Minimum Inhibitory Concentration (MIC) Testing at PBL

Microorganisms can contaminate the drug product during the use or manufacturing of the product, therefore pharmaceuticals that are provided nonsterile often contain preservatives that inhibit the growth of microorganisms.

The Minimum Inhibitory Concentration (MIC) is a test which determines the minimum concentration of the preservative needed to completely inhibit the growth of the challenge organism. A suspension of the challenge organism is prepared at a concentration of one million colony forming units (CFU) per mL. The product is then tested neat or diluted and incubated with the challenge organism. The dilution of the product depends on the specifications of the product. Turbidity within the sample would indicate growth of the challenge organism. The lack of turbidity would indicate that the challenge organism has been inhibited.

Minimum Bactericidal Concentration (MBC) can also be done by taking the minimum inhibitory concentration (MIC) test one step further and subculturing the inoculated and incubated test solution onto agar plates. The goals between the two tests are slightly different. The Minimum Inhibitory Concentration (MIC) test determines the lowest concentration required to inhibit growth of the organism and the Minimum Bactericidal Concentration (MBC) test determines the lowest concentration of preservatives that will kill the organism.

Available Minimum Inhibitory Concentration (MIC) Services

  • Minimum Inhibitory Concentration (MIC)
  • Minimum Bactericidal Concentration (MIB)

Read More About MIC

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