New USP Chapter on Cured Silicone Components

Following the draft chapter on Elastomers for Pharmaceutical Packaging and Manufacturing that was published for comment in Pharmacopeial Forum (PF) 48(3), the final text for USP <383> Cured Silicone Elastomers for Pharmaceutical Packaging and Manufacturing Components has been published in the USP. The chapter will become official on 1 December 2027. Early adoption of the requirements in this chapter is permitted by USP.

Cured silicone components are used as elastomeric closures for pharmaceutical packaging and also as components in manufacturing operations for drug substances and drug products. The chapter is applicable to elastomeric components such as diaphragms, gaskets, O-rings, and tubing. Silicone elastomers are obtained by cross-linking (curing) a linear polysiloxane constructed mainly of dimethylsiloxy units with small quantities of methylvinylsiloxy groups, where the chain ends are blocked by trimethylsiloxy or dimethylvinylsiloxy groups. The cross-linking is usually carried out via high-temperature vulcanization, either by a free-radical reaction using organic peroxides, or by an addition reaction using platinum as a catalyst. However, in all cases, appropriate additives such as silica are used. Organosilicon additives (e.g., dihydroxy polydimethylsiloxane) can also be used in small quantities.

More information is available in the USP.