Bioadhesive chitosan gel for controlling bleeding and for promoting healing with scar reduction without obscuring or interfering with access to a surgical field
Inventors
Bush, Maggie • KUHN, Sam • McCarthy, Simon
Assignees
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Publication Number
US-11160901-B2
Publication Date
2021-11-02
Expiration Date
Abstract
An aqueous chitosan gel system of novel non-scarring, non-interfering, transparent, stable, solubilized chitosan that controls bleeding is described herein. The aqueous chitosan gel system can comprise water, chitosan, an acid, a plasticizer, a rheology modifying agent, an antioxidant stabilizer, an alcohol, and a multi-valent salt. Additional components of the aqueous chitosan gel system can comprise a bifunctional organic acid, a tnfunctional organic acid, a multi-functional organic acid, a phosphoric acid, a polyphosphoric acid and a salt.
Core Innovation
The invention relates to an aqueous gel comprising water and solubilized chitosan formulated as a transparent non-scarring bioadhesive gel for hemostasis. The gel is stable and does not obscure or interfere with surgical-field visualization and access. It controls bleeding by providing gel-to-tissue adherence and chitosan-blood interactions at an injury site.
The gel composition includes an acid component and rheology modifying agents together with an antioxidant stabilizer, an alcohol, and a multi-valent salt. The acid component includes one or more of monofunctional organic acid, difunctional or trifunctional organic acid, polyfunctional organic acid, or inorganic phosphoric, triphosphoric, or polyphosphoric acid, and lactic acid is included. Rheology modifying agents include hydroxyl propyl methyl cellulose, polyethylene oxide, poloxamer, and polypropylene glycol.
The formulation further includes an antioxidant stabilizer selected from methylparaben, tannic acid, trolox, quercetin, catechin, glutathione, ferulic acid, carotenoid, proanthocyanidin, and ascorbic acid, and includes methylparaben. The alcohol component includes ethanol and the multi-valent salt includes CaCl2. Optional components include a plasticizer and antimicrobial agents selected from listed options, and performance is tied to viscosity/tack ranges and stability.
In surgical use, the invention provides applying the aqueous chitosan gel to an injury during or after specified surgeries and to general topical bleeding to control bleeding or facilitate hemostasis. The disclosure includes hemostasis and stability performance assertions, and chitosan degree of deacetylation ranges for bioabsorbable gels and for removable gels.
Claims Coverage
The disclosed claims cover an aqueous chitosan gel composition and surgical methods applying the gel to control bleeding or facilitate hemostasis. Across the independent claims, the inventive features center on defined aqueous chitosan gel formulation parameters and its use to control bleeding or facilitate hemostasis via chitosan interactions with blood components.
Specific aqueous gel composition with defined acid, rheology modifiers, antioxidant stabilizer, alcohol, and multivalent salt
An aqueous gel comprising water; chitosan; an acid component including one or more of a monofunctional organic acid, a difunctional or trifunctional organic acid, a polyfunctional organic acid, or an inorganic phosphoric, triphosphoric, or polyphosphoric acid, wherein lactic acid is included; a rheology modifying agent including hydroxyl propyl methyl cellulose, polyethylene oxide, poloxamer, and polypropylene glycol; an antioxidant stabilizer selected from methylparaben, tannic acid, trolox, quercetin, catechin, glutathione, ferulic acid, carotenoid, proanthocyanidin, and ascorbic acid; an alcohol including ethanol; and a multi-valent salt including CaCl2.
Surgical application of a specific chitosan gel to control bleeding or facilitate hemostasis
A surgical method comprising applying to an injury an aqueous gel with the defined water, chitosan, acid component, rheology modifying agent, antioxidant stabilizer, alcohol, and multi-valent salt, to control bleeding or facilitate hemostasis during or after one or more listed surgeries and general topical bleeding.
Surgical method with an aqueous gel including ascorbic acid and specified chitosan and lactic acid levels
A surgical method comprising applying to an injury an aqueous gel with specified water and chitosan levels, lactic acid, rheology modifying agent, ascorbic acid, ethanol, and CaCl2, to control bleeding or facilitate hemostasis during or after one or more listed surgeries and general topical bleeding.
Surgical method applying an aqueous antimicrobial-containing chitosan gel to control bleeding or facilitate hemostasis
A surgical method comprising applying to an injury an aqueous gel with chitosan, an acid component, a rheology modifying agent, an antioxidant stabilizer, an alcohol, a multi-valent salt, and an anti-microbial agent selected from silver, chitosan derivatives that are polycationic between pH 6.8-7.8, chlorhexidine gluconate, iodine, and polyhexamethyl biguanide, to control bleeding or facilitate hemostasis during or after one or more listed surgeries and general topical bleeding.
Overall claim coverage is directed to an aqueous chitosan gel with defined water/chitosan/acid-component, rheology modifying agent, antioxidant stabilizer, alcohol, and multi-valent salt, and to surgical methods applying such gels to an injury to control bleeding or facilitate hemostasis. The claims also include a variant with ascorbic acid and a variant including an anti-microbial agent selected from listed options.
Stated Advantages
A transparent non-scarring bioadhesive gel for hemostasis.
Does not obscure or interfere with surgical-field visualization and access.
Controls bleeding or facilitates hemostasis.
Provides stable formulations with stability at about 23°C.
Documented Applications
Control bleeding or facilitate hemostasis during or after sinus surgery.
Control bleeding or facilitate hemostasis during or after ear nose and throat procedures.
Control bleeding or facilitate hemostasis during or after oral and maxillofacial surgery.
Control bleeding or facilitate hemostasis during or after orthopedic surgery.
Control bleeding or facilitate hemostasis during or after urological surgery.
Control bleeding or facilitate hemostasis during or after reconstructive surgery.
Control bleeding or facilitate hemostasis during or after cosmetic surgery.
Control bleeding or facilitate hemostasis during or after vascular surgery.
Control bleeding or facilitate hemostasis during or after transplant surgery.
Control bleeding or facilitate hemostasis during or after neurological surgery.
Control bleeding or facilitate hemostasis during or after oncological resection surgery involving the biopsy and removal of tumors.
Control bleeding or facilitate hemostasis during or after gynecological surgery.
Control bleeding or facilitate hemostasis for general topical bleeding.
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