# US 2014/0155654 A1 · Forming Spherical Crystal Habit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0155654 A1 - Document ID: US20140155654A1 - Status: Published application - Kind: A1 - Application number: 13/786,715 - Filed: 2013-03-06 - Published: 2014-06-05 - Earliest claimed: 2012-12-03 - Assignees: Physical Sciences, Inc. - Inventors: Dorin V. Preda; Prakash B. Joshi; Anait (Tsinberg) Scherer; Laurel A. Vernarelli - Web page: https://patentgrep.com/patent/US20140155654A1 ## CPC - C07C 279/02: Guanidine; Salts, complexes or addition compounds thereof - C07C 277/06: Purification or separation of guanidine - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS ## Abstract Methods for forming spherical crystal habit are shown. A needle-shaped crystal habit, a solvent, and a surfactant are combined and dissolved forming a first solution. The first solution and an anti-solvent are combined forming a second solution. The second solution is cooled. Spherical crystal habit is formed. ## Claims ### Claim 1 A method of forming a spherical crystal habit, the method comprising: forming a first solution by combining a needle-shaped crystal habit, a solvent, and a surfactant; dissolving the needle-shaped crystal habit by heating the first solution to a desired temperature; forming a second solution by combining the first solution with an anti-solvent; and cooling the second solution. ### Claim 2 (depends on 1) The method of claim 1 wherein the needle-shaped crystal habit is nitroguanidine. ### Claim 3 (depends on 1) The method of claim 1 wherein the needle-shaped crystal habit that is combined to form the first solution is 3 grams of nitroguanidine ### Claim 4 (depends on 1) The method of claim 1 wherein the solvent comprises N-methylpyrrolidone. ### Claim 5 (depends on 1) The method of claim 1 wherein the solvent that is combined to form the first solution is 9 to 12 milliliters of N-methylpyrrolidone. ### Claim 6 (depends on 1) The method of claim 1 wherein the surfactant comprises Polysorbate 20. ### Claim 7 (depends on 1) The method of claim 1 wherein the surfactant that is combined to form the first solution is 50 to 150 microliters of Polysorbate 20. ### Claim 8 (depends on 1) The method of claim 1 wherein combining the needle-shaped crystal habit, the solvent, and the surfactant further comprises agitating the first solution. ### Claim 9 (depends on 8) The method of claim 8 wherein agitating the first solution further comprises shaking, stirring, manual combining, mechanical combining, or any combination thereof. ### Claim 10 (depends on 1) The method of claim 1 wherein combining the needle-shaped crystal habit, the solvent, and the surfactant further comprises stirring with a magnet. ### Claim 11 (depends on 1) The method of claim 1 wherein heating the first solution further comprises uniformly distributing heat to the first solution. ### Claim 12 (depends on 1) The method of claim 1 wherein the desired temperature is at least 80° C. ### Claim 13 (depends on 1) The method of claim 1 wherein dissolving the needle-shaped crystal habit further comprises shaking, stirring, manual combining, mechanical combining, or any combination thereof. ### Claim 14 (depends on 1) The method of claim 1 wherein dissolving the needle-shaped crystal habit further comprises stirring the first solution with a magnet. ### Claim 15 (depends on 1) The method of claim 1 wherein the anti-solvent comprises acetone. ### Claim 16 (depends on 1) The method of claim 1 wherein the anti-solvent is 120 to 200 milliliters of acetone. ### Claim 17 (depends on 1) The method of claim 1 wherein forming the second solution further comprises cooling the anti-solvent prior to combining the first solution with the anti-solvent. ### Claim 18 (depends on 17) The method of claim 17 wherein cooling the anti-solvent further comprises freezing, refrigerating, maintaining at room temperature, or any combination thereof. ### Claim 19 (depends on 1) The method of claim 1 wherein forming the second solution further comprises combining an amount of anti-solvent greater than an amount of solvent. ### Claim 20 (depends on 1) The method of claim 1 wherein forming the second solution further comprises shaking, stirring, manual combining, mechanical combining or any combination thereof. ### Claim 21 (depends on 1) The method of claim 1 wherein forming the second solution further comprises stirring with a magnet. ### Claim 22 (depends on 1) The method of claim 1 wherein cooling the second solution further comprises freezing, refrigerating, maintaining at room temperature, or any combination thereof. ### Claim 23 A method of forming a spherical crystal habit, the method comprising: forming a first solution by combining a needle-shaped crystal habit, a solvent, and a surfactant; agitating the first solution by shaking, stirring, manually combining, mechanically combining, or any combination thereof; dissolving the needle-shaped crystal habit by uniformly distributing heat to the first solution at a desired temperature of at least 80° C.; cooling an anti-solvent by freezing, refrigerating, maintaining at room temperature, or any combination thereof; forming a second solution by combining the first solution with the anti-solvent; agitating the second solution by shaking, stirring, manually combining, mechanically combining, or any combination thereof; and cooling the second solution by freezing, refrigerating, maintaining at room temperature, or any combination thereof. ### Claim 24 A spherical crystal habit nitroguanidine formed by the process of: forming a first solution by combining a needle-shaped crystal habit, a solvent, and a surfactant; dissolving the needle-shaped crystal habit by heating the first solution to a desired temperature; forming a second solution by combining the first solution with an anti-solvent; and cooling the second solution.