BUA(Blend Uniformity Analysis ) or homogeneity testing can be applied to all dosage forms, but is recommended for those dosage forms for which the USP requires content uniformity testing. These dosage forms include
Coated tablets, other than film coated tablets
Suspensions in single-unit containers or in soft capsules
Pressurized metered-dose inhalers
Under current good manufacturing practices (CGMPS), an applicant is required to perform a test or examination on each commercial batch of all products to monitor the output and validate the performance of processes that could be responsible for causing variability, which includes
adequacy of mixing to ensure uniformity and homogeneity (21 CFR 211.11 O(a)(3)).
The recommended sample size of the blend material is no more than three times the weight of an individual dose. If the firm experiences problems in collecting small samples equivalent to 1 to 3 dosage units and demonstrates that small samples give lower values for BUA due to sampling bias, larger samples (usually no more than 10 dosage units) can be collected.
Samples for BUA can be collected either from the drums or the blenders. For more than one drum or blender, analysis from each drum or blender is encouraged for the bioequivalence ard/ortest batches. The batch size, number of samples (usually 6 to 10), locations of sampling, and equipment should be specified as part of the in-process controls for BUA or homogeneity.Potential differences in mixing efficiency associated with specific types of equipment should be considered when determining sampling locations.
Container : Before seaming the container
a) Collect 10 polythene bags filled with Tab / Cap. Randomly from each batch.
b) Cut the polythene bag.
c) Count the number of tab / cap per polythene bag / container
d) Record the number of the in the test sheet.
e) Confirm that each container is having nos of tab / cap from 98 – 102% o the labeled amount.
f) Calculate average number of units as follows
Average number of Units = Total Units / No of container = Limit not less than labeled amount.
If the above procedure does not comply please follow this:
Count the number of 10 additional containers. Average number of in 20 containers is & not less than labeled amount and the number is not more than one of 20 container is less than 98% or more than 102% of the labeled amount.