Ohio Rev. Code § 1702.37: Usury.

No domestic or foreign corporation, or any one on its behalf, shall interpose the defense or make the claim of usury in any proceeding upon or with reference to any obligation of such corporation; nor shall any corporate note, bond, or other evidence of indebtedness, mortgage, pledge, or deed of trust, be set aside, impaired, or adjudged invalid by reason of anything contained in laws prohibiting usury or regulating interest rates.