.

Pharmaceutical Business Intelligence

  • Anticipate P&T budget requirements
  • Evaluate market entry opportunities
  • Find generic sources and suppliers
  • Predict branded drug patent expiration

► Plans and Pricing

Upgrade to enjoy subscriber-only features like email alerts and data export. See the Plans and Pricing

DrugPatentWatch Database Preview

Details for Patent: 6,033,646

« Back to Dashboard

Details for Patent: 6,033,646

Title: Method of preparing fluorinated gas microspheres
Abstract:Lyophilized lipid compositions, as well as methods for their preparation, are embodied by the present invention. Gas-filled microspheres prepared using the lyophilized lipid composition are particularly useful, for example, in ultrasonic imaging applications and in therapeutic drug delivery systems.
Inventor(s): Unger; Evan C. (Tucson, AZ), Fritz; Thomas A. (Tucson, AZ), Matsunaga; Terry (Tucson, AZ), Ramaswami; VaradaRajan (Tucson, AZ), Yellowhair; David (Tucson, AZ), Wu; Guanli (Tucson, AZ)
Assignee: ImaRx Pharmaceutical Corp. (Tucson, AZ)
Filing Date:Feb 19, 1998
Application Number:09/026,326
Claims:1. A method for preparing a fluorine-containing gas-filled microsphere comprising:

a. reconstituting the lipids dipalmitoylphosphatidylcholine, dipalmitoylphosphatidylethanolaminepolyethylene glycol, and dipalmitoylphosphatidic acid in a ratio of about 70 to about 90 mole %, about 5 to about 15 mole %, and about 5 to about 15 mole %, respectively, in an aqueous solution to a concentration of about 20 mg/ml to about 50 mg/ml to form a lipid-containing aqueous solution;

b. lyophilizing said lipid-containing aqueous solution to form a lyophilized composition such that the dipalmitoylphosphatidylcholine, dipalmitoylphosphatidylethanolamine-polyethylene glycol, and dipalmitoylphosphatidic acid ratio of about 70 to about 90 mole %, about 5 to about 15 mole %, and about 5 to about 15 mole %, respectively, is uniform throughout the composition;

c. dispersing said lyophilized composition in an aqueous-based pharmaceutically acceptable carrier to a concentration of about 0.1 mg/ml to about 5 mg/ml to form an aqueous microsphere-forming solution;

d. introducing a fluorine-containing gas into said aqueous microsphere-forming solution; and

e. shaking said aqueous microsphere-forming solution to form a microsphere filled with fluorine-containing gas.

2. The method of claim 1 wherein the shaking step comprises vortexing.

3. The method of claim 1 further comprising the steps of filtering said aqueous microsphere-forming solution.

4. The method of claim 1 further comprising extruding the aqueous microsphere-forming solution through at least one filter of a selected pore size.

5. The method of claim 4 wherein the pore size is about 10 .mu.m or smaller.

6. The method as in claim 4 wherein the pore size is about 0.22 .mu.m.

7. The method of claim 1 further comprising heating said aqueous microsphere-forming solution.

8. The method of claim 4 further comprising dispersing said aqueous microsphere-forming solution into at least one vessel.

9. The method of claim 1 wherein step d. comprises placing a vessel containing said aqueous microsphere-forming solution in a chamber and introducing a fluorine-containing gas into said chamber, and step e. comprises shaking said vessel to form a microsphere filled with flourine-containing gas.

10. The method of claim 9 further comprising pressurizing said vessel.

11. The method of claim 1 wherein step d. comprises placing a vessel containing said aqueous microsphere-forming solution in a pressurized chamber, evacuating the chamber of gas, and filling the chamber with a fluorine-containing gas such that the head space of the vessel is filled with a fluorine-containing gas and step e. comprises shaking said vessel to form a microsphere filled with a fluorine-containing gas.

12. The method of claim 1 wherein said aqueous solution is selected from the group consisting of water, physiological saline, and normal saline.

13. The method of claim 1 wherein said pharmaceutically acceptable carrier is selected from the group consisting of a mixture of water, glycerol, and propylene glycol and a mixture of saline, glycerol, and propylene glycol in a ratio of 8:1:1, v:v:v, respectively.

14. The method of claim 1 wherein step d. comprises placing a vessel containing said aqueous microsphere-forming solution in a chamber and introducing a perfluorocarbon, and step e. comprises shaking said vessel to form a perfluorocarbon-containing microsphere.

15. The method of claim 14 wherein step d. comprises placing a vessel containing said aqueous microsphere-forming solution in a chamber and introducing a perfluorocarbon selected from the group consisting of perfluoropropane and perfluorobutane into said chamber, and step e. comprises shaking said vessel to form a perfluorocarbon-containing microsphere.

16. The method of claim 1 wherein step d. comprises placing a vessel containing said aqueous microsphere-forming solution in a pressurized chamber, evacuating the chamber of gas, and filing the chamber with a perfluorocarbon such that the head space of the vessel is filled with a perfluorocarbon, and step e. comprises shaking said vessel to form a perfluorocarbon-containing microsphere.

17. The method of claim 16 wherein step d. comprises placing a vessel containing said aqueous microsphere-forming solution in a pressurized chamber, evacuating the chamber of gas, and filing the chamber with a perfluorocarbon selected from the group consisting of perfluoropropane and perfluorobutane such that the head space of the vessel is filled with a perfluorocarbon, and step e. comprises shaking said vessel to form a perfluorocarbon-containing microsphere.

18. The method of claim 1 wherein said fluorine-containing gas is selected from the group consisting of sulfur hexafluoride and a perfluorocarbon.

19. The method of claim 18 wherein said perfluorocarbon gas is selected from the group consisting of perfluoropropane, perfluoropentane, perfluorohexane, and perfluorobutane.

20. A method of claim 1 wherein said lipids comprise a monolayer.

21. A method of claim 20 wherein said gas is selected from the group consisting of sulfur hexafluoride and a perfluorocarbon.

22. A method of claim 21 wherein said perfluorocarbon is selected from the group consisting of perfluorobutane, perfluoropropane, perfluoropentane, and perfluorohexane.
« Back to Dashboard

For more information try a trial or see the database preview and plans and pricing

How are People Using DrugPatentWatch?

Drugs may be covered by multiple patents or regulatory protections. All trademarks and applicant names are the property of their respective owners or licensors. Although great care is taken in the proper and correct provision of this service, thinkBiotech LLC does not accept any responsibility for possible consequences of errors or omissions in the provided data. The data presented herein is for information purposes only. There is no warranty that the data contained herein is error free. thinkBiotech performs no independent verifification of facts as provided by public sources nor are attempts made to provide legal or investing advice. Any reliance on data provided herein is done solely at the discretion of the user. Users of this service are advised to seek professional advice and independent confirmation before considering acting on any of the provided information. thinkBiotech LLC reserves the right to amend, extend or withdraw any part or all of the offered service without notice.

`abc