Details for Patent: 8,920,781

Title:	Carrier particles for use in dry powder inhalers
Abstract:	A powder for use in a dry powder inhaler includes active particles and carrier particles for carrying the active particles. The powder further includes additive material on the surfaces of the carrier particles to promote the release of the active particles from the carrier particles on actuation of the inhaler. The powder is such that the active particles are not liable to be released from the carrier particles before actuation of the inhaler. The inclusion of additive material in the powder has been found to give an increased respirable fraction of the active material.
Inventor(s):	Staniforth; John Nicholas (Bath, GB)
Assignee:	Vectura Limited (Chippenham, Wiltshire, GB)
Filing Date:	Mar 26, 2010
Application Number:	12/748,275
Claims:	1. A powder for use in a dry powder inhaler, the powder comprising active particles and carrier particles for carrying the active particles, the powder further including particles of additive material attached to the surfaces of the carrier particles, wherein particles of additive material adhere to the high energy sites on the surfaces of the carrier particles and wherein the powder comprises more than one additive material, wherein the additive material includes one or more surface active materials; wherein additive particles are also present as agglomerates and act as carriers of the active particles and are separate from or separable from the surfaces of the carrier particles with active particles attached to surfaces of the agglomerates. 2. A powder according to claim 1 wherein the powder includes not more than 5% by weight of additive material based on the weight of the powder. 3. A powder according to claim 2 wherein the powder includes not more than 2% by weight of additive material based on the weight of the powder. 4. A powder according to 1 wherein the carrier particles are comprised of one or more crystalline sugars. 5. A powder according to claim 4 wherein the carrier particles are particles of lactose. 6. A powder according to claim 1 wherein the additive material consists of physiologically acceptable material. 7. A powder according to claim 1, wherein the additive material is an anti-adherent material. 8. A powder according to claim 1, wherein the additive material is an anti-friction agent. 9. A powder according to claim 1, wherein the additive material includes magnesium stearate. 10. A powder according to claim 1, wherein the additive particles are angular or dendritic in shape. 11. A powder according to claim 1, wherein the additive particles are plate-like particles. 12. A powder according to claim 1, wherein the powder consists of not less than 0.1% by weight of additive particles based on the weight of the carrier particles. 13. A powder according to claim 1, wherein the additive material forms a discontinuous covering on the surfaces of the carrier particles. 14. A powder according to claim 1, wherein the active particles include a .beta.2-agonist. 15. A method of producing particles according to claim 1, the method including the step of mixing carrier particles of a size suitable for use in dry powder inhalers with additive material which becomes attached to the surfaces of the carrier particles. 16. A method according to claim 15 wherein the method further includes the step of treating the carrier particles to dislodge small grains from the surfaces of the carrier particles, without substantially changing the size of the carrier particles during the treatment. 17. A method according to claim 16 wherein the small grains become reattached to the surfaces of the carrier particles. 18. A powder for use in a dry powder inhaler, the powder including additive and carrier particles for carrying the additive particles, the powder further including active particles which adhere to the additive particles on the carrier particles, wherein the additive material is magnesium stearate, wherein the additive material is present in an amount of not more than 1% by weight based on the weight of the powder; wherein additive particles are also present as agglomerates and act as carriers of the active particles and are separate from or separable from the surfaces of the carrier particles with active particles attached to surfaces of the agglomerates. 19. A powder according to claim 1, wherein the more than one additive material comprises magnesium stearate. 20. A powder according to claim 1, wherein the additive particles are non-spherical. 21. A powder according to claim 20, wherein the particles are plate-like, angular or dendritic. 22. A powder according to claim 18, wherein the additive particles are non-spherical. 23. A powder according to claim 22, wherein the particles are plate-like, angular or dendritic. 24. A powder for use in a dry powder inhaler, the powder comprising: active particles; carrier particles for carrying the active particles; and particles of additive material attached to surfaces of the carrier particles; wherein the particles of additive material adhere to high energy sites on the surfaces of the carrier particles and provide a discontinuous covering for the carrier particles, wherein the powder comprises more than one additive material in the form of a powder, and wherein the additive material includes one or more surface active materials; wherein additive particles are also present as agglomerates and act as carriers of the active particles and are separate from or separable from the surfaces of the carrier particles with active particles attached to surfaces of the agglomerates.