This document discusses quality control tests for various types of surgical dressings. It describes different types of surgical dressings classified based on function and materials used. Tests are outlined to identify materials like cotton and wool that are commonly used in dressings. These include absorbency, fluorescence and solubility tests. Additional tests for finished products are also summarized, such as count of threads, weight, tensile strength and tests to check for foreign matter and water soluble extractives. Rubber and oil impregnated dressings are also briefly discussed.

1. QUALITY CONTROL TESTS FOR SURGICAL
PRODUCTS

2. SURGICAL DRESSING:
Surgical dressing is a term applied to a wide range of
materials used for dressing wounds or diseased
tissue.
Protect the wound from further damage
Mechanical damage
Microbial invasion
Dehydration
Maceration
Chemical damage
Alteration in pH

4. CLASSIFICATION OF SURGICAL DRESSINGS BASED
ON FUNCTION:
There are two types of dressing based on function
1. Primary dressing
2. Secondary dressing

5. PRIMARY DRESSING:
•Primary dressing directly contacts the wound.
•There are different types of primary dressings
1. Plain gauze
2. Impregnated gauze
3. Film dressing

6. SECONDARY DRESSING:
Secondary dressing is placed over the primary dressing.
•There are different types of secondary dressing
1. Adsorbents
2. Bandages
3. Adhesive tapes
4. Protective's

7. CLASSIFICATION OF SURGICAL DRESSING
BASED ON MATERIALS USED:
dressings
natural
Man-made
animal
vegetable
regenerated
synthatic
protein
cellulose
cellulose
polyamide
Poly ester
wool
silk
cotton
Chemical wood
pulp
rayon
nylon
terelyon

8. SURGICAL DRESSINGS:
1. COTTON:
Cotton consists of the epidermal trichomes of the seeds of
Gossypium herbaceum and other cultivated species of
Gossypium.
IDENTIFICATION TEST:
Moisten with iodine when nearly dry
Add 80% w/w Sulphuric acid blue color is produced

9. TESTS:
Foreign fiber test:
Examined under microscope, it is seen to consist
exclusively of typical cotton fibers, except that
occasionally a few isolated foreign fibers may be
present
FLUORESCENCE:
Examine a layer about under UV light at 365nm
It displays only slight brownish – violet fluorescence and
few yellow particles

10. ABSORBENCY:
APPARATUS: Dry cylindrical copper wire basket
SINKING TIME: Not more than 10 sec.
Weight the basket (m1)
Take total sample from different 5 places & place loosely
in the basket & weigh the filled basket (m2)
Fill the beaker with water at 10ºC
Hold the basket horizontally and drop it from top in to water

11. Measure the time for sinking & calculate result by 3
tests
Remove the basket from water, allow it drain, and weigh
(m3)
Transfer it to tared beaker weigh (m4)
FORMULA:
m4 - (m2+m3)
m2 - m1

12. HOLLOW FIBERS:
With a continuous, hollow lumen have 30µm, thin walled.
COMPARTMENTED FIBERS: 80µm (d), hollow and having
a central lumen which is divided into several compartment,
60µm for each compartment.
TESTS:
Treated with zinc chloride solution it will become violet.
sample + zinc chloride solution heat at 40ºC
allow to stand for 2.5hrs, shaking occasionally
dissolves completely.

13. FINISHED PRODUCT TESTS:
•Foreign fibers
•Fluorescence
•Absorbency
•Surface active substances.

14. WOOL:
It is prepared from the fleece of the sheep, ovies aries, by cleaning
and washing
Tests: Test procedures are same as done for cotton.
FINISHED PRODUCT TEST:
AMMONICAL CUO:
Wool + Ammonical CUO separation of the scales,
colors the fibers into blue
LEAD ACETATE: solution of wool in caustic soda + lead
acetate
Black precipitate will form due to the high Sulphur
content.

15. SOLUBILITY: it is not soluble in warm HCL or cold
concentrated H2SO4 but it is soluble at 100ºc in 4 to 5%
solution of sodium hydroxide.

16. FIBERS: Surgical dressing is woven from yarn of cotton wool or
silk and is usually of plain weave, the material should be of good
quality and free from foreign matter as possible.
STANDARDS: Specified areas of fabric or lengths of
components yarns. Weighing must be done under standard
condition of humidity.
The material must prior to such weighing, be exposed to an
atmosphere of 63 -67 % relative humidity at 18ºc to 25ºc for at
last 6hrs.

17. FINISHED PRODUCT TESTS:
COUNT: The count of yarn is the number of hanks, each of
specified length, in one pound, and it is a measure of its fitness.
Threads per inch: for fabrics of fairy close texture, the no. of
threads in one linear inch is measured by means of a linen tester.
•It is placed on smooth fabric with the sides parallel to the wrap
and weft threads, the no of threads per linear inch may be readily
counted.
•For more open fabrics a length of 10 inches is counted to
increase accuracy. This standard is applied to all fabrics.
weight.

18. Weight:
A specified area of fabrics should have a definite weight.
This is a simple check on the fillers. Count of the yarn used. In
case of plasters and adhesive bandages this is done by extracting
with chloroform or other suitable solvent in continuous extraction
apparatus until the adhesive mass completely dissolved.
Tensile strength:
It is the measure of load necessary to rupture the fabric and
is carried out by means of dead

19. FOREIGN MATTER:
Tallow oils & fats are extracted in a continuous extraction
apparatus, using an organic solvent like ether, chloroform etc.
•After evaporate the solvent, soluble salts are removed by washing
in hot running water.
• starch is present is removed by digestion qt 70 with 0 -5 %
solution of malt extract, then starch is washed out by water.
• Loosen threads and fibers on fine sieve dried at 100º C & weigh.
• Loss in weight is foreign matter.

20. WATER SOLUBLE EXTRACTIVE: This test is carried out on
the dried sample, by washing out foreign matter in the same way
described under “foreign- matter” taking care to collect loosened
fibers on a fine sieve and finally dry at 100ºC and weighing.
Absorbency: Like absorbent cotton.

21. RUBBER AND OIL IMPREGNATED MATERIALS:
•NON – ADHESIVE DRESSING:
Rubber coated: The fabric must comply the usually FABRIC
STANDARD.
Additional standard: weight of water proofing material. Limit of
mineral matter in the proofing. When boiled for 30min or
autoclave for 20 mins at a pressure of 15lb per square inch, it
should not be sticky or deteriote.
B. oil coated: In each of these dressing the fabric, which is of
plain weave, is made water proof by treatment with drying oil or
oil modified synthetic resins. Which produce non- adhesive
dressing.

22. 2. ADHESIVE DRESSING:
Eg: self – Adhesive rubber plaster
Zinc oxide self – adhesive plaster
Zinc oxide elastic self - adhesive plaster.

23. References:
1. The theory and practice of industrial pharmacy second
edition pg no: 260-272
2. Gilbert. S. banker, Modern pharmaceutics,
pg: 577-579.