In recently issued draft guidance, the FDA advocates Quality by Design principles in the manufacture and development of skin-patch drugs. The document covers transdermal and transmucosal drug delivery systems as well as topical patch products.
The guidance addresses an FDA finding that 10 to 95 percent of the drug remains on the patch after use, posing risks to both patients and those around them.
"We recommend that an enhanced design and development approach--specifically Quality by Design (QbD), as described in the International Conference on Harmonization (ICH) guidance for industry Q8(R2) Pharmaceutical Development--be used," according to the document. "The application of QbD, including product monitoring, can lead to continual improvement of the product throughout its lifecycle."
- here's the draft guidance