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WO1991000298A1 - Methode pour la fabrication continue de chitosan microcristallin - Google Patents

Methode pour la fabrication continue de chitosan microcristallin Download PDF

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Publication number
WO1991000298A1
WO1991000298A1 PCT/FI1990/000173 FI9000173W WO9100298A1 WO 1991000298 A1 WO1991000298 A1 WO 1991000298A1 FI 9000173 W FI9000173 W FI 9000173W WO 9100298 A1 WO9100298 A1 WO 9100298A1
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WO
WIPO (PCT)
Prior art keywords
reactor
chitosan
solution
microcrystalline
microcrystalline chitosan
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
PCT/FI1990/000173
Other languages
English (en)
Inventor
Henryk Struszczyk
Antoni Niekraszewicz
Krzystyna WRZES^´NIEWSKA-TOSIK
Stanislaw Koch
Olli KIVEKÄS
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
FIREXTRA Oy
Instytut Wlokien Chemicznych
Original Assignee
FIREXTRA Oy
Instytut Wlokien Chemicznych
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 FIREXTRA Oy, Instytut Wlokien Chemicznych filed Critical FIREXTRA Oy
Priority to SU904894886A priority Critical patent/RU2046800C1/ru
Publication of WO1991000298A1 publication Critical patent/WO1991000298A1/fr
Priority to NO910707A priority patent/NO303339B1/no
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
    • C08B37/00—Preparation of polysaccharides not provided for in groups C08B1/00 - C08B35/00; Derivatives thereof
    • C08B37/0006—Homoglycans, i.e. polysaccharides having a main chain consisting of one single sugar, e.g. colominic acid
    • C08B37/0024—Homoglycans, i.e. polysaccharides having a main chain consisting of one single sugar, e.g. colominic acid beta-D-Glucans; (beta-1,3)-D-Glucans, e.g. paramylon, coriolan, sclerotan, pachyman, callose, scleroglucan, schizophyllan, laminaran, lentinan or curdlan; (beta-1,6)-D-Glucans, e.g. pustulan; (beta-1,4)-D-Glucans; (beta-1,3)(beta-1,4)-D-Glucans, e.g. lichenan; Derivatives thereof
    • C08B37/0027—2-Acetamido-2-deoxy-beta-glucans; Derivatives thereof
    • C08B37/003—Chitin, i.e. 2-acetamido-2-deoxy-(beta-1,4)-D-glucan or N-acetyl-beta-1,4-D-glucosamine; Chitosan, i.e. deacetylated product of chitin or (beta-1,4)-D-glucosamine; Derivatives thereof

