IE50320B1 - Protective adhesive paste for use with ostomy appliances - Google Patents

Abstract

Protective adhesive pastes for use with ostomy appliances which are formulated as mixtures of a water- absorbing particulate hydrocolloid gum (e.g. karaya gum) and an organic solvent (e.g. alcohol) solution of an adhesive film-forming resin e.g. alkyl monoester of poly(methylvinyl ether/maleic acid are provided with increased resistance to urine and intestinal fluids by incorporating a small amount (2 to 6% by weight) of colloidal silica, preferably, fumed silica.

Description

Protective adhesive paste preparations for use with ostomy applicances are known and widely used by ostomates.

Such preparations are commonly formulated with karaya gum, but other hydrocolloid gums can be used. The gum in powder form is mixed with an alcohol or other organic solvent solution of an adhesive film-forming resin. Preparations of this kind are described in O.K. Patent Specification No. 1,430,515, and have been sold, commercially in the United States and other countries for a number of years.

When the person wearing the ostomy appliance (the ostomate) has difficulty in maintaining a liquid-tight seal between the ostomy applicance and the skin around the stoma an adhesive paste may be of great value. The problem of fluid leakage is aggravated where the skin around the stoma is irregular, or where folds of skin occur in this area. Under such conditions, even though the ostomy device is used with a molded sealing member such as a ring, blanket, or the like, a complete liquid-tight seal cannot be assured. To obtain a more perfect seal the ostomate applies a coating of an adhesive in a ring around the stoma, permits the paste to dry, and then applies the ostomy device. Additional paste may also be applied to the skin-engaging side of the ring or blanket before application.

With ileostomies and colostomies the area around the stoma is exposed to intestinal fluids, which in the case of ileostomies may include gastric juices containing, proteolytic enzymes. With urostomies the area around the stoma is exposed -250330 to urine. Therefore, in the use of paste preparations, as described above, one problem is thatt the applied paste is not sufficiently resistant to intestinal fluids or urine. It has been desired to increase the mechanical and adhesive endurance of such adhesive pastes when applied around the stoma, but heretofore no means has been provided for accomplishing this result.

One of the skin irritation problems associated with the use of ostomy appliances is referred to as adhesive trauma, which is the stripping of the skin through repeated application and removal of the adhesively-attached ostomy appliance. Adhesive trauma is aggravated by increases in the frequency with which the ostomy device is removed and reapplied. By providing an adhesive paste preparation of greater endurance, it should be possible to reduce the frequency of removal of the ostomy device, thereby reducing skin irritation caused by the skinstripping effect.

The present invention is based in part on the discovery that a new and surprising result is obtained by the incorporation of a small amount of colloidal silica (SiO2), preferably in the form of fumed silica, in protective adhesive pastes for use with ostomy appliances, which are composed of mixtures of hydrocolloid gum and solutions of film-forming resins. More specifically, the resistance of such pastes to the action of intestinal fluids and/or urine is markedly increased by incorporat ing from 2 to 6% by weight of fumed silica or other high surface -350330 area silica material. The desired liquid-tight sealing engagement of the ostomy device is more effectively maintained and for longer periods of time. In addition, the stability of the paste preparations and their shelf-life prior to application are significantly improved.

Protective adhesive paste fcnailated in accordance with the present invention can be advantageously used in a variety of ostomy applications. The paste can be used in conjunction with every type and form of molded ostomy barriers (rings, blankets, etc.). Further, the paste can be applied in various ways, such as on, under, or next to the other barrier material. In addition, for certain applications, the paste may be used as the only barrier material, being formed into a skin blanket, ring, or other form of barrier by itself. Also, the paste will have an application for use around other surgical fluid drainage openings besides stomas, such as a wound or surgical incision.

The present invention is believed to be generally applicable to the protective adhesive pastes for use with ostomy appliances of the kind which are formulated essentially as mixtures of water-absorbing particulate hydrocolloid gum with an organic solvent solution of an adhesive film-forming resin.

