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 Sutureor Chromic Suture.Both types consist of processed strands of collagen,but Chromic Sutureis 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.Anumber 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 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 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 10strands of Suture as directed under Sutures—Diameter á861ñ.
Collagen suture— The average diameter,and not fewer than 20,of the 30measurements on the 10-strand sample are within the limits on average diameter prescribed in Table 1for 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 2for 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
3and 4 6 0.60 0.699 7.29 71.5
5 7 0.70 0.799 — —
*  The tensile strength of the specified USPsize is measured by straight pull.
Tensile strength— Determine the tensile strength on not fewer than 10strands of Suture as directed for Surgical Suturesunder Tensile Strength á881ñ.
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 20additional 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 á871ñ.
Sterility á71ñ: meets the requirements.
Extractable color (if Suture is dyed)— Prepare the Matching Solutionthat 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 10.0parts.[See under Solutionsin the section Reagents,Indicators,and Solutions,for composition of the Colorimetric Solutions (CS).]
Table 3.Matching Solutions
Parts of Each CSper
10Parts 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 250mg,and place in a conical flask containing 1.0mLof water for each 10mg of the sample.Close the flask,and allow it to stand at 37±0.5for 24hours.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 5mLof the fluid prepared as directed in the test for Extractable colorinto a small test tube.Into a similar tube pipet 5mLof a standard solution of potassium dichromate having a concentration of 2.83µg per mL.To both tubes add 2mLof a 1in 100solution of diphenylcarbazide in alcohol and 2mLof 2Nsulfuric acid:any color that develops in the test solution is not more intense than that in the standard solution (0.0001%of Cr).
Auxiliary Information— Staff Liaison:Radhakrishna S Tirumalai,Scientist
Expert Committee:(GTB)General Toxicology and Biocompatibility
USP28–NF23Page 1842
Phone Number:1-301-816-8339