Definitions

  • This invention relates to continuous manufacture of microcrystalline chitosan.
  • the method is based on periodical precipitation of chitosan with especially a deacetyla- tion degree higher than 30%.
  • the chitosan is dissolved in the aqueous solution of organic or inorganic acid, and it is precipitated by aqueous solutions of alkaline metal hydroxides with application of strong stirring.
  • the precipitated chitosan in a form of gel or disper ⁇ sion is subjected to a purification process by several water washing.
  • microcrystalline chitosan Periodical system of manufacture of microcrystalline chitosan causes that its production cycle is time- consuming, taking up time not less than 12-24 hours. It also causes high consumption of energy as well as washing water.
  • the microcrystalline chitosan obtained is characterized by heterogenenou ⁇ properties in the respective portions.
  • the well-known method does not allow to obtain microcrystalline chitosan with homoge ⁇ founded properties.
  • the object of this invention is continuous manufac ⁇ ture of microcrystalline chitosan, by continuous precipitation of microcrystalline chitosan by an aqueous solution of alkaline metal hydroxides from the standard chitosan dissolved in an aqueous organic or inorganic acid, or in a solution of their salts.
  • the continuous manufacture of micro- crystalline chitosan by initiation of chitosan precipi ⁇ tation from its aqueous solution in the organic or inorganic acids or their salts, by an aqueous solution of alkaline metal hydroxides or their salts comprises that a chitosan solution in the an aqueous acid solution, especially acetic acid with polymer con ⁇ centration not lower than 0.01 wt%, is introduced by a continuous system to a reactor, together with an aqueous solution of an alkaline metal hydroxides or a salt thereof, especially with an aqueous sodium hydroxide solution with a concentration of 0.1-20 wt%.
  • the chitosan solution is introduced into a reactor with a rate of 0.1-20 volume parts per 1 hour and per 1 volume part of working reactor capacity, whereas the alkaline solution is introduced with a rate of 0.1-10 volume parts per 1 hour and per 1 volume part of working reactor capacity.
  • the reagent introduced into a reactor with the above rate assures the maintenance of the pH of the reaction mixture on a level equal to or higher than 7.
  • microcrystalline chitosan dispersion with a pH equal to or higher than 7 is withdrawn by the continuous system with a rate necessary to maintain a constant volume of the reaction mixture.
  • microcrystalline chitosan dispersion is storaged into a container and then it is purified by the continuous water washing or by the ultrafiltration technique, the purification being continued to a moment where the conductivity of the effluent is equal to the con- ducivity of the water used.
  • Purified microcrystalline chitosan dispersion is subjected to eventual concentra ⁇ tion to the polymer content of 0.5-10.0 wt% and drying by the well-known methods.
  • the continuous manufacture of microcrystalline chitosan comprises also that a chitosan solution in aqueous solutions of acids, and the aqueous solutions of alkaline metal hydroxides as well as their salts are introduced continuously with a rate described above into a reactor equipped with a system of continuous circulation and the product is circulated in a closed reactor system, and at the same time a stream of microcrystalline chitosan is continuously withdrawn.
  • the stream is divided in two parts . The first part is returned into the reactor and the second part is directed to a compensation tank and then it is puri- fied.
  • the microcrystalline chitosan dispersion is taken off from the reactor with a rate suitable to keep a constant volume of reaction mixture in the reactor.
  • an additional circulation allows to obtain microcrystalline chitosan with a high degree of properties of homogeneity.
  • an aqueous solution of alkaline metal hydroxide is introduced directly into the circulation system of the reactor.
  • the method according to the invention allows to obtain a microcrystalline chitosan in a form of dispersion characterized by properties suitable for colloids and distinguished by the water retention value of WRV up to 5000%, particles dimension ranging from 0.1 to 50 ⁇ m as well as dispersion form stability.
  • a dried product is characterized by a powder form with a particles dimension within l-100 ⁇ m and it is distinguished by WRV of 200-600%, crystallinity index Krl up to 95% and a minimal dispersion of chitosan parameters.
  • the method according to the invention allows to obtain a high yield of products on a level of 95-99% in relation to the amount of standard chitosan used, and at the same time the method assures the reduction of raw materials and energy consumption as well as the reduction of manufacturing costs, and also the elimina- tion of arduous operation, in comparison to a periodi ⁇ cal process.
  • An important object of method according to the invention is to reduce time for microcrystalline chitosan manufacture in .comparison to a periodical method.
  • the investigations have shown that a microcrys- talline chitosan obtained according to the method of the invention in a time of 1-5 hours is related to an amount of product produced in a time of 12-24 hours according to a periodical method.
  • Another important object of the method according to the invention is to assure the continuous precipitation of microcrystalline chitosan with required particles dimensions as well as properties, regulated by the concentration, the introduction rate of the reagents and also eventually by dispersion circulation rate in a reactor.
  • a method according to the invention allows to manufacture homogenous products with reproducible parameters in a time of production without outside intervention which has required time in the periodical method.
