COMPOSITE PRESSURE SENSITIVE HYDROPHILIC ADHESIVE AND METHOD OF PREPARING THE SAME

Abstract: Composite pressure sensitive hydrophilic adhesive, permeable for water vapor and losing its adhesiveness in contact with liquid water, particularly suitable for temporary glueing medical means to the body surface, comprising a gelled mixture of: (a) a water swellable, water insoluble polymer, soluble in polar water-miscible solvents boiling at atmospheric pressure at temperatures higher than 100 DEG C as well as in their mixtures with minor amounts of water, (b) a hydrophilic water swellable polymer, insoluble in water as well as in polar water-miscible solvents boiling at atmospheric pressure at temperatures higher than 100 DEG C, (c) a polar water-miscible innocuous solvent boiling at atmospheric pressure at temperatures higher than 100 DEG C, if desired mixed with a minor amount of water. A feature of the composite pressure sensitive hydrophilic adhesive of the invention is that the separate polymers (a) and (b) are replaced by a non-crosslinked copolymer of hydrophilic and hydrophobic monomers, only partially soluble in the component (c) but swellable therein. The invention further comprises a method of preparing the composite pressure sensitive hydrophilic adhesive of the invention consisting in the intensive stirring of the dry powdered polymer (a), the water swellable, water insoluble polymer, soluble in polar water-miscible solvents boiling at atmospheric pressure at temperatures higher than 100 DEG C as well as in their mixtures with minor amounts of water and polymer (b), the hydrophilic water swellable polymer, insoluble in water as well as in polar water-miscible solvents boiling at atmospheric pressure at temperatures higher than 100 DEG C, in the (c) a polar water-miscible innocuous solvent boiling at atmospheric pressure at temperatures higher than 100 DEG C, if desired mixed with a minor amount of water, spreading the paste thus obtained on a pad, and setting it to a gelled layer. The method of using the composite pressure sensitive hydrophilic adhesive consists in that the mixing of components is with advantage carried out at temperatures not exceeding 15 DEG C and the thus received mass is afterwards spread to the surface of the medical means to be glued to the body surface, and subsequently the spread layer is left to set at temperatures in the range of from 15 DEG C to about 100 DEG C either by prolonged storage or by heating.

Description: Description Composite pressure sensitive hydrophilic adhesive and method of preparing the same Technical Field The invention relates to a composite pressure sensitive adhesive particularly suitable for temporary glueing medical and cosmetic means to the body surface from which it can be easily removed by liquid water or by innocuous diluted aqueous solutions. Background Art There are known non-tacky hydrogel covers of burnt or wounded skin, consisting of a gelled mixture of water-insolu¬ ble, water swellable polymers such as poly(2-hydroxyethyl methacrylate) , which can be either covalently crosslinked (three-dimensional) or solvent soluble noncrossiinked, with polar high boiling solvent such polyethylene glycol, preferably mixed with water either by sprinkling the liquid component onto skin and then powdering it with the ground dried polymer, or by mixing the two components just before the spreading. The mixture sets af-ter a short spell up to about 50 minutes, forming a non-tacky layer which can be peeled off as such or after further wetting. (US Patent Specifications 4,272,518 and 4,303,066 - D 1 Andrea). A combination of a crosslinked polymer with a polymer soluble in the above mentioned plasticizer is not disclosed. The U.S. Patent Specification No. 4,460,562 - Keith et al, discloses a polymeric diffusion matrix containing a drug (propanol) and consisting of from about 1 to about 60%, of polar highly boiling plasticizer such as glycerol, from about 2 to about 30% of poly(N-vinylpyrrolidone) and from about 6 to about 30 % of least 90 % hydrolyzed poly(vinylacetate) together with transdermally effective amount of propanol. These compositions, as discussed in the Examples, posses an inferior to the skin and insufficient elongation. Moreover, they display a tendency to the syneresis. None of the above mentioned references relates to a pressure sensitive adhesive which could be utilized as such. All of them disclose mixtures of either crosslinked or non- crosslinked hydrophilic polymers - but no combination thereof - with polar highly boiling solvents (plasticizers) and minor amount of water, said mixtures setting on the skin so that they adhere to it. They cannot be used as adhesives for glueing medical means temporarily to the skin. The U.S. Patent Specification No. 4,595,053 (Jeune et all) describes hydrophilic pressure sensitive biomedical adhesives, comprising about from 2 to 50% of poly(N-vinylpyrrolidone) , from about 2 to 5% of polyvinylalcohol, from 5 to about 40% of a polar plasticiser and about 5 to 50% of water. In this case all components are water - soluble and the mixture has to be heated in the presence of water to at least 95°C to form a melt capable to get gelled only upon cooling. The preparation requi¬ res a temperature-controlled stirrable reactor and temperatures up to 130°C. No crosslinked or insoluble polymer is added. The mixture is set by cooling, not by heating. Other pressure sensitive biomedical adhesives such as those described in the European Patent Specifications No EP 0092999 A2 and EP 0 130 061 Al (E.R.Squibb and sons) contain hydrophobic components such as synthetic rubber and mineral oil besides water - soluble gums, resins and