During manufacture, the quality control (QC) of allergen extracts presents a variety of challenges. One important consideration is the expected variability that is inherent with naturally derived source materials. Allergen extracts exhibit a certain degree of lot-to-lot variability that cannot be avoided. However, if the extract manufacturing steps are well controlled this allows each supplier to deliver products that have a reasonable level of batch consistency.
At present, quality monitoring of extracts is primarily accomplished by characterizing the final product with various analytical methods.