CD Formulation Offers Multiple Methods for Microbial Limit Test

Posted by Helen Smith on November 2nd, 2021

High level of microorganisms should not be present in non-sterile products for human use as they may cause adverse incidents. As an expertspecializing in drug formulation, CD Formulation announces to release microbial limit test (MLT) service for drug development projects to determine whether a non-sterile pharmaceutical product complies with the established specifications.

Microbial safety is very important for drugs and should be carefully controlled throughout all stages of drug development, including manufacturing and subsequent storage and use stages. By setting limits on the number of bacteria will ensure drug product safety.

“We know that solid oral dosage formulations, such as pills and tablets, are manufactured and sold worldwide as non-sterile formulations. By conducting MLT, the number of microorganisms present in non-sterile pharmaceutical samples, either raw materials or final products, can be specified to determine if certain microorganisms exceed quantitative limits,” says the Marketing Chief of CD Formulation.

With a cGMP-compliant laboratory and state-of-the-art analytical instruments, CD Formulation is capable of performing microbial limit tests for the pharmaceutical and cosmetic industries according to USP and EP. There are numerous analytical techniques to evaluate MLT, and the most commonly used methods are membrane filtration method, standard plate count, pour plate method, most probable number, direct enrichment, membrane filtration enrichment and more.

Usually, a microbial limit test starts with system suitability, a step performed initially to determine if the product being evaluated will enhance or inhibit bacterial or fungal growth. Once system suitability is determined, the next step is total aerobic count, in which the product bioburden, namely, the amount of bacterial contamination can be determined in a given amount of sample. At the same time, Total Yeast and Mold Count (TYMC) is also conducted in the same manner as the total aerobic count, despite there being a few differences.

Guided by USP and EP, CD Formulation provides the following microbial limit test services:


  MLT Method Suitability Test

  Microbial Enumeration (Total Aerobic Microbial Count and Total Combined Yeasts and Mold Count)

  Screening Test for Specified Microorganisms (including P. aeruginosa,   E. coli, S. aureus, Salmonella, Bile-tolerant gram-negative bacteria, C. albicans, Clostridium,   Burkholderia cepacia complex)

For more information about CD Formulation’s microbial limit test services, please visit or directly send an email to

About CD Formulation

As a science-driven company, CD Formulation has accumulated rich experience in drug formulation and is qualified to serve the pharmaceutical industry by providing CRO services to develop, produce and design pharmaceutical excipients for solid, semi-solid and liquid dosage forms. With an innovative spirit and a down-to-earth attitude, the company is missioned to address the long-standing issue of new API development such as API-excipient compatibility. It has completed several development projects and proudly extends its capability, which covers generic to innovative formulation with an ambition to enhance the solubility and bioavailability of difficult-to-formulate compounds.

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Helen Smith

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Helen Smith
Joined: February 19th, 2021
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