Method of drug formulation based on increasing the affinity of crystalline microparticle surfaces for active agents

• US 7,799,344 B2
• Filed: 09/14/2006
• Issued: 09/21/2010
• Est. Priority Date: 09/14/2005
• Status: Active Grant

• Current Assignee: Mannkind Corporation
• Original Assignee: Mannkind Corporation
• Inventors: Oberg, Keith A.
• Primary Examiner(s): Ha; Julie
• Application Number:
  US11/532,063
• Publication Number:
  US 20070059373A1
• Time in Patent Office: 1,468 Days
• Field of Search: None
• US Class Current: 424/489
• CPC Class Codes: A61K 38/13 Cyclosporins
• CPC Class Codes: A61K 38/22 Hormones derived from pro-opiomelanocortin, pro-enkephalin or pro-dynorphin A61K38/33, e.g. corticotropin A61K38/35
• CPC Class Codes: A61K 38/25 Growth hormone-releasing factor [GH-RF], i.e. somatoliberin
• CPC Class Codes: A61K 38/26 Glucagons
• CPC Class Codes: A61K 38/27 Growth hormone [GH], i.e. somatotropin
• CPC Class Codes: A61K 38/28 Insulins
• CPC Class Codes: A61K 38/29 Parathyroid hormone, i.e. parathormone; Parathyroid hormone-related peptides
• CPC Class Codes: A61K 9/0073 Sprays or powders for inhalation; Aerolised or nebulised preparations generated by other means than thermal energy; nasal sprays A61K9/0043; inhalation of vapours of volatile or heated drugs, e.g. essential oils or nicotine, A61K9/007; devices A61M
• CPC Class Codes: A61K 9/1611 Inorganic compounds
• CPC Class Codes: A61K 9/1617 Organic compounds, e.g. phospholipids, fats
• CPC Class Codes: A61K 9/1623 Sugars or sugar alcohols, e.g. lactose; Derivatives thereof; Homeopathic globules
• CPC Class Codes: A61K 9/167 with an outer layer or coating comprising drug; with chemically bound drugs or non-active substances on their surface with further drug-free outer coating A61K9/5073
• CPC Class Codes: A61K 9/1676 having a drug-free core with discrete complete coating layer containing drug adsorbates of liquid drug formulations on inert powders without simultaneous granulation step A61K9/141; with further drug-free outer coating A61K9/5078; drug conjugated to non-active particles A61K47/6921
• CPC Class Codes: A61K 9/5052 Proteins, e.g. albumin
• CPC Class Codes: A61K 9/5089 Processes
• CPC Class Codes: A61P 25/00 Drugs for disorders of the nervous system
• CPC Class Codes: A61P 3/00 Drugs for disorders of the metabolism of the blood or the extracellular fluid A61P7/00
• CPC Class Codes: A61P 31/00 Antiinfectives, i.e. antibiotics, antiseptics, chemotherapeutics
• CPC Class Codes: A61P 31/12 Antivirals
• CPC Class Codes: A61P 35/00 Antineoplastic agents
• CPC Class Codes: A61P 37/00 : Drugs for immunological or allergic disorders
• CPC Class Codes: A61P 37/04 : Immunostimulants
• CPC Class Codes: A61P 5/18 : of the parathyroid hormones
• CPC Class Codes: A61P 5/48 : of the pancreatic hormones
• CPC Class Codes: A61P 5/50 : for increasing or potentiating the activity of insulin
• CPC Class Codes: A61P 7/02 : Antithrombotic agents; Anticoagulants; Platelet aggregation inhibitors

Abstract

Methods are provided for coating crystalline microparticles with an active agent by altering the surface properties of the microparticles in order to facilitate favorable association on the microparticle by the active agent. Type of surface properties that are altered by the disclosed methods include by electrostatic properties, hydrophobic properties and hydrogen bonding properties.

Claims

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.