Transdermal patches having a siliconic adhesive matrix stabilized with methacrylic copolymers

Patch suitable for transdermal or local administration of active principles s comprising: (a) a matrix based on pressure sensitive adhesive silicone polymers containing: (a-1) said active principle in concentrations between 1 and 10% by weight on the, total weight of said DEG dry adhesive matrix, (a-2) said silicone polymers in quantities, between 80 and 98% by,weight on the io total weight of said DEG dry adhesive matrix, (a-3) a copolymer of cationic type of acrylic and/or methacrylic esters containing amino groups or salified ammonium groups in a concentration between 1 and 10% by weight on the total weight of said adhesive silicone polymers, (b) a support layer on which said adhesive matrix (a) is located, (c) a protective layer disposed on said adhesive matrix and removable on use.