GB/T 35511-2017Biological requirements and test methods for closures of butyl rubber (English PDF)

4.1 General

The closures shall not release any substances that may adversely affect the therapeutic effectiveness and safety of the pharmaceutical solution, or substances that can exhibit toxic or febrile reactions.

When selecting biological tests and analyzing the results, comprehensive considerations shall be taken into account, including the chemical composition of the materials, the environment in which they are exposed, the properties of the materials, and the degree, frequency, and duration of exposure.

Type inspection of closures shall include cytotoxicity, intracutaneous toxicity, and systemic toxicity. Monitoring shall include bacterial endotoxins and bioburden.

4.2 Bacterial endotoxins

The bacterial endotoxins shall be tested according to Annex A, where the endotoxin content in the extracts of closures shall meet the requirements agreed upon between supplier and user, expressed in endotoxin units per milliliter (EU/mL) extractable endotoxins or endotoxin units per square centimeter (EU/cm2) of closure.

4.3 Bioburden

The bioburden shall meet the requirements agreed upon between supplier and user, expressed in colony forming units per square centimeter (CFU/cm²) or colony forming units per closure.

The test method shall be validated.

Note. GB/T 19973.1 can be used as a guideline to establish and validate the test method.

4.4 Toxicity

4.4.1 General

The in vitro cytotoxicity of the extracts of closures shall be determined according to

4.4.2.Closures that meet the requirements of 4.4.2 do not require further testing;

otherwise, the intracutaneous toxicity and systemic toxicity of the extracts of closures in vivo shall be determined according to 4.4.3 and 4.4.4, respectively.

4.4.2 Cytotoxicity

Tested according to Annex B, there shall be no cytotoxicity.

4.4.3 Intracutaneous toxicity

Tested according to Annex C, there shall be no intracutaneous toxicity.

4.4.4 Systemic toxicity

Tested according to Annex D, there shall be no systemic toxicity.

Annex A (Normative)

Test for bacterial endotoxins

A.1 General

This Annex specifies a conventional method for determining bacterial endotoxins in the extracts from the surface of closures.

A.2 Principle

Prepare the extracts by placing the closures in endotoxin-free water and shaking.

Determine bacterial endotoxins in the extract using LAL reagent according to the test method specified in Chapter 4 of GB/T 14233.2-2005.LAL reagent (also known as

Tachypleus Amebocyte Lysate) is obtained from horseshoe crab (Limulus polyphemus).

A.3 Reagents and materials

A.3.1 Pyrogen-free glassware and heat-resistant apparatus (e.g., tweezers).

A.3.2 Water for bacterial endotoxin testing.

A.3.3 Bacterial endotoxin working standards, as specified in Chapter 4 of GB/T

14233.2-2005.

A.4 Depyrogenation of glassware and heat-resistant apparatus

A.4.1 Clean the apparatus using a laboratory dishwasher, ensuring that any residual

foam on the surface of the apparatus is completely removed. After cleaning, use water for bacterial endotoxin testing to rinse thoroughly.

A.4.2 After cleaning, air-dry or oven-dry the apparatus before wrapping them in

aluminum foil, as follows.

-- Wrap test tubes completely;

-- Wrap sample containers only on the neck;

-- Wrap tweezers completely.

A.4.3 Wrapped apparatus shall be depyrogenated, for example, dried at 250 °C for at least 30 minutes.

A.4.4 After the depyrogenation, the apparatus shall still be placed in the aluminum foil.

A.5 Extracts of closures

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