some non - limiting embodiments are described hereinafter to further clarify the understanding of the nature , shape and structure and of the method of obtaining the patch . 8 . 7 kg of a non - crosslinked solvent acrylic adhesive ( for example duro - tak 387 - 2353 adhesive by national starch & amp ; chemical ) and 323 grams of pure ichthyol are introduced into a container under cold conditions and mixed with a propeller stirrer until a uniform mass is obtained . the mass is left to stand to enable any air bubbles to escape . using a patch spreading machine and with the aid of a compressed air pump , the mixture is fed into the rotating roller doctor blade with the doctor blade thickness adjusted to about 300 micron . the mixture is filmed onto a siliconized polyester which passes through 4 oven stations , the first set at 40 ° c ., the second at 50 ° c ., the third at 70 ° c . and the fourth at 80 ° c ., at a rate of 8 metres per minute . at the oven exit the film is completely free of solvents , which have evaporated within the oven stations , the body of the adhesive mass is blackish in colour showing the presence of 10 % pure ichthyol , the weight of the adhesive mass being about 90 grams per square metre . the polyester on which the adhesive film was spread and dried is bonded to a polyester and viscose non - woven fabric of 100 grams per square metre and rewound onto a bobbin . the result is that the adhesive film grips the non - woven fabric to form an adhesive fabric containing 10 % ichthyol protected by the siliconized polyester . round patches of 4 centimetres diameter are then punched from the obtained bobbin and packaged . these patches were tested by hplc to verify the quantity of pure ichthyol present , in each patch a quantity of 11 . 3 mg of ichthyol being found , equal to 10 % of the total adhesive mass . tests subsequently undertaken by organized clinical structures on persons with anorectal fistulas or abscesses demonstrated the absolute effectiveness of the product . the abscess was found to re - absorb with complete resolution of pain and tissue symptomology . in the space of 8 - 10 hours there is a progressive recession of characteristic symptoms : anoperineal pain and swelling , irritation and reddening of the perineal skin ( itching , burning , and pus ). 20 kg of a crosslinked solvent acrylic adhesive with average viscosity 2500 / 3000 mpa . s ( for example duro - tak 387 - 2054 adhesive by national starch and chemical ) and 5 kg of solvent acrylic adhesive with 700 - 800 mpa . s low viscosity were introduced under cold conditions into a container then mixed slowly for 20 minutes with a vertical agitator . while slowly agitating , 2100 grams of pure ichthyol ( ammonium sulfoichthyolate ), 247 g of tumenol and 123 grams of fluid aloe vera extract are introduced as a thin stream . mixing continues slowly until a uniform mass is obtained then left to stand to release any air bubbles . using a patch spreading machine and with the aid of a compressed air pump , the mixture is fed into the rotating roller doctor blade with the doctor blade thickness adjusted to about 320 micron . the mixture is filmed onto a siliconized polyester which passes through 4 oven stations , the first set at 40 ° c ., the second at 50 ° c ., the third at 80 ° c . and the fourth at 90 ° c ., at a rate of 8 metres per minute . at the oven exit the film is completely free of solvents , which have evaporated within the oven stations , the body of the adhesive mass is blackish in colour showing the presence of 8 % pure ichthyol , 1 % tumenol , 0 . 5 % aloe vera , the weight of the adhesive mass being about 100 grams per square metre . the polyester on which the adhesive film has been spread and dried is bonded to a micro - perforated corona treated polythene film of 90 g / m 2 and rewound on a bobbin . the result is that the adhesive film grips the micro - perforated polythene to form an adhesive fabric containing 8 % ichthyol , 1 % tumenol and 0 . 5 % aloe vera protected by the siliconized polyester . round patches of 4 centimetres diameter are then punched from the obtained bobbin and packaged . these patches were tested by hplc to verify the quantity of pure ichthyol present , in each patch a quantity of 8 . 9 mg of ichthyol being found , equal to 8 % of the total adhesive mass . preparation of an ichthyol based patch for treating inflammatory changes of the skin 28 kg of demineralised water , 0 . 120 kg of parabens ( preservatives ), 4 . 4 kg of polyvinyl alcohol and 0 . 5 kg of carboxymethyl cellulose are introduced into a mixer heated to 70 ° c . to obtain a uniform mass ( phase a ) which is cooled to ambient temperature and then poured into a kneader into which phase c , formed of 3 kg of ichthyol ( ammonium sulfoichthyol ), 2 . 0 kg of carboxymethyl beta - glucan ( having cicatrising action ), and 18 kg of sodium alginate are added under cold conditions ( over a period of about 15 - 20 minutes ). the mixture is agitated in both directions for 15 - 20 minutes , after which a phase b , prepared separately by mixing 1 . 8 kg of demineralised water and 0 . 5 kg of sodium tetraborate in a steel container at a temperature of 20 - 30 ° c . until completely dissolved , is slowly added in a thin stream to give a gel whose viscosity can be increased by increasing the quantity of phase b or decreased by increasing the quantity of phase a . the gel is spread by means of a rotating two roller doctor blade onto a web of non - woven fabric formed from viscose fibres ( 50 %) and polypropylene fibres ( 50 %), with a weight of 150 g / m 2 , a thickness of 200 micron and a density of 87 g / dm 3 . the protection sheet is a 75 g / m 2 siliconized polyester sheet . the composite web which leaves the rollers is transported to a machine where it is cut and punched , for example into the form of a 10 × 15 cm rectangular patch saturated throughout . the patch thus obtained is found to be particularly effective for applications in very irritated areas , in that the refreshing action of the gel offers an immediate soothing and calming effect , the therapeutic action being attributable to the ichthyol and to the skin repairing activity ( mainly due to the carboxymethyl beta - glucan ). 6 kg of a styrene and isopropene based copolymer ( for example kraton d - 1161n by shell chemicals ), 2 kg of an alpha pinene terpene resin ( for example dercolyte a 115 by drt ), 10 kg of toluene and 4 kg of mek are introduced into a container and mixed slowly for 20 minutes with a vertical agitator . 500 grams of pure ichthyol ( ammonium sulfoichthyol ) are added as a thin stream under slow agitation . mixing is continued slowly until a uniform mass is obtained . the mass is left to stand to release any air bubbles . using a patch spreading machine and with the aid of a compressed air pump , the mixture is fed into the rotating roller doctor blade with the doctor blade thickness adjusted to about 320 micron . the mixture is filmed onto a siliconized polyester which passes through 4 oven stations , the first set at 40 ° c ., the second at 50 ° c ., the third at 80 ° c . and the fourth at 90 ° c ., at a rate of 8 metres per minute . at the oven exit the film is completely free of solvents , which have evaporated within the oven stations , the body of the adhesive mass is blackish in colour showing the presence of 10 % pure ichthyol , the weight of the adhesive mass being about 100 grams per square metre . the polyester on which the adhesive film was spread and dried is bonded to pure viscose non - woven fabric of 100 g / m 2 and rewound on a bobbin . the result is that the adhesive film grips the unwoven fabric to form an adhesive fabric containing 10 % ichthyol protected by the siliconized polyester . round patches of 4 centimetres diameter are punched from the bobbin obtained and packaged these patches were tested by hplc to verify the quantity of pure ichthyol present , in each patch a quantity of 7 mg of ichthyol being found , equal to 10 % of the total adhesive mass .
a patch consisting of a porous or occlusive woven , non - woven or plastic support , to one face of which is applied a skin adhesive polymer layer containing tars used as reducers or resolvents in dermatology , in particular ichthyol . the patch is able to gradually release the active substances in order to maximize their therapeutic properties .