阅读说明：本技术 戊聚糖多硫酸酯以及含有戊聚糖多硫酸酯的药物 (Pentosan polysulfate and medicament containing same ) 是由 石川杰 于 2018-12-18 设计创作，主要内容包括：本发明提供具有7.0质量％～15.0质量％的糖醛酸含量和0质量％～2.0质量％的乙酰基含量的戊聚糖多硫酸酯或其药学上可接受的盐、或所述戊聚糖多硫酸酯或其药学上可接受的盐的药学上可接受的溶剂化物。所述戊聚糖多硫酸酯或其药学上可接受的盐、或所述戊聚糖多硫酸酯或其药学上可接受的盐的药学上可接受的溶剂化物,用作用于预防和/或治疗由于FGF-2功能的异常亢进引起的疾病的药物的有效成分、以及pH缓冲剂。(The present invention provides pentosan polysulfate or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said pentosan polysulfate or a pharmaceutically acceptable salt thereof, having an uronic acid content of 7.0-15.0 mass% and an acetyl content of 0-2.0 mass%. The pentosan polysulfate or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of the pentosan polysulfate or the pharmaceutically acceptable salt thereof, for use as an active ingredient of a medicament for preventing and/or treating diseases caused by hyperactivity of FGF-2 function, and a pH buffer.)

1. A pentosan polysulfate, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said pentosan polysulfate or said pharmaceutically acceptable salt thereof, said pentosan polysulfate having an uronic acid content of 7.0-15.0 mass%, and an acetyl content of 0-2.0 mass%.

2. The pentosan polysulfate, the pharmaceutically acceptable salt thereof, or the pharmaceutically acceptable solvate of said pentosan polysulfate or said pharmaceutically acceptable salt thereof, according to claim 1, wherein said pentosan polysulfate has an uronic acid content of 7.5 to 13.0 mass%.

3. The pentosan polysulfate, the pharmaceutically acceptable salt thereof, or the pharmaceutically acceptable solvate of said pentosan polysulfate or said pharmaceutically acceptable salt thereof, of claim 1 or 2, wherein said pentosan polysulfate has a weight average molecular weight of 5000 or less.

4. The pentosan polysulfate, the pharmaceutically acceptable salt thereof, or the pharmaceutically acceptable solvate of said pentosan polysulfate or said pharmaceutically acceptable salt thereof, according to claim 3, wherein said pentosan polysulfate has an acetyl content of 0-0.3 mass%.

5. The pentosan polysulfate, or a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said pentosan polysulfate or a pharmaceutically acceptable salt thereof, according to any one of claims 1 to 4, wherein said pentosan polysulfate has a structure represented by formula II:

wherein R each independently represents a hydrogen atom, -COCH₃or-SO₃X¹And at least one R in one molecule is-SO₃X¹Wherein X is¹Represents a hydrogen atom or a monovalent or divalent metal; x represents a hydrogen atom or a monovalent or divalent metal; and

n1 and n2 each independently represent an integer of 0 or more and 30 or less, and at least one of n1 and n2 is an integer of 1 or more.

6. Pentosan polysulfate according to claim 5, or a salt thereofA pharmaceutically acceptable salt, or a pharmaceutically acceptable solvate of said pentosan polysulfate or a pharmaceutically acceptable salt thereof, wherein each R independently represents a hydrogen atom or-SO₃X。

7. The pentosan polysulfate, its pharmaceutically acceptable salt, or a pharmaceutically acceptable solvate of said pentosan polysulfate or its pharmaceutically acceptable salt of claim 5 or 6, wherein X is sodium.

8. A medicament comprising the pentosan polysulfate, its pharmaceutically acceptable salt, or a pharmaceutically acceptable solvate of said pentosan polysulfate or its pharmaceutically acceptable salt according to any one of claims 1 to 7 as an active ingredient.

9. The medicament according to claim 8, which is used for the prevention and/or treatment of a disease caused by hyperactivity of FGF-2 function.

10. The medicament according to claim 9, wherein the disease caused by hyperactivity of FGF-2 function is cancer, an autoimmune disease, an allergic disease, an inflammatory disease, cardiac dysplasia, vascular dysplasia, or skeletal dysplasia.

11. The medicament according to claim 9, which is used for the prevention and/or treatment of cystitis or arthritis.

12. The medicament according to any one of claims 8 to 11, which is an injection.

13. A pH buffering agent comprising the pentosan polysulfate, its pharmaceutically acceptable salt, or a pharmaceutically acceptable solvate of said pentosan polysulfate or its pharmaceutically acceptable salt according to any one of claims 1 to 7.

Technical Field

The present invention relates to pentosan polysulfate and to medicaments containing pentosan polysulfate.

Background

Basic fibroblast growth factor (FGF-2 or b-FGF) is known to be involved in diseases associated with abnormal angiogenesis, such as tumors or arthritis (patent document (PT L) 1) FGF-2 is a heparin-binding growth factor that binds to FGF-2 receptors of cells by binding heparan sulfate (heparin sulfate).

Pentosan polysulfate is known as one of substances that inactivate FGF-2 pentosan polysulfate has been reported to inhibit angiogenesis and the like (non-patent document (NP L) 1 to non-patent document (NP L) 3.) pentosan polysulfate is believed to bind to FGF-2 and thereby inhibit the binding of FGF-2 to heparan sulfate.

Pentosan polysulfate has been reported to actually inhibit tumor growth (patent literature (PT L) 2 and non-patent literature (NP L) 4).

Pentosan polysulfate is generated by chemical sulphation of xylan obtained from broad-leaved trees, such as beech, pentosan polysulfate consists of sulphated linear polysaccharides in which β -D-xylopyranose is a linear bond, and has approximately 4-O-methylglucuronic acid, i.e. uronic acid, per 10 xylopyranose units (patent document (PT L) 3 and patent document (PT L) 4) patent document (PT L) 5 discloses pentosan polysulfate having an uronic acid content of 4.3 to 6% obtained by a method comprising fractionating commercially available pentosan polysulfate (SP-54).

Disclosure of Invention

Problems to be solved by the invention

The object of the present invention is to provide novel pentosan polysulfate with preferred activity for pharmaceutical use, or for use in pH buffers.

