CA1057595A - Coated bead-shaped activated carbon for purifying blood - Google Patents
Coated bead-shaped activated carbon for purifying bloodInfo
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- CA1057595A CA1057595A CA255,516A CA255516A CA1057595A CA 1057595 A CA1057595 A CA 1057595A CA 255516 A CA255516 A CA 255516A CA 1057595 A CA1057595 A CA 1057595A
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- activated carbon
- coated
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/30—Processes for preparing, regenerating, or reactivating
- B01J20/32—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating
- B01J20/3231—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating characterised by the coating or impregnating layer
- B01J20/3242—Layers with a functional group, e.g. an affinity material, a ligand, a reactant or a complexing group
- B01J20/3268—Macromolecular compounds
- B01J20/3272—Polymers obtained by reactions otherwise than involving only carbon to carbon unsaturated bonds
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M1/00—Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
- A61M1/36—Other treatment of blood in a by-pass of the natural circulatory system, e.g. temperature adaptation, irradiation ; Extra-corporeal blood circuits
- A61M1/3679—Other treatment of blood in a by-pass of the natural circulatory system, e.g. temperature adaptation, irradiation ; Extra-corporeal blood circuits by absorption
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
- B01J20/20—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising free carbon; comprising carbon obtained by carbonising processes
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/30—Processes for preparing, regenerating, or reactivating
- B01J20/32—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating
- B01J20/3202—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating characterised by the carrier, support or substrate used for impregnation or coating
- B01J20/3204—Inorganic carriers, supports or substrates
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/30—Processes for preparing, regenerating, or reactivating
- B01J20/32—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating
- B01J20/3231—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating characterised by the coating or impregnating layer
- B01J20/3242—Layers with a functional group, e.g. an affinity material, a ligand, a reactant or a complexing group
- B01J20/3268—Macromolecular compounds
- B01J20/327—Polymers obtained by reactions involving only carbon to carbon unsaturated bonds
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/30—Processes for preparing, regenerating, or reactivating
- B01J20/32—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating
- B01J20/3231—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating characterised by the coating or impregnating layer
- B01J20/3289—Coatings involving more than one layer of same or different nature
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/30—Active carbon
- C01B32/354—After-treatment
- C01B32/372—Coating; Grafting; Microencapsulation
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Analytical Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Inorganic Chemistry (AREA)
- Heart & Thoracic Surgery (AREA)
- Vascular Medicine (AREA)
- Anesthesiology (AREA)
- Engineering & Computer Science (AREA)
- Cardiology (AREA)
- Biomedical Technology (AREA)
- Hematology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
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- Veterinary Medicine (AREA)
- External Artificial Organs (AREA)
- Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Activated carbon for use as an adsorbent in purifying blood is prepared by coating a bead-shaped particle of activated carbon with a film-forming material. The coated particles of activated carbon exhibit excellent properties with regard to the amount of free carbon dust present, ash dissolvable out, residual solvent present, the degree of coagulation of the blood, and high safety, as compared with conventional absorbents.
Activated carbon for use as an adsorbent in purifying blood is prepared by coating a bead-shaped particle of activated carbon with a film-forming material. The coated particles of activated carbon exhibit excellent properties with regard to the amount of free carbon dust present, ash dissolvable out, residual solvent present, the degree of coagulation of the blood, and high safety, as compared with conventional absorbents.
Description
This invention relates to activated carbon useful as an adsorbent for purification of blood.
Two types of apparatus are currently commonly used for purification of blood, for treating patients suffering from disfunction of the kidney or the liver. The two types of apparatus are the dialysis type which utilizes a dialysis dia-phragm and the adsorption type which utilizes adsorbents. The dialysis type is more popularly used at the present time. However, this type has the drawbacks that the apparatus is so large that the treatment is difficult and that a long time is required for the purification of the blood. Studies are therefore now in pro-gress for developing adsorption type apparatus wherein the above-mentioned drawbacks are absent. However, such adsorption type apparatus has drawbacks other than those present in the dialysis type apparatus. The adsorbents used presently for the adsorption type apparatus are those which are prepared by coating crushed carbon originating from plants (hereinafter referred to as "coated crushed active carbon"), for example, active carbon made of carbonized coconut sheIl (hereinafter referred to as "coated coconut active carbon"). Coated crushed active carbon is prepared, for example, by dipping the initial carbon into an ethyl alcohol-ethyl ether solution of pyroxylin, and thereafter drying the carbon. Electromicroscopic observation shows that a coated crushed active carbon, for example, the active carbon coated by the pyroxylin solution dissolved in the mixture of ethyl alcohol and ethyl ether, is not coated uniformly with a pyroxylin film but has some uncoated areas in which free carbon dust is exposed because the crushed active carbon has an irregular form with many sharp edges and strict cleavage surfaces. The edge portions of such carbon are often broken off, even by slight outer shock, resulting in free carboncdust being formed. When blood is treated with such carbon the carbon dust may be ~, -. ,. ~
- 1 - ~
J~
taken into the blood and deposited on internal organs. The adsorbent is usually further covered with a film of albumin or the like over the above-mentioned coating in order to avoid sticking and coagulating of blood components. When the crushed carbon is used, however, it is difficult to ensure that this outer covering is adequate. Also the sticking of blood platelets and the like often occurs due to the large number of sharp projections and edges of the carbon. Consequently, a temporary reduction of the number of blood platelets can not be avoided.
