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WO2010148357A1 - Compositions et procédés associés à des mélanges contenant du chitosane solide - Google Patents

Compositions et procédés associés à des mélanges contenant du chitosane solide Download PDF

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Publication number
WO2010148357A1
WO2010148357A1 PCT/US2010/039259 US2010039259W WO2010148357A1 WO 2010148357 A1 WO2010148357 A1 WO 2010148357A1 US 2010039259 W US2010039259 W US 2010039259W WO 2010148357 A1 WO2010148357 A1 WO 2010148357A1
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WO
WIPO (PCT)
Prior art keywords
solid
chitosan
acid
water
blend
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Application number
PCT/US2010/039259
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English (en)
Inventor
Everett J. Nichols
James R. Scott
Original Assignee
Halosource, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Halosource, Inc. filed Critical Halosource, Inc.
Priority to CN2010800271963A priority Critical patent/CN102469782A/zh
Priority to CA2764857A priority patent/CA2764857A1/fr
Priority to BRPI1014029-8A priority patent/BRPI1014029A2/pt
Priority to US12/852,098 priority patent/US8168767B2/en
Publication of WO2010148357A1 publication Critical patent/WO2010148357A1/fr
Priority to US13/440,706 priority patent/US8357787B2/en

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F1/5263—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using natural chemical compounds
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/66—Treatment of water, waste water, or sewage by neutralisation; pH adjustment

Definitions

  • the present invention relates to a formulation of solid chitosan and a solid acid or a solid agent that generates a proton in situ in the presence of water blend having improved solubilization properties.
  • the invention further relates to a process for solubilizing the solid chitosan contained in the blend.
  • the invention further relates to a process for using the method of solubilization to achieve flocculation in an aqueous medium, such as a stream, containing matter, such as suspended sediment, insoluble organic matter, or soluble organic matter.
  • the invention further relates to kits for use in flocculation in aqueous systems or streams containing such matter.
  • Chitin is a linear polysaccharide composed of ⁇ -(l-4)-linked
  • Soluble chitosan is useful as a coagulant and flocculant in removing impurities such as suspended sediment, proteins, fats, tannins, and metals from aqueous mediums. Soluble chitosan is more commonly used to remove contaminants such as suspended sediment and particulate matter from stormwater running off of construction sites.
  • Chitosan is insoluble in water, alkali solutions, and most organic solvents. Its effectiveness as a flocculant and coagulant requires it to be dissolved and delivered in soluble form to the aqueous medium containing the material to be coagulated or flocculated.
  • concentration of soluble chitosan delivered to the aqueous medium containing the material to be coagulated or flocculated affects its effectiveness as a flocculant or coagulant.
  • Chitosan is soluble in certain solutions of acids at defined acid and chitosan concentrations and slightly soluble to insoluble in other acid solutions. The type of the acid can influence the consistency of the chitosan rendering it paste-like, gelatinous, or more like a pseudo-plastic.
  • chitosan In soluble form, chitosan is most commonly found, in commercial applications, to be dissolved in dilute acetic or lactic acid. Because of the high viscosity that chitosan exhibits in dissolved form, commercial chitosan solutions typical exhibit concentrations ranging from 1% (wt./wt.) to 3% (wt./wt.). In flocculation/coagulation applications, the dissolved chitosan in the l%-3% solutions is metered into the aqueous medium containing the impurity, such as stormwater or industrial water using a metering pump. Higher concentrations (>3%) of dissolved chitosan exhibit such high viscosities that delivery using a metering pump becomes difficult and not practical. Therefore, this limits the commercial applications of liquid chitosan solutions due to the cost of shipping, which is based on weight. For example, a 3% chitosan solution is essentially ⁇ 97% water and the shipping cost is primarily attributed to water.
  • chitosan dissolved in acidic solutions or solid water soluble chitosonium salts is to prepare a blend of (a) solid chitosan and (b) a solid acid or a solid agent that generates a proton in situ in the presence of water (also referred to herein as a "solid agent") such that the blend, when added to a relatively low volume of water, results in the solubilization of the chitosan.
  • This solution of solubilized chitosan may then be diluted with water to a desired chitosan concentration, such as a 3% chitosan solution.
  • some embodiments of the present invention contemplate a method of solubilizing chitosan comprising: (1) selecting a desired final chitosan concentration having a total volume of water, V F ; (2) obtaining a blend comprising: a solid chitosan that may be partially protonated but is greater than 80% insoluble when added to water and in a dry, free-flowing, particulate form, and a solid acid or a solid agent that generates a proton in situ in the presence of water, wherein the solid acid or the solid agent that generates a proton in situ in the presence of water is in a dry, free-flowing, particulate form, wherein the solid chitosan and the solid acid or the solid agent that generates a proton in situ in the presence of water are not reacted together or otherwise chemically bound, and wherein the solid chitosan in the blend is not soluble when added to the total volume of water, V F ; (3) adding one or more volumes of water, V ] , tol
  • Also contemplated is a method of solubilizing chitosan comprising: (1) selecting a desired final chitosan concentration having a total volume of water, Vp; (2) obtaining a blend consisting of: a solid chitosan that may be partially protonated but is greater than 80% insoluble when added to water and in a dry, free-flowing, particulate form, a solid acid defined as solid malic acid, solid citric acid, or solid tartaric acid, wherein each solid acid is in a dry, free-flowing, particulate form, wherein the solid chitosan and the solid acid are not reacted together or otherwise chemically bound, and wherein the solid chitosan in the blend is not soluble when added to the total volume of water, V F ; and optionally a component selected from the group consisting of solid sodium acetate, glycerin, a solid salt of the solid acid or a solid salt of a different solid acid, a solid preservative acid, a solid salt of
  • the solid chitosan does not swell and dissolve after the predetermined time period; and (4) after the solid chitosan has swelled and dissolved, adding water to bring the total volume of added water to Vp, thereby producing solubilized chitosan of a desired concentration.
