Polysaccharide microparticles containing biological agents: their preparation and applications

• US 8,932,633 B2
• Filed: 07/20/2006
• Issued: 01/13/2015
• Est. Priority Date: 08/29/2005
• Status: Active Grant

• Current Assignee: Biodvery Pharmatech, Ltd.
• Original Assignee: BioPharm Solutions, Inc.
• Inventors: Jin, Tuo, Wu, Fei, Yuan, Weien
• Primary Examiner(s): Krass, Frederick
• Assistant Examiner(s): Shomer, Isaac
• Application Number:
  US12/065,310
• Publication Number:
  US 20080248098A1
• Time in Patent Office: 3,099 Days
• Field of Search: None
• US Class Current: 424/489
• CPC Class Codes: A61K 39/00 Medicinal preparations containing antigens or antibodies materials for immunoassay G01N33/53
• CPC Class Codes: A61K 9/0024 Solid, semi-solid or solidifying implants, which are implanted or injected in body tissue compositions for intravenous administration, normal injectable solutions or dispersions for, e.g. subcutaneous administration A61K9/0019; brain implants A61K9/0085; (coated) prostheses, catheters or stents A61L
• CPC Class Codes: A61K 9/1623 Sugars or sugar alcohols, e.g. lactose; Derivatives thereof; Homeopathic globules
• CPC Class Codes: A61K 9/1647 Polyesters, e.g. poly(lactide-co-glycolide)
• CPC Class Codes: A61K 9/1652 Polysaccharides, e.g. alginate, cellulose derivatives; Cyclodextrin homeopathic globules A61K9/1623
• CPC Class Codes: A61K 9/1694 resulting in granules or microspheres of the matrix type containing more than 5% of excipient
• CPC Class Codes: A61K 9/19 lyophilised , i.e. freeze-dried, solutions or dispersions lyophilised products with subsequent particle size reduction A61K9/14; granules or pellets made by lyphilisation A61K9/1682; solid oral dosage forms made by lyophilisation A61K9/2095; lyophilisation additives A61K47/00
• CPC Class Codes: A61K 9/7007 Drug-containing films, membranes or sheets A61K9/0041, A61K9/0043, A61K9/006, A61K9/0063 take precedence
• CPC Class Codes: A61L 27/48 with macromolecular fillers
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61L 31/129 containing macromolecular fillers
• CPC Class Codes: A61P 43/00 Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00

Abstract

A method of preparing polysaccharide glassy microparticles which are less than 10 μum in diameter and contain structurally delicate agents, such as proteins, peptides, gene materials, vaccines, antibodies, viruses and liposomes using low-temperature aqueous-aqueous emulsification (free of polyelectrolytes) and freezing-induced phase separation. When delicate agents are added to a polysaccharide-PEG two phase system followed by homogenization (or other shear adding process), the agents partition into the polysaccharide dispersed phase preferentially. These processes help to avoid aggregation of proteins caused by interaction with charged polyelectrolytes used for stabilizing the polysaccharide dispersed phase in our previously reported aqueous-aqueous emulsion. When this system is frozen and lyophilized, glassy particles less than 10 μm in diameter containing delicate agents can be formed. These fine polysaccharide particles protect proteins within their hydrophilic glassy matrix, and can therefore be easily suspended in hydrophobic polymer solutions and formulated to various forms of sustained release devices such microsphere, sheets, fibers, coating layers, and scaffolds. The particles can also be dispersed in hydrophilic gels to improve releasing kinetics and to deliver vaccines and antibodies for immune therapy.

Claims

1. A method of preparing polysaccharide glassy particles comprising bioactive biological agents without using surface active agents, the method comprising the steps of:

a) preparing a single-phase aqueous solution consisting of a polysaccharide, a soluble polymer, a bioactive biological agent, and optionally either a sugar or glycerol to stabilize the biological agent during lyophilization;

b) freezing the aqueous solution prepared in step a) gradually, wherein the polysaccharide undergoes freezing-induced phase separation out from the solution;

c) lyophilizing the frozen solution in step b) to powders;

d) suspending the powder prepared in step c) in an organic solvent which dissolves the soluble polymer but not the polysaccharide;

e) removing the supernatant of the suspension in step d) and collecting the remaining polysaccharide glassy particles.

2. The method of claim 1, wherein the biological agents are selected from the group consisting of proteins, peptides, DNA, RNA, vaccines, antibodies, and viruses.

3. The method of claim 1, wherein the polysaccharide is selected from the group consisting of dextran, starch, cellulose, and derivatives of dextran or cellulose.

4. The method of claim 1, wherein the soluble polymer is selected from the group consisting of polyethylene glycol (PEG), polyethylene oxide (PEO), poly(N-vinylpyrrolidone) (PVP) and polyvinyl alcohol (PVA).

5. The method of claim 1, wherein the sugar is selected from trehalose, mannitol, sucrose, lactose, and maltose.

6. The method of claim 1, wherein the concentration of the sugar is 1 w/w % in the aqueous solution.