Patent ID: 7718163

Claim:
A method of preparing a powder for use in a dry powder inhaler, the powder comprising active particles, carrier particles for carrying active particles, and particles of additive material; said method comprising: (a) mixing carrier particles of a size suitable for use in dry powder inhalers with particles of additive material, so that the particles of additive material become attached to the surfaces of the carrier particles; and then (b) mixing active particles with the carrier particles and additive material from step (a), so that the active particles adhere to the surfaces of the carrier particles and/or additive material; wherein the additive material is a physiologically acceptable material and promotes the release of the active particles from the carrier particles on actuation of the inhaler, wherein some of the particles of additive material may act as carriers of active particles and may be separate from or may separate from the surfaces of the carrier particles with active particles attached to their surfaces, and wherein the powder has a post-vibration homogeneity measured as a percentage coefficient of variation of less than about 5%.