|Title:|| Dispersible macromolecule compositions and methods for their preparation and use|
|Abstract:||A process for preparing ultrafine powders of biological macromolecules comprises atomizing liquid solutions of the macromolecules, drying the droplets formed in the atomization step, and collecting the particles which result from drying. By properly controlling each of the atomization, drying, and collection steps, ultrafine dry powder compositions having characteristics particularly suitable for pulmonary delivery for therapeutic and other purposes may be prepared.|
|Inventor(s):|| Platz; Robert M. (Half Moon Bay, CA), Brewer; Thomas K. (Walnut Creek, CA), Boardman; Terence D. (Palo Alto, CA) |
|Assignee:|| Inhale Therapeutic Systems (San Carlos, CA) |
1. A method for preparing dispersible dry powders of biological macromolecules, said method comprising:
providing an evaporable liquid medium containing a predetermined concentration of the macromolecule and excipients, wherein the macromolecule is a protein having a molecular weight above 2 kD and is present at a concentration below 10% by weight
and wherein the liquid medium is an aqueous medium consisting essentially of water, the macromolecule, and the excipients;
flowing the liquid medium and an atomization gas stream at a gas:liquid mass flow ratio above 5 under conditions selected to form droplets having an average size below 11 .mu.m;
flowing the droplets in a heated gas stream under conditions selected to form dispersible particles of the composite material containing the biological macromolecules, said particles having a moisture content below 10% by weight and a rugosity
measured by air permeametry above 2, and collecting the particles.
2. A method as in claim 1, wherein the total solids content in the liquid medium is in the range from 0.5% to 10% by weight.
3. A method as in claim 2, wherein the concentration of macromolecule is in the range from 1% to 5% by weight.
4. A method as in claim 1, wherein the aqueous medium consists essentially of the macromolecule and the excipients.
5. A method as in claim 1, wherein the average droplet size is in the range from 5 .mu.m to 11 .mu.m.
6. A method as in claim 1, wherein the flowing step comprises flowing the liquid medium and an atomization gas stream through a two fluid nozzle.
7. A method as in claim 6, wherein the gas:liquid mass flow ratio is in the range from 8 to 10.
8. A method as in claim 6, wherein the fluid nozzle has a liquid orifice diameter in the range from 0.015 in. to 0.075 in. and wherein the air pressure upstream of the orifice is maintained above 25 psi.
9. A method as in claim 1, wherein the droplets are flowed concurrently with the gas stream and wherein the gas stream has an temperature above 90.degree. C.
10. A method as in claim 9, wherein the gas stream has an inlet temperature above 90.degree. C. and an outlet temperature above 50.degree. C.
11. A method as in claim 1, wherein the droplets are dried under conditions selected to provide particles having a rugosity measured by air permeability in the range from 3 to 6.
12. A method as in claim 1, wherein the drying step produces a powder having at least 90% of the mass of particles in the size range from 0.4 .mu.m to 5 .mu.m and the particle collecting step comprises separating substantially the entire
particle output of the drying step from the gas stream.
13. A method as in claim 1, further comprising packaging at least some of particles in a container after the separating step, wherein the particles have not been size classified prior to packaging.
14. A method as in claim 13, wherein the portion is packaged in a unit dosage container.
15. A method as in claim 1, wherein the particle separating step comprises passing substantially the entire gas stream through a separator which removes at least about 90% by weight of all particles having a size above 1 .mu.m from said gas
16. A method as in claim 15, wherein the separator is a sintered metal fiber filter.
17. A method as in claim 15, wherein the separator is a bag filter, cartridge filter, or cloth filter.
18. A method as in claim 15, wherein the separator is a high efficiency cyclone.
19. A method as in claim 1, wherein the macromolecule is a protein selected from the group consisting of calcitonin; erythropoietin (EPO); factor IX; granulocyte colony stimulating factor (G-CSF), granulocyte macrophage colony stimulating
factor (GM-CSF); growth hormone; insulin; interferon alpha, interferon beta; interferon gamma; interleukin-2; luteinizing hormone releasing hormone (LHRH); somatostatin analog; vasopressin analog; follicle stimulating hormone (FSH); amylin;
ciliary neurotrophic factor;, growth hormone releasing factor (GRF); insulin-like growth factor; insulinotropin; interleukin-1 receptor antagonist; interleukin-3, interleukin-4; interleukin-6; macrophage colony stimulating factor (M-CSF); nerve
growth factor; parathyroid hormone; thymosin alpha 1; factor IIb/IIIa inhibitor; alpha-1 antitrypsin; anti-RSV antibody; deoxyribonuclease (DNase); bactericidal/permeability increasing protein (BPI); anti-CMV antibody; interleukin-1 receptor;
and interleukin-1 receptor antagonist.
20. A macromolecule composition prepared by the method of any of claims 1-8 or 11-19.