  • Microcrystalline chitosan obtained by the method according to the invention is applied to the polymeric films formation in the chemical industry, medicine, pharmaceutical as well as cosmetic industries and also in agriculture.
  • Amethod for continuous manufacture of microcrystalline chitosan according to the invention is realized by an installation, which as an example is presented on the appended schematic figure.
  • the installation for microcrystalline chitosan anufac- ture is equipped with a reactor !_ containing a stirrer 2.
  • a pipe- 3 for introduction of chitosan solution and a pipe 4 for introduction of the precipitating agent, such as hydroxide solution.
  • a pipe 5 for microcrystal- line chitosan dispersion drained off from the reactor 1 is equipped with a pump 6, whose exit is joined to a circulation system 7 for continuous returning of part of dispersion into -the reactor 1 and secondly the exit is joined to a pipe 8 for the dispersion conveyed into a compensation tank 9.
  • the pipe 5 is located in a lower part of the reactor 1.
  • the compensa ⁇ tion tank 9 is joined to an installation 10 for continuous purification of microcrystalline chitosan dispersion, which is equipped with pipes 11 for introduction and draining of purification water as well as with a pipe 12 for the draining of the purified product.
  • the installation 10 can have also the form of a ultrafiltration system.
  • the circula ⁇ tion system 7 of the reactor 1 is equipped in its upper part with a pipe 13 for introduction of the precipitating agent, such as hydroxide solution.
  • the action of the installation is the following: The initiation of the precipitation process after the raw materials introduction into the reactor 1 with the working stirrer 2 is performed such that the raw materials are continuously introduced into the reac ⁇ tor 1.
  • a hydroxide solution is introduced into the reactor 1 by the pipe 4, or by the pipe 13 into the circulation system 7, in dependence of the chosen system.
  • the neutralization of the reaction mixture up to the value of pH equal to or higher than 7 takes place in the reactor 1 with continuous stirring and optional dispersion circulation.
  • the microcrystalline chitosan dispersion obtained is simultaneously taken off from the reactor 1 by a continuous system by the pipe 5 and it is completely conveyed into the compensa- tion tank 9, or it is divided in two parts whereof the first is conveyed into the compensation tank 9 and the second part is introduced into the circulation system 7 • and returned into back into the reactor 1.
  • the microcrystalline chitosan present in the compensation tank 9 is next delivered into the purification instal ⁇ lation 10.
  • the microcrystalline chitosan is delivered after purification to a storage installation or to a dryer.
  • chitosan solution 500 volume parts of 1% chitosan solution in a 4% aqueous solution of acetic acid and 2.5% aqueous sodium hydroxide solution are introduced into a reactor of the type presented on the Figure having the working volume of 1000 volume parts.
  • the chitosan used in the reaction was characterized by average molecular weight of 6.07x10 ⁇ , deacetylation degree of 71.8% and WRV of 129%.
  • microcrystalline chitosan was precipitated with the working stirrer to obtain a pH of 8.0 and then, by a continuous system, a 1% chitosan solution in 4% aqueous acid solution with an introduction rate of 2400 volume parts per 1 hour and a 4% aqueous hydroxide solution with an introduction rate of 1728 volume parts per 1 hour were introduced to obtain a mixture pH of 8.0 + 0.3.
  • microcrystalline chitosan disper ⁇ sion was taken off from the reactor with a rate suitable to keep a constant volume of mixture in the reactor.
  • the dispersion was delivered into a compensation tank and it was next continuously deliver ⁇ ed into a purification installation, where it was continuously washed by water to obtain a product with an EMP value of 28mV (electromotive power), whereas the initial product was characterized by the EMP value of 95 mV.
  • the product was obtained in a form of stable gel with a white colour and it was charac ⁇ terized by a microcrystalline chitosan content of 2.45 wt% calculatied on a dry polymer weight, WRV of 906% and an average molecular weight of 3.59x10 ⁇ .
  • the product yield was 30.9 weight parts of microcrys ⁇ talline polymer per 1000 volume parts of reactor and 1 hour.
  • Example 1 400 volume parts of 1.0% solution of chitosan with the properties shown in Example 1 in a 4% aqueous actic acid solution were introduced into the reactor as in Example 1.
  • the microcrystalline chitosan disper ⁇ sion was precipitated under continuous stirring with 2.5% aqueous sodium hydroxide solution to obtain a mixture of pH 7.5, whereas 1.0% chitosan solution in a 4% aqueous acetic acid solution with introduction rate of 2940 volume parts per 1 hour and 2,5% aqueous sodium hydroxide solution with a rate of 3060 volume parts per hour were continuously introduced into the reactor to obtain a mixture reaction having a pH of 7.5 ⁇ 0.2.
  • microcrystalline chitosan formation process was realized with the incorporated circulation system characterized by a rate of circulation of 2940 volume parts per 1 hour.
  • the preci- pitated microcrystalline chitosan dispersion was taken off for a compensation tank with a rate suitable to keep a constant volume in the reactor.
  • the microcrystalline chitosan dispersion with a value of EMP of 112 mV was delivered to a purification installa ⁇ tion to obtain an eluate with an EMP value of 34 mV.
  • the product was obtained in a form of stable gel with a white colour and yield of 30.9 weight parts of microcrystalline chitosan per 1 hour and 1000 volume parts of reactor.
  • the product was characterized by 4.8 wt% of microcrystalline chitosan calculated on a dry weight of polymer, and WRV of 3993%.
  • microcrystalline chitosan dispersion was made in the reactor as in Example 1 with the application of an 1% chitosan solution in a 4% aqueous acetic acid solution with an introduction rate of 3780 volume parts per 1 hour and with the application of 4% aqueous sodium hydroxide solution with the rate of 3960 volume parts per hour, maintaining other conditions as in Example 1.