There is also known an improved method, wherein coating of the active coconut carbon with pyroxylin is carried out by a phase separation process using dioxan as a solvent. Although this method may provide a better coating film and a considerably reduced amount of free carbon dust, the amount of free carbon dust is still such as to prevent the carbon being used practically, and in addition, this method has also the drawback that blood components stick to the carbon. The greatest drawback of this method is that a large amount of harmful dioxan remains in the carbbn as residual solvent due to the difficulty of removing it, resulting in the dioxan inevitably dissolving in the blood.
Further, although the coated crushed carbon exhibits a high adsorp~ion capacity for materials having low molecular weights, it shows a lower adsorption capacity for materials having medium molecular weights.
The so-called "kidney toxin" in the blood of a patient suffering from kidney failure, whose blood must be purified, comprises various materials having different molecular weights.
The components of medium molecular weights, having unknown chemical structure, are more important than those of low molecular weights.
Thus an important drawback of the coated crushed active carbon is that the adsorption capacity on the medium molecular ~,~t~ 't, weight materials is low.
Ther~e is also known a granular active carbon which is prepared by mixing a powdery carbon with a binder, granulating the resulting mixture, and carbonizing the resulting granules to thereby activate them. When such granular active carbon is coated, the coated granular acti~e carbon is superior to coated crushed carbon with regard to the free carbon dust, sticking of blood and facility of coating, but the granular active carbon has very low adsorption capacity. . This granular active carbon 10. is, for the latter reason, unsuitable to use:for purification of blood.
Thus hitherto blood purification appar.atus of the adsorption type has not been .available.
The present inventors have carried out studies on activated carbon in the form of bead-shaped bodies to determine whether the such activated carbbn coated with a film can be employed as an adsorbent .in blood purification. The inventors have found that activated carbon in the form of bead-shaped particles can be easily coate:d by a conventional coating method without using the phase separation method using dioxan and that the resulting coated activated carbon has superior properties to the prior adsorbents from the viewpoints of the strength, free carbon dust, ignited ash, residual solvent and sticking of blood.
It has been further observed that such coated activated carbon shows high adsorption capacity for materials of medium molecular weight.
Accordingly the present invention provides activated carbon for purification of blood prepared by coating, by melt molding with a film-forming material, bead-shaped particles of activa*ed carbon obtained from pitch as a source material.
The activated carbon to.be used in the present invention is preferably an active carbon having a nearly perfect sphere ~ $-form and obtained from pi.tch as a source material by melt molding, that is, by molding melted` material. Such~activated carbon is different from conventional crushed or granulated active carbon.
Such activated carbon can be prepared by, for ex`ample, dispersing pitch in the melted state in water to form spheres, making said spheres non-fusible and carbonizing the same. For detailed descriptions of the preparation for such activated carbon refer-ence is directed to Japanese Patent Publications No. 25117/74 and No. 18879/75. Such:activated carbon is available in the market under the name of bead-shaped activated carbon (BAC) [Trade Mark, manufactured and sold by Taiyokaken Kabushiki Kaisha in Japan].
The film-forming:material is selected from the materials which may provide a semipermeab.le film. Such materials include pyroxylin, polypropylene,' copolymer of vinyl chl:oride-vinylidene chloride, ethylene glycol polymethacrylate and collagen.
The'activated carbon in the form of bead-shaped particles may be coated wi.th.the film-forming materials by a conventional process. Examp.les of such processes include pan coating, air suspension coating and spray drying. As a solvent to be'employed for dissolving the film-forming material to be used to coat the particles, it is desirable to use a solvent which'can be easily remo.ved in a drying step and which has a low toxicity even if dissolved in the blood.
In view of this,: ethanol is an especially preferred solvent when pyroxylin is used as the film-forming material.
