In the BP’s monograph we can see difference for assay limits. For some product the limit is 95-105% (narrow) but for some it is 90-115% (Broad) in the monograph. What would be reason behind this difference. e.g. for Clotrimazole Cream assay limit is 95% to 105%, where as for Tretinoin Gel the assay limit is 90 to 120%. Does this broader limit for Tretinoin Gel like product hints for addition of overages for instability of the formulation during manufacturing.