> ## Content Index
> Fetch the complete content index at: https://www.fdaweb.com/llms.txt
> Use this file to discover other available public pages before exploring further.

# FDA Regulatory Review Period for Ionsys is 4,835 Days
- URL: https://www.fdaweb.com/fda-regulatory-review-period-for-ionsys-is-4-835-days/
- Published: 2016-09-28T12:00:00.000Z
- Updated: 2026-09-14T21:35:35.000Z
- Author: David McFarland
- Tags: FDA Policy/General, #legacy-id-D5136930

*Federal Register* Notice: FDA has determined the regulatory review period for a Medicines Company NDA for Ionsys (fentanyl iontophoretic transdermal system) that applies to a patent extension for the product. The agency determined that the applicable regulatory review period for the drug is 4,835 days. To view this notice, click [here](https://www.gpo.gov/fdsys/pkg/FR-2016-09-28/pdf/2016-23330.pdf?ref=fdaweb.com).