Granted Patent B2

US 7,799,344 · App. 11/532,063 · Granted Sep 21, 2010

Abstract

Claims (34)

1. A method for coating a preformed crystalline microparticle with an active agent in a suspension, said method comprising the steps in the sequence set forth of:

i) obtaining a preformed crystalline diketopiperazine microparticle wherein said preformed crystalline diketopiperazine microparticle does not comprise an active agent;

ii) providing a suspension comprising said preformed crystalline diketopiperazine microparticle, said active agent, and a solvent;

iii) then altering suspension conditions in said provided suspension to modify an energetic interaction between said active agent and said preformed crystalline diketopiperazine microparticle wherein said altering suspension conditions is selected from the group consisting of altering the pH of the solvent, adding monovalent or multivalent ions, altering the polarity, and adding hydrogen bond donors or acceptors to modify a surface property of said preformed crystalline diketopiperazine microparticle wherein said altering step does not include a step of removing said solvent from said suspension; and

iv) adsorbing said active agent onto a surface of said preformed crystalline diketopiperazine microparticle to provide a coating of said active agent on said crystalline microparticle without removing solvent from said suspension; wherein said altering step causes said adsorbing of said active agent onto a surface of said preformed crystalline diketopiperazine microparticle.

2. The method of claim 1 further comprising the step of removing or exchanging said solvent after said adsorbing step.

3. The method of claim 1 wherein said modified surface property comprises an electrostatic property.

4. The method of claim 1 wherein said modified surface property comprises a hydrophobic property.

5. The method of claim 1 wherein altering suspension conditions comprises altering the pH of said suspension.

6. The method of claim 1 wherein altering suspension conditions comprises adding monovalent or multivalent ions.

7. The method of claim 1 wherein altering suspension conditions comprises altering the polarity.

8. The method of claim 1 wherein altering suspension conditions comprises adding hydrogen bond donors or acceptors thereby modifying a surface property of said crystalline microparticle.

9. The method of claim 1 wherein said diketopiperazine crystalline microparticle comprises fumaryl diketopiperazine.

10. The method of claim 1 wherein said adsorbing produces a monolayer of said active agent on a surface of said crystalline microparticle.

11. The method of claim 1 wherein said adsorbing produces a continuous monolayer of said active agent on a surface of said crystalline microparticle.

12. The method of claim 1 wherein said active agent comprises insulin, an insulin analog, or combinations thereof.

13. The method of claim 1 wherein said crystalline microparticle comprises pores and comprises interior surfaces accessible to said solvent.

14. The method of claim 10 or 11 wherein said active agent in said monolayer has a preferred orientation.

15. A method for coating a preformed crystalline microparticle with insulin in a suspension, said method comprising the steps in the sequence set forth of:

i) dissolving said insulin in a solvent, wherein said insulin comprises insulin, an insulin analog or combinations thereof;

ii) obtaining a preformed crystalline diketopiperazine microparticle wherein said preformed crystalline diketopiperazine microparticle does not comprise an active agent;

iii) forming a suspension comprising said preformed crystalline diketopiperazine microparticle, said insulin, and said solvent;

iv) then altering suspension conditions in said provided suspension to modify the energetic interaction between said insulin and said crystalline microparticle wherein said altering step modifies a surface property of said crystalline microparticle;

v) adsorbing said active agent onto a surface of said crystalline diketopiperazine microparticle to provide a coating of said active agent on said crystalline diketopiperazine microparticle without removing solvent from said suspension and wherein said altering step causes said adsorption of insulin onto a surface of said crystalline microparticle; and

vi) removing or exchanging said solvent after said adsorbing step.

16. The method of claim 15 wherein altering suspension conditions comprises altering the pH of said suspension.

17. A method for coating a preformed crystalline microparticle with insulin in a suspension, said method comprising the steps in the sequence set forth of:

i) dissolving said insulin in a solvent, wherein said insulin comprises insulin, an insulin analog or combinations thereof;

ii) obtaining a preformed crystalline diketopiperazine microparticle in a suspension, wherein said preformed crystalline diketopiperazine microparticle does not comprise an active agent;

iii) altering suspension conditions in said preformed crystalline diketopiperazine microparticle suspension wherein said altering step modifies a surface property of said crystalline microparticle;

iv) then forming a suspension comprising said surface-modified preformed crystalline diketopiperazine microparticle, said insulin, and said solvent wherein said altering step has modified the energetic interaction between said insulin and said crystalline microparticle;

v) then adsorbing said active agent onto a surface of said crystalline microparticle to provide a coating of said active agent on said crystalline microparticle without removing solvent from said suspension and wherein said altering step causes said adsorption of insulin onto a surface of said crystalline microparticle; and

vi) removing or exchanging said solvent after said adsorbing step.

18. The method of claim 17 wherein said altering step comprises altering the pH of said suspension.

Assignments (8)