Based on present usage, the hydrocolloid gum is preferably karaya gum, but other hydrocolloid gums can be used as a partial or complete substitute for karaya. The class of water-absorbing hydrocolloid gums is well known and such gums have comparable properties. For example, useable hydrocolloid gums include: -450320 plant exudate gums like zedou, ghatti, arabic, and tragacanth; plant extract gums like pectin; plant seed gums like guar and locust bean; and seaweed extract gums like carrageenan. Other gums, such as cellulose and cellulose derivative gums may also be used, such as carboxymethyl cellulose and hydroxyethyl cellulose. Such hydrocolloid gums are characterized by being polysaccharides, and by being hydrophilic and water-absorbing.

For the purpose of the present invention, the hydrocolloid gums are used in a fine particulate form, that is, as powders. For example, the gum may be employed in a sufficiently fine state of subdivision so that it will pass a 100 mesh or finer screen. The powdered gums as used are air-dry, that is, dry to the touch, but may contain some moisture. For example, karaya gum powder may contain from 10 to 18% by weight moisture.

The adhesive film-forming resin should be non-toxic and applicable to the skin. Such resins are those which can be used as medical adhesives. The resin should be soluble in alcohol or other organic solvent which can be used in the formulation.

The resin must be film-forming, that is, on evaporation of the solvent, a resin film will be formed. For example, particularly desirable resins include the monoester resins sold by GAF Corporation., Chemical Division, New York, N.Y. as the Gantrez , (Trade Mark) ES resins. In terms of chemical structure, these resins are alkyl monoesters of poly (methyl vinyl ether/raaleic acids). The alkyl groups may be ethyl, isopropyl, or butyl. These resins are soluble in the lower primary alcohols, and are supplied in alcohol solution, so they are readily adapted for use in preparations of the present invention. A preferred Gantrez resin is sold under -5the code designation ES-335-I. It is the isopropyl monoester and is supplied as 50% solution in isopropanol. Other of the Gantrez resins, such as ES-225 are supplied as solutions in ethanol. (ES-225 is the ethyl monoester.) For the purpose of the present invention, both isopropanol and ethanol are especially desirable solvents. Other film-forming resins may be used instead of or in addition to the above-described monoester resins. For example, polyvinyl pyrrolidone has similar properties. One suitable commercial product is the K-30n polyvinyl pyrrolidone product of GAF, which has a molecular weight of about 40,000.

(GAF Corp., Chemical Division, New York, Ν. Y.) The organic solvent for dissolving the resin is preferably ethanol, isopropanol, or mixtures thereof. However, other organic solvents in which the resin is soluble can be employed, providing the solvent is non-toxic and applicable to the skin. Where the resin is supplied as an ethanol or isopropanol solution it is convenient to use an additional amount of the same alcohol to complete the solvent system.

In general, the ingredients are combined in the required proportions to produce a paste, which is relatively stiff and yet readily spreadable. For example, from 40 to 70 parts by weight of the resin can be used per 100 parts of the karaya or other hydrocolloid gum,· and sufficient alcohol or other organic solvent will be used to form a paste of the desired_sonsistency.

As indicated, the resin will be dissolved in the solvent, and the hydrocolloid' particles dispersed in the resin solution. For example, from 150 to 175 parts by weight of isopropanol may be used per 100 parts of resin. -65032U In accordance with the present invention a colloidal silica material is incorporated in the paste preparation to provide increased resistance to urine and/or intestinal fluids. Fumed silica is preferred, although precipitated silica can also be used. Fumed silica is produced by flame hydrolysis of silicon tetrachloride. It can be obtained from various manufacturers, including the Cab-O-Sil (Trade Mark) products of Cabot Corporation, Boston, Massachusetts, and the Aerosil (%rade Mai£) products of Degussa, Inc., New York, N.Y. These products are collidal silicon dioxide of very high surface areas. They are supplied as dry white powders. For example, one suitable specific product is the Grade M-5 of CabO-Sil. Colliodal silica formed by precipitation from aqueous solutions are also available commercially. These products have the general formula SiOj. x HjO. One suitable product is Quso G-30 of Philadelphia Quartz, Valley Forge, Pennsylvania.

Preferably, from 2 to 6% by weight of the fumed silica or other colloidal silica is incorporated in the paste product. Since the silica has a thickening action on the preparation, the maximum useable amount is limited if the desired paste-like consistency of, the product is to be maintained.

