RESULTS AND INTERPRETATION
When verifying the suitability of the membrane filtration method or the plate-count method,a mean count of any of the test organisms not differing by a factor greater than 2 from the walue of the control defined in inoculation and dilution in the absence of product must be obtained.when verifying the suitability of the MPN method ,the calculated value from from the inoculum must be within 95% confidence limits of the results obained with the control .
If the above criteria cannot be met for for one of more of the organisms tested with any of the described methods ,the method and test conditiongs that come closest to the criteria are used to test the product.
TESTING OF PRODUCTS
AMOUNT USED FOR THE TEST
Unless otherwise directed,use 10 g or 10 ml of the product to be examined taken with the precautions referred to above .for fluids or solids in aerosol form ,sample 10 containers.for transdermal patches ,sample 10 patches.
The amount to be tested may be rebuced for active substances that will be formulated in the following conditions: the amount per dosage unit (e.g ,tablet,capsule,injection)is less than or equal to 1 mg .or the amount per g or ml (for preparations not presented in dose units)is less than I mg .in these cases ,the amount of sample to be tested is not less than the amount present in 10 dosage units or 10 g or 10 ml of the product.
For materials used as active substances where the sample quantity is limited or biatch size is extremely small(i.e,less than 1000 ml or 1000 g ),the amount tested shall be 1% of the batch unless a lesser amount is prescribed or justified and authorized.
Foe products where the total number of entities in a batch is less than 200(e.g samples used in clinical trials),the sample size may be reduced to two units ,or one uint if the size is less than 100.
Select the samle(s) at random from the bulk material or from the available containers of the preparation. To obtain the required quantity, mix the contents of a sufficient number of containers to provide the sample.