Pharmaceutical compositions

Abstract

The present invention provides a solid composition for oral administration comprising: (i) a drug compound; (ii) chitosan or a derivative thereof or a salt of chitosan or salt of a derivative of chitosan; and (iii) an organic acid. Preferably the drug compound is a polar molecule having a molecular weight of 1 KDa or less, a peptide, a protein or a polysaccharide. The compositions of the invention provide enhance absorption of the drug compound.

1 . A solid composition for oral administration comprising: 
 (i) a drug compound;    (ii) chitosan or a derivative thereof or a salt of chitosan or a salt of a derivative of chitosan; and    (iii) an organic acid wherein at least part of the acid is in the form of an agglomerate.    
   
   
       2 . A composition according to  claim 1 , wherein the acid is lactic, glutamic, succinic, tartaric, citric, fumaric or propionic acid.  
   
   
       3 . A composition according to  claim 2 , wherein the acid is succinic acid.  
   
   
       4 . A composition according to  claim 1 , wherein the acid agglomerate is in the form of a granule, a pellet, a tablet or an acid particle engineered to a specific size.  
   
   
       5 . A composition according to  claim 1 , wherein the acid agglomerate is coated with a material which modifies its dissolution properties.  
   
   
       6 . A composition according to  claim 1 , wherein chitosan is present in the form of chitosan base.  
   
   
       7 . A composition according to  claim 1 , wherein the drug compound is a polar molecule having a molecular weight of 1 KDa or less, a peptide, a protein or a polysaccharide.  
   
   
       8 . A composition according to  claim 7 , wherein the drug compound is a bisphosphonate, a nucleoside analogue antiviral drug, or an oligonucleotide.  
   
   
       9 . A composition according to  claim 8 , wherein the bisphosphonate is clodronate, alendronate, etidronate, pamidronate or residronate.  
   
   
       10 . A composition according to  claim 8 , wherein the nucleoside analogue antiviral drug is aciclovir.  
   
   
       11 . A composition according to  claim 7 , wherein the peptide is octreotide, insulin, glucagon, a calcitonin, parathyroid hormone or a derivative thereof, ADH (vasopressin) or an analogue thereof or a GnRH agonist.  
   
   
       12 . A composition according to  claim 7 , wherein the protein is a growth hormone, an interferon, erythropoetin, an interleukin, GM-CSF or G-CSF.  
   
   
       13 . A composition according to  claim 7 , wherein the polysaccharide is heparin or a low molecular weight heparin.  
   
   
       14 . A composition according to  claim 1 , wherein the acid and the chitosan are present in a weight ratio of from 6:1 to 1:1.  
   
   
       15 . A composition according to  claim 1  coated with a material that prevents the drug compound and chitosan or a derivative thereof or a salt of chitosan or a salt of a derivative of chitosan from being released, after administration, until the composition reaches the target site of drug absorption.  
   
   
       16 . A composition according to  claim 1  in the form of a compressed tablet, a moulded tablet, a hard shell capsule or a soft shell capsule.  
   
   
       17 . The use of chitosan or a derivative thereof or a salt of chitosan or a salt of a derivative of chitosan and an organic acid, wherein at least a part of the acid is in the form of an agglomerate, to enhance the absorption of a drug compound that is a polar molecule having a molecular weight of 1 KDa or less, a peptide, a protein or a polysaccharide, following oral administration of the drug.  
   
   
       18 . The use of chitosan or a derivative thereof or a salt of chitosan or a salt of a derivative of chitosan and an organic acid, wherein at least a part of the acid is in the form of an agglomerate, in the manufacture of a medicament for the oral administration of a drug compound that is a polar molecule having a molecular weight of 1 KDa or less, a peptide, a protein or a polysaccharide.  
   
   
       19 . A process for preparing a composition according to  claim 1 , which process comprises: 
 (i) mixing the drug compound with chitosan or a derivative thereof or a salt of chitosan or a salt of a derivative of chitosan and the acid; or    (ii) incorporating the drug into agglomerates with the acid and mixing the agglomerates with chitosan or a derivative thereof or a salt of chitosan or a salt of a derivative of chitosan; or    (iii) forming agglomerates of the drug compound and mixing these agglomerates with the acid and chitosan or a derivative thereof or a salt of chitosan or a salt of a derivative of chitosan; or    (iv) forming agglomerates of the drug compound with chitosan or a derivative thereof or a salt of chitosan or a salt of a derivative of chitosan and mixing these agglomerates with the acid.