Fortunately, for the purpose of the present invention, the desired improvement in endurance properties appears to be optimized in the range of about 3 to 5% by weight, and in this range the paste character of the preparation can be maintained.

It will be understood, however, that where necessary the amount of solvent can be increased, or the resin or hydrocolloid solids decreased to maintain the paste form of the product. -750330 In combining theingredients to produce the paste, the order of addition is not highly critical. However, it is advan tageous to first form the solvent solution of the resin, then add the silica, and finally the hydrocolloid. Where other minor ingredients are to be incorporated, these can first be dissolved in a portion of the alcohol, and the silica can be dispersed therein before combining with the alcohol solution of the resin. Whatever the order of addition of the other ingredients, it is desirable to add the hydrocolloid last.

Other minor ingredients which may be included are solvents or co-solvents such as glycerine or propylene glycol, and preservatives or anti-bacterial agents, such as methylor butyl paraben (para-hydroxy benzoate). A small amount of water may also be added, but this is not usually necessary and provides no advantage unless ingredients are to be incorporated which are water-soluble but not alcohol-soluble.

In general, the combined minor ingredients will constitute less than 10% by weight of the complete formulation. For example, the resin, the alcohol solvent, and the hydrocolloid may comprise 80% or more of the formulation, with the amount of colloidal silica being less than 6%.

The practice of the present invention in a preferred embodiment and the results obtained thereby are further illustrated by the following examples. -850320 EXAMPLE I A protective adhesive paste for use with ostomy appliances is prepared according to the following formula.

Formula Ingredient No. _ Wt. % (1) Isopropanol 12.8 (2) Glycerin (OSP 99%) 7.0 (3) Methylparaben 0.14 (4) Butylparaben 0.06 (5) Fumed silica 4.0 (6) Isopropanol solution of film-forming resin (50%) 40.0 (7) Gum karaya powder 36.0 100.00 In compounding the above ingredients, ingredients 1 to 4 may be first mixed, the methyl and butylparaben dissolving in the part of the isopropanol employed for this purpose. Ingredient 5, the fumed silica, is then mixed into the solution of ingredients 1 to 4, and thoroughly dispersed therein. Next, ingredient 6, the isopropanol solution of the resin is added. Since the resin is a 50% solids solution in isopropanol, the total of isopropanol in the formula is approximately 32.8% (12.8% + 20.0%). As a final step, ingre25 dient 7, the gum karaya powder, is mixed into the solution of ingredients 1 to 6. The mixing is continued until a smooth, homogeneous paste is obtained. -950320 In the foregoing example, the fumed silica is Cab-0Sil M-5 (Cabot Corporation, Boston, Massachusetts). The resin solution is Gantrez ES-351-I (GAF Corporation, Chemical Divison, New York, N. Y.). The gum karaya is in the form of a powder passing a 140 mesh screen, and may contain from 10 to 18% moisture.

EXAMPLE II The karaya paste of Example I was compared for endurance properties with a commercial karaya paste product manufactured by Hollister Incorporated, Chicago, Illinois. The commercial product was composed primarily of gum karaya in admixture with an isopropanol solution of the same film-fonaing resin identified in Example I (Gantrez ES 351-1). Both preparations were compared as freshly prepared, and after seven weeks of room temperature storage. For the test, the simulated intestinal fluid was prepared as described in U.S.P XIX Intestinal Fluid, Simulated, TS, pc. 765 (1974). The simulated urine was prepared as described in Remington's Pharmaceutical Sciences, Urine, pg. 598-9, Ed 15 (1973).

In preparing the samples, ribbons of the paste were extruded from tubes having 5/16 inch orifices onto silicon release paper.

The test pasted ribbons had lengths of approximately 1 inch, and were standardized to a uniform weight of 3 grams. After airdryiug at room temperature for 20 to 24 hours, the paste ribbons had solidified to a rigid condition, which permitted them to be handled and placed in the test apparatus. -1050320 The test apparatus includes a tank for containing the simulated intestinal fluid or urine, and a plurality of tripod testing fixtures, which nay be placed in the tank in contact with the solution. The testing fixture has a platform at the top with a sample-receiving recess. The center portion of the recess is cut-out to provide an opening through the platform.