When the coated activated carbon in the form of bead-shaped particles is used practically for the purification of the blood, it is desirable to further coat the particles with a film of a material such as albumin on the'surface of the first film described above.for preventing or inhibiting sticking and coagulating of the blood.
The coated activated carbon according to the present invention shows less free carbon dust, ash to be'dissolved out, residual solvent, and adsorption and coagulation of the blood components, and high safety, compared with prior coated coconut active carbon. Moreover, the active carbon according to the present invention shows a high adsorption capacity for toxic components in the blood, a high functionality, and a high facility of coating and operations, compared with coconut active carbon and granular active carbon.
The purification of blood can be thus carried out safely and effectively by using the coated activated carbon according to the present invention.
The accompanying drawing is graph adsorption spectrums of coated activated carbon according to the pres'ent invention (I) (shown by solid line), coated coconut active carbon (II) (shown by dotted line), coated granular active carbon (A) (shown by broken line) and the coated granular active carbbn (B) (shown by chain line). In the graph, adsorption capacity is plotted on the'ordinate and molecular weight is plotted on the abscissa.
This invention is illustrated by the following Examples and Exper'iments.
Example 1 To 5 g of pyroxylin were added 200 ml of absolute ethanol, and the mixture was blended with a homogenizer so as to be micronized. Thereafter, 800 ml of absolute ethanol were added to the solution. The solution was mixed and allowed to stand for 24 hours to make a 0.5% solution for spraying.
500 g of activated carbon (BAC) in the form of bead-shaped particles' having an average diameter of 0.6 mm were placed into a coating pan having a depth of 25 cm, an outside diameter of 30 cm, and a bore of 17 cm. The active carbon was coated by spraying 500 ml of said solution into the pan whilst blowing with rotation. The resulting coated active carbon was then dried at 80C for two days to obtain coated activated carbon in the form of bead-shaped particles.
The resulting coated activated carbon was dipped in water to debubble under a reduced pressure and was sterilized by steam under pressure. The sterilized activated carbon was then charged into a plastics vessel for the purification of the blood, the vessel having diameter of 3 cm, a height of 7 cm, and a volume of 50 ml and equipped with two filters at the upper end and the lower end thereof respectively. The vessel was charged with physiological saline water, which was then replaced with 80 ml. of a 0.5% physiological saline solution of albumin. After standing overnight, the active carbon was washed by a flow of physiological saline water. The blood was purified by being passed through the vesseI.
ExampLe 2 The same procedure was repeated, except that ethylene glycol polymethacrylate (sold under the name of Trade Mark "HYDRON") was substituted for pyroxylin.
Experiment The coated particles of bead-shaped activated carbon obtained as described in Example 1 were tested to determine var-ious properties thereof.
Coated coconut active carbon used as a control in this experiment was prepared by coating coconut active carbon available on the market with pyroxylin according to the phase separation process. Coated granular active carbons (A) and (B) were res-pectiveIy prepared by coating two granular active carbons (A) and (B) selected from those which are available on the market and offered by different manufacturers, with pyroxylin according to the method as described in Example 1.
(1) Amount of free carbon ~dust _ Ten grams of coated activated carbon in the form of bead-shaped particles were charged into a 200 ml conical flask.
There was added into the flask'physiological saline water which had been previously filtered twice by a millipore filter of 0.45 ~. The contents of the flask were degassed under a reduced pressure and decanted to remove excess water. An additional 150 ml of filtered physiological saline water were charged into the flask and the mixture was shaken for 45 minutes at 130 rpm in an incubator. After the shaking,,the number of the free carbon dust particles more than 1.2 micron in size were determined by a coolter counter. Conventional coated crushed coconut active carbon was selected as a control.
The results are'shown below.
