After being coated with chlorobutyl rubber stopper, it has many advantages: for example, by forming a film on the surface of the rubber stopper, it can effectively reduce the absorption, adsorption, leaching and penetration between the rubber stopper and the drug, and improve the long-term stability of the drug; Mechanical lubricity; greatly reducing the increase of insoluble particles in the liquid medicine caused by silicone oil.

In foreign countries, the production technology of I-shaped rubber plugs has been developed for a long time. For example, Japan began to produce J-type rubber stoppers in 1957, and economically developed regions in Europe and the United States also realized mass production of medicinal butyl rubber stoppers in early 1970. In China, it was not until 1992 that mass production of pharmaceutical butyl rubber stoppers began. At the same time, the coating technology of foreign butyl chlorobutyl rubber stopper developed earlier and is relatively mature. There are various types of coated J-type rubber stoppers, and they are all capable of mass production. After a lot of experiments, chlorobutyl rubber stopper technicians continue to explore and communicate, and some manufacturers can mass-produce coated rubber stoppers with relatively stable quality. The long-term stability test of the pharmaceutical factory responds well to the long-term stability of related liquid drugs.