  • compositions of blends are also provided.
  • a composition comprises a blend of: a solid chitosan that may be partially protonated but is greater than 80% insoluble when added to water and in a dry, free-flowing, particulate form, and solid sodium diacetate or solid potassium diacetate, or a combination thereof, that is in a dry, free-flowing, particulate form, wherein the solid chitosan and the solid sodium diacetate or solid potassium diacetate, or combination thereof, are not reacted together or otherwise chemically bound.
  • Methods of solubilizing blends or compositions comprising blends are also provided.
  • a method of solubilizing a composition comprising a blend of a solid chitosan that may be partially protonated but is greater than 80% insoluble when added to water and in a dry, free-flowing, particulate form, and solid sodium diacetate or solid potassium diacetate, or a combination thereof, that is in a dry, free-flowing, particulate form, wherein the solid chitosan and the solid sodium diacetate or solid potassium diacetate, or combination thereof, are not reacted together or otherwise chemically bound, the method comprising: (1) selecting a desired final chitosan concentration having a total volume of water, Vp; (2) obtaining the blend; (3) adding one or more volumes of water, Vj, to the blend, wherein Vj is less than Vp and Vj is effective to swell and dissolve the solid chitosan within a predetermined time period, and optionally adding subsequent volumes of water Vj or fractions thereof, when after an addition of Vj, the solid chitosan
  • any blend described herein may be solubilized by adding a volume of water that results in a chitosan concentration of greater or equal to about 1.0%.
  • FIGURE 1 shows a representative embodiment of a device of the present invention comprising a segmented body (partially cut away); and FIGURE 2 shows a cross-sectional view of the device shown in FIGURE X which more clearly shows the blend disposed within the device.
  • the method comprises adding the blend to a relatively small volume of water, as compared to the total amount of water added to achieve a desired chitosan concentration, and stirring to dissolve the chitosan to produce a highly viscous paste or gel followed by slowly adding increasing amounts of water to achieve the desired chitosan concentration.
  • solids herein that are in a dry, free-flowing, particulate form refer to solids that behave much like sand flowing from one portion of an hourglass to another.
  • solid is intended to exclude other states of matter such as liquids and gases.
  • a method of solubilizing chitosan comprising: (1) selecting a desired final chitosan concentration having a total volume of water, Vp; (2) obtaining a blend comprising: a solid chitosan that may be partially protonated but is greater than 80% insoluble when added to water and in a dry, free-flowing, particulate form, and a solid acid or a solid agent that generates a proton in situ in the presence of water, wherein the solid acid or the solid agent that generates a proton in situ in the presence of water is in a dry, free-flowing, particulate form, wherein the solid chitosan and the solid acid or the solid agent that generates a proton in situ in the presence of water are not reacted together or otherwise chemically bound, and wherein the solid chitosan in the blend is not soluble when added to the total volume of water, V F ; (3) adding one or more volumes of water, Vj, to the blend, wherein V j is
  • the predetermined time may be about, at most about, or at least about 5, 10, 25, 20, 25, or 30 minutes, or any range derivable therein.
  • the volume V j is greater than zero.
  • the volume Vj may be up to about 10% by volume of Vp.
  • the volume V j may be up to about 5% by volume of Vp.
  • the volume V ] may be up to about 1% by volume of Vp.
  • the volume may range from about, at least about, or at most about 0.1%, 0.5%, 1%,
  • the method of step (4) described above comprises adding a plurality of incremental volumes of water, such as 2, 3, 4, 5, 6, 7, 8, 9, or 10 increments, or any range derivable therein, wherein each incremental volume may be the same or different, with mixing after each addition, until Vp is achieved, thereby providing solubilized chitosan of a desired concentration.
  • the solid chitosan may have an average molecular weight of between about
  • the average molecular weight is about, at most about, or at least about 20,000, 50,000, 100,000, 150,000, 200,000, 250,000, 500,000, 750,000, 1,000,000, 1,250,000, 1,500,000, 1,750,000, or 2,000,000, or any range derivable therein.
  • the solid chitosan may have a percent deacetylation of greater than about 50%. In some embodiments, the solid chitosan may have a percent deacetylation of about, at least about, or at most about 50%, 60%, 70%, or 80%, or more, or any range derivable therein.
  • the particle size or the average particle size of the solid chitosan ranges from about 125 microns to about 850 microns. In some embodiments, about 90% of the particles of solid chitosan in a blend range from about 125 microns to about 850 microns, or have an average particle size that ranges from about 125 microns to about 850 microns. In some embodiments, the particle size or the average particle size of the solid chitosan is greater than 850 microns. In some embodiments, the particle size or average particle size of the solid chitosan ranges from about 850 microns up to about 1 cm. In some embodiments, the particle size or average particle size ranges from about 0.5 cm to about 1 cm.
  • the particle size or the average particle size of the solid acid or solid agent ranges from about 125 microns to about 850 microns. In some embodiments, about 90% of the particles of solid acid or solid agent in a blend range from about 125 microns to about 850 microns, or have an average particle size that ranges from about 125 microns to about 850 microns. In some embodiments, the particle size or the average particle size of the solid acid or solid agent is greater than 850 microns. In some embodiments, the particle size or average particle size of the solid acid or agent ranges from about 850 microns up to about 1 cm.
  • the particle size or average particle size of the solid acid or solid agent is less than the solid chitosan particle size or average particle size. In some embodiments, the particle size or average particle size of the solid acid or solid agent is greater than the solid chitosan particle size or average particle size.
  • the particle size of the solid chitosan is within about 20% of the particle size of the solid acid or the solid agent that generates a proton in situ in the presence of water. In some embodiments, the particle size of the solid chitosan is within about, at most about, or at least about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, or 25%, or any range derivable therein, of the particle size of the solid acid or the solid agent.
  • the solid acid is a protic acid.
