Coated rubber stoppers for injections have been developed rapidly, especially for more sensitive drugs, and the coated stoppers are highly recommended, and then promoted to the packaging of biological agents, such as pistons for prefillable syringes.

What Is Coated Rubber Stopper?

The coated rubber stopper refers to the rubber stopper or piston that is "covered" with a layer of "film material" on the part of the contact surface with the drug, which is a kind of diaphragm plug (ISO8871-2:2020), which is different from the film-coated rubber stopper formed by dipping and spraying technology.

How the Coated Rubber Stopper Perform?

The coating technology of butyl rubber stoppers has been developed earlier in foreign countries, and the technology is relatively mature, such as the West Company of the United States, the Daikyo Nippon Nippon Company of Japan, and the Helvoet Company of Belgium, all of which have the ability of mass production. As early as the 80s of the 20th century, Daikyo Seiko (Daikyo Seiko) of Japan was the first to develop a coated rubber stopper and applied for a patent. At present, some domestic butyl stopper manufacturers can also mass-produce coated butyl stoppers with relatively stable quality. Most of the coated rubber stoppers approved by the State Bureau use fluorine-containing film materials, which is the main form of film materials used in domestic coated rubber stoppers.

Problems in the Use of Coated Rubber Stoppers for Injections

1. Self-styledness

Due to the different resilience of rubber and the covered film, after the coated rubber plug is punctured by the needle, there will be a gap on the side of the film, which will affect the sealing performance, which will affect the sealing ability of the liquid medicine after puncture, and the liquid medicine will be exposed from the gap slightly, and there is a serious risk of microbial invasion.

Solution:

In order to solve the above problems, producers have taken corresponding measures. Some lower the test standard, such as reducing the concentration of the solution or the vacuum level, while others increase the thickness of the needle ring, which on the one hand increases the puncture force, which creates a certain obstacle for the user and increases the risk of falling chips on the other.

2. Puncture chipping problems

Compared with uncoated stoppers (bare stoppers), the probability and number of chips after needling are significantly increased, mainly due to the lack of elasticity of the plastic film.

Solution:

The first way to reduce needle lint drop is to reduce the thickness of the needle. 
 

Conclusion

Coated rubber stoppers bring light and hope to users with their excellent chemical stabi
lity, but the problems that arise during their use cannot be ignored. Whether it is the manufacturer of coated rubber stoppers or the pharmaceutical companies that were early users, Everyone should consider the issue from the perspective of human health and truly comply with GMP regulations.