Powders comprising anti-adherent materials for use in dry powder inhalers
A powder for use in a dry powder inhaler comprises active material and additive material. The additive material comprises an anti-adherent material and the powder includes at least 60% by weight of active material. The inclusion of the additive material in the powder has been found to give an increased respirable fraction of the active material.
1 . A powder for use in a dry powder inhaler, the powder comprising additive material and particles comprising active material, the additive material comprising an anti-adherent material and forming at least a partial covering on the surfaces of particles comprising active material so that cohesion and adhesion of the powder is reduced; wherein the powder includes at least 60% by weight of active material based on the weight of the powder.
2 . A powder according to claim 1 , wherein the reduction in powder cohesion and adhesion improves the respirable fraction of the powder.
3 . A powder according to claim 1 , wherein the powder comprises agglomerates of particles, the agglomerates having a size of at least 45 μm, and wherein the agglomerates break up upon actuation of the inhaler so that particles comprising active material are of a size suitable for delivery to the lower lung.
4 . A powder according to claim 1 , wherein the powder comprises at least 0.1% by weight of additive material based on the weight of the powder.
5 . A powder according to claim 1 , wherein the the powder comprises not more than 10% by weight of additive material based on the weight of the powder.
6 . A powder according to claim 5 , wherein the powder comprises not more than 8% by weight of additive material based on the weight of the powder.
7 . A powder according to claim 1 , wherein the powder comprises at least 80% by weight of active material based on the weight of the powder.
8 . A powder according to claim 1 , wherein at least 95% by weight of the particles comprising active material have a particle size less than 10 μm.
9 . A powder according to claim 7 , wherein at least 95% by weight of the particles comprising active material have a particle size between about 0.1 μm and 5 μm.
10 . A powder according to claim 1 wherein at least 90% by weight of the particles of the powder have a particle size of less than 63 μm.
11 . A powder according to claim 1 , wherein the powder includes less than 20% by weight of constituents other than the active material and the anti-adherent material.
12 . A powder according to claim 1 , wherein the additive material includes one or more compounds selected from the group consisting of amino acids and derivatives thereof, peptides and polypeptides having a molecular weight of between about 0.25 to 1000 kDa, and derivatives thereof.
13 . A powder according to claim 12 , wherein the additive material is selected from the group consisting of leucine, isoleucine, lysine, valine, methionine, cysteine, pheylalanine and derivatives thereof.
14 . A powder according to claim 1 , wherein the additive material includes one or more water soluble compounds.
15 . A powder according claim 14 , wherein the additive material is lecithin.
16 . A powder according to claim 1 , wherein the additive material includes dipolar ions.
17 . A powder according to claim 16 , wherein the additive material includes zwitterions.
18 . A powder according claim 1 , wherein the additive material includes a glidant material.
19 . A powder according to claim 1 , wherein the active material includes one or more materials selected from the group consisting of peptides and polypeptides β 2- agonists, steroids, cromones, leukotriene receptor antagonists, and carbohydrates.
20 . A powder according to claim 1 , wherein the additive material is in the form of particles.
21 . A dry powder inhaler including a powder according to claim 1 .
22 . A method of forming a powder according to claim 1 , wherein the active material and additive material are co-spray dried.
23 . A method according to claim 22 , wherein the additive material is selected from the group consisting of leucine, a derivative of leucine and lecithin.
24 . A method according to claim 23 , wherein the active material is heparin.
25 . A method according to claim 1 , wherein the active material and additive material are co-micronised.
26 . A method according to claim 25 , wherein the additive material is selected from the group consisting of leucine, a derivative of leucine and lecithin.
27 . A method according to claim 26 , wherein the active material is heparin.
28 - 36 . (canceled)