  • the product was obtained in a form of stable gel with a white colour, characterized by microcrystalline chitosan content of 7.44 wt% calculated on a polymer weight, and WRV of 1459%.
  • the yield of product was 36 weight .parts of polymer from 1000 reactor volume parts and 1 hour.
  • Example 4 400 volume parts of 0.5% chitosan solution in 4% aqueous acetic acid solution characterized by proper- ties as in Example 1 was introduced into the reactor as in Example 1.
  • the microcrystalline chitosan disper ⁇ sion was precipitated during a continuous stirring by 2.5% aqueous sodium hydroxide solution to obtain a pH of 7.8.
  • a 0.5.% chitosan solution in 4% aqueous acetic acid solution with a constant rate of introduction of 5280 volume parts per 1 hour, and 2.5% aqueous sodium hydroxide solution with an introduction rate of 5900 volume parts per 1 hour were continuously introduced to obtain a mixture pH of 7.7+0.3.
  • Production and purification process were the same as in Example 1.
  • the product was obtained in a form of stable gel with white colour, characterized by microcrystalline chitosan content of 6.5 wt% calculated on a dry polymer weight, and WRV of 1994%.
  • the reaction yield was 26.4 weight parts of microcrystalline polymer per 1000 reactor volume parts and 1 hour.
  • Example 4 400 volume parts of 0.5% chitosan solution in 2% aqueous acetic acid solution characterized by proper ⁇ ties as in Example 1 was introduced into the reactor as in Example 1.
  • the microcrystalline chitosan disper ⁇ sion was precipitated with a continuous stirring using a 2.5% aqueous sodium hydroxide solution to obtain a mixture pH of 7.4, and a 0.5% chitosan solution in a 2% aqueous acetic acid solution was continously introduced with the sodium hydroxide solution rate as in Example 4 to obtain a mixture pH of 7.4 , +0.1
  • Production and purification processes were the same as in Example 1.
  • the initial microcrystalline chitosan dispersion was characterized by the value of EMP of 85 mV and after purification process the value of EMP of was 15 V.
  • the product was obtained in a form of stable white gel characterized by microcrystalline chitosan content of 9.25 wt% calculated on a dry polymer weight and WRV of 850%.
  • the product yield was 15.7 weight parts of microcrystalline polymer per 100 reactor volume parts and 1 hour.
  • the microcrystalline chitosan dispersion was obtained in a reactor as in Example 1 using 1% chitosan solution in a 4% aqueous acetic acid solution, as well as a 7.5% aqueous sodium hydroxide solution introduced into a working circulation system. Then 1% chitosan solution in a 4% aqueous acetic acid solution with a constant introduction rate of 5280.volume parts per 1 hour, as well as a 7.5% aqueous sodium hydroxide solution with an introduction rate of 1944 volume parts per 1 hour were continuously introduced into the reaction mixture having the initial pH of 7.8, to obtain a mixture pH of 7.7+0.2. Production and purification processes were analogous to those in Example 1.
  • the initial dispersion produced was characterized by EMP value of 99 mV and after purification the EMP was 29 mV.
  • the product was obtained in a form of stable white gel characterized by microcrystalline chitosan content of 9.05 wt%, calculated on a dry polymer weight, WRV of 587% and average molecular weight of 3.62x10 ⁇ .
  • the product yield was 36 weight parts of microcrystal ⁇ line polymer per 1000 reactor volume parts and 1 hour.
  • Example 1 500 volume parts of 0.5% chitosan solution in a 4% aqueous acetic acid solution was introduced into the reactor as in Example 1.
  • the chitosan used was charac ⁇ terized by average molecular weight of 7.7x10 ⁇ , deacetylation degree of 67.5% and WRV of 230%.
  • the microcrystalline chitosan dispersion was precipitated with stirring the 0.5% chitosan solution in the 4 % aqueous acetic acid to obtain a pH of 7.9, and then with a continuous method using the continuous circula ⁇ tion system as in Example 2.
  • a 0.5% chitosan solution in 4% aqueous acetic acid solution with a constant introduction rate of 5280 volume parts per 1 hour, as well as 5.0% aqueous sodium hydroxide solution with a constant introduction rate of 2880 volume parts per 1 hour were introduced into the reactor, thus obtaining a mixture pH of 7.7.+.0.3.
  • Production process was realized as in Example 2, whereas the purification process was realized in a ultrafiltration installation to obtain an EMP value of 9 mV.
  • the product was obtained in a form of stable white gel characterized by microcrystalline chitosan content of 9.05 wt%, calculated on a dry polymer weight, WRV of 830% and average molecular weight of 4.9.10 5 .
  • the product yield was 36 weight parts of microcrystalline polymer per 1000 reactor volume parts and 1 hour.
  • Example 7 • properties as in Example 7 was introduced into a reactor as in Example 1.
  • the microcrystalline chitosan dispersion was precipitated with a continuous stirring using a 5.5 wt% aqueous sodium carbonate solution to obtain a mixture with a pH of 7.6, whereafter 0.75 wt% chitosan solution in a 1.5 wt% aqueous acetic acid solution was continuously introduced with constant rate of 6250 volume parts per 1 hour, and a 5.5 wt% aqueous sodium carbonate solution at a rate of 9500 volume parts per 1 hour was introduced to obtain a mixture pH of 7.6 ⁇ 0.1.
  • Production and purification procedure was the same as in Example 7.
  • the initial microcrystalline chitosan dispersion was characterized by the value of EMP of 70 mV and after purification of the EMP was 8 mV.
  • the product was obtained in a form of stable white gel characterized by microcrystalline chitosan content of 4.5 wt% calculated on a dry polymer weight, and WRV of 1450%.
  • the product yield was 19.8 weight parts of microcrystalline polymer per 1000 reactor volume parts and 1 hour.

