Preservative Efficacy Test

Preservative Efficacy Test
Preservative Efficacy Test
Preservative Efficacy Test

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.

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 higher risk of microbial contamination.

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 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.

The Preservative efficacy test is useful in stability study of the product to determine effectiveness of preservative during its shelf life. It is also used to check the robustness of formulation.

Principle of Preservative Efficacy Test

Principle of preservative efficacy test is to inoculate a product with microorganism and then evaluating the product at defined time interval to see whether there is 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 parellel 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 in to 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.

Arbro Pharmaceuticals Limited (Analytical Divison) is 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. Arbro has 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.

Related Articles


Your email address will not be published. Required fields are marked *

  1. Preservative Efficacy recoveries
    Regarding the recoveries observed in different multidose products, it is observed that many products show comparably higher log reduction to the value mentioned in pharmacopeia. Hence should we conclude on the basis of higher log reduction obtained for a product as toxic amount of preservative or any other parameter is also considered for judging the preservative value?

    1. Hi Nasrat, Along with the activity the data needs to be supported with quantification of the added preservatives by HPLC or some other technique to establish that it has been added within the permitted levels and is safe for use.

  2. Is there any different in procedure for preservative efficacy testing if food and pharmaceutical product were tested?

  3. Woah! I’m really loving the template/theme of this
    site. It’s simple, yet effective. A lot of times it’s hard to get that “perfect balance” between user friendliness and appearance.
    I must say you’ve done a great job with
    this. Additionally, the blog loads very fast for
    me on Safari. Outstanding Blog!


Dont Get left Out!

over 20,000 scientists read our weekly Newsletter!