Nanodispersions

Abstract

The invention provides process for making water-soluble nano-dispersions of water-insoluble materials in a water-soluble carrier material comprising the steps of: (i) providing a single phase mixture of: (a) a non-aqueous solvent or a mixture of miscible non-aqueous solvents, (b) at least one carrier material soluble in non-aqueous solvent (a), said carrier material being also soluble in water and solid at ambient temperature, (c) at least one water-insoluble payload material which is soluble in non-solvent (a), and, (ii) drying the mixture to remove solvent (a) and thereby obtain the carrier material (b) in solid form with payload (c) dispersed therein as nanoparticles, wherein the product of the drying step is water dispersible to give an aqueous solution of (b) and an aqueous nano-dispersion of (c).

1 . A process for making water-soluble nano-dispersions of water-insoluble materials in a water-soluble carrier material comprising the steps of:
 (i) providing a single phase mixture of:
 a) a non-aqueous solvent or a mixture of miscible non-aqueous solvents, 
 b) at least one carrier material soluble in non-aqueous solvent (a), said carrier material being also soluble in water and solid at ambient temperature, 
 c) at least one water-insoluble payload material which is soluble in non-solvent (a), and, 
   (ii) drying the mixture to remove solvent (a) and thereby obtain the carrier material (b) in solid form with payload (c) dispersed therein as nanoparticles, wherein the product of the drying step is water dispersible to give an aqueous solution of (b) and an aqueous nano-dispersion of (c).   
     
     
         2 . A process according to  claim 1  wherein the solvent (a) comprises one or more of dichloromethane, chloroform, methanol, ethanol, isopropanol, isobutanol, formic acid, acetic acid, formamide, N,N-dimethylformamide, aceto-nitrile, ethyl acetate, methyl ethyl ketone, acetone, tetrahydrofuran, and dialkylsulphoxide. 
     
     
         3 . A process according to  claim 1  wherein the carrier (b) comprises one or more of Polyethylene glycol (PEG), Polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), hydroxypropyl cellulose, hydroxypropyl methyl-cellulose (HPMC), alginate PEG/PPG alkoxylated non-ionic surfactant, PEG/alcohol non-ionic surfactant, aromatic non-ionic surfactant, alkyl sulphonate surfactant, ether-sulphate surfactants, ester surfactant and cationic surfactant. 
     
     
         4 . A process according to  claim 1  wherein the carrier (b) comprises:
 a) at least one of: polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), poly(2-ethyl-2-oxazaline), polyvinyl alcohol (PVA) hydroxypropyl cellulose and hydroxypropyl-methyl cellulose (HPMC), alginate, and, 
 b) at least one of: alkoxylated nonionic's, phenol-ethoxylates, alkyl sulphonates (preferably SDS), ether-sulphates (preferably SLES), ester surfactants, cationics (preferably cetyltrimethylammonium bromide—CTAB). 
 
     
     
         5 . A process according to  claim 1  wherein the drying step comprises spray drying. 
     
     
         6 . A process according to  claim 1  wherein the redispersed product of the drying step has a particle size of 2-500 nm (expressed as a diameter) when measured using a Malvern™ ‘Nano-S’ apparatus. 
     
     
         7 . A process according to  claim 1  wherein the payload material has a water solubility of below 5 g/L. 
     
     
         8 . A process according to  claim 1  wherein the feedstock to the drying step has a solids content of less than 5% wt.