Frequently Asked Questions
9. What is an extractables study?
An extractables study (also known as a controlled extractables or extraction study) is an assessment performed on a material, which attempts to identify the substances from that material, which may potentially leach into the final product.
There are various types of extractables study, but by far, the two most common are
Exhaustive extractables studies
Targeted extractables studies (aka Simulated leachables studies)
An exhaustive extractables study involves placing the material of interest (a plastic; an elastomer; etc) into a range of strong organic solvent systems, and subjecting these systems to vigorous laboratory extraction conditions, in order to maximize the levels of extractables derived from that material.
A targeted extractables study is an option used, where strong solvents systems may not be the most appropriate for predicting likely product leachables (e.g. aqueous drug products, aqueous manufacturing product streams, etc.). The material of interest is once again placed in a range of solvent systems, which in this case, much more closely resemble either the solvent system of the product stream (in the case of single use manufacturing systems) or the solvent system of the product. Again, vigorous laboratory extraction conditions are used to try and maximize the levels of extractables derived from that material, this time however under the targeted solvent conditions.
The resulting solutions from either type of study are then interrogated via a series of analytical techniques, in order to identify and quantify individual extractables.
Overall, a well designed and executed extractables study can provide 'worst-case' leachable levels for an individual material, and provide valuable information for the development of appropriate analytical methods for leachables studies. Conversely, a poorly designed and poorly executed extractables study, almost always involves wasting large amounts of resource, time and budget, and can create significant problems during any subsequent leachables studies.
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