US 2764976 A
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Description (OCR text may contain errors)
0d. 1956 w. c. SKILES, JR., EFAL 2,764,976
. DRESSING Filed Jan. 10, 1955 HENRY/.- .450
5) ATTaR DRESSiNG William C. Skiles, In, Milltown, Joseph N. Masci, Metuchen, and Henry F. Maso, New Brunswick, N. J assignors to Johnson & "Johnson, a corporation of New Jersey Application January 10, .1955, Serial No. 480,674
-I-9 Claims. (Cl. 128-1 5 6) This invention relates to surgical dressings and, in particular, to dressings impregnated with an oil composition to impart improved therapeutic properties to the dressing.
Ordinarysurgical dressings, when left in contact with'a wound, will adhere firmly in a relatively short time. This is primarily due to the fact that blood and'serous exudates -form a coagulum which enmeshes the fabric threads'of the dressing and, being firmly adherent to the surface of the wound, binds the dressing to it very firmly. Secondly, in dressings which must be left in contact with a wound for prolonged periods there is danger that granulation tissue -will actually grow into'and adhere to the dressing.
Removal of adherent dressings 'is 'difiicult and painful, and tends to cause further damage to tissue.
'It has been known to impregnate dressings with ordinary petrolatum in an attempt to increase non-stic'lring and other therapeutic properties of the dressing. However, a disadvantage of such dressings is that they tend to dam up fluid exudate, 'tlrere'by'produ'cing maceration of the tissue.
Further, a serious disadvantage of prior art dressings is theextrerne difii'culty in sterilizing the dressings. In fact, it has been necessary to sterilize the gauze 'or other dressing material, separately sterilize the impregnant, and then combine the two, using aseptic technique. This procedure is manifestly cumbersome, expensive and diflicult to control. Further, the elevated temperatures necessary to sterilize the anhydrous impregnant, such as petrolatu'm, cause deterioration 'or decomposition of many desirable .me'dicinals. that may be incorporated therein.
zable using a time cycle and temperauire not substantially difierent from those used in conventional steam steriliia tion procedures.
A preferred object and advantage lies in an-impfoved dressing incorporating desirable medicinals the utility of which in the past has been limited by elevated'temperatures necessary for sterilization of prior art dressings.
-A particular. object of the invention is to prepare a dressing having little or no tendency to fray or shed loose threads, even when out on the bias. I g
A further particular object of the invention is to prepare a surgical dressing having one or more of the reregoing properties and further having the ability to be stretched substantially in the lateral or cross direction with minimum tendency to stretch on the longitudinal dimension of the dressing.
The dressingof the present invention comprises a hacking of open mesh fabric having regularly spaced openings of acertain size described hereinafter, impregnated with particularamounts of an oil containing certain othermaiteatent "rialsalso'described below, which materials are important "in producin the desired objects or the invention.
"tend to permit projection of fibers from superposed ab- 'sorbent dre'ssings through the openings and adherence of solidified exudate to the fabric threads; so average -open- 'i'ng size is maintained less than about 0.04 'sqiin. Con- 'v'ersely, extremely small openings tend to produce inaeeration'of underlying wou'n-d tissue; so aver-age area of the openings is greater than about 000015 sq. in.
Preferred average opening size is about 0.00035 sq. in.
Which' approximates the size for standard surgical gauze having a thread 'count of approximately '44 x '36. The types of meshes which may be used in the fabric are descr'ibe'd ingreater detail below.
The impregnant is an 'oil with emulsifying agent or a'gents dispersed therein. This oil composition is present on the fabric in amount sufiicient to prevent the fibers from sticking to the wound. The oils employed have the inherent property of making coagulum of wound e'xudates adhere only slightly to the threads of the dressing. The
wetting agents promote rapid 'wicking of wound exudation through the impregnated dressings and into seconnary dressings of standard absorbent type. This prevents damming of fluids, maceration of the wound, and prevents the dressing from being engulfed by coa g ultltn which would cause the 'dressihg to Stick to the wound. To achieve the desired objectives, the amout of oil present in the oil composition in the dressing is at least about 5 based on the dry weight of dressing.
