Pulmonary insulin crystals

Abstract

The present invention provides methods and compositions for treating diabetes by administering acylated insulin or an acylated insulin analog via a pulmonary route. The insulin or insulin analog may be in the form of a dry powder or a solution.

1 . Zinc free insulin crystals having a diameter below 10 μm.  
     
     
         2 . Zinc free insulin crystals according to    claim 1    having a crystal structure belonging to the cubic crystal system.  
     
     
         3 . Zinc free insulin crystals according to    claim 2    in the octadecahedral or dodecahedral crystal forms.  
     
     
         4 . Zinc free insulin crystals according to any one of the preceding claims having a diameter in the range of 0.2 to 5 μm, preferably in the range of 0.2 to 2 μm, more preferably in the range of 0.5 and 1 μm.  
     
     
         5 . Zinc free insulin crystals according to any one of the preceding claims wherein the insulin is selected from the group consisting of human insulin, bovine insulin, porcine insulin, des(B30) human insulin, Asp B28  human insulin, Lys B28 Pro B29  human insulin, Lys B28 (N-ε acylated)-Pro B29  human insulin, Lys B29 (N-ε acylated) human insulin, or Lys B29 (N-ε acylated) des(B30) human insulin.  
     
     
         6 . Zinc free insulin crystals according to    claim 5    wherein the insulin is human insulin.  
     
     
         7 . Zinc free insulin crystals according to    claim 5    wherein the insulin is Ly B29 (N-ε acylated) des(B30) human insulin.  
     
     
         8 . Zinc free insulin crystals according to any one of the preceding claims wherein the insulin has been purified by chromatography, preferably MC® insulin, Single Peak® insulin or RI® insulin.  
     
     
         9 . A therapeutic powder formulation suitable for pulmonary administration comprising the zinc free crystals according to any one of the preceding claims.  
     
     
         10 . A therapeutic powder formulation according to    claim 9    which further comprises an enhancer which enhances the absorption of insulin in the lower respiratory tract.  
     
     
         11 . A therapeutic powder formulation according to    claim 10    wherein the enhancer is a surfactant.  
     
     
         12 . A therapeutic powder formulation according to    claim 11    wherein the surfactant is a salt of a fatty acid, a bile salt or a phospholipid, preferably a bile salt.  
     
     
         13 . A therapeutic powder formulation according to    claim 12    wherein the surfactant is a salt of taurocholate, preferably sodium taurocholate.  
     
     
         14 . A therapeutic powder formulation according to anyone of    claims 9    to    13    which further comprises a carrier, preferably selected from the group consisting of trehalose, raffinose, mannitol, sorbitol, xylitol, inositol, sucrose, sodium chloride and sodium citrate.  
     
     
         15 . A method for the preparation of zinc free insulin crystals according to any of the    claims 1    to    8   , comprising the steps of: 
 a) providing a solution of insulin having a pH between 7.0 and 9.5;  
 b) mixing said solution with a solution of a salt of an alkali metal or an ammonium salt; and  
 c) recovering the formed crystals.  
 
     
     
         16 . A method according to    claim 15   , wherein the salt of an alkali metal or ammonium is selected from the group consisting of the hydrochloride or acetate of sodium, potassium, lithium or ammonia, or mixtures thereof, preferable sodium acetate.  
     
     
         17 . A method according to    claim 15    or    16   , wherein the solution of insulin and/or the solution of a salt of an alkali metal or an ammonium salt comprises a water miscible organic solvent in an amount which corresponds to 5 to 25% (v/v) in the solution obtained after mixing.  
     
     
         18 . A method according to any one of    claims 15    to    17   , wherein the water miscible organic solvent is selected from the group consisting of ethanol, methanol, acetone and 2-propanol, preferably ethanol.  
     
     
         19 . A method according to any one of    claims 15    to    18   , wherein the two solutions are mixed within a period of less than 2 hours, preferably less than 1 hour, more preferably less than 15 minutes, still more preferably less than 5 minutes.  
     
     
         20 . A method according to any one of    claims 15    to    19   , wherein the concentration of insulin after mixing is between 0.5% and 10%, preferably between 0.5% and 5%, more preferably between 0.5% and 2%.  
     
     
         21 . A method according to any one of    claims 15    to    20   , wherein the concentration of salt after mixing is between 0.2 M and 2 M, preferably about 1 M.  
     
     
         22 . A method according to any one of    claims 15    to    21   , which further comprises a washing step, in which the crystals obtained are washed with a solution comprising auxiliary substances to be included in the final dry powder, preferably an enhancer and/or a carbohydrate, and optionally comprising 5-25% of an alcohol, preferably ethanol, 5-50 mM of a preservative preferably phenol, and 0.1-2 M of a salt such as sodium acetate.  
     
     
         23 . Use of zinc free crystals according to any one of the    claims 1    to    8    for the manufacture of a therapeutic powder formulation suitable for pulmonary administration in the treatment in diabetes mellitus.  
     
     
         24 . A method of treating diabetes mellitus comprising administering to a person in need of such treatment an effective amount of a therapeutic powder formulation according to any one of the    claims 9    to    14   .