Means for solving the problems

As a result of intensive studies to solve the above problems, the present inventors have found a novel pentosan polysulfate having high inhibitory activity against the binding between FGF-2 and heparan sulfate, as compared to conventional pentosan polysulfate. The inventors have further found that the pentosan polysulfate may also act as a pH buffer. The present invention has been completed based on these findings.

Specifically, the present invention provides the following [1] to [13 ].

[1] A pentosan polysulfate, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said pentosan polysulfate or said pharmaceutically acceptable salt thereof, said pentosan polysulfate having an uronic acid content of 7.0-15.0 mass%, and an acetyl content of 0-2.0 mass%.

[2] The pentosan polysulfate, the pharmaceutically acceptable salt thereof, or the pharmaceutically acceptable solvate of the pentosan polysulfate or the pharmaceutically acceptable salt thereof according to [1], wherein the uronic acid content of the pentosan polysulfate is 7.5-13.0 mass%.

[3] The pentosan polysulfate, the pharmaceutically acceptable salt thereof, or the pharmaceutically acceptable solvate of said pentosan polysulfate or the pharmaceutically acceptable salt thereof according to [1] or [2], wherein the weight average molecular weight of the pentosan polysulfate is 5000 or less.

[4] The pentosan polysulfate, the pharmaceutically acceptable salt thereof, or the pharmaceutically acceptable solvate of the pentosan polysulfate or the pharmaceutically acceptable salt thereof according to [3], wherein the acetyl content of the pentosan polysulfate is 0 to 0.3 mass%.

[5] The pentosan polysulfate, the pharmaceutically acceptable salt thereof, or the pharmaceutically acceptable solvate of said pentosan polysulfate or the pharmaceutically acceptable salt thereof, according to any one of [1] to [4], wherein said pentosan polysulfate has a structure represented by formula II:

wherein R each independently represents a hydrogen atom, -COCH₃or-SO₃X¹And at least one R in one molecule is-SO₃X¹Wherein X is¹Represents a hydrogen atom or a monovalent or divalent metal; x represents a hydrogen atom or a monovalent or divalent metal; and n1 and n2 eachIndependently represents an integer of 0 or more and 30 or less, and at least one of n1 and n2 is an integer of 1 or more.

[6]According to [5]]The pentosan polysulfate, the pharmaceutically acceptable salt thereof, or the pharmaceutically acceptable solvate of the pentosan polysulfate or the pharmaceutically acceptable salt thereof, wherein each R independently represents a hydrogen atom or-SO₃X。

[7] The pentosan polysulfate, the pharmaceutically acceptable salt thereof, or the pharmaceutically acceptable solvate of said pentosan polysulfate or the pharmaceutically acceptable salt thereof according to [5] or [6], wherein X is sodium.

[8] A medicament comprising the pentosan polysulfate, its pharmaceutically acceptable salt, or a pharmaceutically acceptable solvate of said pentosan polysulfate or its pharmaceutically acceptable salt according to any one of [1] to [7] as an active ingredient.

[9] The medicament according to [8], which is used for the prevention and/or treatment of a disease caused by abnormally hyperactivity of FGF-2 function.

[10] The medicament according to [9], wherein the disease caused by hyperactivity of FGF-2 function is cancer, an autoimmune disease, an allergic disease, an inflammatory disease, cardiac dysplasia, vascular dysplasia, or skeletal dysplasia.

[11] The medicament according to [9], which is used for the prevention and/or treatment of cystitis or arthritis.

[12] The medicament according to any one of [8] to [11], which is an injection.

[13] A pH buffering agent comprising a pentosan polysulfate, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said pentosan polysulfate or a pharmaceutically acceptable salt thereof, according to any one of [1] to [7 ].

Viewed from another perspective, the present invention provides:

a method for preventing and/or treating a disease caused by hyperactivity of FGF-2 function, which comprises administering an effective amount of the pentosan polysulfate, the pharmaceutically acceptable salt thereof, or the pharmaceutically acceptable solvate of the pentosan polysulfate or the pharmaceutically acceptable salt thereof, according to any one of [1] to [7], to a human being or an animal;

use of a pentosan polysulfate, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said pentosan polysulfate or a pharmaceutically acceptable salt thereof, according to any one of [1] to [7], in the manufacture of a medicament for the prevention and/or treatment of a disease caused by hyperactivity of FGF-2 function;

use of a pentosan polysulfate, a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate of said pentosan polysulfate or a pharmaceutically acceptable salt thereof, according to any one of [1] to [7], for the prevention and/or treatment of a disease caused by hyperactivity of FGF-2 function; and

the pentosan polysulfate, the pharmaceutically acceptable salt thereof, or the pharmaceutically acceptable solvate of said pentosan polysulfate or the pharmaceutically acceptable salt thereof according to any one of [1] to [7] for use as a medicament for the prevention and/or treatment of diseases caused by hyperactivity of FGF-2 function.

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention provides pentosan polysulfate having high inhibitory activity against the binding between FGF-2 and heparan sulfate. The pentosan polysulfate of the present invention is useful as a medicament for preventing and/or treating diseases caused by hyperactivity of FGF-2 function, such as cancer or arthritis. Furthermore, the pentosan polysulfate of the invention can also be used as a pH buffer.

Drawings

FIG. 1 is a graph showing the effect of uronic acid content of pentosan polysulfate on inhibitory activity for inhibiting binding between FGF-2 and heparan sulfate.

FIG. 2 is a graph showing the effect of acetyl content of pentosan polysulfate on the inhibitory activity of inhibiting the binding between FGF-2 and heparan sulfate.

FIG. 3 is a graph showing the relationship between the uronic acid content of pentosan polysulfate and the amount of 0.01N aqueous hydrochloric acid solution (m L) required to adjust the pH from pH 6 to pH4 in a titration of 100mg/100m L pentosan polysulfate solution.

Detailed Description

The present invention is described in detail below. Based on representative embodiments and specific examples, constituent features may be described below; however, the present invention is not limited to such an embodiment.

In the present specification, "including as an active ingredient" means being contained as a main active ingredient and means being contained in an amount to exhibit an effect.

The phrase "preventing and/or treating" refers to "preventing", "treating", or "prevention and treatment". For example, a "medicament for prevention and/or treatment" may function as a prophylactic agent alone, or as a therapeutic agent; or may have the function of both a prophylactic and a therapeutic agent.