  • the solid acid may be malic acid, citric acid, tartaric acid, sodium diacetate, or potassium diacetate, for example.
  • the solid acid may be sodium diacetate or potassium diacetate.
  • the solid agent that generates a proton in situ in the presence of water is selected from the group consisting of a solid sulfite salt, a solid organic acid lactone, and a solid organic acid anhydride.
  • the ratio of a solid chitosan to a solid acid or solid agent that generates a proton in situ in the presence of water may vary. In some embodiments, the ratio of the solid chitosan to the solid acid or the solid agent that generates a proton in situ in the presence of water ranges from about 1 :10 to about 10:1 (wt./wt.). In other embodiments, the ratio of solid chitosan to the solid acid or the solid agent that generates a proton in situ in the presence of water is about 1 :1 (wt./wt.). In yet other embodiments, the ratio of solid chitosan to the solid acid or the solid agent that generates a proton in situ in the presence of water is about 1 :2 (wt./wt.).
  • a blend may comprise additional components.
  • the blend further comprises glycerin. Addition of glycerin may aid in the solubility of chitosan.
  • a blend may comprise a solid salt of the solid acid or a salt of a different solid acid, wherein the salt is in a dry, free-flowing, particulate form.
  • a blend may comprise a solid preservative acid, a solid salt of a preservative acid, or a solid antimicrobial agent, wherein the solid preservative acid, the solid salt of a preservative acid, or the solid antimicrobial agent is in a dry, free-flowing, particulate form.
  • a blend may comprise a solid metal salt that is in a dry, free-flowing, particulate form.
  • a blend may comprise a solid, neutral polysaccharide that is in a dry, free-flowing, particulate form.
  • a blend may comprise a solid cationic or solid anionic polysaccharide, wherein the solid cationic or solid anionic polysaccharide is in a dry, free-flowing, particulate form.
  • a blend may comprise a solid organic amine that is in a dry, free- flowing, particulate form.
  • a blend further comprises a solid inorganic amine that is in a dry, free-flowing, particulate form.
  • a blend is further defined as a blend of a solid chitosan, a solid protic acid, and a solid organic acid anhydride, wherein the solid chitosan, the solid protic acid, and the solid organic acid anhydride are each in a dry, free-flowing, particulate form.
  • Any blend described herein may further comprise sodium acetate.
  • the acetate ion may aid in chitosan solubility.
  • the chitosan-containing blends described herein may be used to prepare a desired final chitosan concentration, such as a desired final chitosan concentration that ranges from about 1% to about 5% (wt./wt). In some embodiments, the desired final chitosan concentration ranges from about 1% to about 3% (wt./wt.).
  • a solid acid or the solid agent that generates a proton in situ in the presence of water is selected by a method comprising: (A) preparing a test blend of a test solid chitosan and a test solid acid or a test solid agent that generates a proton in situ in the presence of water, wherein the ratio of test solid chitosan to test solid acid or test solid agent that generates a proton in situ in the presence of water is about 1 :1:1 (gram: gram: liter); wherein the test solid chitosan and the test solid acid or the test solid agent that generates a proton in situ in the presence of water are each in a dry, free- flowing, particulate form, and wherein the test solid chitosan and the test solid acid or the test solid agent that generates a proton in situ in the presence of water are not reacted together or otherwise chemically bound; (B) adding a test volume of water (Vj) to the test blend and mixing; (C)
  • Also contemplated is a method of solubilizing chitosan comprising: (1) selecting a desired final chitosan concentration having a total volume of water, Vp; (2) obtaining a blend consisting of: a solid chitosan that may be partially protonated but is greater than
  • a solid acid defined as solid malic acid, solid citric acid, or solid tartaric acid, wherein each solid acid is in a dry, free-flowing, particulate form, wherein the solid chitosan and the solid acid are not reacted together or otherwise chemically bound, and wherein the solid chitosan in the blend is not soluble when added to the total volume of water, Vp; and optionally a component selected from the group consisting of solid sodium acetate, glycerin, a solid salt of the solid acid or a solid salt of a different solid acid, a solid preservative acid, a solid salt of a preservative acid, a solid antimicrobial agent, a solid metal salt, a solid neutral aqueous-soluble polysaccharide, a solid cationic aqueous- soluble polysaccharide, a solid anionic aqueous-soluble polysaccharide, a
  • the solid chitosan does not swell and dissolve after the predetermined time period; and (4) after the solid chitosan has swelled and dissolved, adding water to bring the total volume of added water to V F , thereby producing solubilized chitosan of a desired concentration.
  • the predetermined time period may be about
  • the predetermined time may be about, at most about, or at least about 5, 10, 25, 20, 25, or 30 minutes, or any range derivable therein.
  • the volume Vj is greater than zero.
  • the volume Vj may be up to about 10% by volume of Vp.
  • the volume Vj may be up to about 5% by volume of Vp.
  • the volume Vj may be up to about 1% by volume of Vp.
  • the volume may range from about, at least about, or at most about
  • the method of step (4) may comprise adding a plurality of incremental volumes of water, such as 2, 3, 4, 5, 6, 7, 8, 9, or 10 increments, or any range derivable therein, wherein each incremental volume may be the same or different, with mixing after each addition, until Vp is achieved, thereby providing solubilized chitosan of a desired concentration.
  • compositions comprising blends are also provided.
  • a composition comprises a blend of: a solid chitosan that may be partially protonated but is greater than 80% insoluble when added to water and in a dry, free-flowing, particulate form, and solid sodium diacetate or solid potassium diacetate, or a combination thereof, that is in a dry, free-flowing, particulate form, wherein the solid chitosan and the solid sodium diacetate or solid potassium diacetate, or combination thereof, are not reacted together or otherwise chemically bound.
  • the ratio of solid chitosan to solid sodium diacetate or sodium potassium diacetate may range from about 1:1 to about 1 :5 (wt./wt).
