YY/T 0334-2022General specification for surgical implants made of silicone elastomer (English PDF)

3.1 Heat-vulcanization; heat-curing

Through heating, the silicone compound (3.3) is cross-linked into an elastic material (silicone elastomer).

3.2 Silicone elastomer

A synthetic elastomer obtained by cross-linking silicon-reinforced silicone polymer chains consisting essentially of repeating diorganosiloxane units.

3.3 Silicone compound

A material composed of polysiloxane mixed with suitable fillers and cross-linking agents, without cross-linking.

3.4 Silicone, polysiloxane

A polymer whose main chain is alternately linked by silicon and oxygen atoms, and whose side chains contain organic groups.

3.5 Post-curing; secondary curing

After vulcanization, a process performed at a certain temperature to enhance the physical properties of the material and / or remove excess decomposition products.

5.1 General

The implants made of silicone elastomer shall be tested as supplied. If the implants made of silicone elastomer have two or more separable different types of silicone elastomer, each type of silicone elastomer shall be respectively sampled and tested.

5.2 Biological Evaluation

Carry out biological evaluation of the implants made of silicone elastomer in accordance with

GB/T 16886.1.The evaluation results shall have no unacceptable biological hazards.

5.3 Material Requirements

5.3.3 Identification

In accordance with the 0402 infrared spectrophotometry of the Pharmacopoeia of the People's Republic of China (2020) Volume IV, carry out the test. The infrared spectrum of the implants made of silicone elastomer shall be consistent with the standard control spectrum provided by the manufacturer.

5.4 Requirements for Soluble Substances

5.4.1 Solution appearance

In accordance with B.3, take the filtrate. In accordance with the 0901 solution color inspection method and the 0902 clarity inspection method in Pharmacopoeia of the People's Republic of China (2020) Volume IV, carry out the test. The test solution shall be colorless and clear.

5.4.3 pH

When tested in accordance with Appendix D, the difference in pH value between the test solution and the blank solution shall not be greater than 1.5.

5.4.4 Catalyst residue

For the peroxide type of implants made of silicone elastomer, when tested in accordance with Appendix E, the difference in the volume of the sodium thiosulfate standard titration solution [c (Na2S2O3) = 0.01 mol/L] consumed by the tested solution and the blank solution shall not exceed 0.2 mL.

5.4.5 Reducing substances (easily oxidized)

When tested in accordance with Appendix F, the difference in the volume of the potassium permanganate standard titration solution [c(1/5KMnO4) = 0.01 mol/L] consumed by the test solution and the blank solution shall not exceed 3.0 mL.

5.4.6 Ultraviolet absorption

When tested in accordance with Appendix G, the absorption value in the wavelength range of 220 nm ~ 340 nm shall not exceed 0.4.

5.4.7 Heavy metals

In accordance with B.3, take the filtrate. When tested in accordance with GB/T 14233.1, the heavy metal contents shall not exceed 1 mg/L.

A.1 Principle

The sample is digested in a sealed mode through nitric acid and hydrofluoric acid to prepare a specimen solution. Use atomic absorption spectrophotometry or inductively coupled plasma atomic emission spectrometry or inductively coupled plasma mass spectrometry to directly determine the contents of arsenic, cadmium, lead, chromium, iron and platinum.

A.2 Preparation of Reagents and Solutions

A.2.1 Standard solutions of arsenic, cadmium lead, chromium, iron and platinum. in accordance with the above-mentioned conventional methods, respectively prepare stock solutions containing 1 mg/mL of arsenic, cadmium, lead, chromium, iron and platinum. Before use, use nitric acid solution with a volume fraction of 1% to dilute to the required concentration. A.2.2 Nitric acid. superior-grade purity.

A.3 Preparation of Test Solution

Accurately weigh-take 1.0 g of the sample, place it in a polytetrafluoroethylene cup, add 5 mL of nitric acid and 5 mL of hydrofluoric acid, cover and seal it; tighten the stainless-steel sheath and heat it in the oven at 160 C for 2 hours; take it out and let it cool to room temperature.

Take out the polytetrafluoroethylene cup, and heat it uncovered on an electric hot plate at low temperature, until it approaches almost dryness. Along the wall of the cup, add 0.5 mL of nitric acid, evaporate again to nearly dryness. Add 5 mL of nitric acid with a volume fraction of 1%, heat it to nearly boiling, and let it cool. Use a polyethylene tube to absorb the solution, transfer the solution into a 25 mL volumetric flask. Use nitric acid with a volume fraction of 1% to wash the polytetrafluorethylene cup several times, put the washing solution into a volumetric flask, and use nitric acid with a volume fraction of 1% to dilute it to the scale.

The microwave digestion method can also be used to prepare the test solution.

A.4 Test Method

In accordance with the 0406 atomic absorption spectrophotometry or the 0411 inductively coupled plasma atomic emission spectrometry or the 0412 inductively coupled plasma mass spectrometry in Pharmacopoeia of the People's Republic of China (2020) Volume IV, determine the digested solution.

B.1 Reagents

B.1.1 Distilled or deionized water. B.1.2 n-hexane (analytically pure).

B.2 Instruments

B.2.1 Reflux device made of borosilicate glass, with a capacity of 250 mL ~ 500 mL.

B.2.2 Vacuum filtration device (including borosilicate sand core filtration device, 0.45 m aqueous filter membrane and vacuum filtration pump). B.2.3 Analytical balance (accurate to 0.01 g).

B.3 Distilled Water Extraction

Cut the sample into pieces smaller than 10 mm, use a balance to weigh 12.50 g 0.25 g of sample, accurate to 0.01 g, and record the sample mass. Place the sample in a reflux device, add 250 mL of distilled water or deionized water, and heat to reflux for 5 hours.

After stopping heating, cool the reflux device and immediately use a vacuum filtration device to filter it. If the filtrate needs to be placed, place it in a covered borosilicate container.

B.4 N-hexane Extraction

Cut the sample into pieces smaller than 5 mm, use a balance to weigh 5.00 g 0.50 g of sample, accurate to 0.01 g, and record the sample mass. Place the sample in a reflux device, add 250 mL of n-hexane, and heat to reflux for 4 hours.

After stopping heating, cool the reflux device and immediately use a vacuum filtration device to filter it. If the filtrate needs to be placed, place it in a covered borosilicate container.