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Abstract

Procédé de fabrication continue de chitosan microcristallin par précipitation de chitosan à partir de ses solutions aqueuses dans de l'acide organique ou inorganique, ou ses sels. La solution de chitosan dans une solution acide aqueuse, en particulier dans l'acide acétique, ayant une concentration de polymère qui n'est pas inférieure à 0,01 % em poids, de préférence ayant une concentration de polymère comprise entre 0,1 et 2,0 % en poids, est introduite continuellement, avec une solution alcaline, telle qu'une solution aqueuse d'un hydroxyde métallique alcalin ou son sel ayant une concentration allant de 0,1 à 20,0 % en poids, dans un réacteur. La solution de chitosan est introduite dans le réacteur à un taux compris dans une étendue de 0,1-20 parties de volume par 1 heure et 1 partie de volume de réacteur et la solution alcaline est introduite dans un réacteur à un taux compris entre 0,1 et 10,0 parties de volume par 1 heure et 1 partie de volume de réacteur de manière à obtenir un mélange pH égal ou supérieur à 7. La dispersion de chitosan microcristallin possédant ledit pH est enlevée simultanément dudit réacteur par un système continu à un taux permettant de maintenir un volume de mélange de réaction constant dans le réacteur, ladite dispersion de chitosan microcristallin étant récupérée dans un réservoir de compensation et continuellement purufiée, en particulier par un lavage à l'eau continu ou par un procédé d'ultrafiltration. Le chitosan microcristallin purifié est enfin concentré de manière à obtenir une teneur en polymère comprise entre 0,5 et 10,0 % en poids et séché par un procédé de séchage connu.
PCT/FI1990/000173 1989-06-30 1990-07-02 Methode pour la fabrication continue de chitosan microcristallin Ceased WO1991000298A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
SU904894886A RU2046800C1 (ru) 1989-06-30 1990-07-02 Способ получения микрокристаллического хитозана
NO910707A NO303339B1 (no) 1989-06-30 1991-02-22 FramgangsmÕte for kontinuerlig tilvirkning av mikrokrystallisk chitosan