  • the ratio ranges from about 1 :2 to about 1:3 (wt./wt.).
  • the particle size of each may be any particle size or average particle size described herein.
  • the particle size or the average particle size of the solid chitosan and solid sodium diacetate or solid potassium diacetate are each about 125 microns to about 850 microns.
  • about 90% of the solid chitosan or the solid sodium diacetate or solid potassium diacetate ranges from about 125 microns to about 850 microns.
  • a volume of water may be added to result in a chitosan concentration of greater than or equal to about 0.1%.
  • a volume of water may be added to result in a chitosan concentration of greater than or equal to about 0.1%.
  • the chitosan concentration may be from about 1% to about 5%, for example.
  • the chitosan concentration may, in some embodiments, range from about 1% to about 3%.
  • the ratio of chitosan to sodium diacetate or potassium diacetate may be about 1 :2 or greater.
  • Chitosan is a copolymer of 2-amino-2-deoxy-D-glucose and 2-acetoamido-2-deoxy-D-glucose units. Chitosan is commercially available from a variety of sources, and the average molecular weight range and percent deacetylation may vary. For example, solid chitosan may have an average molecular weight of between about 20,000 Da and 2,000,000 Da and may have a percent deacetylation of greater than about 50%.
  • a solid chitosan may be partially protonated but is typically greater than about, at least about, or at most about 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 99% insoluble, or any range derivable therein, when added to water and in a dry, free-flowing, particulate form. In other words, greater than a particular percentage of the solid chitosan does not dissolve.
  • Solid chitosan employed in blends described herein is in dry, free-flowing, particulate form that excludes any solvent, such as water or an organic solvent. Solid chitosan in blends also excludes chitosan complexes. In some embodiments, chitosan may be further defined as excluding a metal, such as chelated metal.
  • Solid Acids Solid acids employed in blends described herein are in dry, free- flowing, particulate form. Solid acids are typically protic acids which, on dissociation, provide at least one proton (H + ). Both mono and polyprotic (e.g., diprotic) acids may be used.
  • monoprotic is intended to refer to an acid having one displaceable hydrogen atom per molecule.
  • polyprotic should be construed accordingly.
  • Non-limiting examples of protic acids include lactic acid, adipic acid, pyruvic acid, phenyl pyruvic acid, p-hydroxyphenylpyruvic acid, p-hydroxypyruvic acid, 2-keto-glutaric acid, glyoxylic acid, ⁇ -ketoisocaproic acid, oxalacetic acid, levulinic acid, acetoacetic acid, malonaldehydric acid, glutaraldehydic acid, malonaldehydic acid, glutaraldehydic acid, p-(3-formylpropyl)benzoic acid, 3 -oxo valeric acid, 2-keto-3-hydroxybutyric acid, 3-benzoylpropionic acid, 4-benzoylbenzoic acid, caprylic acid, citraconic acid, citamalic acid, citrazinic acid, hexanoic acid, n-capric acid, glutamic acid, citric acid, tartaric acid, malic acid, male
  • the solid acid is malic acid, citric acid, ' tartaric acid, sodium diacetate (a combination of acetic acid and sodium acetate), or potassium diacetate (a combination of acetic acid and potassium acetate). It is understood that liquid acids can be made into solid forms, i.e., solid lactic acid is commercially available in a solid form.
  • Solid agents that generate a proton in situ in the presence of water may also be employed (e.g., the solid agent provides at least one proton when dissolved in water).
  • solid agents that generate a proton in situ in the presence of water sulfite salts, organic acid lactones, organic acid anhydrides are contemplated.
  • Sulfite salts may be used because they form sulfurous acid when dissolved in water.
  • Organic acid lactones can also be used to formulate blends of solid chitosan.
  • the lactones undergo hydrolysis in water and produce the corresponding organic acid in situ.
  • the hydrolysis rate of organic acid lactones into the corresponding acid can vary between different organic acid lactones.
  • the in situ generation of the acid in an aqueous medium can likely influence the solubility profile of chitosan and may be very different compared to the solubility profile of the chitosan contained in the solid corresponding solid acid-solid chitosan blend. This is one way to control the solubilization rate of the chitosan.
  • organic acid lactones examples include glucuronic acid lactone, D-glucono-l,4-lactone, gluconic acid lactone, galacturonic acid lactone, mannuronic acid lactone, glyconic acid lactone, D-glucofuranurono-6,3 -lactone, and D- galactopyranurono-6,3 -lactone.
  • Solid organic acid anhydrides can also be used in the blends of solid chitosan.
  • the solid organic acid anhydrides undergo hydrolysis in water and produce the corresponding organic acid in situ.
  • the hydrolysis rate of solid organic acid anhydrides into the corresponding acids can vary between different organic acid lactones.
  • the in situ generation of the acid in an aqueous medium can likely influence the solubility profile of chitosan and may be very different compared to the solubility profile of the chitosan contained in the solid corresponding acid-solid chitosan blend. This is one way to control the solubilization rate of the chitosan.
  • Non-limiting examples include succinic anhydride, maleic anhydride, malic anhydride, and citraconic anhydride.
  • chitosan derivative is no longer cationic, but exhibits anionic properties due to covalent attachment of carboxyl functional groups derived from the anhydride, such as from succinylation with succinic anhydride. It is envisioned that a solid acid-solid chitosan blend containing the corresponding or different organic acid anhydride can result in formation of chitosan derivatives in situ that contain both cationic and anionic properties attributed to covalently bound carboxyl functions and protonated primary amines.
  • the nature and properties of the chitosan derivative can be influenced and controlled by the ratio of solid acid to chitosan and the ratio of solid organic acid anhydride. It also envisioned that by controlling the ratio of organic acid anhydride added to solid chitosan in an organic acid anhydride blend without the addition of an added solid organic acid, the normal cationic chitosan could be converted into an anionic chitosan in situ.