tackifiers. They differ therefore distinctly from the present ones as defined below. Disclosure of Invention The object of the present invention is a composite pressure sensitive hydrophilic adhesive. permeable for water vapor and losing its adhesivness in contε t with liquid water, particularly suitable for temporary glueing medical means to the body surface, consisting of the gelled mixture of a (a) a water swellable, water insoluble polymer, soluble in polar water-miscible solvents, boiling at atmospheric pressure at temperatures higher than 100°C as well as in their mixtures with minor amounts of water, a (b) hydrophilic water swellable polymer, insoluble in water as well as in polar water-miscible solvents boiling at atmospheric pressure at temperatures higher than 100°C and a (c) a polar water-miscible inocuous solvent, boiling at atmospheric pressure at temperatures higher than 100°C, if desired mixed with a minor amount of water. Another object of the invention is a composite pressure sensitive hydrophilic adhesive, permeable for water vapor, and losing its adhesivness in contact with liquid water, particu- larly suitable for temporary glueing medical means to the body surface, wherein the separate polymers (a) and (b) are replaced by a non-crosslinked copolymer of hydrophilic and hydrophobic monomers, only partially soluble in the component (c) but swellable therein. The invention furthermore comprises a method of preparing the composite pressure sensitive hydrophilic adhesive according to the invention consisting in the short-time intensive stirring of the dry pulverized polymers (a) being- the water swellable, water insoluble polymer, soluble in polar water- miscible solvents boiling at atmospheric pressure at temperatu¬ res higher than 100°C as well as in their mixtures with minor amounts of water and (b) being the hydrophilic water swellable polymer, insoluble in water as well as in polar water-miscible solvents boiling at atmospheric pressure at temperatures higher than 100°C, in the solvent (c) being a polar water-miscible innocuous solvent boiling at atmospheric pressure at temperatu¬ res higher than 100°C, if desired mixed with a minor amount of water, spreading the paste thus obtained on a pad, and setting it to a gelled layer. The stirring of the components according to the method of the invention is carried out preferable at a temperature not exceeding 15°C and the setting of the stirred mixture is carried out at temperatures in the range of from about 15° to 100°C. The inventive composite pressure sensitive hydrophilic adhesive can according to the invention be used in such a way that the mixing of components is with advantage carried out at temperatures not exceeding 15°C and the thus recieved mass is afterwards spread to the surface of the medical means to be glued to the body surface, and subseqently the spread layer is left to set at temperatures in the range of from 15°C to about 100°C either by prolonged storage at room temperature or by heating. As polymer (a) water swellable, water insoluble polymer, soluble in polar water-miscible solvents boiling at atmospheric pressure at temperatures higher than 100°C as well as in their mixtures with minor amounts of water, there are used noncross- linked polymers either linear or branched, whereas as polymer (b), the hydrophilic water swellable polymer, insoluble in water as well as in polar water-miscible solvents, there is used a covalently crosslinked polymer which is thus insoluble in any liquid and swellable but in water and water-miscible liquids and their mixtures. The expression "medical means" comprises devices and means utilizable externaly in medicine, e.g. pouches with drug for transdermal application, contact with various medical measuring apparatures, special dressing, stopper-like means for restrai¬ ning urinary incontinence device etc. The expression "polymer" includes both homo- and copoly- itiers with purely carbonaceous or hetero-atoms containing main chain. Most common examples of water-miscible, polar high-boiling innocuos liquids are glycerol and its partial esters such as glycerol mono- and diacetate, alkylene glycols such as ethylene and propylene glycols, dimethylsulfoxide. The solubility of the polymers (a) in polar, water-misci- ble solvents is caused by the presence of hydrophilic side substituents or also of oxygen atoms in the main chain. The insolubility of the polymers (b) is due usually to covalent crosslinking, in some cases also to the presence of hydrophobic comonomer units, although covalently crosslinked polymers such as poly(2-hydroxyethyl methacrylate) crosslinked by a small amount (up to about 2%) of ethyleneglycol dimethacrylate, or methaσrylamide copolymerized with a similary amount of ethyle- ne-bis-methacrylamide are prefered. As water swellable polymers (b) , insoluble in water as well as in polar water miscible, high boiling solvents defined sub (c) and in their mixtures with water e. g. following ones can be used. Copolymers of minor amount of hydrophobic monomers such as methylmethacrylate, butylacrylate and methacrylate, or vinylacetate, with a major amount of essentially nonionizable hydrophilic monomers, the hydrophility of which is caused by the content of free hydroxylic or other non-substituted or mono- or disubstituted amide groups, lactone, lactame, pyrroli- done etc. , provided of course that such copolymers are innocu- os. If desired, the copolymer of this kind, belonging to the sort defined sub (b) , can contain a small amount of units ionizable in water such as those acrylic, methacrylic or vinyl sulfonic acid in form of their sodium salts. The adhesives of the invention can be prepared by