Number of free carbon dust particles per ml Coated activated carbon in the form of bead-shaped particles 0 - 200 Coated crushed coconut active carbon 3000 - 5000
Two types of apparatus are currently commonly used for purification of blood, for treating patients suffering from disfunction of the kidney or the liver. The two types of apparatus are the dialysis type which utilizes a dialysis dia-phragm and the adsorption type which utilizes adsorbents. The dialysis type is more popularly used at the present time. However, this type has the drawbacks that the apparatus is so large that the treatment is difficult and that a long time is required for the purification of the blood. Studies are therefore now in pro-gress for developing adsorption type apparatus wherein the above-mentioned drawbacks are absent. However, such adsorption type apparatus has drawbacks other than those present in the dialysis type apparatus. The adsorbents used presently for the adsorption type apparatus are those which are prepared by coating crushed carbon originating from plants (hereinafter referred to as "coated crushed active carbon"), for example, active carbon made of carbonized coconut sheIl (hereinafter referred to as "coated coconut active carbon"). Coated crushed active carbon is prepared, for example, by dipping the initial carbon into an ethyl alcohol-ethyl ether solution of pyroxylin, and thereafter drying the carbon. Electromicroscopic observation shows that a coated crushed active carbon, for example, the active carbon coated by the pyroxylin solution dissolved in the mixture of ethyl alcohol and ethyl ether, is not coated uniformly with a pyroxylin film but has some uncoated areas in which free carbon dust is exposed because the crushed active carbon has an irregular form with many sharp edges and strict cleavage surfaces. The edge portions of such carbon are often broken off, even by slight outer shock, resulting in free carboncdust being formed. When blood is treated with such carbon the carbon dust may be ~, -. ,. ~
- 1 - ~
J~
taken into the blood and deposited on internal organs. The adsorbent is usually further covered with a film of albumin or the like over the above-mentioned coating in order to avoid sticking and coagulating of blood components. When the crushed carbon is used, however, it is difficult to ensure that this outer covering is adequate. Also the sticking of blood platelets and the like often occurs due to the large number of sharp projections and edges of the carbon. Consequently, a temporary reduction of the number of blood platelets can not be avoided.
There is also known an improved method, wherein coating of the active coconut carbon with pyroxylin is carried out by a phase separation process using dioxan as a solvent. Although this method may provide a better coating film and a considerably reduced amount of free carbon dust, the amount of free carbon dust is still such as to prevent the carbon being used practically, and in addition, this method has also the drawback that blood components stick to the carbon. The greatest drawback of this method is that a large amount of harmful dioxan remains in the carbbn as residual solvent due to the difficulty of removing it, resulting in the dioxan inevitably dissolving in the blood.
Further, although the coated crushed carbon exhibits a high adsorp~ion capacity for materials having low molecular weights, it shows a lower adsorption capacity for materials having medium molecular weights.
The so-called "kidney toxin" in the blood of a patient suffering from kidney failure, whose blood must be purified, comprises various materials having different molecular weights.
The components of medium molecular weights, having unknown chemical structure, are more important than those of low molecular weights.
Thus an important drawback of the coated crushed active carbon is that the adsorption capacity on the medium molecular ~,~t~ 't, weight materials is low.
Ther~e is also known a granular active carbon which is prepared by mixing a powdery carbon with a binder, granulating the resulting mixture, and carbonizing the resulting granules to thereby activate them. When such granular active carbon is coated, the coated granular acti~e carbon is superior to coated crushed carbon with regard to the free carbon dust, sticking of blood and facility of coating, but the granular active carbon has very low adsorption capacity. . This granular active carbon 10. is, for the latter reason, unsuitable to use:for purification of blood.
Thus hitherto blood purification appar.atus of the adsorption type has not been .available.
The present inventors have carried out studies on activated carbon in the form of bead-shaped bodies to determine whether the such activated carbbn coated with a film can be employed as an adsorbent .in blood purification. The inventors have found that activated carbon in the form of bead-shaped particles can be easily coate:d by a conventional coating method without using the phase separation method using dioxan and that the resulting coated activated carbon has superior properties to the prior adsorbents from the viewpoints of the strength, free carbon dust, ignited ash, residual solvent and sticking of blood.
It has been further observed that such coated activated carbon shows high adsorption capacity for materials of medium molecular weight.
Accordingly the present invention provides activated carbon for purification of blood prepared by coating, by melt molding with a film-forming material, bead-shaped particles of activa*ed carbon obtained from pitch as a source material.
The activated carbon to.be used in the present invention is preferably an active carbon having a nearly perfect sphere ~ $-form and obtained from pi.tch as a source material by melt molding, that is, by molding melted` material. Such~activated carbon is different from conventional crushed or granulated active carbon.
Such activated carbon can be prepared by, for ex`ample, dispersing pitch in the melted state in water to form spheres, making said spheres non-fusible and carbonizing the same. For detailed descriptions of the preparation for such activated carbon refer-ence is directed to Japanese Patent Publications No. 25117/74 and No. 18879/75. Such:activated carbon is available in the market under the name of bead-shaped activated carbon (BAC) [Trade Mark, manufactured and sold by Taiyokaken Kabushiki Kaisha in Japan].
The film-forming:material is selected from the materials which may provide a semipermeab.le film. Such materials include pyroxylin, polypropylene,' copolymer of vinyl chl:oride-vinylidene chloride, ethylene glycol polymethacrylate and collagen.