  • the solid organic acid anhydride-solid chitosan blend or solid organic acid-solid organic acid anhydride-solid chitosan blend could also be contained within a porous containment device capable of releasing the derivatized chitosan, as described below. The released derivatized chitosan would have desirable properties useful for flocculation, coagulation, precipitation (dissolved substances), coatings, etc.
  • the solid acid is not hyaluronic acid, nicotinic acid (see U.S. Patent No. 5,736,532), a fatty acid, a nucleic acid, lactic acid (see U.S. Publ. Appl. No. 2005/0239657), or succinic acid (see U.S. Publ. Appl. No. 2005/0239657).
  • the solid acid is not a non-phytotoxic acid, such as arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine, alanine, aspartic acid, citrulline, cystine, glutamic acid, glycine, hydroxyglutamic acid, norleucine, proline, serine, and tyrosine, adipic acid, hydrochloric acid, tartaric acid, nitric acid, formic acid, or citric acid (see U.S. Patent No. 4,964,894).
  • arginine histidine
  • isoleucine leucine
  • lysine methionine
  • phenylalanine threonine
  • tryptophan valine
  • alanine aspartic acid
  • citrulline cystine
  • cystine glutamic acid
  • glycine hydroxyglutamic acid
  • the solid acid or solid agent that generates a proton in situ in the presence of water is not a polymer (see WO 2010/023463).
  • the solid acid is not glyoxylic acid (see WO 2008/087845).
  • the solid acid is not ascorbic acid (see WO 00/024785).
  • Blends refer to any combination of a solid chitosan and one or more of the solid acids or agents discussed herein, and may optionally comprise additional components, as explained herein.
  • Blends of a solid chitosan and a solid acid or a solid agent that generates an acid in situ in the presence of water refer to mixtures or formulations of dry, free-flowing, particulates of each component.
  • the solid chitosan and the solid acid or the solid agent are not reacted together or otherwise chemically bound while in the blended condition. That is, the solid chitosan and the solid acid or the solid agent are chemically separate from each other.
  • the solid chitosan and the solid acid or the solid agent are not covalently bound together, do not form a complex, and are not cross-linked together, nor does one component "cage" the other component.
  • Blends may comprise, consist essentially of, or consist of a solid chitosan and a solid acid or a solid agent that generates an acid in situ in the presence of water.
  • the only two components of the blend are a solid chitosan and a solid acid or a solid agent.
  • the blend excludes components that do not materially affect the novel and basic characteristics of the solid chitosan and the solid acid or the solid agent.
  • a blend consisting essentially of a solid chitosan and a solid acid or a solid agent may exclude water and organic solvents.
  • a blend may comprise, consist essentially of, or consist of a solid chitosan, a solid acid, and a solid agent. Trace amount of impurities may be present in blends. Impurities may include, for example, digested proteinaceous material from the processing of chitin into chitosan, or mineral salts such as potassium or calcium carbonate or potassium or calcium phosphate.
  • Blends comprising a solid chitosan and a solid acid or a solid agent may, in some embodiments, be further defined as not comprised in a film, coating, or tablet. In some embodiments, the blend is not in layer form. In some embodiments, the blend is not comprised in a hydrogel.
  • a blend does not comprise, nor is comprised in, a slurry, a liquid, or a solution.
  • carbonates or bicarbonates are excluded from a blend (see U.S. Publ. Appl. No. 2008/0190861).
  • drugs are excluded from a blend (see U.S. Publ. Appl. No. 2006/0115525).
  • the ratio of solid chitosan to solid acid or solid agent ranges from about 1 :10 to about 10:1. In some embodiments, the ratio is about, at least about, or at most about 1 :10, 1 :5, 3:10, 2:5, 1:2, 3:5, 7:10, 4:5, 9:10, 1 :1, 10:9, 5:4, 10:7, 5:3, 2:1, 5:2, 10:3, 5:1, or 10:1, or any range derivable therein.
  • the particle size range of the solid chitosan and the particle size range of the solid acid or solid agent in a blend may vary. It is expected that there would be an optimum particle size range for both the solid chitosan and the solid acid or solid agent.
  • Existing data presented in the examples demonstrate that particles of solid chitosan that are less than 850 microns, such as ranging from about 125 to about 850 microns, can be effectively blended with solid acids exhibiting particle sizes that range in size from table salt and granulated refined sugar to powders. Larger particle sizes of solid acids and solid agents may also be used.
  • about 90% of the solid chitosan in a blend has a particle size of about 125 microns to about 850 microns.
  • particle sizes of chitosan greater than about 850 microns would also be effectively blended with solid acids or solid agents of a similar size range, or larger or smaller size range.
  • the particle size of the solid chitosan is within about, at most about, or at least about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 70%, 80%, or 90% of the particle size of the solid acid or the solid agent, or any range derivable therein.
  • particle sizes are comparable in size, the chance of settlement of larger particles is minimized.
  • coarse-ground chitosan which is typically between about 0.25 cm to about 0.5 cm, may be further ground to approach the particle size of a solid acid or solid agent, which may be more of a powder.
  • a blend containing solid chitosan and a solid acid or solid agent may comprise one or more additional components. Combinations of the following components are also contemplated. Typically, an additional component will be in a solid, dry, free-flowing, particulate form. However, embodiments contemplate blends containing glycerin to enhance the solubility of the solid chitosan.
  • solid chitosan blended with combinations of solid acids together with solid salts of organic acids, wherein each salt is in a dry, free-flowing, particulate form examples include solid chitosan blended with lactic acid and calcium lactate; chitosan blended with lactic acid, calcium lactate in combination with sodium acetate; chitosan blended with adipic acid in combination with sodium or potassium acetate; chitosan blended with adipic acid in combination with sodium or potassium hexanoate; chitosan blended with glutamic acid in combination with sodium or potassium acetate; chitosan blended with glutamic acid in combination with sodium or potassium hexanoate; chitosan blended with solid adipic acid in combination with solid benzoic acid.