< pentosan polysulfate >

Pentosan polysulfate is a compound obtained by sulfating at least one of the hydroxyl groups of xylo-oligosaccharides. In the present specification, pentosan polysulfate includes salts of pentosan polysulfate, solvates of pentosan polysulfate, and solvates of salts of pentosan polysulfate. The salt of pentosan polysulfate is preferably a pharmaceutically acceptable salt, and examples include sodium pentosan polysulfate, potassium pentosan polysulfate, calcium pentosan polysulfate, and the like. The solvate is preferably a pharmaceutically acceptable solvate. Examples of the solvent include water.

Pentosan polysulfate has a structure represented by formula II. Pentosan polysulfate may contain one structure represented by formula II, or may contain more than two structures represented by formula II. When the pentosan polysulfate comprises two or more structures represented by formula II, the structure represented by formula II is a structure representing a repeating unit of the pentosan polysulfate.

In the general formula II, R each independently represents a hydrogen atom, -COCH₃or-SO₃X¹And at least one R in one molecule is-SO₃X¹Wherein X is¹Represents a hydrogen atom or a monovalent or divalent metal, and X¹Preferably a hydrogen atom, sodium, potassium or calcium, more preferably sodium, potassium or calcium, and particularly preferably sodium; x is a hydrogen atom or a monovalent or divalent metal, and X is preferably sodium, potassium, or calcium, and particularly preferably sodium; and n1 and n2 each independently represent an integer of 0 or more and 12 or less, and at least one of n1 and n2 is an integer of 1 or more.

In the general formula II, n1+ n2 is preferably 1 to 10, more preferably 2 to 8, and even more preferably 3 to 6.

The portion at the end of the structure represented by formula II and the portion not bonded to the structure represented by formula II may be — OR. That is, -OR may be bonded to the left terminal (n1 side) of formula II, and-R may be bonded to the right terminal (n2 side) of formula II. Particularly preferred is-OR^1XBonded to the left terminal end (n1 side) of the formula II, and-R^1XTo the right terminal (n2 side) of the formula II. In the general formula II, R^1XIs a hydrogen atom or-SO₃X¹；X¹Is a hydrogen atom or a monovalent or divalent metal; and X¹Preferably a hydrogen atom, sodium, potassium or calcium, more preferably sodium, potassium or calcium, and particularly preferably sodium.

In the above formula, X is preferably a monovalent or divalent metal. Pharmaceutically acceptable salts of pentosan polysulfate are preferred. For example, X is preferably sodium, potassium, or calcium. In this case, the salts of pentosan polysulfate are sodium pentosan polysulfate, potassium pentosan polysulfate, and calcium pentosan polysulfate. Among these, sodium pentosan polysulfate is particularly preferred as the salt of pentosan polysulfate.

The pentosan polysulfate of the present invention has an uronic acid content of 7.0 to 15.0 mass%. The pentosan polysulfate of the present invention preferably has an uronic acid content of 7.5 to 14.0 mass%, and more preferably 7.7 to 13.0 mass%. The above proportions need not be satisfied in one molecule, but may be satisfied by pentosan polysulfate as an integral mixture of individual molecules.

The pentosan polysulfate of the invention may be a mixture of individual molecules represented by the general formula II which differ from one another with respect to the values of n1 and n2, the kind of substituents R, and/or the degree of substitution.

Pentosan polysulfate has a structure obtained by sulfating xylo-oligosaccharides. The pentosan polysulfate of the invention is preferably obtained by sulfating acidic xylooligosaccharides. In the xylo-oligosaccharide having a structure obtained by sulfating xylo-oligosaccharide, neutral xylo-oligosaccharide is xylo-oligosaccharide containing no uronic acid. The acidic xylo-oligosaccharide is xylo-oligosaccharide in which at least one uronic acid is bonded to at least one xylose unit in one xylo-oligosaccharide molecule. That is, acidic xylo-oligosaccharides have more than one uronic acid residue as a side chain in each xylo-oligosaccharide molecule. The number of uronic acid residues contained in each xylo-oligosaccharide molecule can be measured by carbazole-sulfuric acid method, or colorimetric method using sodium tetraborate. As described in the examples, the uronic acid content (mass%) of pentosan polysulfate refers to a value calculated from the number of uronic acid residues in a predetermined amount of pentosan polysulfate obtained by the carbazole-sulfuric acid method.

The pentosan polysulfate of the present invention preferably has a sulfur content of 10.0% by mass or more, more preferably 12.0% by mass or more, even more preferably 15.5% by mass or more, and particularly preferably 16.5% by mass or more. The sulfur content of the pentosan polysulfate is preferably 20.0% by mass or less. Here, the sulfur content of pentosan polysulfate is a value measured according to the oxygen flask combustion method described in japanese pharmacopoeia (japanese pharmacopoeia).

The known pentosan polysulfate is believed to contain an amount of more than one of its acetyl groups (-COCH)₃) Xylose units bonded together with uronic acid residues (see, e.g., WO 2014/114723). In contrast, the pentosan polysulfate of the present invention preferably has an acetyl group content of 0 to 2.0 mass%, more preferably 0 to 1.0 mass%, even more preferably 0 to 0.4 mass%, even more preferably still 0 to 0.3 mass%, and particularly preferably substantially 0 mass%. In order to obtain pentosan polysulfate having an acetyl content of 0 to 2.0% by mass, the pentosan polysulfate of the invention is preferably chosen such that it has a high content of acetyl groupsPrepared by the following deacetylation procedure.

Can be prepared from¹The integrated ratio of the peaks in the H-NMR measurement calculated the acetyl content in the pentosan polysulfate. Specifically, first, a composition containing a specified amount of pentosan polysulfate and a specified amount of an internal standard substance is used¹H-NMR measurement of the solution to¹H-NMR measurement. The molar amount of acetyl groups in the solution was obtained by comparing the peak of acetyl groups in the obtained spectrum with the peak of a specific group of the internal standard substance to obtain the integrated ratio thereof. The molar amount of acetyl groups was then multiplied by 43; and dividing the obtained value by the average molecular weight obtained respectively to obtain the mass% of acetyl group.

The weight average molecular weight (Mw) of the pentosan polysulfate of the present invention is not particularly limited, and may be, for example, 5000 or less, 4000 or less, 3900 or less, 3800 or less, or 3750 or less. In this case, the lower limit of the weight average molecular weight (Mw) of the pentosan polysulfate is preferably 1000.

