# US 9,517,268 B2 · Process for producing inorganic particulate material

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- Number: US 9,517,268 B2
- Document ID: US9517268B2
- Status: Granted
- Kind: B2
- Application number: 14/117,041
- Filed: 2012-04-25
- Published: 2014-11-13
- Granted: 2016-12-13
- Earliest claimed: 2011-05-13
- Assignees: Merck Patent GmbH
- Applicants: Mario Maio; Eugenia Breininger; Karin Cabrera Perez; Ulrich Lang; Benjamin Peters; Thomas Puchert; Christoph Saal; Michael Schulz
- Inventors: Mario Maio; Eugenia Breininger; Karin Cabrera Perez; Ulrich Lang; Benjamin Peters; Thomas Puchert; Christoph Saal; Michael Schulz
- Web page: https://patentgrep.com/patent/US9517268B2

## CPC

- A61K 47/02: Inorganic compounds
- A61K 31/496: Non-condensed piperazines containing further heterocyclic rings, e.g. rifampin, thiothixene or sparfloxacin
- A61P 31/10: Antimycotics
- C01B 33/14: Colloidal silica, e.g. dispersions, gels, sols
- C01B 33/143: of aqueous solutions of silicates
- C01B 33/18: Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof (preparation of aerogels by dehydrating gels C01B33/158; treatment to enhance the pigmenting or filling properties C09C)
- C01B 33/193: of aqueous solutions of silicates
- Y10T 428/2982: Particulate matter [e.g., sphere, flake, etc.]
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The present invention is directed to a process for producing inorganic particulate material, the material obtainable by such process, a modified release delivery system comprising the material and the use of the material for the administration of a bioactive agent.

## Claims

### Claim 1

A process for producing inorganic particulate material mainly composed of silicon oxide, wherein the particulate material comprises mesopores and macropores and the process includes the steps of:
(a) dissolving a water-soluble polymer or another pore forming agent and a precursor for a matrix dissolving agent in a medium that promotes the hydrolysis of a metalorganic compound;
(b) mixing a metalorganic compound or a mixture of metalorganic compounds which contains hydrolyzable ligands to promote a hydrolysis reaction;
(c) solidifying the mixture through a sol-gel transition, wherein a gel is prepared which has three dimensional interconnected phase domains, one rich in solvent and the other rich in inorganic component, in which surface pores are contained;
(d) disintegrating the gel into particles 15 to 120 minutes after the phase separation of step (c), wherein a uniform particle size distribution is determined by controlling the time from phase separation to disintegration, resulting in particles having a mean diameter from 1 μm to about 2000 μm;
(e) setting the matrix dissolving agent free from its precursor, wherein the matrix dissolving agent modifies the structure of said inorganic component; and
(f) removing the solvent by evaporation drying and/or heat-treatment.

### Claim 2 (depends on 1)

The process according to claim 1, further including the step
(g) calcining the particles.

### Claim 3 (depends on 1)

The process according to claim 1, wherein the macropores have a mean diameter >0.1 μm and the mesopores have a mean diameter between 2 and 100 nm.

### Claim 4 (depends on 1)

The process according to claim 1, wherein said precursor of the matrix dissolving agent is a compound having an amido group or an alkylamido group.

### Claim 5 (depends on 1)

The process according to claim 1, wherein step (d) is executed by stirring with an agitator.

### Claim 6 (depends on 1)

The process according to claim 1, wherein the pore forming agent is a non-ionic surfactant.

### Claim 7 (depends on 1)

The process according to claim 1, wherein said precursor of the matrix dissolving agent is a compound having a urea group.

### Claim 8 (depends on 1)

The process according to claim 1, wherein the mean diameter of the particles is from about 1 μm to about 500 μm.

### Claim 9 (depends on 1)

The process according to claim 1, wherein the particles have an irregular non-spherical shape.

### Claim 10 (depends on 1)

The process according to claim 1, wherein step (d) is the disintegrating of the gel into particles 15 to 30 minutes after the phase separation of step (c).