Silicones are used in many healthcare applications, but not all medical silicones are the same. For example, platinum-cured silicones are purer and cleaner than peroxide-cured silicones. Yet choosing the right silicone is about more than just the cure system.
Medical manufacturers need high-quality, easy-to-source, on-time, and cost-effective materials. They also need proof that silicones are properly tested and validated. Without this, compliance issues or product recalls may result.
Regulations and Compliance
Some medical silicones must meet USP Class VI, FDA CFR 21 177.2600, and RoHS requirements. RoHS, a European Union Directive, restricts the use of certain substances, but manufacturers also need to know whether all the ingredients in a medical silicone are made of compliant materials.
For its part, USP publishes test instructions and standards for plastics, polymers and elastomers used in medical applications. These tests measure biocompatibility and correspond to numbered classes so that the healthcare industry can identify materials in a standard way.
USP Class VI materials meet the most stringent requirements and include silicones that pass a systemic toxicity test, an intracutaneous test, and an implantation test. Yet some suppliers that use compliant ingredients may still not be able to guarantee a compliant end-product.
To mitigate these risks, medical manufacturers need silicones with certificates.
Certified USP Class VI Silicones
Specialty Silicone Products (SSP) provides complete certifications to demonstrate the quality of its SSP-2390 Series USP Class VI, FDA, and RoHS compliant silicones.
Certificates of Analysis (COAs) report the test results for a specific batch of materials.
Certificates of Conformance (COC) attest to a batch’s compliance with those requirements.
In 2018, SSP submitted a sample of 50-durometer SSP-2390 to NAMSA, a contract research organization for medical devices and ISO 17025 accredited test laboratory, to prove that SSP-2390 meets all USP Class VI requirements. NAMSA performed USP Biological Reactivity Tests in vivo with a test article.
The USP Systemic Toxicity Study injected it into mice, and the USP Intracutaneous Study injected it into rabbits. The saline, alcohol in saline, polyethylene glycol and sesame oil extracts did not produce a significantly greater systemic reaction than blank extractants.
NAMSA also performed a Muscle Implantation Study in rabbit muscle for one week. The macroscopic reaction was not significant when compared to the USP negative-control plastic. For all tests, the SSP article was prepared at a ratio of 60cm2:20mL and extracted at 121°C for an hour.
Choose Medical Silicones from SSP
SSP’s USP Class VI platinum-cured silicones are translucent, supplied as compression-moulded sheet stock or continuous rolls, which support a variety of cutting methods, and available in custom colours and as ready-to-mould compounds that support transfer and compression moulding.
Specialty Silicone Products offers shorter lead times than many other suppliers and provides on-time deliveries. SSP’s ISO 9001:2015 certification underscores its commitment to quality. To request a To request a quote or for more information, contact SSP on-line or email Dominic Testo.Â
