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Preservative Efficacy Test

Preservative Efficacy Testing
Preservative Efficacy Testing

Preservative efficacy test is performed to determine the type and minimum effective concentration of preservative required for satisfactory preservation of pharmaceuticals, food and biotechnology products.

The preservative to be effective in the final packaged product should be considerably below the concentrations of the preservative that may be toxic to human beings.

Do not worry if you are not aware of preservative efficacy testing methods. We have compiled details about it, along with information on preservatives and their usage in different industries. So you will be able to understand the complete concept of preservatives and efficacy testing.

What Is a Preservative Efficacy Test?

The Preservative efficacy test is a laboratory test that determines the level of antimicrobial activity of a product and to evaluate how well a product withstands microbial contamination during use.

Preservative efficacy test is an important parameter for both pharmaceutical and food products where there is a higher risk of microbial contamination.

The testing provides two benefits to these industries:

  • Firstly, it evaluates the products to see what maximum quantity of preservatives they should have. 
  • Secondly, it evaluates the products to see whether or not they are within the preservatives’ described limits and for preservative effectiveness testing. 

However, food and pharmaceuticals are not the only two industries utilizing the tests. Preservative efficacy test for cosmetic products is also conducted to ensure that the products are safe to be used by consumers directly onto their skin.

Now, let’s see what preservatives are and why these different industries use them in their range of products. 

What are preservatives and why are they used?

Preservatives are substances added to non-sterile preparation in order to protect them from unwanted microbial growth or from microorganisms which are unknowingly introduced during the manufacturing process.

The primary purpose of adding antimicrobial preservatives to dosage forms is to prevent adverse effects arising from contamination by microorganisms that may be introduced inadvertently during or subsequent to the manufacturing process.

In the case of sterile articles packed in multiple-dose containers, antimicrobial preservatives are added to inhibit the growth of microorganisms that may be introduced from repeatedly withdrawing individual doses.

If preservatives will not be used in different products, they will get contaminated within no time and will be of no use for all the people who buy them.


  • Food Industry: Here, preservatives are used to keep the food safe from spoilage due to the growth of fungus, bacteria, yeast, or moulds in them. The element can further help in maintaining the texture, colour, and flavour of the food by delaying rancidity. Therefore, keeping the food items consumable for a more extended period of time. 
  • Pharmaceuticals Industry: Medicines are only effective when they themselves are in good condition. In order to attain this, preservatives are used in them. It helps in keeping microorganisms’ growth in them, keeping them efficient and harmless for a longer time. 
  • Cosmetics Industry: The cosmetic and personal care industry also utilizes preservatives to prevent any harmful bacterias from contaminating their product. This way, the products remain safe to be used by people on their skin. 


All in all, we can say that all these industries use preservatives to ensure no bacteria or other harmful microorganisms grow in their products. Hence, keeping their products intact to be utilized by its customers. 

On the other hand,the Preservative efficacy test is useful instability study of the product to determine the effectiveness of preservative during its shelf life. It is also used to check the robustness of formulation.

The principle of Preservative Efficacy Test

The principle of preservative efficacy test procedure is to inoculate a product with microorganism and then evaluating the product at a defined time interval to see whether there is a reduction in the microbial population, or not, to desired levels in a given time.

Neutralizing studies for the preservative must be carried out before or in parallel with the preservative efficacy test, to ensure the neutralization of biologically active agents, and if the neutralization study fails, alternate neutralization approaches like membrane filtration may have to be used.

The preservative properties of the product are considered adequate if there is either a fall or no increase in the number of microorganisms inoculated into the preparation.

The organisms specified for use in the tests are intended to be representative of those that might be expected to be found in the environment in which the preparation is manufactured, stored and used. Environmental isolate from manufacturing side also considered for this test.

Get Your Products Tested with ARBRO!

We are a multidisciplinary contract research and testing organization and a Government approved laboratory with years of experience working with premier clients across industries and around the world. We have a complete micro lab with all required facility in its Delhi and Baddi facility. With a team of over 200 professionals backed by cutting edge technology and world-class infrastructure spread across multiple locations, Arbro is one of the best solution partners for all microbiological testing requirements.

From preservative effectiveness testing to preservative testing pharmaceutical products and food items, you will find all sorts of efficacy testing solutions in one place with us. 

In case you have any queries about the preservative efficacy test, or you want your products to be tested, feel free to reach us through the given form. You can also call us on +91-11-45754575 for any of your doubts. We will offer you the most effective solution and service according to your requirements. 

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