https://patentbrief.org/company/green-cross-corp-japan Plain-English explanations of patents assigned to Green Cross Corp Japan, newest first. en-us Mon, 15 Jun 2026 06:02:21 GMT https://patentbrief.org/patent/us/5002952/duragesic-fentanyl-patch A method for mixing specific chemical compounds with surfactants to help the body absorb them more effectively. Tue, 26 Mar 1991 00:00:00 GMT https://patentbrief.org/patent/us/5002952/duragesic-fentanyl-patch