-It has been a common fault of the prior dressings that excessive amounts of oil were used, thereby seriously interfering with the escape of body fluids from the wound through the dressing immediately in contact therewith and into absorbent layers or regions on the opposite side of the impregnated dressing. According to the present invention, the amount otoil composition is controlled within a minimum amount needed to impart the desired non sticking properties to the fabric, and a maximum amount beyond whichthere is found excessive dammin'g of fluid exudates. A major proportion of fabric openings is thereby left open for passage of fluid. Within the broader scope of the'invent-ion, amounts of oil'composition based on dry'weight of fabric within the approximate range 20% to 200% are contemplated. Preferred'objects from the standpoint of non-sticking properties consistent with negative maceration are realized Within the approximate range to by weight of oil composition based on the dry fabric.
As indicatedabove, the diiiiculties in sterilizing prior art petrolatum dressings arise from the practical impossibilityof permeating ordinary petrolatum with moisture. According to the present invention, therefore, there is uniformly dispersed in the petrolatum or other oil described hereinafter a certain amount of finely divided water which isnecess'ar to bring about sterilization of the composition under conditions of elevated temperature ordinarily maintained in steam sterilization procedures. From this standpoint, the amount of Water present is at least about 4% based on the weight of the oil composition. Larger amounts may be employed, if desired, as will appear from the examples given below. Although Water-ih-oil emulsions have been indicated and are prenut, corn or almond oil.
ferred, certain advantages of the invention may be realized by use of oil-in-Water emulsions.
Petrolatum or other mineral oil is a particular type of oil found suitable for purposes of the present invention. However, bland non-tonic vegetable oils may alternatively be employed. Examples of such oils are peanut, cocoa- Animal fats and oils are suitable, such as tallow, wool grease, and whale oil. Hydrogenated vegetable oils and fats are also satisfactory.
Silicone oils, i. e. polysiloxanes having viscosity from about 40 centistokes at 33 C. to 100,000 centistokes at 25 C., with suitable wetting agents, may be used and objects and advantages of the invention realized.
A primary function of the wetting or emulsifying agent, as aforesaid, is to impart wettability to the impregnant and thereby minimize the tendency to dam fluids adjacent the body and produce maceration. The wetting agents also facilitate irrigation of the wound and removal of any portions of the oil composition which may have adiered thereto. Preferably, two types of emulsifiers are employed: first, an oil-soluble emulsifier which expedites wound drainage as described above; and, second, a watersoluble emulsifier. In some instances both types are mixed in a single composition sold in commerce. Although two emulsifiers may be used, a single emulsifier incorporating the properties of both may be substituted. Satisfactory oil-soluble emulsifiers include sorbitan sesquiolcate sold under the trademark Arlacel C. This type dissolves in the oil phase and increases its hydrophilic properties. Partial esters of fatty acids and polyhydric alcohols, such as glyceryl monostearate, are suitable. Lanolin is another example. Fatty alcohols, fatty acids, fatty acid amides and similar agents may also be emloyed.
The water-soluble emulsifiers contribute to the wettability of the fabric. Their principal function is in forming an emulsion of the oil with Water so that the dressing may be readily sterilized. A suitable material is the polyoxyethylene derivative of sorbitan monooleate sold in cornmerce under the trademark Tween 80. sorbitol derivative, a mannitol derivative may be stituted; instead of polyoxyethylene derivative, a polypropylene derivative may be substituted; and instead of oleate, a similar derivative of other high molecular weight fatty acid may be substituted. Other suitable emulsifiers known in the art may be substituted.
It will now be apparent that each of the emulsifiers is used in amount sufficient to produce the desired emulsifying effect. According to the invention, at least about 2% total emulsifier (1% of each of the water-soluble and oilsoluble emulsifiers) is used based on the total weight of the oil composition. Preferably, at least about 2% or each of the two types is present.
Certain features of the invention may be understood by reference to the attached drawing.
Fig. l is a detail view on an enlarged scale of a fabric according to one embodiment of the invention impregnoted with an oil composition. The knit chains are shown enlarged in proportion to the rest of the fabric.
Fig. 2 illustrates the dressing of Fig. 1 on a smaller scale and is intended to demonstrate the reaction of the material to lateral stress.
Fig. 3 shows a dressing incorporating a different type open-mesh fabric.
Fig. 4 is a sectional view of a wound and dressings ap plied thereto.
Fig. 5 is an isometric view of an adhesive bandage having a dressing pad according to the invention.
