YY/T 1746-2020 English PDF (YYT1746-2020)

This Standard specifies the test method for the retention value of breaking strength of absorbable surgical suture (hereinafter referred to as suture) in the in vitro simulated environment. This Standard applies to the absorbable surgical suture which is processed from synthetic polymers that are hydrolyzed and degraded.

YY/T 1746-2020
YY
PHARMACEUTICAL INDUSTRY STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
ICS 11.040.30
C 30
Absorbable surgical suture - Test method for breaking
strength in vitro hydrolytic degradation
ISSUED ON: SEPTEMBER 27, 2020
IMPLEMENTED ON: SEPTEMBER 01, 2021
Issued by: National Medical Products Administration
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Principle ... 4
3 Apparatus and reagents ... 4
4 Test procedure ... 5
5 Test report ... 7
References ... 8
Absorbable surgical suture - Test method for breaking
strength in vitro hydrolytic degradation
1 Scope
This Standard specifies the test method for the retention value of breaking strength of absorbable surgical suture (hereinafter referred to as suture) in the in vitro simulated environment.
This Standard applies to the absorbable surgical suture which is processed from synthetic polymers that are hydrolyzed and degraded.
2 Principle
Test the retention value of suture breaking strength in different time periods in an in vitro simulated environment, which provides reference information for whether the suture can maintain sufficient tension during the critical period of wound healing.
3 Apparatus and reagents
3.1 Material testing machine
The tensile speed is 300 mm/min ± 10 mm/min; the test gauge length is 130 mm ± 5 mm.
Note: If the suture length cannot meet the requirements of the specified test gauge length, the test gauge length can be adjusted according to the
actual length of the suture; the corresponding stretching speed is set to 2 times the adjusted test gauge length. If the adjusted test gauge length is set to 50 mm, the stretching speed is set to 2×50 = 100 mm/min.
3.2 Electric-heating constant-temperature oscillating water tank or constant- temperature oscillator
The temperature is 37 °C ± 1 °C; the oscillation frequency: 60 r/min (or other suitable oscillation methods).
3.3 pH meter
The accuracy of the pH meter is not less than 0.02.
3.4 Container
4.2.4 Calculate the average of the 10 recorded force values, which is the initial breaking strength.
4.3 Test of residual breaking strength
4.3.1 Take 10 sutures of the same batch as the initial test value (4.2); put them into the container (3.4), so that the sutures are completely immersed in the test solution (3.5) (the ratio of the volume of the test solution to the mass of the suture is at least 10 mL:1 g).
Note: If the suture length can meet the test conditions, take the same suture to test the initial breaking strength value and the residual breaking strength value, respectively.
4.3.2 Place the container in the electric-heating constant-temperature
oscillating water tank (3.2); select the corresponding test period according to the material of the suture and the intended use. During the test period, the pH value of the test solution in the container shall be monitored as needed. If the pH value of the buffer exceeds the specified limit value (7.4 ± 0.2), use the 0.1 mol/L sodium hydroxide solution or dilute phosphoric acid to adjust or replace the buffer, to make it meet the requirements (3.5).
4.3.3 At the end of the test period, take out the suture and remove the water on the surface of the suture until there is no dripping.
Note: The method of removing water shall not affect the breaking strength of the suture.
4.3.4 Carry out the test according to steps 4.2.1 ~ 4.2.3.
4.3.5 Calculate the average of the 10 recorded force values, which is the residual breaking strength.
4.4 Result calculation
Calculate the retention value of breaking strength according to Formula (1): Where:
BSR -- Retention value of breaking strength;
F0 -- Initial breaking strength;
F1 -- Residual breaking strength.