Chewables: FDA Finalizes Guidance on Quality Attributes
The US Food and Drug Administration (FDA) on Monday finalized draft guidance that provides manufacturers of chewable tablets with current thinking on the critical quality attributes that should be assessed during the development of these drugs.The draft guidance, released in June, comes as FDA has warned that for “numerous approved” chewable tablets, companies have not evaluated critical quality attributes such as hardness, disintegration and dissolution "as may have been warranted.”
Specifically, the agency says that some applications contained insufficient data on quality attributes or used "widely ranging values that were not justified as acceptance criteria."
Even companies with already-approved chewable tablets should reevaluate their products' critical quality attributes, as the agency said it will take "appropriate action … to alleviate the risk to public health" posed by any tablets that do not meet FDA's quality expectations.
The guidance discusses the Chewing Difficulty Index (CDI), a new quality attribute concept that was developed internally, the findings of which were published in a peer reviewed journal.
As far as changes between the draft and final, FDA said it “provided additional clarifications in this guidance whereby sponsors and/or applicants would accrue CDI data during drug product development and submit it in their applications. We intend to evaluate the data to inform future guidance on this topic, as needed.”
FDA defines a CDI as a value derived from the relationship between two methods used for measuring tablet strength: diametral compression (diametrical tensile strength) and flexural bending (flexure tensile strength test).
The first appendix in the guidance also notes, “Early publications have shown that the variations in fracture strength were due to inaccuracies of the instrumental scales of the various hardness testers as well as variations in the method of application of the load, physical dimensions, and shape of the tablet.
“Of the several approaches applied to measure tablet breaking strength, tensile strength measurement is indicated as a more reliable approach where variations due to the method are minimized. Tensile strength measurement is applied as a more fundamental measure of the tablet’s ability to withstand breaking force due to the inherent strength of the compacted material,” the guidance says.
Quality Attribute Considerations for Chewable Tablets Guidance for Industry