USP Monographs: Absorbable Surgical Suture

Absorbable Surgical Suture

» Absorbable Surgical Suture is a sterile, flexible strand prepared from collagen derived from healthy mammals, or from a synthetic polymer. Suture prepared from synthetic polymer may be in either monofilament or multifilament form. It is capable of being absorbed by living mammalian tissue, but may be treated to modify its resistance to absorption. Its diameter and tensile strength correspond to the size designation indicated on the label, within the limits prescribed herein. It may be modified with respect to body or texture. It may be impregnated or treated with a suitable coating, softening, or antimicrobial agent. It may be colored by a color additive approved by the FDA. The collagen suture is designated as either Plain Suture or Chromic Suture. Both types consist of processed strands of collagen, but Chromic Suture is processed by physical or chemical means so as to provide greater resistance to absorption in living mammalian tissue.

Packaging and storage— Preserve dry or in fluid, in containers (packets) so designed that sterility is maintained until the container is opened. A number of such containers may be placed in a box.

Labeling— The label of each individual container (packet) of Suture indicates the size, length, type of Suture, kind of needle (if a needle is included), number of sutures (if multiple), lot number, and name of the manufacturer or distributor. If removable needles are used, the labeling so indicates. Suture size is designated by the metric size (gauge number) and the corresponding USP size. The label of the box indicates also the address of the manufacturer, packer, or distributor, and the composition of any packaging fluids used.

NOTE—If the Suture is packaged with a fluid, make the required measurements for the first four of the following tests within 2 minutes after removing it from the fluid.

Length— Determine the length of Suture without stretching: the length of each strand is not less than 95.0% of the length stated on the label.

Diameter— Determine the diameter of 10 strands of Suture as directed under Sutures—Diameter

861

Collagen suture— The average diameter, and not fewer than 20, of the 30 measurements on the 10-strand sample are within the limits on average diameter prescribed in Table 1 for the respective size. None of the individual measurements is less than the midpoint of the range for the next smaller size or more than the midpoint of the range for the next larger size.

Synthetic suture— The average diameter of the strands being measured is within the tolerances prescribed in Table 2 for the respective size. None of the observed measurements is less than the midpoint of the range for the next smaller size or more than the midpoint of the range for the next larger size.

Table 1. Collagen Suture

		Limits on Average Diameter (mm)		Knot-Pull Tensile Strength (kgf)		Knot-Pull Tensile Strength (in N)
USP Size	Metric Size (Gauge No.)	Min.	Max.	Limit on Average Min.	Limit on Individual Strand Min.	Limit on Average Min.	Limit on Individual Strand Min.
9-0	0.4	0.040	0.049	—	—	—	—
8-0	0.5	0.050	0.069	0.045	0.025	0.44	0.24
7-0	0.7	0.070	0.099	0.07	0.055	0.69	0.54
6-0	1	0.10	0.149	0.18	0.10	1.76	0.98
5-0	1.5	0.15	0.199	0.38	0.20	3.73	1.96
4-0	2	0.20	0.249	0.77	0.40	7.55	3.92
3-0	3	0.30	0.339	1.25	0.68	12.2	6.67
2-0	3.5	0.35	0.399	2.00	1.04	19.6	10.2
0	4	0.40	0.499	2.77	1.45	27.2	14.2
1	5	0.50	0.599	3.80	1.95	37.3	19.1
2	6	0.60	0.699	4.51	2.40	44.2	25.5
3	7	0.70	0.799	5.90	2.99	57.8	29.3
4	8	0.80	0.899	7.00	3.49	68.6	34.2

Table 2. Synthetic Suture

		Limits on Average Diameter (mm)		Knot-Pull Tensile Strength (in kgf) (except where otherwise specified)* Limit on Average Min.	Knot-Pull Tensile Strength (in N) (except where otherwise specified)
USP Size Min.	Metric Size (Gauge No.) Max.	Min.	Max.
12-0	0.01	0.001	0.009	—	—
11-0	0.1	0.010	0.019	—	—
10-0	0.2	0.020	0.029	0.025*	0.24*
9-0	0.3	0.030	0.039	0.050*	0.49*
8-0	0.4	0.040	0.049	0.07	0.69
7-0	0.5	0.050	0.069	0.14	1.37
6-0	0.7	0.070	0.099	0.25	2.45
5-0	1	0.10	0.149	0.68	6.67
4-0	1.5	0.15	0.199	0.95	9.32
3-0	2	0.20	0.249	1.77	17.4
2-0	3	0.30	0.339	2.68	26.3
0	3.5	0.35	0.399	3.90	38.2
1	4	0.40	0.499	5.08	49.8
2	5	0.50	0.599	6.35	62.3
3 and 4	6	0.60	0.699	7.29	71.5
5	7	0.70	0.799	—	—
* The tensile strength of the specified USP size is measured by straight pull.

Tensile strength— Determine the tensile strength on not fewer than 10 strands of Suture as directed for Surgical Sutures under Tensile Strength

881

Collagen suture— The tensile strength, determined as the minimum strength for each individual strand tested, and calculated as the average strength from any one lot, is as set forth in Table 1. If not more than one strand fails to meet the limit on individual strands, repeat the test with not fewer than 20 additional strands: the requirements of the test are met if none of the additional strands falls below the limit on individual strands, and if the average strength of all the strands tested does not fall below the stated limit in Table 1.

Synthetic suture— The minimum tensile strength of each size of synthetic suture, calculated as the average strength from any one lot, is as set forth in Table 2.

Needle attachment— Suture on which eyeless needles are swaged meets the requirements under Sutures—Needle Attachment

871

Sterility

: meets the requirements.

Extractable color (if Suture is dyed)— Prepare the Matching Solution that corresponds to the extractable color of the Suture by combining the Colorimetric Solutions in the proportions indicated in Table 3, and adding water, if necessary, to make 10.0 parts. [See under Solutions in the section Reagents, Indicators, and Solutions, for composition of the Colorimetric Solutions (CS).]

Table 3. Matching Solutions

	Parts of Each CS per 10 Parts of Total Volume
Color of Suture (Extractable Color)	Cobaltous Chloride CS	Ferric Chloride CS	Cupric Sulfate CS
Yellow-brown	0.2	1.2	—
Pink-red	1.0	—	—
Green-blue	—	—	2.0
Violet	1.6	—	8.4

Weigh a quantity of Suture, equivalent to not less than 250 mg, and place in a conical flask containing 1.0 mL of water for each 10 mg of the sample. Close the flask, and allow it to stand at 37 ± 0.5

for 24 hours. Cool, decant the water from the Suture, and compare it with the Matching Solution: any color present is not more intense than that of the appropriate Matching Solution.

Soluble chromium compounds— Pipet 5 mL of the fluid prepared as directed in the test for Extractable color into a small test tube. Into a similar tube pipet 5 mL of a standard solution of potassium dichromate having a concentration of 2.83 µg per mL. To both tubes add 2 mL of a 1 in 100 solution of diphenylcarbazide in alcohol and 2 mL of 2 N sulfuric acid: any color that develops in the test solution is not more intense than that in the standard solution (0.0001% of Cr).

Residual solvents

467

: meets the requirements.

(Official January 1, 2007)

Auxiliary Information— Staff Liaison : Radhakrishna S Tirumalai, Scientist

Expert Committee : (GTMDB05) General Toxicology and Medical Device Biocompatibility

USP29–NF24 Page 2050

Phone Number : 1-301-816-8339