The design of a stability schedule such that only samples on the extremes of certain design factors, e.g., strength, package size, are tested at all time points as in a full design.
The design assumes that the stability of any intermediate levels is represented by the stability of the extremes tested.
Where a range of strengths is to be tested, bracketing is applicable if the strengths are identical or very closely related in composition (e.g., for a tablet range made with different compression weights of a similar basic granulation, or a capsule range made by filling different plug fill weights of the same basic composition into different size capsule shells).
Bracketing can be applied to different container sizes or different fills in the same container closure system.
Related Topics: