Self-adhesive patches made of fibres for the controlled release of bioactives
The present invention falls within the area of polymeric materials based on ultrafine fibres for use in the pharmaceutical, nutraceutical and cosmetic sector, relating to the method of producing self-adhesive patches and the use thereof as a platform for the controlled release of bioactives by electrohydrodynamic and/or aerohydrodynamic processing techniques.
1. A self-adhesive patch as a platform for controlled release of bioactives comprising at least:
i) a first block A which is in contact with the corporal mucosa or skin to which it adheres characterised in that it is formed by at least one layer made of hydrophilic polymers, and in that it has a surface density of at least 0.2 g/m 2 , wherein the hydrophilic polymers of the block A form an emulsified mixture of polyethylene oxide and polyvinylpyrrolidone;
ii) a second block B deposited on the block A obtained by electrohydrodynamic processing, aerodynamic processing or combination of the two, containing the encapsulated bioactive(s), characterised in that it is formed by at least one layer of fibres made of at least one hydrophobic polymer, and in that it has a surface density of at least 0.2 g/m 2 ;
iii) a third block C deposited on the block B, wherein the block C is formed by at least one layer, characterized in that it is obtained by electrohydrodynamic processing, aerodynamic processing or combination of the two and made up of one or more hydrophobic polymers which are selected from poly-ε-caprolactone, poly-ε-caprolactone copolymers, polylactic acid and the copolymers thereof, and polyhydroxyalkanoates, or any of the mixtures thereof, and in that it has a surface density of at least 0.2 g/m 2 .
2. The patch according to claim 1 , wherein the block B is formed by a combination of hydrophilic and hydrophobic polymers.
3. The patch according to claim 1 , wherein the hydrophilic polymers are independently selected from polyethylene oxide and derivatives thereof as non-ionic water-soluble resins, polyvinylpyrrolidone and the copolymers thereof, polyvinyl alcohols and the copolymers thereof with ethylene, polyacrylates, polyacrylic acid, water-soluble polyacronitriles, lignin and derivatives, acrylic and methacrylic ester polymers, polysaccharides and derivatives, hyaluronic acid, pullulan, alginate, tragacanth, carrageenan, chitin and derivatives, celluloses, gluocogen, starch and polymers derived from it, pectin, guar gum, xanthan gum, fructosan, gellan, collagen, gelatin, soy protein, whey protein, zein, gluten, casein, lectins, thiolated polymers, polyanhydrides, and PAA polyethylene glycol copolymers, as well as the mixtures thereof.
4. The patch according to claim 2 , wherein the hydrophilic polymers are independently selected from polyvinylpyrrolidone, polyethylene oxide, polyvinyl alcohols, polyacrylates, zeins, gluten derivatives, and cellulosic materials, or combinations thereof.
5. The patch according to claim 1 , wherein the hydrophobic polymers are independently selected from non-water-soluble proteins, polyhydroxyalkanoates, medium-chain-length polyhydroxyalkanoates, and all the possible copolymers thereof, poly-ε-caprolactone and all the copolymers thereof, polylactic acid and all the copolymers thereof, polyphosphazenes, polyorthoesters, polyesters obtained from natural precursors, silicones, polyesters, polyurethanes, polysulphones, halogenated polymers, polycarbonates, acrylonitrile butadiene styrene, latex, and polyamides, as well as the mixtures thereof.
6. The patch according to claim 5 , wherein the hydrophilic polymer is polyethylene oxide.
7. The patch according to claim 1 , wherein block A further contains at least one other polymer which is selected from acrylates, zein, gluten derivatives, ethylcellulose, or a mixture thereof.
8. The patch according to claim 1 , wherein block C also contains the same or another bioactive as the one contained in block B.
9. The patch according to claim 1 , wherein the block C further contains other components such as flavours or flavour enhancers if it is applied in the oral cavity, or aromatic substances or flavour enhancers.
10. The patch according to claim 1 , wherein between the blocks B and C, at least one layer (B′) is incorporated which is formed by at least one hydrophilic polymer.
11. The patch according to claim 1 , wherein the block A contains at least one adhesive material.
12. The patch according to claim 11 , wherein the adhesive material is hypoallergenic.
13. The patch according to claim 12 , wherein the adhesive material is porous.
14. The patch according to claim 12 , wherein the adhesive material is permeable to the bioactive.
15. The patch according to claim 1 , wherein the bioactive is an active pharmaceutical ingredient.
16. A method for obtaining a self-adhesive patch obtained by electrospinning processing as a platform for controlled release of bioactives according to claim 1 , comprising the following steps:
a) Preparation of the block A starting from a solution of the hydrophilic polymer or polymers at a concentration between 0.01 and 98% by weight, wherein the voltage of the emitter used is between 0.01 and 500 kV and a voltage in the collector between 0 kV and −500 kV, with a flow rate between 0.0001 to 1,000,000 ml/h, at a temperature between 1° C. and 100° C. and a relative humidity between 0% and 100%;
b) Preparation of the block B starting from a solution of the hydrophobic polymer or polymers at a concentration between 0.01 and 98% by weight, and at least one bioactive in a concentration between 0 and 98% by weight, wherein the voltage of the emitter used is between 0.01 kV and 500 kV and the voltage in the collector between 0 kV and −500 kV, with a flow rate between 0.0001 to 1,000,000 ml/h at a temperature between 1° C. and 100° C. and a relative humidity between 0% and 100%;
c) Preparation of the block C starting from a solution of the hydrophobic polymer or polymers at a concentration between 0.01 and 98% by weight, and optionally one or more bioactives in a concentration between 0 and 98% by weight, wherein the voltage of the emitter used is between 0.01 kV and 500 kV and the voltage in the collector between 0.01 kV and −500 kV, with a flow rate between 0.0001 to 1,000,000 ml/h at a temperature between 1° C. and 100° C. and a relative humidity between 0% and 100%;
d) Processing of the blocks produced either continuously or separately in steps (a), (b), and (c), laminated together, wherein the lamination is carried out by low-temperature calendering.
17. The method according to claim 16 , wherein the calendering of the layers produced is carried out such that it is the last layer of the block C which is in contact with the roller at low-temperature.
18. The method according to claim 17 , wherein controlled-outlet, multi-outlet or multi-emitter injectors are used.
19. The method according to claim 17 , wherein the resulting variation in the fibre diameter is less than 35%.
20. The method according to claim 17 , wherein the variation in the fibre diameter for a given system with a multi-outlet injector is at least 5% less than that which would be produced with uncontrolled outlet injectors.
21. The method according to claim 17 , wherein the variation in the fibre diameter for a given system with a multi-outlet injector is at least 15% less than that which would be produced with uncontrolled outlet injectors.
22. The method according to claim 17 , wherein the adhesive material of block A is not manufactured by electrohydrodynamic or aerohydrodynamic processing techniques.