grinding from about 0,2 parts to about 75 parts of dry polymer (a), a water swellable, water insoluble polymer, soluble in polar water-miscible solvents, boiling at atmospheric pressure at temperatures higher than 100°C as well as in their mixtures with minor amounts of water, with from about 2 to about 75 parts of dry polymer (b) , a hydrophilic water swellable polymer, insoluble in water as well as in polar water-miscible solvents boiling at atmospheric pressure at temperatures higher than 100°C to a fine powder which is rapidly stirred into from about 15 parts to about 90 parts of liquid (c), a polar water- miscible innocuous solvent, boiling at atmospheric pressure at temperatures higher than 100°C, if desired mixed with a minor amount of water, which has been preferably cooled under +5°C. The intensive stirring lasts but several minutes and the mash thus obtained is spread onto a pad or a release sheet or foil such as siliconized or parafinized paper or Mylar foil. Thanks to the content of the insoluble, but swellable polymer (b) the not yet gelled mixture displays no tendency to cool flow and forms easily a uniform layer which is then set either by prolonged storage at room temperature or, better, by heating up to about 100°C. The gelled layer does not flow even at increa- sed temperatures. The mixture of non-crosslinked and crosslinked polymers can be prepared either separately in two different batches, or also in one batch by first carrying out linear (or branched) polymerization and, prior to its end when the batch still contains the monomer and initiator and is still easily stirra- ble, by adding a suitable soluble crosεlinking agent. The ratio of the components (a) and (b) is chosen so as to obtain the required tackiness and elongation of the set or gelled adhesive. Said properties can be influenced in a known way by the ratio of high and low molecular weight of the poly¬ mer. When using poly(2-hydroxyethyl methacrylate) (polyHEMA) no separate crosslinking agent has to be added since the bifuncti- onal monomer contains always a small but sufficient amount of the tetrafunctional ethyleneglycol dimethacrylate. The main advantage of the present adhesive lies in the absence of plastic cool flow due to the content of the polymer (b) , a hydrophilic water swellable polymer, insoluble in water as well as in polar water-miscible solvents boiling at at¬ mospheric pressure at temperatures higher than 100°C, particu¬ larly when the same is partly or sparingly crosslinked and/or but partially swellable in the component (c) a polar water- miscible innocuous solvent, boiling at atmospheric pressure at temperatures higher than 100°C, if desired mixed with a minor amount of water as well as in water. Furthermore, the present adhesive is easily permeable for water vapors so that the skin does not sweat below it, provided that the medical means glued by it is also water vapor permeable. The adhesive of the invention has good affinity to hydrophilic surfaces, e.g. to medical means to be adhered to the skin made from hydrophilic materials such as hydrophilic polyurethanes, to many metals, china etc. Adhesion to the otherwise hydrophobic polymers such as porous (micro- or macroporous) polyolefines can be achieved by chemical sulfona- tion or oxidation by means of silent discharge and neutraliza¬ tion. Other examples of materials compatible with the present adhesive are various hydrogels and their composites such as polysiloxane/polyHEMA and others. Obviously, mixtures of two or more polar water miscible sol-vents can be used without exceeding the scope of the invention. The expression minor amount means less than 50%. Used abbreviation polyHEMA = poly(2-hydroxyethyl methacrylate) . Examples Example l 14.7 g of non-crosslinked poly(2-hydroxyethyl methacrylate) (polyHEMA) ( ol. weight average 1.5 x 10 5 ) are finely ground with 6.3 g of dry poly(2-hydroxyethylmethacrylate) , crosslinked with 0.8% ethyleneglycol dimethacrylate. The powdered mixture of the two polymers is added to 39 g of polyethyleneglycol (PEG 400) while stirring intensively at 7°C for two minutes. Then the paste is spread onto a pad of hydrophilic polyurethane and heated 20 minutes to 75°C. The gelled adhesive layer is provided with a release sheet of siliconized paper and packed. Example 2 Dry powdered mixture of 22 g ethoxyethyl methacrylate polymer with 5g poly(2-hydroxyethyl methacrylate) crosslinked with 0.8g ethyleneglycol dimethacrylate is stirred at 15°C intensively for two minutes in 31 g of polypropyleneglycol (PPG 400) The thin paste thus obtained is spread onto a foil of porous hydro¬ philic polyurethane and heated 30 minutes to 80°C. The layer has high adhesivity to the skin and the whole can be easily removed by rinsing with water. Example 3 20 g of hydroxypropyl cellulose with 15% of the original hydroxylic groups left free is dryed, ground and mixed with a mixture of polyethylene glycol PEG 500/water (ratio 6:4). Then the mixture is heated to 80°C until a major part of the polymer is dissolved. The mash-like mixture is then extruded at 90°C onto a textile pad forming upon cooling a pressure sensitive dressing. Example 4 30 g of the dry powdered copolymer of methyl methacrylate, hydroxyethyl methacrylate and methacrylic acid, ratio of the units 20:19:1, with an average molecular weight about 2xl0 5 , are stirred intensively for 3 minutes into 45 g of a mixture of polyethylene glycol PEG 400 with propylene glycol in a ratio of 80:20. The paste is spread in an about 1 mm thick layer onto a foil of hydrophilic polyurethane and left 4 hours at room temperature. The adhesive layer loses itό adhesiveness if brought in contact with a surplus of water.