Referring to Fig. 1, reference number indicates a series of parallel chains formed on conventional warp knitting equipment. Each chain 10 is formed of a series of needle loops i1 drawn one through the other in succession. Floats or ties 12 connect the end of one needle loop with the beginning of the next. Each row of simultaneously formed and oppositely disposed needle loops in Instead of the the cross direction of the fabric is designated by the term course. That is, in Fig. 1 there are shown five courses of needle loops. It will be noted that each of the needle loops of Fig. l is formed in the same direction, that is, by movement of the thread from left to right over the needle. However, this is not limiting. If desired, the fabric may be formed by first moving the threads from right to left across the needle in one course and in the opposite direction, i. e. from left to right in the succeeding course, and so on.
Sinuous fill threads are indicated at 15. The fill threads 15 are looped between different chains in the fabric, the loops being formed around a link of one of the chains and then around a link of another of the chains, each loop 16 of each fill thread 15 being in a course different from the course in which the other loopings thereof occur. In the Fig. 1 construction the fill thread, after looping itself around the link in one chain, moves over to the link in the next course of the adjoining chain, and then back to the first chain two courses removed from the previous link in the first chain. It will be noted further that, moving from the bottom to the top of the drawing, the leading part17 of each thread loop 16 is bound in between a thread loop and a float of that course. Following part 18 of the same thread loop is bound in between the thread loop or" the following course in the same chain. The focal point of action of thread loop 16 on a chain is, therefore, the point 20 at which two chain loops meet.
As the fabric, for example in Fig. 1, is stretched walewise, the chain loop knots tend to tighten and are relatively inentensible. This makes the fabric more manageable. However, if the fabric is stretched in the crosswise direction, the thread loops which point to the right will tend to distort the focal points 20 between adjacent chain loops to the left. The thread loops which point to the left, however, will act upon focal chain points 21 one course removed from focal points 20 so as to urge points 2i in the same course the entire width of the fabric toward the right. Any given chain, therefore, will be distorted in a zigzag fashion, first to the left by the loops pointing to the right in one course, farther on to the right by the thread loops pointing to the left. The over-all effect will be a stretching of the fabric widthwise and some contraction lengthwise, as shown in Fig. 2. This is also an advantage since it makes the dressing readily conformable to irregular body contours.
One significant advantage of the invention arises by reason of the fact that the fill threads 15 are bound in by the chains as described above. When the fabric is cut, whether longitudinally, transversely or diagonally, ravelling such as is characteristic of woven or usually knitted goods will be minimized or entirely absent due to this binding-in feature.
The number of chains or wales 10 per inch width of the fabric, the spacing of the fill threads 15 and the diameter of the threads are controlled or chosen so as to produce an open-mesh fabric having regularly spaced openings of size described above.
' The oil impregnant is indicated at disposed in such a fashion and according to the specifications set forth above so that the major portion of openings 13 remain free.
Fig. 3 illustrates a dressing having a fabric of ordinary woven surgical gauze of warp threads 36 and fill threads 37 interwoven with each other. The mesh of the gauze may suitably be 44 x 36. The oil impregnant is shown at 40 and is so disposed, as indicated above, that the major portion of openings 41 remain free. A non-woven fabric conforming to the above specifications may be used.
In Fig. 4, an invention dressing is shown applied to wound 61, with absorbent material, such as cotton 62 on the opposite side. According to the invention, the size of openings and the amount of oil composition used is such that exudate from the wound passes-through dressing 60 into layer 62, but dressing 60 does not *stick to the Wound, nor do the fibers from62 project substantially throughthe openings of dressing 60.
In Fig. 5, there is shown an adhesive bandage havinga conventional adhesive-coated backing strip 70. The dressing pad "71 has a top layer of gauze 72, preferably 44 x 36 gauze, impregnated with an oil composition as described above to impart non-sticking properties. Preferably, an unimpregnated, absorbent sheet is disposed underneath impregnated layer '72 to'absorb exudate transmitted through the latter. in use, the pad is placed in contact with the wound and the adhesive tabs are secured to adjacent portions of the The dressing may be prepared by warming together the oil and emulsifying agent to an elevated temperature, for example about 70 C. The Water is warmed to thesame temperature and is added slowly while agitating the mix to form a finely divided dispersion of the water in the oil phase. A controlled quantity of this preparation then may be impregnated on an open-mesh fabric by either saturation of the fabric followed by a wringing-out of excess emulsion between squeeze rollers, or by direct application of the oil composition to the-fabric by means of printing or roller coating techniques.
