance with USP and ISO standards.

Topical Antimicrobial Efficacy Testing

Our specialized GCP-compliant facility in Texas supports regulated antimicrobial studies for FDA, Health Canada, and EU submissions.

Key methods include:

• Healthcare Personnel Hand Wash (ASTM 1174)
  
  
• European Hand Wash & Rub (EN 1499 & EN 1500)
  
  
• Surgical Scrub Evaluation (ASTM 1115)
  
  
• Persistent & Residual Efficacy Testing
  
  
• Food Service Hand Wash Studies
  
  
• Finger Pad Methods – Bacterial (ASTM 2276) & Viral (ASTM 1838)
  
  
• Hand Sanitizer Efficacy (ASTM 2755)
  
  
• CHG Compatibility Testing

FAQs 

Q1: What is Preservative Efficacy Testing (PET)?

Preservative Efficacy Testing evaluates whether a product’s preservative system is strong enough to prevent microbial contamination during its shelf life. It ensures safety and stability for water-containing cosmetic and pharmaceutical products.

Q2: Why is efficacy testing of preservatives important?

Efficacy testing of preservatives confirms that antimicrobial agents in a product remain effective over time. This helps meet regulatory requirements and supports consumer safety.

Q3: What is an antimicrobial efficacy test?

An antimicrobial efficacy test measures the product’s ability to reduce or eliminate harmful microorganisms. It is essential for substantiating claims on hand sanitizers, soaps, and surface disinfectants.

Q4: What does Microbial Limits Testing (MLT) involve?

MLT ensures finished products are free from objectionable pathogens and quantifies the overall bioburden. This test is critical for quality control and regulatory compliance.

Q5: Why are Time-Kill & Germicidal Activity Studies performed?

Time-Kill studies evaluate how quickly and effectively an antimicrobial product works. These tests are used to substantiate marketing claims for rapid antimicrobial action.

Protect Product Integrity. Request Comprehensive QC & Preservative Testing Today.