This drug was originally applied for by a foreign company, but its expiration date has long expired.
I checked the drug ibuprofen for you in a foreign language. There are more than 600 patents for the research and development of related drugs.
The main foreign companies include:
Gist Brogard Company, International Shell Research Co., Ltd., Hoechst Rayon Company, Murreldo Pharmaceutical Company, etc. The company develops related drugs.
Domestic ones include: Shandong Xinhua Pharmaceutical Factory, Hubei Province Tianmen Veterinary Drug Factory and other factories. They all applied a long time ago. At that time, companies had not yet been restructured and many were called factories.
Because the drug applications are old, the patents applied by these domestic and foreign companies have expired.
The earliest batch of patent numbers are: (the earliest batch found in the past 30 years)
87100031, 88105203, 88102150, 89103727.6.