The number average molecular weight (Mn) of the pentosan polysulfate is not particularly limited, and may be, for example, 5000 or less, 4000 or less, 3900 or less, 3800 or less, or 3750 or less. In this case, the lower limit of the number average molecular weight (Mn) of the pentosan polysulfate is preferably 300.

The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the pentosan polysulfate of the invention can be measured by GPC (gel permeation chromatography). As the GPC column, YMC-Pack Diol-300 and YMC-Pack Diol-60 (both manufactured by YMC) linked to each other can be used. The GPC conditions may be, for example, the following conditions.

Eluent: 25mM potassium dihydrogen phosphate/25 mM dipotassium hydrogen phosphate/50 mM potassium chloride

Flow rate of 0.7m L/min

Measuring the temperature: 40 deg.C

A detector: differential refractive detector

The dispersity of the pentosan polysulfate of the present invention is preferably 1.00 or more and 1.6 or less, more preferably 1.00 or more and 1.5 or less. The dispersity of the pentosan polysulfate is also preferably 1.00 or more and 1.4 or less. The degree of dispersion (D) of the pentosan polysulfate was calculated by the following formula.

Dispersity (D) ═ weight average molecular weight (Mw)/number average molecular weight (Mn)

Pentosan polysulfate obtained by the production method of the present invention described later has high purity and tends to have a narrow molecular weight distribution. The pentosan polysulfate obtained by the production method of the present invention has excellent quality stability.

< use of pentosan polysulfate: medicine >

The pentosan polysulfate of the present invention can be used, for example, in pharmaceutical, food, cosmetic, and other composition components.

In particular, the pentosan polysulfate of the invention is used as an active principle of a medicament.

Examples of the medicament include medicaments for preventing and/or treating diseases caused by hyperactivity of FGF-2 function.

FGF-2 (basic fibroblast growth factor) is a growth factor and is secreted by a variety of cells. FGF-2 is deeply involved in cell proliferation and differentiation at a developmental stage and exhibits high expression during tissue repair in vivo. In addition, FGF-2 is involved in abnormal angiogenesis and has a strong proliferation and migration promoting effect on vascular endothelial cells. FGF-2 having these functions is known to be involved in diseases such as tumors. FGF-2, which promotes angiogenesis and bone destruction, has been elucidated as a key molecule involved in the pathology of chronic rheumatoid arthritis. It has been reported that particularly high serum FGF-2 concentration is present in a tumor having many blood vessels, such as kidney cancer. FGF-2 is also present in a variety of other tumors, such as prostate, breast, and lung cancers.

Binding of FGF-2 to FGF receptors (FGFRs) induces the expression of various cytokines and receptor genes. FGF-2 has a heparin binding region and binds to heparin and heparan sulfate. It is believed that FGF-2 secreted from cells, when bound to FGFR, first binds to heparan sulfate of the extracellular matrix, concentrates, and is protected from proteases. Therefore, the activity of inhibiting the binding between FGF-2 and heparan sulfate can be an index for judging the effect of preventing and/or treating a disease caused by the hyperactivity of FGF-2 function.

As shown in the examples, pentosan polysulfate has the activity of inhibiting the binding between FGF-2 and heparan sulfate; and the inhibitory activity is high when the pentosan polysulfate has an uronic acid content of 7.0 to 15.0 mass% and an acetyl group content of 0 to 2.0 mass%. Accordingly, the pentosan polysulfate of the present invention is particularly useful for preventing and/or inhibiting diseases caused by hyperactivity of FGF-2 function.

Specific examples of the hyperfunction of FGF-2 include abnormal angiogenesis caused by FGF-2. Hyperactivity of FGF-2 function can be judged, for example, by using an increase in serum FGF-2 concentration as an indicator.

Specific examples of diseases caused by hyperactivity of FGF-2 function include tumors, chronic inflammation such as arthritis, autoimmune diseases, allergic diseases, inflammatory diseases such as cystitis, cardiac dysplasia, vascular dysplasia, skeletal dysplasia, psoriasis, age-related macular degeneration, periodontal disease, scleroderma, and neovascular glaucoma, and the like.

The pentosan polysulfate of the invention is also useful as an active principle of a medicament for the prevention and/or treatment of cystitis, in particular interstitial cystitis.

The dosage form of the drug of the present invention is not particularly limited, and the drug may be administered orally or parenterally. Preferably, the medicament is administered parenterally by intravenous injection or infusion.

The drug of the present invention may consist of only pentosan polysulfate as an active ingredient. Preferably, however, one or more suitable pharmacologically and pharmaceutically acceptable additives may be added to the pentosan polysulfate to provide a drug in a dosage form well known to those skilled in the art.

Examples of the pharmacologically and pharmaceutically acceptable additives include excipients, disintegrants or disintegration aids, binders, lubricants, coating agents, pigments, diluents, base agents (bases), solubilizers or solubilization aids, isotonic agents, buffers, pH adjusters, stabilizers, spraying agents, binders, and the like.

Examples of pharmaceutical preparations suitable for oral administration include tablets, capsules, powders, fine granules, liquids, syrups and the like. Examples of formulations for parenteral administration include injections, instillations, suppositories, inhalants, patches (patches) and the like. For the preparation of a formulation suitable for oral, transdermal or transmucosal administration, for example, the following pharmacologically and pharmaceutically acceptable additives may be added. Examples of the additives include excipients such as glucose, lactose, D-mannitol, starch, crystalline cellulose and the like; disintegrants or disintegration aids such as carboxymethylcellulose, starch, and carboxymethylcellulose calcium; binders such as hydroxypropyl cellulose, hydroxypropyl methylcellulose, polyvinylpyrrolidone, gelatin, and the like; lubricants such as magnesium stearate and talc; coating agents such as hydroxypropylmethylcellulose, sucrose, polyethylene glycol, and titanium dioxide; such as vaseline, paraffin oil, polyethylene glycol, gelatin, kaolin, glycerin, purified water, and stearin. Other examples include propellants such as chlorofluorocarbon (chlorofluorocarbon), diethyl ether, or compressed gas; binders such as sodium polyacrylate, polyvinyl alcohol, methyl cellulose, polyisobutylene, and polybutene; and base fabrics such as cotton cloth and plastic sheets. Pharmaceutical preparations can be produced by using these additives for pharmaceutical preparations.

