Drug-coated balloon catheter and method for the production thereof
The invention relates to a drug-coated balloon catheter and to a method for producing the same. The balloon of the catheter includes (i) a main membrane, and (ii) an asymmetrical polymer membrane which is applied to an outside of the main membrane and into which at least one pharmaceutical active ingredient is introduced.
1. A method for producing a drug-coated balloon catheter, comprising the following steps:
a) providing a balloon blank having a main membrane;
b) wetting the main membrane with a homogeneous polymer solution comprising a solvent and a polymer;
c) inducing a phase separation of the polymer from the polymer solution by a measure selected from the group consisting of:
(i) temperature change,
(ii) immersing the wetted balloon blank in a bath of a liquid which can be mixed with the solvent of the polymer solution, but which does not dissolve, or hardly dissolves, the polymer, and
(iii) exposing the wetted balloon blank to an atmosphere which comprises a gaseous constituent which can be mixed with the solvent of the polymer solution, but does not dissolve, or hardly dissolves, the polymer;
d) drying the balloon after the phase separation, and subsequently embedding a pharmaceutical active ingredient in the polymer membrane by applying an active ingredient solution, or a pure active ingredient, onto the polymer membrane in the expanded state of the balloon blank, wherein the pharmaceutical active ingredient or the pure active ingredient is embedded into the inner lumen of the polymer membrane.
2. The method according to claim 1 , wherein the polymer solution is a solution of polyurethane or polyether-polyurethane in tetrahydrofurane (THF) or dimethylformamide (DMF).
3. The method according to claim 1 , wherein step c) is carried out in an expanded state of the balloon blank.