(a) This part sets forth procedures and requirements for the Food and Drug Administration's review of applications for the extension of the term of certain patents under 35 U.S.C. 156 . Patent term restoration is available for certain patents related to drug products (as defined in 35 U.S.C. 156(f)(2) ), and to medical devices, food additives, or color additives subject to regulation under the Federal Food, Drug, and Cosmetic Act or the Public Health Service Act. Food and Drug Administration actions in this area include:(1) Assisting the United States Patent and Trademark Office in determining eligibility for patent term restoration;(2) Determining the length of a product's regulatory review period;(3) If petitioned, reviewing and ruling on due diligence challenges to the Food and Drug Administration's regulatory review period determinations; and(4) Conducting hearings to review initial Food and Drug Administration findings on due diligence challenges.(b) References in this part to the Code of Federal Regulations are to chapter I of title 21, unless otherwise noted.53 FR 7305, Mar. 7, 1988, as amended at 57 FR 56261, Nov. 27, 1992