Nonabsorbable Surgical Suture
»Nonabsorbable Surgical Suture is a flexible strand of material that is suitably resistant to the action of living mammalian tissue.It may be in either monofilament or multifilament form.If it is a multifilament strand,the individual filaments may be combined by spinning,twisting,braiding,or any combination thereof.It may be either sterile or nonsterile.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,or to reduce capillarity,and may be suitably bleached.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.
Nonabsorbable Surgical Suture is classed and typed as follows.Class ISuture is composed of silk or synthetic fibers of monofilament,twisted,or braided construction where the coating,if any,does not significantly affect thickness (e.g.,braided silk,polyester,or nylon;monofilament nylon or polypropylene).Class IISuture is composed of cotton or linen fibers or coated natural or synthetic fibers where the coating significantly affects thickness but does not contribute significantly to strength (e.g.,virgin silk sutures).Class IIISuture is composed of monofilament or multifilament metal wire.
Packaging and storage— Preserve nonsterilized Suture in well-closed containers.Preserve sterile Suture dry or in fluid,in containers (packets)so designed that sterility is maintained until the container is opened.Anumber of such containers may be placed in a box.
Labeling— The label of each individual container (packet)of Suture indicates the material from which the Suture is made,the size,construction,and length of the Suture,whether it is sterile or non-sterile,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 USPsize.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 2minutes after removing it from the fluid.
Length— Determine the length of Suture while the strand is laid out smooth,without tension,on a plane surface:the length of the strand is not less than 95.0%of the length stated on the label.
Diameter— Determine the diameter of 10strands of Suture as directed under Sutures—Diameter á861ñ.The average diameter of the strands being measured is within the tolerances prescribed in the accompanying table for the size stated on the label.In the case of braided or twisted Suture,none of the observed diameters is less than the midpoint of the range for the next smaller size or is greater than the midpoint of the range for the next larger size.
Tensile strength— Determine the tensile strength on not fewer than 10strands of Suture as directed for Surgical Suturesunder Tensile Strength á881ñ.Average all observations obtained:the average tensile strength is not less than that set forth in the accompanying table for the class and the size stated on the label.
Needle attachment— Suture on which eyeless needles are swaged meets the requirements under Sutures—Needle á871ñ.
Sterility á71ñ: Suture that is claimed to be sterile meets the requirements.
Extractable color (if Suture is dyed)— Proceed as directed in the test for Extractable colorunder Absorbable Surgical Suture,but instead of allowing to stand at 37±0.5for 24hours,cover the flask with a short-stemmed funnel,heat the contents of the flask at the boiling point for 15minutes,cool,and restore the volume by the addition of water,if necessary,to replace that lost by evaporation.
Average Knot-Pull Limits of Various Sizes and Diameters of Sutures
Limits on
Average
Diameter
(mm)		 Limits on Average Knot-Pull
(except where otherwise
specified)†Tensile Strength (in kgf)*		 Limits on Average Knot-Pull
(except where otherwise
specified)†Tensile Strength (in N)*
USP Size Metric Size (Gauge No.) Min. Max. Class I
Min.		 Class II
Min.		 Class III
Min.		 Class I
Min.		 Class II
Min.		 Class III
Min.
12-0 0.01 0.001 0.009 0.001† — 0.002† 0.01† — 0.02†
11-0 0.1 0.010 0.019 0.006† 0.005† 0.02† 0.06† 0.05† 0.20†
10-0 0.2 0.020 0.029 0.019† 0.014† 0.06† 0.194† 0.14† 0.59†
9-0 0.3 0.030 0.039 0.043† 0.029† 0.07† 0.424† 0.28† 0.68†
8-0 0.4 0.040 0.049 0.06 0.04 0.11 0.59 0.39 1.08
7-0 0.5 0.050 0.069 0.11 0.06 0.16 1.08 0.59 1.57
6-0 0.7 0.070 0.099 0.20 0.11 0.27 1.96 1.08 2.65
5-0 1 0.10 0.149 0.40 0.23 0.54 3.92 2.26 5.30
4-0 1.5 0.15 0.199 0.60 0.46 0.82 5.88 4.51 8.04
3-0 2 0.20 0.249 0.96 0.66 1.36 9.41 6.47 13.3
2-0 3 0.30 0.339 1.44 1.02 1.80 14.1 10.0 17.6
0 3.5 0.35 0.399 2.16 1.45 3.40† 21.2 14.2 33.3†
1 4 0.40 0.499 2.72 1.81 4.76† 26.7 17.8 46.7†
2 5 0.50 0.599 3.52 2.54 5.90† 34.5 24.9 57.8†
3and 4 6 0.60 0.699 4.88 3.68 9.11† 47.8 36.1 89.3†
5 7 0.70 0.799 6.16 — 11.4† 60.4 — 112†
6 8 0.80 0.899 7.28 — 13.6† 71.4 — 133†
7 9 0.90 0.999 9.04 — 15.9† 88.6 — 156†
8 10 1.00 1.099 — — 18.2† — — 178†
9 11 1.100 1.199 — — 20.5† — — 201†
10 12 1.200 1.299 — — 22.8† — — 224†
*  The limits on knot-pull tensile strength apply to Nonabsorbable Surgical Suture that has been sterilized.For nonsterile Sutures of Class Iand Class II,the limits are 25%higher.
†  The tensile strength of sizes smaller than USPsize 8-0(metric size 0.4)is measured by straight pull.The tensile strength of sizes larger than USPsize 2-0(metric size 3)of monofilament Class III(metallic)Nonabsorbable Surgical Suture is measured by straight pull.
Silver wire meets the tensile strength values of Class ISutures but is tested in the same manner as Class IIISutures.
Auxiliary Information— Staff Liaison:Radhakrishna S Tirumalai,Scientist
Expert Committee:(GTB)General Toxicology and Biocompatibility
USP28–NF23Page 1844
Phone Number:1-301-816-8339