  • These examples are not meant to be exhaustive but merely to provide examples of the types and possible varieties of combinations that are possible. These blends may act to influence chitosan's solubility properties and provide benefits in certain applications.
  • Another embodiment contemplates blends containing solid preservative acids or solid salts of preservative acids or solid antimicrobial agents that retard or prevent the growth of microorganisms such as molds, yeasts, fungi, and bacteria in the wetted blend.
  • Such components are in a dry, free-flowing, particulate form.
  • solid preservative acids include benzoic acid, propionic acid, sorbic acid, or solid salts of these acids blended with solid acids such as glutamic acid, citric acid, adipic acid, tartaric acid, etc.
  • Non-limiting examples of solid antimicrobial agents include parabens and methylparabens, sulfite salts, sodium and potassium sulfite, sodium or potassium metabisulfite, zinc salts, pyrithiones, essential oils, etc.
  • Another embodiment contemplates blends containing a solid metal salt that is in a dry, free-flowing, particulate form.
  • Non-limiting examples of solid metal salts include lanthanum chloride, lanthanum oxide, lanthanum acetate, zirconium acetate, zirconium oxychloride, aluminum sulfate, aluminum chloride, ferric chloride, ferric sulfate, sodium aluminate, copperas (FeSC ⁇ '7H ⁇ O), and iron salts.
  • blends containing solid, neutral (non-ionic) polysaccharides in a dry, free-flowing, particulate form that are typically water-soluble.
  • Non-limiting examples include guar, starch, glucomannans, glucans, methylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, galactomannans, mannans, xyloglucans.
  • These blends can also contain solid metal salts to aid in coagulation or flocculation and removal of impurities in water.
  • Another embodiment contemplates blends containing solid anionic polysaccharides in a dry, free-flowing, particulate form that are typically water-soluble.
  • Non-limiting examples include agars, carrageenans, xanthans, polygalacturonates, pectins, alginates, gellans, and carboxymethylcellulose.
  • Blends may also comprise solid cationic polysaccharides in a dry, free-flowing, particulate form that are typically water-soluble.
  • Non-limiting examples include cationic guars or cationic starches.
  • Blends may comprise solid organic or inorganic amines in a dry, free-flowing, particulate form.
  • Non-limiting examples include diallyl-dimethyl ammonium chloride, dimethylamine, dimethylaminoethyl-methacrylate, ethanolamine, methylamine, and triethylamine.
  • solid metal salts or solid organic amines can be used in various combinations with solid cationic polysaccharides alone, solid neutral polysaccharides alone, or solid anionic polysaccharides alone.
  • a solid cationic polysaccharide may be combined in a blend with a solid metal salt or a solid organic amine, wherein each component is in a dry, free-flowing, particulate form.
  • a solid, anionic polysaccharide may be combined in a blend with solid chitosan, a solid acid, and a solid metal salt, wherein each component is in a dry, free- flowing, particulate form.
  • a solid neutral polysaccharide may be combined in a blend with a solid metal salt or a solid organic amine, a solid chitosan, and a solid metal acid, wherein each component is in a dry, free-flowing, particulate form.
  • Devices may be employed that contain blends described herein such that solubilized chitosan is released into water surrounding part or all of the device.
  • a permeable soluble chitosan delivery device may contain any blend of a solid chitosan and a solid acid or a solid agent that generates a proton in situ in the presence of water as described herein.
  • Such devices are porous, wherein the pores allow water to enter and hydrate the blend, dissolving the solid chitosan and releasing soluble chitosan through the pores into the aqueous medium outside of the device.
  • the pore size and quantity or configuration of the device can be made in a way to influence the release of the soluble chitosan.
  • a delivery device may be a porous fabric (e.g., a porous "sock") or metal or plastic container.
  • the delivery device may be a woven or non-woven porous material.
  • Another embodiment contemplates blends contained within a device for controlling the rate of release or dose of chitosan.
  • the rate of solubilization and release of soluble chitosan can be controlled by, for example, the solubility of the acid chosen.
  • a solid chitosan/solid malic acid blend versus a solid chitosan/solid lactic acid-solid calcium lactate blend contained in a textile sachet were compared with respect to their release rates of solubilized chitosan into water at pH 8.
  • the solid chitosan/solid lactic acid-solid calcium lactate blend dissolved faster and exhibited a faster release rate from the sachet into the water compared to the solid chitosan/solid malic acid blend in conditions as set forth in Example 5. It is envisioned that a fast dissolving blend containing a solid chitosan and a solid acid or solid agent would be advantageous for certain waters containing impurities that need to be removed more rapidly. This could be due to a higher amount of impurities in the water requiring a higher dose rate of dissolved chitosan.
  • the containment of solid organic acid lactones together with solid chitosan in porous permeable devices represents another embodiment.
  • the hydrolysis rate of the lactone into the corresponding acid can influence the solubility rate and release of the dissolved chitosan and can be influenced by the size and quantity of pores of the containment device. It is also understood that solid organic acid lactones and solid chitosan can be blended together with solid organic acids in various ratios to influence the rate of solubilization of the chitosan.
  • a permeable soluble chitosan delivery device comprising a blend of a solid chitosan that may be partially protonated but is greater than 80% insoluble when added to water and in a dry, free-flowing, particulate form, a solid acid or a solid agent that generates a proton in situ in the presence of water, wherein the solid acid or the solid agent that generates a proton in situ in the presence of water is in a dry, free-flowing, particulate form, wherein the solid chitosan and the solid acid or the solid agent that generates a proton in situ in the presence of water are not reacted together or otherwise chemically bound as described herein, and a porous container that holds the blend.
  • the porous container may be, for example, a segmented fabric sock.
  • the sock may be exposed to running water, wherein a blend comprised in the sock dissolves.