For the preparation of a pharmaceutical preparation suitable for injection or infusion, for example, the following additives for pharmaceutical preparations may be added. Examples of suitable additives include solubilizing agents or solubilizing aids that can form aqueous or ready-to-use injections, such as distilled water for injection, physiological saline, and propylene glycol; isotonic agents such as glucose, sodium chloride, D-mannitol, and glycerol; buffers such as phosphates (e.g., disodium hydrogen phosphate and sodium dihydrogen phosphate), citrates, and acetates; and pH adjusting agents such as inorganic acids, organic acids, inorganic bases, and organic bases.

As described below, the pentosan polysulfate of the present invention has a higher pH buffering capacity than pentosan polysulfate having a lower uronic acid content. Thus, when it is desired to adjust the pH, for example, when the pentosan polysulfate of the present invention is provided in the form of a liquid formulation, injection, instillation, or the like, it is not necessary to use a pH-adjusting agent, or the amount of the pH-adjusting agent used may be reduced.

The dose of the drug of the present invention is not particularly limited, and may be in accordance with the administration form; the age, severity of the disease, symptoms, and weight of the patient; and other conditions are appropriately selected. For example, when administered intravenously, subcutaneously, or intramuscularly, the drug may be administered in an amount of 0.1 to 20mg/kg, preferably 0.2 to 10mg/kg, as the active ingredient per day by an adult.

< use of pentosan polysulfate: anticoagulant agent >

The pentosan polysulfate of the invention is useful as an active ingredient in anticoagulants.

The anticoagulant containing pentosan polysulfate of the present invention can be used not only as a drug, but also as a surface treatment agent for medical devices or medical materials. For example, such anticoagulants may be used as surface treatment agents for implantable artificial organs, artificial blood vessels, catheters (cathters), stents, blood bags, contact lenses, intraocular lenses (intraocular lenses), and surgical aids. Examples of the method of fixing the pharmaceutical composition on the surface of the medical device or the medical material include a method comprising bringing the pharmaceutical composition into contact with the medical device or the medical material and irradiating the contacted portion with radiation.

< use of pentosan polysulfate: pH buffer >

As shown in the examples, the pentosan polysulfate of the present invention has a higher pH buffering capacity than pentosan polysulfate having a lower uronic acid content. Thus, the pentosan polysulfate of the invention can be used as a pH buffer. The pentosan polysulfate of the invention exhibits a buffering action which maintains the pH in the range of 4-6. For example, injections having a pH of less than 4 cause pain to the patient. The pentosan polysulfate of the invention is an effective component of a medicament, and can also function as a pH regulator in an injection. The pentosan polysulfate of the present invention is useful for food, medicine, or any other composition whose pH must be maintained within the range of pH 4-6 from the viewpoint of stabilization and prevention of deterioration.

The concentration of the pentosan polysulfate in a composition such as an aqueous solution containing the pentosan polysulfate of the present invention as a pH buffer is preferably 10 to 500mg/m L, and more preferably 50 to 300mg/m L.

< Process for producing pentosan polysulfate >

The pentosan polysulfate of the invention can be obtained, for example, by a process for the production of pentosan polysulfate, said process comprising a 1 st step of obtaining acidic xylooligosaccharides from a raw material derived from a plant, and a 2 nd step of obtaining pentosan polysulfate from acidic xylooligosaccharides; and further comprises a deacetylation process. In this method, the 1 st step includes a step of depolymerizing a plant-derived raw material. Since the method sequentially includes a depolymerization step and a sulfation step of a plant-derived raw material, the method can efficiently produce pentosan polysulfate. The process for the production of pentosan polysulfate may further comprise a deacetylation step. By including a deacetylation step, the process can produce pentosan polysulfate with low acetyl content.

[ plant-derived Material ]

The acidic xylo-oligosaccharide can be obtained by depolymerizing a plant-derived raw material. Examples of the plant-derived raw material include a wood-derived raw material, a seed-derived raw material, a grain-derived raw material, a fruit-derived raw material, and the like. Further, examples of the plant-derived raw material that can be used include cotton such as cotton linter and cotton lint; and herbaceous plants such as kenaf, hemp, ramie, and rice straw; and the like. As the plant-derived raw material, the above-mentioned raw materials derived from various sources may be used in combination.

Among them, wood-derived raw materials are preferably used as the plant-derived raw materials. Examples of usable raw materials derived from wood include wood raw materials such as coniferous trees, broadleaf trees, and the like. The raw material derived from wood is preferably at least one selected from the group consisting of coniferous trees and broadleaf trees; and more preferably broadleaf trees are used. The wood-derived feedstock may be a mixture of coniferous and broadleaf trees. Bark may also be used as a raw material derived from wood.

Examples of broad-leaved trees include beech, Eucalyptus globulus, Eucalyptus grandis (Eucalyptus globulus), Eucalyptus grandis (Eucalyptus grandis), Eucalyptus urophylla (Eucalyptus urograndis), Eucalyptus pellita (Eucalyptus pellita), Eucalyptus fusca (Eucalyptus brachiana), and Acacia mearsoni (Acacia mearensii), and the like. Examples of conifers include Japanese cedar, Japanese cypress, pine, cypress, Japanese hemlock, and the like.

The specific gravity of the raw material derived from wood is preferably 450kg/m³Above and 700kg/m³Below, and more preferably 500kg/m³Above 650kg/m³The following. When the specific gravity of the raw material derived from wood is within the above range, the production efficiency of the acidic xylo-oligosaccharide can be further improved.

The raw material derived from wood is preferably wood chips (wood chips) obtained by crushing one or more of the above-mentioned woods. When wood chips are used as the plant-derived raw material, depolymerization of the plant-derived raw material can be efficiently performed, and the production efficiency of the acidic xylooligosaccharide can be improved.

[ step 1]

(depolymerization step)

The 1 st step includes a step of depolymerizing a plant-derived raw material. In the step of depolymerizing the plant-derived raw material, the plant-derived raw material is chemically and/or physically decomposed to produce acidic xylooligosaccharides. Examples of the chemical and/or physical decomposition step include a heat treatment step, an alkali treatment step, an acid treatment step, an enzyme treatment step, an ionic liquid treatment step, a catalyst treatment step, and the like. Among these steps, the depolymerization step is preferably a heat treatment step or an enzyme treatment step; and more preferably a heat treatment process. The heat treatment step may be a heat and pressure step.

