# US 2023/0265249 A1 · Urethane-crosslinked polymeric microparticles and processes of manufacturing the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0265249 A1 - Document ID: US20230265249A1 - Status: Published application - Kind: A1 - Application number: 18/173,404 - Filed: 2023-02-23 - Published: 2023-08-24 - Earliest claimed: 2022-02-24 - Assignees: The Secant Group, LLC - Applicants: The Secant Group, LLC - Inventors: Manasi Chawathe BAKER; Stephanie REED - Web page: https://patentgrep.com/patent/US20230265249A1 ## CPC - A61K 9/1641: {obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyethylene glycol, poloxamers} - C08J 5/02: Direct processing of dispersions, e.g. latex, to articles - A61K 9/1694: {resulting in granules or microspheres of the matrix type containing more than 5% of excipient} - C08G 18/0895: {Manufacture of polymers by continuous processes (C08G18/0838 takes precedence)} - C08G 18/24: of tin - C08G 18/4236: {containing only aliphatic groups} - C08G 18/73: acyclic - C08J 3/12: Powdering or granulating - C08J 3/24: Crosslinking, e.g. vulcanising, of macromolecules (mechanical aspects B29C35/00; crosslinking agents C08K) - A61K 31/573: substituted in position 21, e.g. cortisone, dexamethasone, prednisone or aldosterone - C08G 2230/00: Compositions for preparing biodegradable polymers - C08J 2367/02: Polyesters derived from dicarboxylic acids and dihydroxy compounds; (C08J2367/06 takes precedence) - C08J 2375/06: from polyesters - 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) - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS ## Abstract A first process produces poly(glycerol sebacate) urethane (PGSU)-based microparticles. The first process includes forming a first composition including a poly(glycerol sebacate) (PGS) resin and dispersing the first composition in a continuous fluid phase in the presence of an isocyanate crosslinker to produce PGSU-based microparticles. A second process also produces PGSU-based microparticles. The second process includes forming a first composition including a PGS resin, forming a second composition and combining the first composition and the second composition to produce PGSU-based microparticles, where at least one of the first and the second composition includes an isocyanate crosslinker. An extrusion-spheronization process of crosslinking includes extruding an extrudate including a crosslinkable compound into a continuous fluid phase in a spheronization bath and dispersing the extrudate in the continuous fluid phase to crosslink the crosslinkable compound, where at least one of the extrudate and the continuous fluid phase includes a crosslinker. ## Claims ### Claim 1 A process of producing poly(glycerol sebacate) urethane (PGSU)-based microparticles, the process comprising: forming a first composition comprising a poly(glycerol sebacate) (PGS) resin; and dispersing the first composition in a continuous fluid phase in the presence of an isocyanate crosslinker to produce the PGSU-based microparticles. ### Claim 2 (depends on 1) The process of claim 1, wherein the crosslinker is present only in the first composition prior to the dispersing. ### Claim 3 (depends on 1) The process of claim 1, wherein the crosslinker is present only in the continuous fluid phase prior to the dispersing. ### Claim 4 (depends on 1) The process of claim 1, wherein the crosslinker is present in both the first composition and the continuous fluid phase prior to the dispersing. ### Claim 5 (depends on 1) The process of claim 1, wherein the dispersing occurs in the presence of a catalyst. ### Claim 6 (depends on 5) The process of claim 5, wherein the catalyst is present, prior to the dispersing, in a location selected from the group consisting of only in the first composition, only in the continuous fluid phase, and in both the first composition and the continuous fluid phase. ### Claim 7 (depends on 1) The process of claim 1, wherein the first composition further comprises an active pharmaceutical ingredient in a form selected from the group consisting of amorphous, semi-crystalline, crystalline, and combinations thereof. ### Claim 8 (depends on 1) The process of claim 1, wherein the PGS resin is present at a concentration in the range of about 40 wt % to about 60 wt % in the first composition, and a ratio of a viscosity of the first composition to a viscosity of the continuous fluid phase is in the range of about 10:1 to about 50:1. ### Claim 9 (depends on 1) The process of claim 1, wherein the PGSU-based microparticles have an average particle size in the range of about 25 μm to about 100 μm and a span value of less than 2.0. ### Claim 10 (depends on 1) The process of claim 1, wherein the process is an emulsification-solvent evaporation process, where the first composition is dispersed as an emulsion in the continuous fluid phase and the continuous fluid phase comprises a continuous phase liquid. ### Claim 11 (depends on 10) The process of claim 10, wherein the first composition further comprises a dispersed phase solvent. ### Claim 12 (depends on 11) The process of claim 11 further comprising removing the dispersed phase solvent after the dispersing. ### Claim 13 (depends on 10) The process of claim 10, wherein the dispersing comprises homogenizing the first composition in the continuous fluid phase. ### Claim 14 (depends on 10) The process of claim 10, wherein the dispersing comprises flowing the first composition through a membrane having a pore size in the range of about 2 to about 15 μm. ### Claim 15 (depends on 1) The process of claim 1, wherein the process is an extrusion-spheronization process, wherein the first composition is an extrudate and the continuous fluid phase is a spheronization bath. ### Claim 16 (depends on 15) The process of claim 15 further comprising producing the extrudate by co-extruding a second composition and a third composition to meet and intermingle to form the first composition. ### Claim 17 (depends on 16) The process of claim 16, wherein the co-extruding comprises co-extruding the second composition from a first barrel and the third composition from a second barrel of a dual-barrel syringe. ### Claim 18 (depends on 16) The process of claim 16, wherein the second composition comprises the crosslinker and the third composition comprises a catalyst. ### Claim 19 (depends on 15) The process of claim 15, wherein the continuous fluid phase comprises mineral oil and further comprising washing the PGSU-based microparticles to remove the mineral oil. ### Claim 20 (depends on 15) The process of claim 15, wherein the extrudate is substantially free of any solvent. ### Claim 21 A process of producing poly(glycerol sebacate) urethane (PGSU)-based microparticles, the process comprising: forming a first composition comprising a poly(glycerol sebacate) (PGS) resin; forming a second composition; wherein at least one of the first composition and the second composition comprises an isocyanate crosslinker; and combining the first composition and the second composition to produce the PGSU-based microparticles. ### Claim 22 (depends on 21) The process of claim 21, wherein the process is a phase separation-coacervation process, where the first composition comprises the PGS resin dissolved in a solvent and the second composition comprises a non-solvent. ### Claim 23 An extrusion-spheronization process of crosslinking, the extrusion-spheronization process comprising: extruding an extrudate comprising a crosslinkable compound into a continuous fluid phase in a spheronization bath; and dispersing the extrudate in the continuous fluid phase in the spheronization bath to crosslink the crosslinkable compound; wherein at least one of the extrudate and the continuous fluid phase comprises a crosslinker. ### Claim 24 (depends on 23) The extrusion-spheronization process of claim 23, wherein the extruding comprises co-extruding a first composition and a second composition different from the first composition to form the extrudate.