  • Non-limiting examples of devices are set forth in U.S. Patent Nos. 6,749,748 and 6,821,427, each of which is incorporated herein by reference.
  • the present invention provides a device for reducing the amount of contaminants in water, each device comprising a blend as described herein disposed within a body defining a multiplicity of pores, wherein the pores may have an average diameter in the range of from 1 ⁇ m to 2000 ⁇ m.
  • FIGURE 1 shows one embodiment of a device 10 of the present invention, which includes a body 12 that has a first end 14 and a second end 16, and a handle 18 attached to body first end 14.
  • body 12 includes a body wall 20 defining an inner surface 22 and an outer surface 24.
  • body wall 20 includes stitching 26, perpendicular to the long axis of body 12, at regularly spaced intervals along its length that divide body wall 20 into segments 28. Each segment 28 defines a lumen 30.
  • Body wall 20 is penetrated by a multiplicity of pores 32 (shown more clearly in FIGURE 2) that connect body inner surface 22 and body outer surface 24.
  • a blend 34 is disposed within lumen 30 of each segment 28.
  • lumen 30 closest to first end 14 is only partially filled with blend 34 in order to more clearly show lumen 30.
  • Each segment 28 can include the same or different blend 34 as one or more of the other segments 28.
  • the embodiment of device 10 shown in FIGURE 1 is flexible. Flexibility is facilitated by the segmentation of body 12.
  • Device body 12 includes a first half 36, extending from body first end 14 to body midpoint 38, and a second half 40, extending from body midpoint 38 to body second end 16.
  • device 10 is at least partially immersed in moving water that contains one or more contaminants.
  • the water penetrates pores 32 and contacts blend 34 which begins to dissolve.
  • Dissolved blend 34 leaves lumen 30 through pores 32 and forms insoluble complexes with contaminants in the water (although the formation of insoluble complexes can begin at the moment that blend 34 is dissolved by the water).
  • the embodiment of device 10 shown in FIGURE 1 has a generally cylindrical (although segmented) shape when filled with blend 34, device 10 can be any shape that is adapted for use in a particular application.
  • Device body 12 can be made from any material that is sufficiently strong to retain blend 34 and to resist the forces exerted by water moving over device 10, and which is sufficiently porous to allow water to penetrate device 10 to contact blend 34 within lumen 30, although pores 32 should not be so large that they permit rapid escape and dissolution of blend 34. Some embodiments of device body 12 are stretchable. Device 10 can optionally include an attachment means, such as handle 18, that is attached to device body 12 and which is used to attach device 10 to a support, such as to a metal or plastic pipe when device 10 is disposed therein.
  • an attachment means such as handle 18, that is attached to device body 12 and which is used to attach device 10 to a support, such as to a metal or plastic pipe when device 10 is disposed therein.
  • the remainder of the water can be added to bring the final chitosan concentration to that which is desired, such as 1-5% (wt./wt.) or 1-3% (wt./wt.).
  • the predetermined time may be about, at least about, or at most about 5, 10, 15, 20, 25, or 30 minutes, or any range derivable therein.
  • blends will dissolve in high volumes of water. Therefore, methods for solubilizing blends that are capable of dissolving when added to high volumes of water such that the chitosan concentration is at least 0.1% are also contemplated. Also contemplated is a method of releasing soluble chitosan into water comprising contacting the permeable soluble chitosan delivery device with water to release soluble chitosan into the water. In some embodiments, flocculation or precipitation of matter in the water is induced after soluble chitosan is released into the water. As used herein, "flocculation” refers to a process of contact and adhesion whereby particles of a dispersion form larger-size clusters. Flocculation is synonymous with coagulation.
  • precipitation refers to the sedimentation of a solid material from a liquid solution.
  • the matter may be organic matter.
  • the matter may be selected from the group consisting of particles, sediment, suspended matter, and dissolved substances.
  • the water may be moving water, stream water, or stormwater.
  • solubility of chitosan are well-known in the art. One may determine solubility by, for example, weighing a sample of solid chitosan and correcting for moisture, form a solution with dilute acid, filter the solution through tared filter paper and collect insoluble material on the tared filter paper, dry and weigh the paper, and then calculate the percent of material that did not dissolve.
  • Methods may comprise steps described herein, or may consist of only of such steps, to the exclusion of any other steps. Methods may alternatively consist essentially of steps described herein. Methods consisting essentially of steps are methods that exclude components or steps that do not materially affect the novel and basic characteristics of the method or its effects. For example, methods consisting essentially of solubilizing chitosan in a chitosan-containing blend described herein to achieve a desired final chitosan concentration may exclude addition of a volume of a dilute acid solution. It is contemplated that any embodiment discussed herein can be implemented with respect to any method, composition, or blend of the invention, and vice versa. Furthermore, blends and compositions described herein can be used to achieve methods of the invention.
  • Test 1 Mix 1 gm of solid acid and 1 gm of solid chitosan. Then slowly pour this blend into 1 L of stirring deionized water. Determine if chitosan is soluble. See Table 1 below.
  • Test 2 The acids used for this experiment were chosen from the acids that did not solubilize chitosan from Test 1. See Table 1 above. Mix 1 gm of solid acid and 1 gm of solid chitosan. Then slowly add water (2.5-5.0 ml) to this admixture and mix. Allow time (up to 5 minutes) for the chitosan to swell, then slowly add more water, about 2.5-5.0 ml at a time. Allow time for the chitosan to swell and dissolve. Determine if chitosan is soluble. If chitosan is not swelling and dissolving after 10 ml of water, the acid will not work under these conditions.
  • EXAMPLE 3 DISSOLUTION OF DIFFERENT TYPES OF CHITOSAN Test 3.
  • the solid chitosan used in Examples 1 and 2 was derived from crab shell.
  • a different solid chitosan was then prepared from Icelandic shrimp shell, ground to a particle size where about 90% of the particles ranged from about 125 microns to about 850 microns, as before.