The'activated carbon in the form of bead-shaped particles may be coated wi.th.the film-forming materials by a conventional process. Examp.les of such processes include pan coating, air suspension coating and spray drying. As a solvent to be'employed for dissolving the film-forming material to be used to coat the particles, it is desirable to use a solvent which'can be easily remo.ved in a drying step and which has a low toxicity even if dissolved in the blood.
In view of this,: ethanol is an especially preferred solvent when pyroxylin is used as the film-forming material.
When the coated activated carbon in the form of bead-shaped particles is used practically for the purification of the blood, it is desirable to further coat the particles with a film of a material such as albumin on the'surface of the first film described above.for preventing or inhibiting sticking and coagulating of the blood.
The coated activated carbon according to the present invention shows less free carbon dust, ash to be'dissolved out, residual solvent, and adsorption and coagulation of the blood components, and high safety, compared with prior coated coconut active carbon. Moreover, the active carbon according to the present invention shows a high adsorption capacity for toxic components in the blood, a high functionality, and a high facility of coating and operations, compared with coconut active carbon and granular active carbon.
The purification of blood can be thus carried out safely and effectively by using the coated activated carbon according to the present invention.
The accompanying drawing is graph adsorption spectrums of coated activated carbon according to the pres'ent invention (I) (shown by solid line), coated coconut active carbon (II) (shown by dotted line), coated granular active carbon (A) (shown by broken line) and the coated granular active carbbn (B) (shown by chain line). In the graph, adsorption capacity is plotted on the'ordinate and molecular weight is plotted on the abscissa.
This invention is illustrated by the following Examples and Exper'iments.
Example 1 To 5 g of pyroxylin were added 200 ml of absolute ethanol, and the mixture was blended with a homogenizer so as to be micronized. Thereafter, 800 ml of absolute ethanol were added to the solution. The solution was mixed and allowed to stand for 24 hours to make a 0.5% solution for spraying.
500 g of activated carbon (BAC) in the form of bead-shaped particles' having an average diameter of 0.6 mm were placed into a coating pan having a depth of 25 cm, an outside diameter of 30 cm, and a bore of 17 cm. The active carbon was coated by spraying 500 ml of said solution into the pan whilst blowing with rotation. The resulting coated active carbon was then dried at 80C for two days to obtain coated activated carbon in the form of bead-shaped particles.
The resulting coated activated carbon was dipped in water to debubble under a reduced pressure and was sterilized by steam under pressure. The sterilized activated carbon was then charged into a plastics vessel for the purification of the blood, the vessel having diameter of 3 cm, a height of 7 cm, and a volume of 50 ml and equipped with two filters at the upper end and the lower end thereof respectively. The vessel was charged with physiological saline water, which was then replaced with 80 ml. of a 0.5% physiological saline solution of albumin. After standing overnight, the active carbon was washed by a flow of physiological saline water. The blood was purified by being passed through the vesseI.
ExampLe 2 The same procedure was repeated, except that ethylene glycol polymethacrylate (sold under the name of Trade Mark "HYDRON") was substituted for pyroxylin.
Experiment The coated particles of bead-shaped activated carbon obtained as described in Example 1 were tested to determine var-ious properties thereof.
Coated coconut active carbon used as a control in this experiment was prepared by coating coconut active carbon available on the market with pyroxylin according to the phase separation process. Coated granular active carbons (A) and (B) were res-pectiveIy prepared by coating two granular active carbons (A) and (B) selected from those which are available on the market and offered by different manufacturers, with pyroxylin according to the method as described in Example 1.
(1) Amount of free carbon ~dust _ Ten grams of coated activated carbon in the form of bead-shaped particles were charged into a 200 ml conical flask.
There was added into the flask'physiological saline water which had been previously filtered twice by a millipore filter of 0.45 ~. The contents of the flask were degassed under a reduced pressure and decanted to remove excess water. An additional 150 ml of filtered physiological saline water were charged into the flask and the mixture was shaken for 45 minutes at 130 rpm in an incubator. After the shaking,,the number of the free carbon dust particles more than 1.2 micron in size were determined by a coolter counter. Conventional coated crushed coconut active carbon was selected as a control.
The results are'shown below.
