Compositions comprising electrohydrodynamically obtained fibres for administration of specific dosages of an active substance to skin or mucosa

Abstract

The present invention relates to electrospun fibers comprisingi) a hydrophilic polymer that is soluble in a first solvent,ii) a bioadhesive substance that is slightly soluble in said first solvent,iii) optionally, a drug substance.

1 . Electrospun fibers comprising
 (i) a hydrophilic polymer that is soluble in a first solvent, wherein the hydrophilic polymer comprises one or more selected from polyvinylpyrrolidone (PVP), ethylcellulose, hydroxypropylcellulose, acrylates, polymers of acrylic/methacrylic esters, and mixtures thereof; (ii) a bioadhesive substance that has a solubility in said first solvent of 0.5 g/100 ml or less at 25° C., wherein the bioadhesive substance comprises one or more selected from dextrans, polyethylene oxides (PEOs), alginate, tragacanth, carrageenan, pectin, guar, xanthan, gellan, methylcellulose, hydroxypropylmethylcellulose (HPMC), polyvinylalcohol (PVA), polymers of acrylic acids (PAAs), chitosan, lectins, thiolated polymers, nonionic water-soluble polyethylene oxide resins (polyox WSR), and PAA polyethylene glycol copolymers (PAA-co-PEG), and mixtures thereof; and   (iii) optionally, a drug substance,   wherein at least a portion of the bioadhesive substance is attached to the fibers in an undissolved form, wherein the portion of the bioadhesive substance attached to the fibers in an undissolved form is not an integral part of the fibers.   
     
     
         2 . Electrospun fibers according to  claim 1  comprising the optional drug substance. 
     
     
         3 . Electrospun fibers according to  claim 1 , wherein the bioadhesive substance comprises dextran having an average molecular weight of from 400,000 Da to 2,000,000 Da. 
     
     
         4 . Electrospun fibers according to  claim 1 , wherein the bioadhesive substance comprises dextran having an average molecular weight of about 2,000,000 Da. 
     
     
         5 . A method for preparing electrospun fibers according to  claim 2 , comprising:
 (i) dissolving the hydrophilic polymer in the first solvent to obtain a solution;   (ii) suspending the bioadhesive substance in the solution to obtain a dispersion;   (iii) adding the drug substance to the dispersion to obtain a mixture; and   (iv) electrospinning the mixture;   wherein, in the electrospun fibers, at least 90% w/w of the bioadhesive substance is present in an undissolved form attached to the fibers.   
     
     
         6 . A method for preparing electrospun fibers according to  claim 2 , comprising:
 (i) dissolving the hydrophilic polymer in a first portion of the first solvent to obtain a solution;   (ii) dissolving or suspending the drug substance in the first solution to obtain a mixture;   (iii) suspending the bioadhesive substance in a second portion of the first solvent to obtain a dispersion,   (iv) dual-electrospinning the mixture obtained and the dispersion,   wherein, in the electrospun fibers, at least 90% w/w of the bioadhesive substance is present in an undissolved form attached to the fibers.