What is Preservative? Importance, Types, Uses and Efficacy Test

The word “Preservative” was derived from the term “Preservation” (storage). A preservative is a synthetic compound that prevents or inhibits microbial growth and extends the shelf life of various products, including pharmaceutical drugs, cosmetic products, biological products (vaccines), food products, woods, paints, etc.

Preservatives are mostly chemical compounds that need to exhibit heat stability, work effectively over a wide range of pH levels, and be soluble in water. They should possess biocidal properties, enabling them to inhibit the growth and proliferation of microorganisms.

While, “Preservation” refers to keeping something in its original state or in good condition, unaffected by the passage of time or weather. Since ancient times, various preservation methods have been developed for items like pickles, jams, and tomato sauce. These methods involve the use of natural preservatives such as salts, sugars, and jaggery, as well as processes like drying or heating.

In general, preservation techniques are executed in two modes: Chemical and Physical. Chemical preservation involves adding preservatives, which are chemical compounds, to the product. Physical preservation, on the other hand, includes processes like refrigeration or drying.

The practice of preservation continues to this day, adhering to established standards in various industries such as pharmaceuticals, cosmetics, and food. Precise quantities of preservatives are used in accordance with guidelines provided by organizations like the World Health Organization (WHO), the Bureau of Indian Standards (BIS), and the Food Safety and Standards Authority of India (FSSAI).

The Preservative Efficacy Test (PET) is a crucial test in the field of pharmaceutical and cosmetic microbiology, specifically for non-sterile products. This test is also known as the Preservative Challenge Test (PCT) or Antimicrobial Effectiveness Test (AET).

The primary purpose of adding preservatives to various forms of food, pharmaceuticals, and personal care products is to prevent adverse effects resulting from contamination by microorganisms. These microorganisms can be introduced during or after the manufacturing process or even during product use.

There are mainly three types of preservatives that are widely used in pharmaceuticals, cosmetics, and food products: Antimicrobial, Antioxidants, and Enzymes.

• Antimicrobial preservatives: These prevent the growth of microorganisms such as bacteria, fungi, and mold, as well as the development of toxins.
• Antioxidants: The oxidation process can spoil many food products, especially those with a high fat content. Antioxidants slow down or completely prevent deterioration caused by oxidation, such as fat rancidity, color changes, flavor changes, and texture changes.
• Enzymes: Enzymes are used to extend the shelf life of cosmetic and similar products, effectively delaying their expiration.

Preservative Efficacy Testing is a process used to evaluate the effectiveness of preservatives in preventing microbial growth and ensuring the microbiological stability of products such as cosmetics, pharmaceuticals, and personal care items. The purpose of this testing is to determine whether the selected preservative system is capable of adequately preserving the product throughout its intended shelf life.

The term Preservative Efficacy Test (PET) is also known as the Preservative Challenge Test (PCT) or the Antimicrobial Effectiveness Test (AET).

The fundamental procedure of the Preservative Efficacy Test is to inoculate a product with microorganisms and evaluate the product at defined time intervals. The aim is to determine whether there is a reduction in the microbial population to the desired levels within the specified time and at the prescribed temperatures.

This test is useful in stability studies to assess the effectiveness of the preservative throughout the product’s shelf life. Additionally, it is employed to check the robustness of the formulation.

Preservative Efficacy Testing serves as a critical quality control measure for manufacturers and regulatory agencies. Its primary objective is to determine whether the selected preservative system is capable of effectively preventing microbial growth and maintaining the microbiological stability of the product. Without adequate preservation, products can become a breeding ground for harmful bacteria, fungi, and other microorganisms, posing significant risks to consumer health.

Preservative efficacy testing is a critical step in product development. By evaluating the effectiveness of the selected preservative system, manufacturers can ensure that their products remain safe, stable, and free from microbial contamination. This testing helps identify potential weaknesses in the preservation strategy and enables necessary adjustments to be made to enhance product quality.

Moreover, preservative efficacy testing is essential for regulatory compliance. Regulatory agencies, such as the FDA and the European Medicines Agency (EMA), require manufacturers to demonstrate the effectiveness of their preservative systems. Complying with these regulations not only ensures product safety but also facilitates market access and consumer confidence.

• Pseudomonas aeruginosa (ATCC 9027)
  
• Staphylococus aureus (ATCC 6538)
  
• Escherichia coli (ATCC 8739)
  
• Candida Albicans (ATCC 10231)
• Aspergillus brasiliensis (ATCC 16404)