Number of free carbon dust particles per ml Coated activated carbon in the form of bead-shaped particles 0 - 200 Coated crushed coconut active carbon 3000 - 5000
(2) Adsorption capacity 2 gram samples of the coated activated carbon in the form of bead-shaped particles were`placed in vessels. To each of the vessels was added 200 ml of physiological phosphoric acid buffer solution containing 20 mg/ml of materials having various molecular weights and the respective mixtures were shaken at 115 rpm for 2 hours in an incubator. Thereafter, the adsorption cap-acity of each'sample was determined. Coated crushed coconut active carbon and coated granular active carbons (A) and (B) were selected as the controls. The results of the determinations are recorded on the graph of the accompanying drawing, with molecular weight being plotted on the abscissa and adsorbed concentration being 7~
plotted (mg/dl) on the ordinate. As clearly shown in the graph, the coated activated carbon according to present invention and in the form of bead-shaped particles has a hiyh adsorption capacity not only on materials having low molecular weights but also on the materials having medium molecular weights. ~owever, the coated crushed coconut active carbon shows a considerably high adsorption capacity for the former materials but does not show such an adsorption capacity for the latter materials. The coated granular active carbons (A) and (B) exhibit low adsorption capacity on the former materials and scarceIy any adsorption capacity on the latter materials.
In the kidney toxin present in a patient suffering from kidney failure, substances of medium molecular weight with unknown chemical structure~play an essential part, rather than the substances of relatively low molecular weight, such as urea, creatine and uric acid. It is considered that marked nervous lesions are mainly caused by substances of medium molecular weight. Therefore, it is an important merit of the coated activated carbon according to the present invention that, in the purification of the blood, it exhibits high adsorption capacity for the materials having medium molecular weight.
t3) Sticking of components of the blood 10 g samples of a coated activated carbon in the form of bead-shaped particles and coated activated carbon in the form of bead-shaped particles and further covered with albumin were charged into respective columns. Through each of the columns, 25 ml of the blood were passed at a velocity of 25 ml/min. The same operation was repeated 25 times. 100 ml of physiological saline water were passed, followed by each 100 ml of distilled water. The respective active carbons were taken out from the columns and lyophilized. The stic]cing of components of the blood was inspected by observing the surface with an electron microscope. Both coated crushed coconut active carbon and the coated crushed coconut active carbon further covered with albumin were selected as controls.
Sticking of the Sticking of the blood platelet_ blood corpuscle Coated activated carbon in the form of bead-shaped particles +
Ditto, but further coated with albumin Coated crushed coconut active carbon ++ +
Ditto, but further coated with albumin In the above table, - represents no sticking, +
represents a little sticking, + represents considerable sticking, and ++ represents sticking to such an extent that the most of surface is covered.
(4) Residual solvent Only an amount of from about 150 to about 200 ppm of ethanol remained in the coated activated carbon in the form of bead-shaped particles of Example 1. The ethanol could not be detected in the blood, after the blood had been treated by this coated activated carbon. However, in the case o~ the coated crushed coconut active carbon which is prepared by the phase separation method using dioxan as a solvent, the residual dioxan amounted to as much as about 50,000 ppm, notwithstanding thorough treatments for removing the dioxan, for example, by vacuum-drying or lyophilization. About 20,000 ppm of the dioxan remains, even if the active carbon has been dried at a high temperature ranging from 80C to 120C for 10 days. ~his dioxan will be released gradually into the blood. When the blood is treated with such a coated crushed coconut active carbon.
(5~ Priming volume The larger is the priming volume, the larger is the amount of the blood which is recycled out of the body and the risk of failure is increased accordingly. The priming volume may become as small as from abo:ut 60 to 110 ml when the coated activated carbon in the form of bead-shaped particles according to the present invention is used for the adsorbent, while the amount is about 400 ml when the conventional dialysis type of artifical kidney is used.
plotted (mg/dl) on the ordinate. As clearly shown in the graph, the coated activated carbon according to present invention and in the form of bead-shaped particles has a hiyh adsorption capacity not only on materials having low molecular weights but also on the materials having medium molecular weights. ~owever, the coated crushed coconut active carbon shows a considerably high adsorption capacity for the former materials but does not show such an adsorption capacity for the latter materials. The coated granular active carbons (A) and (B) exhibit low adsorption capacity on the former materials and scarceIy any adsorption capacity on the latter materials.
In the kidney toxin present in a patient suffering from kidney failure, substances of medium molecular weight with unknown chemical structure~play an essential part, rather than the substances of relatively low molecular weight, such as urea, creatine and uric acid. It is considered that marked nervous lesions are mainly caused by substances of medium molecular weight. Therefore, it is an important merit of the coated activated carbon according to the present invention that, in the purification of the blood, it exhibits high adsorption capacity for the materials having medium molecular weight.
t3) Sticking of components of the blood 10 g samples of a coated activated carbon in the form of bead-shaped particles and coated activated carbon in the form of bead-shaped particles and further covered with albumin were charged into respective columns. Through each of the columns, 25 ml of the blood were passed at a velocity of 25 ml/min. The same operation was repeated 25 times. 100 ml of physiological saline water were passed, followed by each 100 ml of distilled water. The respective active carbons were taken out from the columns and lyophilized. The stic]cing of components of the blood was inspected by observing the surface with an electron microscope. Both coated crushed coconut active carbon and the coated crushed coconut active carbon further covered with albumin were selected as controls.
