| 摘要 |
1. Process for preparing inhalable powders, characterised in that N+m substantially equal portions of a substance having a larger particle size distribution (excipient) and N equal portions of a substance having a smaller particle size distribution (active substance) are placed in alternate layers in a suitable mixing vessel and after they have all been added the 2N+m layers of the two components are mixed together using a suitable mixer, a portion of the substance having the larger particle size being put in first, while N is an integer >0, preferably >5, and m denotes 0 or 1. 2. Process according to claim 1, characterised in that the individual fractions are added in layers through a suitable screening apparatus. 3. Process according to claim 1 or 2, characterised in that m denotes the number 1. 4. Process according to one of claims 1, 2 or 3, characterised in that inhalable powders are obtained containing less than 5%, preferably less than 2% of active substance. 5. Process according to one of claims 1 to 4, characterised in that the active substance used has a particle size of from 0.5 to 10 mum, preferably from 1 to 6 mum. 6. Process according to one of claims 1 to 5, characterised in that the excipient used has a mean particle size of from 10 to 100 mum, preferably 15 to 80 mum. 7. Process according to one of claims 1 to 5, characterised in that the excipient consists of a mixture of coarser excipient with an average particle size of 15 to the proportion of finer excipient constituting 1 to 20% of the total amount of excipient. 8. Process according to one of claims 1 to 7, characterised in that the active substance present consists of one or more compounds selected from among the betamimetics, anticholinergics, corticosteroids and dopamine agonists. 9. Inhalable powder obtainable by a process according to one of claims 1 to 8. |