The depolymerization step is preferably carried out under non-alkaline conditions (at a pH of 9 or less, and preferably at a pH of 8 or less).

The heat treatment step is a step of heating the plant-derived material in the presence of a solution. Since the plant-derived material is hydrolyzed in such a heat treatment step, the heat treatment step is sometimes referred to as a hydrolysis treatment step or a prehydrolysis treatment step. The solution used in the heat treatment step is preferably water. The ratio (mass ratio) of water to the plant-derived raw material is preferably in the range of 1:1 to 1: 10. When the ratio of water to the plant-derived raw material is set within the above range, the hydrolysis reaction can be efficiently performed. The water used in the heat treatment step may be water added separately from the plant-derived raw material; or a portion of the water may be water originally contained in the plant-derived material.

In the heat treatment step, other chemicals may be added in addition to the plant-derived material and water. Examples of such other chemicals include bases, acids, and chelating agents. In addition, chemicals such as scale inhibitors (scaleinhibitors), resin control agents (pitch control agents), and ionic liquids that directly or indirectly assist in depolymerization of polysaccharides may also be added.

The heat treatment step is a step of heating a plant-derived material in the presence of water. The heating temperature (liquid temperature) in this step is preferably 30 ℃ or more, more preferably 50 ℃ or more, even more preferably 75 ℃ or more, even more preferably 90 ℃ or more, particularly preferably 100 ℃ or more, and most preferably 120 ℃ or more. On the other hand, the heating temperature (liquid temperature) is preferably 300 ℃ or less, more preferably 250 ℃ or less, and even more preferably 200 ℃ or less.

The treatment time in the heat treatment step can be appropriately determined depending on the treatment temperature. The treatment time is, for example, preferably 5 minutes or more, more preferably 10 minutes or more, and even more preferably 20 minutes or more. The P-factor represented by the following formula is the product of the heat treatment temperature and the heat treatment time. The P factor is preferably adjusted to be within the preferred range.

In the above formula, P represents a P factor, T represents an absolute temperature (. degree. C. +273.5), T represents a heat treatment time, and K_H1(T)/K_100℃Indicating the relative rate of hydrolysis of the glycosidic bond.

In the heat treatment process, the P-factor is preferably set to 200 or more, more preferably 250 or more, and even more preferably 300 or more. On the other hand, the P-factor is preferably 1000 or less. In the heat treatment step, the P factor is appropriately adjusted so that the average polymerization degree and molecular weight of the acidic xylooligosaccharide may be within desired ranges, whereby the molecular weight of the obtained pentosan polysulfate may be adjusted.

In the heat treatment process, the pH of the solution containing the plant-derived raw material is preferably 9 or less, more preferably 8 or less, and even more preferably 7 or less. That is, the heat treatment step is preferably performed under non-alkaline conditions. The pH value refers to the pH of the solution before the heat treatment.

In the heat treatment process, acid originating from the raw material may be dissociated, and the acid hydrolysis may be at least partially performed. Examples of acids derived from plant materials include organic acids such as acetic acid and formic acid. In this case, the pH of the solution containing the plant-derived raw material is further lowered after the acid hydrolysis.

The process for producing pentosan polysulfate preferably comprises a heat treatment step as the initial step. This can improve the production efficiency of acidic xylooligosaccharide and further improve the production efficiency of pentosan polysulfate. When the method is provided with a heat treatment step as an initial step, the number of steps required for producing the acidic xylooligosaccharide can be significantly reduced as compared with the conventional method. By setting the heat treatment under non-alkaline conditions as the initial step, the method can efficiently produce acidic xylooligosaccharide with suppressed coloration because acidic xylooligosaccharide is not substituted by hexenuronic acid.

The depolymerization step is preferably a heat treatment step; however, it may be a process other than the heat treatment process. For example, when the depolymerization step is an enzyme treatment step, the depolymerization step includes a step of mixing a plant-derived material with an enzyme. Examples of enzymes that can be used include hemicellulases and the like. Specific examples include commercially available Enzyme preparations such as Cellulosin HC100 (trade name, manufactured by HBI Enzymes Inc.), Cellulosin TP25 (trade name, manufactured by HBI Enzymes Inc.), Cellulosin HC (trade name, manufactured by HBI Enzymes Inc.), Cartazyme (trade name, manufactured by Clariant AG), Ecopulp (trade name, manufactured by Rohm Enzyme GmbH), Sumizyme (trade name, manufactured by Shin Nihon Chemicals Corporation), Pulpzyme (manufactured by Novo disk), and Mufect 720 (Genencor); and xylanases produced by microorganisms belonging to the genus Trichoderma (Trichoderma), Thermomyces (Thermomyces), Aureobasidium (Aureobasidium), Streptomyces (Streptomyces), Aspergillus (Aspergillus), Clostridium (Clostridium), Bacillus (Bacillus), Thermomyces (Thermotoga), Thermoascus (Thermoascus), Thermomyces (Caldocellum), Thermomonospora (Thermomonospora), or the like.

In the enzyme treatment process, an enzyme is added to a solution prepared by mixing a plant-derived raw material with water. The temperature of the solution during this treatment is preferably 10 ℃ or more and 90 ℃ or less, and more preferably 30 ℃ or more and 60 ℃ or less. The temperature of the solution is preferably a temperature close to the optimum temperature of the enzyme to be used. It is also preferable to adjust the pH of the solution to a range in which the activity of the enzyme is increased. For example, the pH of the solution is preferably adjusted to a pH of 3 or more and 10 or less.

When the depolymerization step is an alkali treatment step or an acid treatment step, the depolymerization step includes a step of mixing the plant-derived material with an alkali solution or an acid solution. In the alkali treatment step, sodium hydroxide or potassium hydroxide is preferably added. In the acid treatment step, hydrochloric acid, sulfuric acid, acetic acid, or the like is preferably added. In such a case, heating or pressurization may be appropriately performed.

When the depolymerization step is at least one selected from the group consisting of an enzyme treatment step, an alkali treatment step and an acid treatment step, the production method may further include a pressing step, an extraction step, a heating step, a filtration step, a separation step, a purification step, a concentration step, a desalting step, or the like after the treatment step. The method may further comprise a molecular weight reduction step performed after the treatment step. Examples of other processes include the process described in JP2003-183303a, the contents of which are incorporated herein by reference.