Sticking of the Sticking of the blood platelet_ blood corpuscle Coated activated carbon in the form of bead-shaped particles +
Ditto, but further coated with albumin Coated crushed coconut active carbon ++ +
Ditto, but further coated with albumin In the above table, - represents no sticking, +
represents a little sticking, + represents considerable sticking, and ++ represents sticking to such an extent that the most of surface is covered.
(4) Residual solvent Only an amount of from about 150 to about 200 ppm of ethanol remained in the coated activated carbon in the form of bead-shaped particles of Example 1. The ethanol could not be detected in the blood, after the blood had been treated by this coated activated carbon. However, in the case o~ the coated crushed coconut active carbon which is prepared by the phase separation method using dioxan as a solvent, the residual dioxan amounted to as much as about 50,000 ppm, notwithstanding thorough treatments for removing the dioxan, for example, by vacuum-drying or lyophilization. About 20,000 ppm of the dioxan remains, even if the active carbon has been dried at a high temperature ranging from 80C to 120C for 10 days. ~his dioxan will be released gradually into the blood. When the blood is treated with such a coated crushed coconut active carbon.
(5~ Priming volume The larger is the priming volume, the larger is the amount of the blood which is recycled out of the body and the risk of failure is increased accordingly. The priming volume may become as small as from abo:ut 60 to 110 ml when the coated activated carbon in the form of bead-shaped particles according to the present invention is used for the adsorbent, while the amount is about 400 ml when the conventional dialysis type of artifical kidney is used.
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of forming a bead-shaped activated carbon coated with semi-permeable film-forming material for purification of blood, wherein the bead-shaped activated carbon is prepared by dispersing molten pitch into water to form spheres, rendering said spheres infusible, and carbonizing said infusible spheres and said bead shaped activated carbon is coated with said material.
2. A method according to claim 1, wherein the semi-permeable material is selected from pyroxylin, polypropylene vinyl chloride-vinyl chloridene copolymer, ethylene glycol polymethacry-late and collagen.
3. A method according to claim 1, further comprising a coating of albumin applied to the surface of the coating of film-forming material.
4. A method according to claim 1, wherein bead-shaped particles of activated carbon have been prepared by dispersing the pitch in the molten state in water to form spheres, making said spheres non-fusible and carbonizing the same.
5. Coated bead-shaped activated carbon when produced by the method as claimed in claim 1, 2 or 3.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP50075640A JPS51151693A (en) | 1975-06-23 | 1975-06-23 | Coated bead-like activated carbon for blood purification |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1057595A true CA1057595A (en) | 1979-07-03 |
Family
ID=13582037
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA255,516A Expired CA1057595A (en) | 1975-06-23 | 1976-06-23 | Coated bead-shaped activated carbon for purifying blood |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS51151693A (en) |
| CA (1) | CA1057595A (en) |
| DE (1) | DE2627824C3 (en) |
| FR (1) | FR2315483A1 (en) |
| GB (1) | GB1560556A (en) |
| SE (1) | SE416946B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9707331B2 (en) | 2011-11-07 | 2017-07-18 | Delcath Systems, Inc. | Apparatus for removing chemotherapy compounds from blood |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4761284A (en) * | 1977-12-27 | 1988-08-02 | Kureha Kagaku Kogy Kabushiki Kaisha | Antidote including activated carbon particles |
| JPS5489010A (en) * | 1977-12-27 | 1979-07-14 | Kureha Chem Ind Co Ltd | Spherical activated charcoal antidote |
| JPS6037046B2 (en) * | 1978-02-06 | 1985-08-23 | 呉羽化学工業株式会社 | Low-pulverization high-strength activated carbon and its manufacturing method |