  • the solid acid used was adipic acid. The results were very comparable to the results with the previous lot and type of solid chitosan: the solid chitosan dissolved fast and only a few particles were left.
  • Test 4 Table 3 below shows the results from an experiment in which a very high volume of water was used to attempt to dissolve the chitosan acid blends, very much like Test 1 above. But unlike Test 1 above, the concentration of both solid chitosan and solid acid was 10 times less: the concentration of solid chitosan was 0.01% vs. 0.1% in Test 1 above and the concentration of solid acid was 0.01% vs. 0.1% in Test 1. The experiment entailed mixing 0.1 gm of solid chitosan with 0.1 gm of solid acid, then slowly adding it to 1 L of mixing water.
  • Test 5 the blends were put into fabric bags or sachets made from the same material as what is used for the StormKlear® Gel FloeTM contactor.
  • the fabric has small holes or pores to allow the release of the solubilized chitosan.
  • the size of the sachet was about 2-1/4" x 2-1/4" and contained 2.25 gm of solid acid mixed with 2.25 gm of solid chitosan.
  • the particle size of the solid acid was typically smaller than the particle size of the chitosan, e.g., the solid acid was more of a powder, such as smaller than about 125 microns.
  • the sachets were then placed into flowing tap water to determine if soluble chitosan would be released.
  • Two sachets were placed in 4 gallons of recirculating water at first, then placed into 20 gallons later in the day.
  • a pH controller and 0.1 N NaOH was used to keep the pH at approximately 8.4-8.8.
  • One sachet used solid malic acid and the other used solid lactic acid.
  • the 20 gallons of water was changed twice a day, once in the morning and once in the afternoon. The reason the water was changed was to remove any solubilized chitosan building up, so that the solubility limit of chitosan at that pH was not reached, which would retard the release of additional chitosan.
  • the test was run over the course of 3 days and the sachets were examined periodically.
  • the sachets released chitosan immediately upon placement in the high pH water, and solubilized chitosan gel could be seen on the outside of the sachets.
  • the sachet had swelled and, when pressed, chitosan gel came out.
  • the sachet with the lactic acid was less swollen but the sachet with the malic acid was about the same. Both seem to have solubilized chitosan gel in them. It seems under these conditions the high pH of 8.5 does not seem to prevent the solubilization of the chitosan.
  • the size and weight of the sachets were different, demonstrating that the release rate of the chitosan between the two blends was different.
  • the water containing the released chitosan was able to flocculate sediment suspended in water.
  • the table below shows the results of using larger chitosan particle size (about 1700 microns or less and flake about 0.5 to about 1 cm) compared to previous Examples and the effect on solubility.
  • a solid acid that solubilizes chitosan well such as adipic acid
  • the 0.1% concentration method and low volume solubility (LVS) method have good solubility results.
  • Complete solubility takes longer because of the larger particle size.
  • Solid malic acid which has a good LVS with the standard particles (that is, wherein about 90% of the particles range in size from about 125 microns to about 850 microns, as described above), did not have as good solubility with the larger particles (even allowing hours to dissolve) unless 2 times the normal amount of acid was used. See the table below.
  • the blends with the larger particle size were placed inside sachets as used in Example 5 to determine solubility performance.
  • the sachets were placed in running tap water for 30 minutes then placed into 20 gallons of pH
  • Test 1 Mix 2 gm of sodium diacetate and 1 gm of chitosan. Then slowly pour this admixture into 1 L of stirring deionized water. Solubility, fair; Time, medium.
  • Test 2 Mix 3 gm of sodium diacetate and 1 gm of chitosan. Then slowly pour this admixture into 1 L of stirring deionized water. Solubility, good; Time, medium.
  • Test 3 Low water volume solubility (LVS) method: Mix 1 gm of sodium diacetate and 1 gm of chitosan. Then slowly add water (2.5-5.0 ml) to this admixture and mix. Allow time (up to 5 minutes) for the chitosan to swell, then slowly add more water, about 2.5-5.0 ml at a time. Allow time for the chitosan to swell and dissolve. Chitosan was mostly soluble under this method.
  • LPS Low water volume solubility

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Abstract

La présente invention concerne des mélanges contenant du chitosane et des procédés de dissolution et d'utilisation de chitosane. Un mélange comprend un acide solide ou un agent solide générant un proton in situ en présence d'eau, ainsi qu'un chitosane solide déshydraté, ledit mélange pouvant éventuellement contenir d'autres composants. Ces mélanges se présentent sous une forme particulaire, déshydratée et fluide. Les procédés de dissolution d'un mélange comprennent en règle générale l'adjonction d'une certaine quantité du mélange à un faible volume d'eau et le mélange du tout jusqu'à dissolution du chitosane et de l'acide solide ou de l'agent solide, puis une nouvelle dilution du mélange grâce à l'adjonction d'eau ou, encore, l'utilisation du mélange tel quel. L'invention concerne également des dispositifs contenant lesdits mélanges, ainsi que des procédés d'utilisation desdits dispositifs, par exemple pour la libération contrôlée de chitosane solubilisé dans une masse d'eau, par exemple un cours d'eau, contenant des impuretés (par exemple des particules, des sédiments ou des substances en suspension ou dissoutes), afin de provoquer la floculation ou la précipitation desdites impuretés.
PCT/US2010/039259 2009-06-16 2010-06-18 Compositions et procédés associés à des mélanges contenant du chitosane solide WO2010148357A1 (fr)

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CA2764857A CA2764857A1 (fr) 2009-06-16 2010-06-18 Compositions et procedes associes a des melanges contenant du chitosane solide
BRPI1014029-8A BRPI1014029A2 (pt) 2009-06-16 2010-06-18 Formulações e métodos para misturas contendo quitossana sólida.
US12/852,098 US8168767B2 (en) 2010-06-18 2010-08-06 Formulations and methods for solid chitosan-containing blends
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