YY/T 0471.1-2004Test methods for primary wound dressing - Part 1: Aspects of absorbency (English PDF)

2.1 alginate dressing

dressing containing salts of alginic acids which interact with physiological fluids to form a gel

2.2 amorphous hydrogel

semi-solid gel that contains hydrophilic polymers and water

2.3

fluid affinity of a wound dressing ability to absorb fluid from or donate fluid to a simulated wound

2.4 fluid handling capacity

sum of the fluid absorbed and the fluid transpired through the dressing

2.5 free swell absorptive capacity

total absorptive capacity in the presence of excess test liquid and in the absence of any applied load

2.6 primary wound dressing

material or combination of materials, in any shape, form or size that is intended to remain in direct contact with a wound

Note: primary wound dressing are used as mechanical barriers, for the absorption or transmission of exudates, to manage the micro-environment of the wound, and can enable the wound to heal by primary or secondary intent. Devices which have a metabolic, pharmacological or immunological interaction as their primary intent are excluded.

3.1 Test conditions

Unless otherwise stated, condition the test samples and carry out the tests at a temperature of (21 ± 2) °C and a relative humidity of 60% RH ± 15% RH.

3.2 Free swell absorptive capacity

3.2.1 Significance and use

The test is intended to assess the performance of dressings, typically used on moderately to heavily exuding wounds, where total absorptive capacity is an important feature. It is only appropriate for dressings which will stay physically intact and which will reach their maximum absorptive capacity within 30 min, under the test conditions.

Note: The test is suitable for use with, for example, most types of alginate dressings in either the sheet or rope (packing) form. In the case of alginate dressings, the ratio of test liquid to sample weight is an important factor due to the interaction which takes place.

3.2.2 Equipment

3.2.2.1

Petri dishes, (90 ± 5) mm in diameter.

3.2.2.2

Laboratory oven, with forced air circulation, capable of maintaining a temperature of (37±1) °C.

3.2.2.3

Test solution A, consisting of sodium chloride and calcium chloride solution containing 142 mmol of sodium ions and 2.5 mmol of calcium ions as the chloride salts. This solution has an ionic composition comparable to human serum or wound exudate. It is prepared by dissolving 8.298 g of sodium chloride and 0.368 g of calcium chloride dihydrate in deionised water and making up to 1L in a volumetric flask.

3.2.2.4

Balance, capable of weighing 100 g with to the nearest 0.0001 g.

3.2.3 Procedure

3.2.3.1

Place a single, weighed 5 cm x 5 cm (as presented to the wound) or 0.2 g (for cavity dressing) sample in a Petri dish.

3.2.3.2

Add a quantity of test solution warmed to (37±1) °C corresponding to 40 times the mass of sample being examined, ±0.5g.