(filtration step)

The 1 st step may further include a filtration step performed after the depolymerization step. In the filtration step, the reaction mixture is separated into a solid component of the plant-derived raw material and a solution other than the solid component. More specifically, when the 1 st step is provided with a filtration step performed after the depolymerization step, the reaction product is separated into a solid component serving as a raw material of slurry and a filtrate. A solid component used as a pulp raw material is subjected to a digestion step or the like as a subsequent step to provide a cellulose raw material (dissolving pulp).

The recovered filtrate may be separated into a gas layer and a liquid layer. Since the gas layer contains a large amount of furfural, furfural can be separated by recovering the furfural from the gas layer. In another aspect, the liquid layer comprises a plurality of hemicelluloses comprising acidic xylo-oligosaccharides and neutral xylo-oligosaccharides. In the subsequent step, the acidic xylooligosaccharide contained in the liquid layer can be separated and purified.

(separation and purification Process)

The 1 st step further includes a separation and purification step performed after the depolymerization step. When the 1 st step includes the above-mentioned filtration step, it is preferable to provide a separation and purification step after the filtration step.

The 1 st step may be provided with a separation and purification step immediately after the depolymerization step. However, the 1 st step is preferably provided with a filtration step performed after the depolymerization step; and a step of separating the acidic xylooligosaccharide from the filtrate and purifying the acidic xylooligosaccharide. The filtration process may be provided as part of a separation and purification process; or may be provided as a separate step from the separation and purification step. The separation and purification step is a step of separating and purifying the acidic xylooligosaccharide. Since the filtrate obtained in the filtration step contains various sugars such as neutral xylooligosaccharide in addition to the acidic xylooligosaccharide, the separation and purification step is also a step of removing such xylooligosaccharide in addition to the acidic xylooligosaccharide.

In the separation and purification step, for example, a method such as ion exchange chromatography, affinity chromatography, gel filtration, ion exchange treatment, NF membrane treatment, UF membrane treatment, RO membrane treatment, or activated carbon treatment is preferably used. In the separation and purification step, it is also preferable to carry out the above methods in combination. In particular, when inWhen ion exchange chromatography is performed in the separation and purification step, the acidic xylooligosaccharide can be selectively separated and purified. In the ion exchange chromatography, the acidic xylo-oligosaccharide is adsorbed; therefore, acidic xylooligosaccharide can be mainly obtained from the sugar solution (filtrate). More specifically, the sugar liquor is first treated with a strong cation exchange resin to remove metal ions from the sugar liquor. Thereafter, a strong anion exchange resin is used to remove sulfate ions and the like in the sugar solution. The resulting sugar solution was treated with a weak anion exchange resin to adsorb the acidic xylo-oligosaccharide on the resin. By using low concentrations of salts (e.g., NaCl, CaCl)₂KCl, or MgCl₂) Eluting the acidic oligosaccharide adsorbed on the resin to obtain the acidic xylooligosaccharide with less impurities.

(concentration step)

The 1 st process may further include a concentration process. For example, it is preferable to provide a concentration step after the filtration step and before the separation and purification step. When the concentration step is provided in the 1 st step, the separation and purification steps can be more efficiently performed, thereby improving the productivity of the pentosan polysulfate.

Examples of the concentration step include a membrane treatment step using an NF membrane, an ultrafiltration membrane, a reverse osmosis membrane, or the like; and a concentration step by evaporation or the like; and the like.

In the concentration step, the solution is preferably concentrated so that the content of the acidic xylooligosaccharide is 10% or more and 80% or less, and more preferably 20% or more and 60% or less, with respect to the total mass of the concentrated solution.

< dehydration step >

In the step 1, the acidic xylo-oligosaccharide can be obtained in the form of acidic xylo-oligosaccharide solution; or may be subjected to a dehydration procedure and thus obtained in the form of an acidic xylo-oligosaccharide concentrate or an acidic xylo-oligosaccharide powder. When the acidic xylo-oligosaccharide powder is to be produced, the production method is preferably further provided with a powdering step performed after the separation and purification step. When the dehydration step is provided in the present invention, sulfation in the sulfation step described later can be performed more efficiently.

In the powdering step, the acidic xylooligosaccharide solution obtained in the separation and purification step is treated with, for example, a spray dryer, a freeze dryer, a hot air dryer, or a water-soluble organic solvent, thereby obtaining acidic xylooligosaccharide powder.

[2 nd step ]

(sulfation step)

The acidic xylo-oligosaccharides obtained in step 1 are sulfated in step 2, whereby pentosan polysulfate is obtained. That is, the 2 nd step includes a sulfation step.

The average degree of polymerization of the acidic xylooligosaccharides to be sulfated is preferably suitably adjusted according to the molecular weight of the pentosan polysulfate obtained as the final product.

The average degree of polymerization of acidic xylo-oligosaccharide can be calculated by dividing the total sugar amount of acidic xylo-oligosaccharide by the amount of reducing sugar in the calculation of the total sugar amount, first, the xylo-oligosaccharide solution is maintained at 50 ℃ and centrifuged at 15000rpm for 15 minutes, thereafter, the total sugar amount of the supernatant is quantified by the phenol-sulfuric acid method ("quantification method of reducing sugar)", issued by the academic conference publication center, D-xylose (Wako Pure Chemical Industries, L td.) is used to make a calibration curve to be used for quantification.

In the sulfation process, sulfuric acid or a sulfuric acid derivative is added to the acidic xylooligosaccharide solution to sulfate the acidic xylooligosaccharide. Examples of the sulfuric acid derivative include sulfur trioxide pyridine complex, chlorosulfonic acid, and the like. In this step, the concentration of the acidic xylo-oligosaccharide solution is preferably 0.1% by mass or more and 20% by mass or less, and sulfuric acid is preferably added to the acidic xylo-oligosaccharide solution having such a concentration in an amount of 0.1% by mass or more and 50% by mass or less. The pH of the acidic xylooligosaccharide solution after addition of sulfuric acid is preferably 1 or more and 9 or less.

(post-sulfation purification step)

The 2 nd process may further include a post-sulfation purification process performed after sulfation. When the 2 nd step is provided with such a post-sulfation purification step, a high purity pentosan polysulfate can be obtained.