Claims: Claims 1. Composite pressure sensitive hydrophilic adhesive, permeable for water vapor and losing its adhesivness in contact with liquid water, particularly suitable for temporary glueing medical means to the body surface, characterized in that it consists of the gelled mixture of: (a) a water swellable, water insoluble polymer, soluble in polar water-miscible solvents boiling at atmospheric pressure at temperatures higher than 100°C as well as in their mixtures with minor amounts of water, (b) a hydrophilic water swellable polymer, insoluble in water as well as in polar water-miscible solvents boiling at atmospheric pressure at temperatures higher than 100°C, and (c) a polar water-miscible innocuous solvent boiling at atmospheric pressure at temperatures higher than 100°C, if desired mixed with a minor amount of water. 2. Composite pressure sensitive hydrophilic adhesive, permeable for water vapor, and losing its adhesivness in contact with liquid water, particularly suitable for temporary glueing medical means to the body surface, characterized in that the separate polymers (a) and (b) are replaced by a non-crosslinked copolymer of hydrophilic and hydrophobic monomers, only partially soluble in the component (c) but swellable therein. 3. Composite pressure sensitive hydrophilic adhesive, permeable for water vapor of claim 1, wherein as polymer (a) water swellable, water insoluble polymer, soluble in polar water-miscible solvents boiling at atmospheric pressure at temperatures higher than 100°C as well as in their mixtures with minor amounts of water, there are used non-crosslinked polymers and the polymer (b) the hydrophi¬ lic water swellable polymer, insoluble in water as well as in polar water-miscible solvents a covalently crosslinked polymer is used. 4. Method of preparing composite pressure sensitive hydrophi- lie adhesive of claim 1, characterized in the intensive short-time stirring of the dry powdered polymer (a) , the water swellable, water insoluble polymer, soluble in polar water-miscible solvents boiling at atmospheric pressure at temperatures higher than 100°C as well as in their mixtures with minor amounts of water and polymer (b) , the hydrophilic water swellable polymer, insoluble in water as well as in polar water-miscible solvents boiling at at¬ mospheric pressure at temperatures higher than 100°C, in the (c) a polar water-miscible innocuous solvent boiling at atmospheric pressure at temperatures higher than 100°C, if desired mixed with a minor amount of water, spreading the paste thus obtained on a pad, and setting it to a gelled layer. 5. Method of preparing a pressure sensitive hydrophilic adhesive of claim 4, characterized in that the stirring of the components is carried out at a temperature not exceeding 15°C. 6. Method of claim 4, characterized in that the setting of the stirred mixture is carried out at a temperature in the range of from about 15° to 100°C. 7. Method of using the composite pressure sensitive hydrophi- lie adhesive of claim 1, characterized in that the mixing of components is with advantage carried out at temperatu¬ res not exceeding 15°C and the thus recieved mass is afterwards spread to the surface of the medical means to be glued to the body surface, and subseqently the spread layer is left to set at temperatures in the range of from 15°C to about 100°C either by prolonged storage or by heating.

Inventors: KRCOVA ZUZANA, SULC JIRI, KRCOVA, ZUZANA, SULC, JIRI
Applicants: KRCOVA ZUZANA, SULC JIRI, KRCOVA, ZUZANA, SULC, JIRI
Application year: 1995
Main classification: C09J201
IPC codes: A61K9, A61L15, C08K5, C08L5, C09J5, C09J9, C09J101, C09J133, C09J201