| JPS54105897A (en) * | 1978-02-06 | 1979-08-20 | Kureha Chemical Ind Co Ltd | Adsorber for artificial organ |
| JPS5510971A (en) * | 1978-07-12 | 1980-01-25 | Sumitomo Chemical Co | Blood purifying device |
| JPS56158712A (en) * | 1980-05-14 | 1981-12-07 | Teijin Ltd | Oral microcapsule of active carbon |
| JPS5731864A (en) * | 1980-08-04 | 1982-02-20 | Teijin Ltd | Oral activated carbon microcapsule |
| JPS5810056A (en) * | 1981-07-10 | 1983-01-20 | 株式会社クラレ | Blood purifying apparatus |
| DE3304349C3 (en) * | 1983-02-09 | 1995-10-26 | Bluecher Hubert | Surface filter and process for its manufacture |
| JPS59193826A (en) * | 1983-04-20 | 1984-11-02 | Mochida Pharmaceut Co Ltd | Activated carbon for oral administration |
| DE3801457A1 (en) * | 1988-01-20 | 1989-08-03 | Hasso Von Bluecher | Activated carbon having high abrasion resistance and low moisture sensitivity |
| WO1993012753A2 (en) * | 1991-12-26 | 1993-07-08 | Ukrainian State Joint Stock Consortium Ekosorb | Method of obtaining a sorbent for medicinal use |
| BE1005999A4 (en) * | 1992-06-19 | 1994-04-12 | Leuven K U Res & Dev | Absorbent FOR CULTURE MEDIUM AND ITS ANTICIPATED HOLDER. |
| GB201204696D0 (en) * | 2012-03-16 | 2012-05-02 | Ucl Business Plc | Therapy |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE830992C (en) * | 1949-12-30 | 1952-02-11 | Degussa | Process for the production of preparations containing activated carbon |
| US3533961A (en) * | 1966-02-07 | 1970-10-13 | Huber Corp J M | Method of producing spherical pellets of activated carbon |
| US3516791A (en) * | 1967-07-14 | 1970-06-23 | Canadian Patents Dev | Microporous carbon preparation |
| JPS4925117A (en) * | 1972-06-29 | 1974-03-06 | ||
| GB1466702A (en) * | 1973-02-09 | 1977-03-09 | Sandoz Ltd | Polymer encapsulated-activated carbon |
| JPS53752B2 (en) * | 1973-03-19 | 1978-01-11 | ||
| JPS5332637B2 (en) * | 1973-05-09 | 1978-09-09 | ||
| JPS5039636B2 (en) * | 1973-05-29 | 1975-12-18 | ||
| JPS5018879A (en) * | 1973-06-20 | 1975-02-27 | ||
| CA1060728A (en) * | 1973-07-26 | 1979-08-21 | Jack Fennimore | Treatment of particulate carbon with biocompatible polymer |
| GB1465519A (en) * | 1973-07-31 | 1977-02-23 | Nat Patent Dev Corp | Sorbents coated with a synthetic solid water-insoluble hydro philic polymer |
| JPS51148291A (en) * | 1975-06-13 | 1976-12-20 | Teijin Ltd | Artificial organ |
-
1975
- 1975-06-23 JP JP50075640A patent/JPS51151693A/en active Pending
-
1976
- 1976-06-21 SE SE7607077A patent/SE416946B/en not_active IP Right Cessation
- 1976-06-22 DE DE2627824A patent/DE2627824C3/en not_active Expired
- 1976-06-22 GB GB25833/76A patent/GB1560556A/en not_active Expired
- 1976-06-22 FR FR7618978A patent/FR2315483A1/en active Granted
- 1976-06-23 CA CA255,516A patent/CA1057595A/en not_active Expired
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9707331B2 (en) | 2011-11-07 | 2017-07-18 | Delcath Systems, Inc. | Apparatus for removing chemotherapy compounds from blood |
| US10098997B2 (en) | 2011-11-07 | 2018-10-16 | Delcath Systems, Inc. | Apparatus for removing chemotherapy compounds from blood |
| US10369264B2 (en) | 2011-11-07 | 2019-08-06 | Delcath Systems, Inc. | Apparatus for removing chemotherapy compounds from blood |
| US10569004B2 (en) | 2011-11-07 | 2020-02-25 | Delcath Systems, Inc. | Apparatus for removing chemotherapy compounds from blood |
| US11241522B2 (en) | 2011-11-07 | 2022-02-08 | Delcath Systems, Inc. | Apparatus for removing chemotherapy compounds from blood |
| US11633528B2 (en) | 2011-11-07 | 2023-04-25 | Delcath Systems, Inc. | Apparatus for removing chemotherapy compounds from blood |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2627824A1 (en) | 1977-01-13 |
| DE2627824C3 (en) | 1982-04-15 |
| FR2315483B1 (en) | 1978-06-30 |
| SE416946B (en) | 1981-02-16 |
| DE2627824B2 (en) | 1981-06-11 |
| SE7607077L (en) | 1976-12-24 |
| JPS51151693A (en) | 1976-12-27 |
| GB1560556A (en) | 1980-02-06 |
| FR2315483A1 (en) | 1977-01-21 |
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