The dressing may be packaged between layersof plasticcoated foil with the plastic-coated surfaces adjacent each other, to form a heat-sealed bond. Sterilization may be effected by subjecting the sealed packages to a temperature of 240 F. for 30 minutes. If foilpackages are utilized, sterilization may be carried out according'to the procedure described in Masci U. S. P. 2,478,931 of August 16, 1949, to prevent undue distortion .of the package. Rigid-walled containers for the dressing of the invention may be utilized if desired.
The following examples are presented as illustrating .the invention but not in a limiting sense.
Example I An emulsion having the following composition was prepared according to the procedure describ d above:
The emulsion was spread on 44 x 36 gauze, which was woven of threads having 6 mils diameter, in the amount about 1.0 to 1.3 times the gauze weight. Care wastaken that the mesh openings of the gauze were not filled snb- .stantially by the impregnant. The dressing was sealed-between layers of foil and sterilized according to the procedure described in Masci U. S. P. 2,478,931 by sub jecting it to temperature of 240 F. for .30 minutes. It was found to be sterile. The sterile material was used in clinical tests on traumatized tissue and found to be substantially free of sticking to the wound. Little or no maceration of the tissue was apparent during the clinical test.
Example 11 An emulsion having the following composition was prepared according to the procedure described above:
Percent U. S. P. white petrolatum 80.0 Sorbitan sesquioleate 4.9 Polyoxyethylene sorbitan monooleate 4.9 Water 10.2
of the weight of the fabric and was so disposed as not to fill-the openings. The dressing was sterilized in a'hermetically sealed package by subjecting it to temperature of 240'F. for 30 minutes. 'The dressing was sterile. It was found in clinicalntests to have minimum tendency to stick tothe wound. 'It produced no maceration.
Exampleilll The following emulsion was prepared according to the procedure described above:
Percent Cetyl alcohol--- 3.0 Stearyl alcohol 3.0 'Stear'ic acid 3.0 Mineral oil 5.5 Glycerol monostearate (self-emulsifying) 4.5 Water 8.1.0
The glycerol monostearate contained substantial amounts of potassium stearate :soap which made the material selfemulsifying. The emulsion was spread on 28 x 24 gauze in amount of about 175% of the weight of the gauze. The impregnated gauze was packaged and sterilized according to the procedure described in Masci Examples 1 and 2.
It waslater clinically tested and found to have minimum tendency to stick to'wounds and no tendency to produce maceration.
Example IV An emulsion having the following composition was prepared:
. Percent Glycerol monostearate (self-emulsifying) 6. 5 Peanut oil 62.10 Water 31.5
Example -V The following oil composition-was prepared:
Petrolatum? parts by weight ,Sorbitan sesquioleate parts 4.9 'Polyoxyethylene sorbitan monooleate do 4.9
The petrolatum and the other materials were warmed and stirred together at about 70 C. thereby to effect a uniform dispersion. The dispersion maybe sterilized by application of heat at about C. for 10 hours. 44 x 36 gauze is sterilized separately and is coated with thesterilized emulsion using aseptic technique. An .aluminum foil package is similarly sterilized and is loaded "with the impregnated gauze using aseptic technique. The amount of emulsion on the gauze is about 1.0 to 1.3 times the gauze weight. The dressing, when used in contact with a wound will be found to have outstanding nonsticking and non-maceration properties.
Example VI An emulsion having the following composition is pre- The emulsion was spread on 44 x 36 gauze to the extent of about of the gauge weight. It was hermetically sealed in a package and sterilized by heating to a temperature of 240 F. for 30 minutes. The sterilized dressing was found to have excellent non-sticking and non-maceration properties in contact with the wound.
Although specific embodiments have been described in the foregoing specification, it is understood that this presentation is made in an illustrative and not a limiting sense. Accordingly, it is intended to cover in the appended claims all modifications and equivalents within the spirit of the invention.