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI893223 1989-06-30
FI893223A FI83426C (fi) 1989-06-30 1989-06-30 Foerfarande foer kontinuerlig framstaellning av mikrokristallin kitosan.

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WO1991000298A1 true WO1991000298A1 (fr) 1991-01-10

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FI (1) FI83426C (fr)
NO (1) NO303339B1 (fr)
RU (1) RU2046800C1 (fr)
WO (1) WO1991000298A1 (fr)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1994006484A1 (fr) * 1992-09-14 1994-03-31 Novasso Oy Pansement protecteur pour blessure
US5554445A (en) * 1992-07-29 1996-09-10 Novasso Oy Method for seed encrusting
WO1998034625A1 (fr) * 1997-02-06 1998-08-13 Novasso Oy Substance aux fins de la reduction de teneurs en lipides et en cholesterol et technique afferente
WO2000005974A1 (fr) * 1998-07-30 2000-02-10 E-Nutriceuticals, Inc. Nouvelles compositions liquides contenant des chitosanes et methodes de preparation et d'utilisation correspondantes
WO2000024785A1 (fr) * 1998-10-23 2000-05-04 Novasso Oy Substance utilisee pour la reduction du taux de cholesterol et de lipides
WO2001000044A1 (fr) * 1999-06-25 2001-01-04 E-Nutriceuticals, Inc. Compositions liquides contenant du chitosane et procedes de preparation et d'utilisation
WO2001087988A1 (fr) * 2000-05-12 2001-11-22 The Procter & Gamble Company Preparation de particules de chitosane
RU2209069C1 (ru) * 2001-11-29 2003-07-27 Майер Борис Олегович Биологически активная композиция
WO2003066682A1 (fr) * 2002-02-07 2003-08-14 Abbott Laboratories De Costa Rica Ltd Procede de deproteinisation de chitosane
US6740752B2 (en) 2000-05-12 2004-05-25 The Procter & Gamble Company Process for preparing chitosan particles
WO2004078790A1 (fr) * 2003-03-06 2004-09-16 The Procter & Gamble Company Poudre de chitosan
WO2004087307A1 (fr) * 2003-03-31 2004-10-14 Boris Olegovich Maier Produit a base de chitosane, son procede de preparation, procede de preparation de derives dudit produit a base de chitosane et compositions a base de ceux-ci.
US7482019B2 (en) * 2002-01-09 2009-01-27 Abbott Laboratories Methods of producing modified microcrystalline chitosan and uses therefor
CN100572399C (zh) * 2006-09-19 2009-12-23 宁波新芝生物科技股份有限公司 一种超微化几丁聚糖产品的加工方法
WO2011117111A1 (fr) 2010-03-25 2011-09-29 Lenzing Aktiengesellschaft Utilisation d'une fibre cellulosique
US8524326B2 (en) 2008-01-22 2013-09-03 Lenzing Aktiengesellschaft Process for the treatment of cellulosic molded bodies

Families Citing this family (5)

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RU2147590C1 (ru) * 1998-09-15 2000-04-20 Дальневосточный государственный технический рыбохозяйственный университет Способ получения хитозана
RU2189751C2 (ru) * 2000-01-17 2002-09-27 Северо-Кавказский государственный технический университет Способ приготовления коллоидного раствора хитозана
GB201309607D0 (en) * 2013-05-29 2013-07-10 Medtrade Products Ltd Process for producing low endotoxin chitosan
GB201309606D0 (en) * 2013-05-29 2013-07-10 Medtrade Products Ltd Process for producing low endotoxin chitosan
RU2627540C1 (ru) * 2016-04-14 2017-08-08 Сергей Вадимович Левитин Способ получения нанокристаллитов низкомолекулярного хитозана