When placed in test position, the solidified paste ribbons bridge the openings, ϋ-shaped weights are then placed over the ribbons, these weights in the form of steel hooks weighing approximately 7.4 grams. In use, the hooks are placed over the samples so that when the hooks break through the samples they would fall freely through the openings in the platforms. Nylon strings are attached to the upper cross-arm portions of the inverted U-shapec hooks and the strings are attached to the operating levers of micro switches, the lengths of strings being selected so that when the sample is broken, the micro switch will be activated, and a timing clock for the particular sample will be stopped. In starting the test, after the samples have been placed in the tank and the strings attached to the micro switch levers, the simulated urine or intestinal fluid is added to the tanks to a level above the position of the samples, and the timing clocks for each sample are started. The elapsed time for breakthrough of each sample is thereby automatically recorded. The results of the test are summarized below in Table A.

Table A Test Solution Urine Intestinal Fluid Time (Hours to Break-Thru) Commercial Example I Fresh 7 wks 0.26 1.95 0.20 -.50 Fresh 7 wks 168+ 168+ 168+ 168+ -11In Table A the designation 168+ indicates that the test with the Example I preparation, both as freshly prepared and after seven weeks of aging, were discontinued after an elapsed time of 168 hours. Since no breakthroughs had occurred by that time, further testing was discontinued. Each of the reported values in Table A represent three samples, the average times being shown.

The results with respect to the commercial preparation indicate that the preparation was somewhat more resistant to the simulated urine and the simulated intestinal fluid after it had aged for seven weeks. However, the aging involves some separation of the preparation so that it was no longer homogeneous. Such separation is undesirable. By way of comparison, the Example I preparation was stable and homogeneous after seven weeks of storage.

EXAMPLE III As an alternate to the preferred formulation of Example I, a protective adhesive paste can be prepared according to the following formula.

Formula Ingredient No. Wt. % (1) Isopropanol 22.8 (2) Glycerin (USP 99%) 17.0 (3) Methylparaben 0.14 (4) Butylparaben 0.06 (5) Fumed silica 4.0 (6) Polyvinyl pyrrolidone* 20.0 (7) Gum karaya powder 36.0 100.00 *K-30, GAF · -1250320 The ingredients for the above formula may be compounded in the same manner as described with respect to the corresponding ingredients of Example 1.

OTHER EXAMPLES With reference to the formulas of Examples I and III, other hydrocolloid gums in powder form may be substituted for the gum karaya. The substitution may be on an equal weight basis, or more or less of the substitute gum may be used. On this basis, useable hydrocolloid gums include ghatti, arabic, tragacanth, pectin, guar, locust bean, carrageenan, zedou, sodium carboxymethyl cellulose, and similar gums.

In other variations of the formulas of Examples I and III, ethanol may be substituted on an equal weight basis for the isopropanol, and Gantrez ES-225 may be used therewith. -13'

Claims (9)

1. CLAIMS:1. A protective adhesive paste having increased mechanical and adhesive endurance when in contact with urine and intestinal fluids for use with ostomy appliances said paste being com5 posed essentially of a mixture of a water-absorbing particulate hydrocolloid gum and an organic solvent solution of an adhesive film-forming resin, wherein there is present in said paste colloidal silica.

2. A paste according to claim 1, in which said silica is 10 fumed silica.

3. A paste according to claim 1 or claim 2 containing from 2 to 6% by weight of said silica.

4. A paste according to claim 1 or claim 2 containing from 3 to

5. % by weight of said silica. 15 5. A paste according to any one of claims 1 to 4 wherein said gum is karaya gum powder.

6. A paste according to any preceding claim wherein said organic solvent is an alcohol.

7. A paste according to any preceding claim in which said 2 q resin is an alkyl monoester of poly(methyl vinyl ether/maleic acid) . -1450320

8. A paste according to any preceding claim containing from 40 to 70 parts by weight of said resin per 100 parts of said gum.

9. A paste according to claim 1 substantially as described 5 herein with reference to any one of the Examples.