In the post-sulfation purification step, for example, a method such as centrifugal separation, membrane filtration, dialysis, treatment with a water-soluble organic solvent, or treatment with activated carbon is preferably used. Among them, the treatment with a water-soluble organic solvent and the treatment with activated carbon are preferable because sulfated pentosan polysulfate can be selectively separated and purified.

(powdering Process)

In step 2, the sulfated pentosan polysulfate is obtained in the form of a solution of pentosan polysulfate; or may be subjected to a powdering procedure and thus obtained in the form of a pentosan polysulfate powder. When a pentosan polysulfate powder is to be produced, the 2 nd process is preferably further provided with a powdering process carried out after the post-sulfation purification process.

In the powdering step, the pentosan polysulfate solution obtained in the post-sulfation purification step may be treated, for example, using a spray dryer, a freeze dryer, a hot air dryer, a water-soluble organic solvent, or the like, to obtain a pentosan polysulfate powder.

Pentosan polysulfate is obtained by carrying out the above-mentioned step 2. The sulfur content of the pentosan polysulfate thus obtained is preferably 10 to 20 mass% with respect to the total mass of the pentosan polysulfate. The sulfur content of pentosan polysulfate can be measured by the oxygen-bottle combustion method in the general test method of Japanese pharmacopoeia.

[ deacetylation Process ]

In the production of pentosan polysulfate, it is preferred to carry out deacetylation. The deacetylation step is preferably performed at any stage after the depolymerization step. The deacetylation step reduces the acetyl content of the pentosan polysulfate. Specifically, the deacetylation step is as follows: an alkali is added to a solution containing a substance obtained from a plant-derived raw material such as acidic xylooligosaccharide (also referred to as "a solution containing acidic xylooligosaccharide or the like" in the present specification), thereby adjusting the solution to pH 11 or more. In the deacetylation step, the solution obtained after depolymerization, the filtrate obtained by the filtration step, the solution containing acidic xylooligosaccharide after the separation and purification step and before the sulfation step, the solution containing acidic xylooligosaccharide (pentosan polysulfate) after the sulfation step, or the like may be adjusted to pH 11 or more. Among these solutions, when the solution containing acidic xylooligosaccharide after the separation and purification step and before the sulfation step is adjusted to pH 11 or more, pentosan polysulfate having stable quality and reduced acetyl content can be obtained, and the site to which the acetyl group is bonded can also be sulfated. Thus, the efficiency of sulphation and thus the efficiency of production of pentosan polysulfate can be increased. When the solution containing the acidic xylooligosaccharide (pentosan polysulfate) obtained after the sulfation step is adjusted to a pH of 11 or more, the purification step can be performed more efficiently. The solution containing acidic xylooligosaccharide and the like is preferably an aqueous solution. In the present specification, the acidic xylo-oligosaccharide-containing solution may also be referred to as an acidic xylo-oligosaccharide solution.

The pH suitable for the deacetylation step is preferably 11 to 14, and more preferably 12 to 13. The solution to be subjected to the deacetylation step is preferably maintained at pH 11 or more for 0.5 hour or more, more preferably at pH 11 or more for 1.0 hour or more, even more preferably at pH 11 or more for 2.0 hours or more, and particularly preferably at pH 11 or more for 3.0 hours or more. In particular, when the pH is lower than 12, the solution is preferably maintained for 1.0 hour or more. Particularly preferred conditions may be, for example, a condition in which the solution is maintained at pH 12 to 13 for 3 hours or more.

While maintaining the above solution in the above pH range, the solution is preferably stirred. The temperature to be applied when the solution is maintained in the above pH range is not particularly limited, but is preferably room temperature.

In the deacetylation step, an alkali may be added to a solution (e.g., a solution containing acidic xylooligosaccharide) to be subjected to the deacetylation step. The base to be added is not particularly limited as long as the desired pH can be achieved. The base is preferably sodium hydroxide.

The deacetylation step may include a pH adjustment step of adjusting a solution having a pH of 11 or more to a pH of less than 11 due to the addition of a base after maintaining the pH. In the pH adjustment step, the solution may be adjusted to, for example, pH9 or less, pH8 or less, pH 7 or less, pH 6 or less, pH 5 or less, or pH4 or less. Adjustment can be made by addition of acid. Examples of useful acids include hydrochloric acid.

The deacetylation step preferably includes a desalting step performed after the pH adjustment step. Desalination can be performed, for example, using dialysis membranes or NF membranes.

The deacetylation step may further include a step of powdering the product for subsequent treatment.

[ other Processes ]

(molecular weight adjusting step)

The method for producing pentosan polysulfate can further comprise a molecular weight adjustment step between the 1 st step and the 2 nd step. When the process for producing pentosan polysulfate comprises a deacetylation step, the molecular weight adjustment step may be carried out before or after the deacetylation step. In the molecular weight adjusting step, the molecular weight of the acidic xylooligosaccharide obtained in the step 1 is adjusted. For example, in the molecular weight adjustment step, the molecular weight of the acidic xylooligosaccharide can be reduced.

In the molecular weight adjustment step, pentosan polysulfate having a weight average molecular weight of 1000 to 5000 can be obtained by, for example, acid treatment, alkali treatment, enzyme treatment, NF membrane treatment, UF membrane treatment, RO membrane treatment, gel filtration treatment, activated carbon treatment, ion exchange treatment, or electrodialysis treatment. In the molecular weight adjustment step, a method of selectively recovering pentosan polysulfate having a desired weight average molecular weight by performing a film treatment or the like may be employed.

(separation and purification step after molecular weight adjustment)

The method for producing pentosan polysulfate may further comprise a separation and purification step after molecular weight adjustment, which is performed after the molecular weight adjustment step. Examples of the separation and purification step after molecular weight adjustment may include gel filtration, ion exchange treatment, NF membrane treatment, UF membrane treatment, RO membrane treatment, electrodialysis treatment, activated carbon treatment, water-soluble organic solvent treatment, chromatography treatment, and the like. When the production method is provided with such a post-molecular-weight-adjustment separation and purification process, acidic xylooligosaccharide having a desired molecular weight obtained in the molecular-weight-adjustment process can be selectively recovered, and pentosan polysulfate having a narrow molecular weight distribution can be efficiently obtained.