Citations (1)

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CHEMICAL ABSTRACTS, Volume 109, No. 26, 26 December 1988, (Columbus, Ohio, US), YOKOTA HIROSHI, "Microcrystalline Chitosan and Manufacture", page 111, Abstract 233068n; & JP,A,63 182 304 (27-07-1988). *
CHEMICAL ABSTRACTS, Volume 110, No. 26, 26 June 1989, (Columbus, Ohio, US), STRUSZCZYK H. et al., "Chitosan-based Products, Especially Films and Their Manufacture", page 105, Abstract 233521a; & VALTION TEKNILLINEN TUTKIMUSKESKUS, 1988, 28. *
JOURNAL OF APPLIED POLYMER SCIENCE, Vol 33, 1987, HENRYK STRUSZCZYK, "Microcrystalline Chitosan. I. Preparation and Properties of Microcrystalline Chitosan", pages 177-189, page 1, "Introduction", page 2, "Methods". *

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5554445A (en) * 1992-07-29 1996-09-10 Novasso Oy Method for seed encrusting
WO1994006484A1 (fr) * 1992-09-14 1994-03-31 Novasso Oy Pansement protecteur pour blessure
WO1998034625A1 (fr) * 1997-02-06 1998-08-13 Novasso Oy Substance aux fins de la reduction de teneurs en lipides et en cholesterol et technique afferente
US6323189B1 (en) 1998-07-30 2001-11-27 E-Nutriceuticals, Inc. Chitosan-containing liquid compositions and methods for their preparation and use
WO2000005974A1 (fr) * 1998-07-30 2000-02-10 E-Nutriceuticals, Inc. Nouvelles compositions liquides contenant des chitosanes et methodes de preparation et d'utilisation correspondantes
AU747611B2 (en) * 1998-07-30 2002-05-16 E-Nutriceuticals, Inc. Novel chitosan-containing liquid compositions and methods for their preparation and use
WO2000024785A1 (fr) * 1998-10-23 2000-05-04 Novasso Oy Substance utilisee pour la reduction du taux de cholesterol et de lipides
WO2001000044A1 (fr) * 1999-06-25 2001-01-04 E-Nutriceuticals, Inc. Compositions liquides contenant du chitosane et procedes de preparation et d'utilisation
WO2001087988A1 (fr) * 2000-05-12 2001-11-22 The Procter & Gamble Company Preparation de particules de chitosane
US6740752B2 (en) 2000-05-12 2004-05-25 The Procter & Gamble Company Process for preparing chitosan particles
RU2209069C1 (ru) * 2001-11-29 2003-07-27 Майер Борис Олегович Биологически активная композиция
US7482019B2 (en) * 2002-01-09 2009-01-27 Abbott Laboratories Methods of producing modified microcrystalline chitosan and uses therefor
WO2003066682A1 (fr) * 2002-02-07 2003-08-14 Abbott Laboratories De Costa Rica Ltd Procede de deproteinisation de chitosane
WO2004078790A1 (fr) * 2003-03-06 2004-09-16 The Procter & Gamble Company Poudre de chitosan
WO2004087307A1 (fr) * 2003-03-31 2004-10-14 Boris Olegovich Maier Produit a base de chitosane, son procede de preparation, procede de preparation de derives dudit produit a base de chitosane et compositions a base de ceux-ci.
CN100572399C (zh) * 2006-09-19 2009-12-23 宁波新芝生物科技股份有限公司 一种超微化几丁聚糖产品的加工方法
US8524326B2 (en) 2008-01-22 2013-09-03 Lenzing Aktiengesellschaft Process for the treatment of cellulosic molded bodies
WO2011117111A1 (fr) 2010-03-25 2011-09-29 Lenzing Aktiengesellschaft Utilisation d'une fibre cellulosique

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FI83426B (fi) 1991-03-28
NO910707L (no) 1991-02-22
NO303339B1 (no) 1998-06-29
RU2046800C1 (ru) 1995-10-27
FI83426C (fi) 1991-07-10
NO910707D0 (no) 1991-02-22
FI893223L (fi) 1990-12-31
FI893223A0 (fi) 1989-06-30

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