Metered electro-dose

• US 6,868,853 B1
• Filed: 09/18/2000
• Issued: 03/22/2005
• Est. Priority Date: 08/31/2000
• Status: Expired due to Fees

• Current Assignee: Mederio AG (Pfizer Inc.)
• Original Assignee: Microdrug AG
• Inventors: Nilsson, Lars-Gunnar, Nilsson, Thomas
• Primary Examiner(s): Bennett, Henry
• Assistant Examiner(s): PATEL, MITAL B
• Application Number:
  US09/664,385
• Time in Patent Office: 1,646 Days
• Field of Search: 128/203.15, 128/203.12, 604/58, 424/46, 424/489, 514/951, 118/621, 118/624
• US Class Current: 128/203.15
• CPC Class Codes: A61M 15/0065 Inhalators with dosage or measuring devices A61M15/0028 takes precedence; dosage devices incorporated in aerosol cans B65D83/52
• CPC Class Codes: A61M 15/02 with activated or ionised fluids, e.g. electrohydrodynamic [EHD] or electrostatic devices; Ozone-inhalators with radioactive tagged particles
• CPC Class Codes: A61M 2202/064 Powder

Abstract

An electro-dose constitutes a metered medical powder and is formed from an electro-powder constituting an active powder substance or a dry powder medical formulation being transferred onto a device member forming a dose carrier. The electro-dose prepared from an electro-powder presents a fine particle fraction (FPF) having of the order 50% or more of its content with a particle size between 0.5-5 μm. The electro-powder of such a metered electro-dose further provides electrostatic properties regarding absolute specific charge per mass after charging of the order 0.1 to 25 μC/g and presents a charge decay rate constant Q₅₀ of more than 0.1 sec with a tap density of less than 0.8 g/ml and a water activity a_w of less than 0.5. The electro-dose porosity is adjusted to obtain an optimized porosity value in percent of 75 to 99.9 calculated as 100−100×(Density_electro-dose/Density_{electro-powder}).

Claims

1. An electro-dose of a medical powder for use in a dry powder inhaler, the electro-dose having been prepared from an active powder substance or a dry powder medical formulation presenting a fine particle fraction (FPF) of the order 50% or more of its content having a particle size from 0.5 to 5 μ

m, said substance or formulation having been metered onto a device constituting a dose carrier, thereby having formed said electro-dose into a chosen state of dose porosity, the electro-dose further meeting electric specifications regarding absolute specific charge per mass after charging of the order 0.1 to 25 μ

C/g and presenting a charge decay rate constant Q₅₀ of more than 0.1 sec with a tap density of less than 0.8 g/ml and a water activity a_w of less than 0.5.

2. The electro-dose according to claim 1, said metered electro-dose having, onto a surface area of said device member which forms a dose carrier, a height less than 800 μ

m.

3. The electro-dose according to claim 1, said metered electro-dose by using mechanical vibrations of the device member having been adjusted to a porosity having in percent a value between 75 and 99.9.

4. The electro-dose according to claim 1, said metered electro-dose, by using a frequency oscillation in an electrical field, having been adjusted to a porosity having in percent a value between 75 and 99.9.