The claims are:
l. A surgical dressing comprising an open mesh base fabric impregnated with an oil composition, said fabric having regularly spaced openings of average area'in the approximate range 0.00015 to 0.04 sq. in. each, said oil composition comprising at least by Weight of a bland non-toxic oil based on the dry weight of fabric and 2% of wetting agent based on the composition, the amount of said composition being in the approximate range 20 to 200% of the dry weight of the fabric.
2. A dressing according to claim 1 having at least 1% of an oil-soluble wetting agent and at least 1% of a water-soluble wetting agent.
3. A dressing according to claim 2 having at least 2% each of oil-soluble and Water-soluble wetting agents.
4. A dressing according to claim 1 in which the amount of said composition is in the approximate range 100-160% of the dry weight of the fabric.
5. A surgical dressing comprising an open mesh base fabric impregnated with an oil and Water emulsion, said fabric having regularly spaced openings of average area in the approximate range 0.00015 to 0.04 sq. in. each, said emulsion comprising at least 5% by weight of a bland non-toxic oil based on the dry weight of fabric, and 2% oil soluble wetting agent, 2% water-soluble wetting agent, and at least 4% water, each based on the emulsion, the amount of said emulsion being in the approximate range 20 to 200% of the dry weight of the fabric.
6. A dressing according to claim 5 in which the amount of said emulsion is in the approximate range 100-160% of the dry weight of the fabric.
7. A dressing according to claim 6 in which the oil is a petroleum oil and the fabric is approximately 44 x 36 cotton gauze.
8. A sterilized dressing according to claim 7.
9. An adhesive bandage having a pad comprising a surface layer of dressing material according to claim 8.
10. An adhesive bandage according to claim 9'in which said pad comprises a layer of absorbent material beneath and adjacent said surface layer.
11. A surgical dressing comprising an open mesh base fabric impregnated with an oil and Water emulsion, said fabric comprising a base warp knit material composed of walewise parallel chains and filling threads having sinuous configuration looped between said chains, said fill thread loops being formed around a link of one of said chains and then around a link of another of said chains, each loop of each fill thread being in a course different from the course in which the other loopings thereof occur and the loops of different fill threads in the same course pointing in the same direction, said fabric being substantially unstretehable in the walewise direction, but substantially stretchable in the direction normal thereto, said fabric having regularly spacedopenings of average area in the approximate range 0.00015 to 0.04 sq. in. each, said emulsion comprising at least 5% by weight of a bland nontoxic oil based on the dry weight of fabric, and 2% of oil-soluble wetting agent, 2% water-soluble wetting agent, and at least 4% water, each based on the emulsion, the amount of said emulsion being in the approximate range 20 to 200% of the dry weight of the fabric.
12. A dressing according to claim 11 in which the emulsion is a water-in-oil emulsion.
13. A dressing according to claim 11 in which the amount of said emulsion is in the approximate range -160% of the dry weight of the fabric.
14. A dressing according to claim 13 in which the oil is petrolatum and the fabric continuous filament rayon.
15. A sterilized dressing according to claim 14.
16. The method of making a non-sticking sterile surgical dressing which comprises preparing an aqueous emulsion of at least 5% of a petroleum oil based on the weight of fabric subsequently to be impregnated, and at least 2% each of oil-soluble and water-soluble wetting agents, and at least 4% Water, each based on the weight of the emulsion, impregnating an open-mesh fabric with said emulsion, said fabric having regularly spaced openings of average area in the approximate range 0.00015 to 0.04 sq. in. each, the amount of said emulsion being in the approximate range 100 to of the dry Weight of the fabric, sealing said dressing in a container having walls impermeable to micro-organisms, and heating said container and dressing for time and at temperature to sterilize said dressing.
17. A dressing according to claim 5 having an absorbent layer adjacent said base fabric and contacting one side only of said base fabric, adapted to absorb fluid which passes through said base fabric from the wound.
18. A dressing according to claim 5 in which said emulsion contains a medicinal susceptible to deterioration at elevated temperatures.
19. A dressing according to claim 5 in which said oil is a polysiloxane oil.
References Cited in the tile of this patent UNITED STATES PATENTS 2,168,286 Eustis et al. Aug. 1, 1939 2,349,152 Feinstone May 16, 1944 2,711,168 Brickman et a1 June 21, 1955 FOREIGN PATENTS 158,613 Great Britain Jan. 31, 1921