Therapeutic patch

Abstract

The invention relates to a topical patch comprising a therapeutic compound-impermeable backing layer, a self-adhesive matrix based on polysiloxanes and containing capsaicin or a therapeutic compound analogous to capsaicin, and a protective film to be removed before use, in which the matrix contains liquid microreservoirs based on an amphiphilic solvent, in which the therapeutic compound is present in completely dissolved form and the concentration of the therapeutic compound in the microreservoir droplets is below the saturation concentration. The invention furthermore relates to a process for its production and its use in the treatment of neuropathic pain.

1 . A topical patch comprising a therapeutic compound-impermeable backing layer, a self-adhesive matrix based on polysiloxanes containing at least 1% by weight, preferably at least 2% by weight, more preferably at least 3% by weight, most preferably at least 5% by weight, of the therapeutic compound, and a protective film to be removed before use, in which
 a. the matrix contains liquid microreservoir droplets comprising an amphiphilic solvent, in which the therapeutic compound is dissolved, and   b. the concentration of the therapeutic compound in the microreservoir droplets is between 20 and 90% by weight of the saturation concentration
 wherein the therapeutic compound is capsaicin or a capsaicin analog or a mixture thereof. 
   
     
     
         2 . The topical patch as claimed in  claim 1 , in which the therapeutic compound is capsaicin. 
     
     
         3 . The topical patch as claimed in  claim 1 , in which the concentration in the therapeutic compound in the microreservoir droplets is between 40 and 70% by weight of the saturation concentration. 
     
     
         4 . The topical patch as claimed in  claim 1 , in which the amphiphilic solvent is a butanediol, such as 1,3-butanediol, dipropylene glycol, tetrahydrofurfuryl alcohol, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol, dipropylene glycol, carboxylic acid esters of tri- and diethylene glycol, polyethoxylated fatty alcohols of 6-18 C atoms or 2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane, or mixtures of these solvents. 
     
     
         5 . The topical patch of  claim 4  wherein the solvent is diethylene glycol monoethyl ether. 
     
     
         6 . The topical patch as claimed in  claim 1 , in which the microreservoir droplets comprise a viscosity-increasing additive dissolved in the solvent. 
     
     
         7 . The topical patch as claimed in  claim 6 , in which the viscosity-increasing additive is a cellulose derivative or a high molecular weight polyacrylic acid. 
     
     
         8 . The topical patch of  claim 7 , in which the viscosity-increasing additive is ethylcellulose or hydropropylcellulose. 
     
     
         9 . The topical patch as claimed in  claim 1 , in which the proportion of the microreservoir droplets in the matrix is less than 40% by weight, preferably less than 35% by weight, in particular between 20 and 30% by weight. 
     
     
         10 . The topical patch as claimed in  claim 1 , in which the self-adhesive matrix comprises an amine-resistant polysiloxane. 
     
     
         11 . The topical patch as claimed in  claim 10 , in which the self-adhesive matrix comprises a mixture of a polysiloxane of medium tack and a polysiloxane of high tack. 
     
     
         12 . The topical patch as claimed in  claim 10 , wherein the matrix contains from about 0.5 to about 5% by weight of a silicone oil. 
     
     
         13 . The topical patch as claimed in  claim 1 , in which the matrix comprises
 5-10% by weight of capsaicin or a capsaicin analog,   10-25% by weight of diethylene glycol monoethyl ether,   0-2% by weight of ethylcellulose,   0-5% by weight of silicone oil, and   58-85% by weight of self-adhesive polysiloxane and the coating weight of the matrix is between 30 and 200 g/m 2 , preferably between 50 and 120 g/m 2 .   
     
     
         14 . The topical patch as claimed in  claim 1 , in which the matrix consists essentially of
 5-10% by weight of capsaicin or a capsaicin analog,   10-25% by weight of diethylene glycol monoethyl ether,   0-2% by weight of ethylcellulose,   0-5% by weight of silicone oil, and   58-85% by weight of self-adhesive polysiloxane and the coating weight of the matrix is between 30 and 200 g/m 2 , preferably between 50 and 120 g/m 2 .   
     
     
         15 . The patch as claimed in  claims 1  to  14 , in which the backing layer consists of a polyester film 10-20 μm thick. 
     
     
         16 . The topical patch as claimed in  claim 1 , in which the backing layer consists of an ethylene-vinyl acetate copolymer. 
     
     
         17 . The use of a topical patch as claimed in  claim 1  for the treatment of neuropathic pain. 
     
     
         18 . The topical patch as claimed in  claim 1  for use in the treatment of neuropathic pain. 
     
     
         19 . A method for the treatment of neuropathic pain, in which a topical patch as claimed in  claim 1  containing an amount of capsaicin or capsaicin analog effective for this use is applied. 
     
     
         20 . A method for the production of a topical patch as claimed in  claim 1 , which comprises dissolving the therapeutic compound in an amphiphilic solvent, adding this solution to a solution of a polysiloxane or the matrix constituents and dispersing, coating the resulting dispersion onto a protective layer which is removable again and removing the solvent of the polysiloxane and laminating the backing layer onto the dried matrix layer.