JPH0733669A - Cholesterol lowering agent - Google Patents

Abstract

PURPOSE:To obtain the reducing agent capable of being administered as tablets, having reduced side effect and excellent chemical stability, comprising a specific cross-linked copolymer as a main component. CONSTITUTION:The reducing agent comprises a cross-linked copolymer of a structure consisting essentially of preferably 30-99.9mol% of a repeating unit of formula I (R<1> and R<2> are H or 1-3C alkyl) and/or formula II (R<3> to R<5> are R<1>; X<-> is counter ion) and preferably 0.1-40mol% of a repeating unit of formula III (R<6> to R<9> are H or methyl), formula IV (R<10> and R<11> are R<6>; Y is 1-5C alkylene, etc.) and/or formula V (R<12> and R<13> are R<6>) as a main component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cholesterol-reducing agent for reducing cholesterol in blood, which comprises a cross-linked copolymer having a polyvinylamine unit. More specifically, it relates to an orally administered cholesterol-reducing agent that lowers cholesterol in blood by adsorbing bile acids and / or conjugated bile acids secreted from the liver to the intestine.

[0002]

PRIOR ART AND PROBLEMS TO BE SOLVED BY THE INVENTION As a cholesterol-reducing agent for oral administration, Questran (trade name of Bristol-Myers Co.) (styrene type strongly basic gel type resin) has already been used as a medicine. However, these anion exchange resins have low in vivo activity, and therefore the dose is high, which is 16 g / day on average. Therefore, there is a drawback that it is difficult to drink. In addition, imidazole-based gel type resins (JP-A-60-209523), acrylic resins (JP-A-2-212505), linear polymers (JP-A-64-22924) and the like have been proposed. All of these cholesterol-reducing agents are in v
There is a problem of low ivo activity or toxicity.
Further, gel type resins generally have a high degree of swelling in a wet state. As a result, when the resin swells in the stomach, it gives a feeling of fullness in the abdomen. On the other hand, since linear polymers have a positive charge, they are attached to the wall surface of the negatively charged organs of the stomach, duodenum, jejunum, and ileum, and it is reported that some of them are absorbed and exhibit toxicity.

Many of the ion-exchange groups of conventional cholesterol lowering agents are strongly basic groups. Strongly basic anion exchange resins are generally chemically and thermally unstable, so the ion exchange groups are eliminated even in living organisms, causing not only a fishy odor but also a decrease in performance, and quality cannot be guaranteed. It was

[0004]

The present inventors have found that in v
The resin was designed to have a high ion exchange capacity per weight in order to improve the ivo activity. As a result, the anion exchange resin having a vinylamine structure has a high in v
It was found to exhibit ivo activity. Further, it was found that not only the strongly basic ion-exchange group but also the weakly basic ion-exchange group has the same in vivo activity as the strongly basic group as the ion-exchange group. This made it possible to improve the stability of the resin.

That is, the gist of the present invention is the following general formula [I]

[0006]

[Chemical 6]

(Wherein R ¹ and R ² each independently represents a hydrogen atom or a C ₁ -C ₃ alkyl group) and / or the following general formula [II]

[0008]

[Chemical 7]

(In the above formula, R³, R^FourAnd R^FiveIs it
Independently hydrogen atom or C₁~ C ₃The alkyl group of
Represent, X^-Represents the counterion coordinated to the ammonium salt.
You ) And the following general formula [III]

[0010]

[Chemical 8]

(In the above formula, R ⁶ , R ⁷ , R ⁸ and R ⁹
Each independently represent a hydrogen atom or a methyl group. ), The following general formula [IV]

[0012]

[Chemical 9]

[In the above formula, R^TenAnd R¹¹Each is German
Upright to represent a hydrogen atom or a methyl group, and Y is C₁~ C_Fiveof
Alkylene group or-(CH₂CH₂-O)_n-CH₂
-CH ₂-(N represents an integer of 1 to 5) is represented. ]
And / or the following general formula [V]

[0014]

[Chemical 10]

(In the above formula, R ¹² and R ¹³ each independently represent a hydrogen atom or a methyl group, and Y is as defined in the above general formula [IV].) It depends on a cholesterol-reducing agent characterized by having a cross-linked copolymer of the following structure as a main component.

The present invention will be described in detail below. As a method for reducing blood cholesterol, it is already known to use anion exchange resin as a so-called cholesterol reducing agent (US Pat. No. 3,499,960, US Pat. No. 3,780,171). The mechanism of lowering blood cholesterol by taking an anion exchange resin is considered as follows. The basic anion-exchange resin adsorbs and fixes the bile acids present in the intestinal tract and prevents the bile acids from being reabsorbed in the intestine, so that cholesterol, which is in equilibrium with bile acids in the liver, is converted into bile acids. Conversion is facilitated. As a result, it is considered that blood cholesterol is lowered.

The anion exchange resin of the present invention is represented by the repeating unit represented by the above general formula [I] and / or [II] and the above general formula [III], [IV] and / or [V]. It has a cross-linked copolymer having a structure consisting of repeating units, and may further have a third constituent if necessary. Regarding such a resin, the above-mentioned Japanese Patent Publication No.
No. 4, Japanese Patent Application No. 4-237029 (Mitsubishi Kasei) and Tbal
(Eur. Polm. J., 25, 4, 331-3
40 (1989) Reactive, Polymer
17. 207-217 (1989), J. Ma
cro. Sci. (1992) and the like). Preferably, the resin of the present invention hydrolyzes a crosslinked copolymer obtained by copolymerizing N-vinylformamide (abbreviated as NVF) and a copolymerizable polyethylene monomer to convert a formamide group into an amino group. However, it can be obtained by a method of alkylating the amino group, if necessary.

NVF is a raw material monomer, and is inexpensive, easy to hydrolyze, has good copolymerizability with other monomer components, and is a hydrophilic monomer. There is. Since the repeating unit represented by the above general formula [I] and / or [II] is converted from the NVF-derived unit into an ion-exchange group after polymerization, the content thereof is 30 mol based on all monomers. % To 99.9 mol%, particularly preferably 40 mol% to 99 mol%.

The above-mentioned polyethylene monomer is
For example, divinylbenzene “abbreviated as DVB” hereinafter, divinylmethylbenzene, divinyldimethylbenzene, C
^{_{H 2 = CR 10 -COO-Y}} -OCO-CR 11 = CH
₂ (wherein R ¹⁰ , R ¹¹ and Y are as defined in the above general formula [IV]), CH ₂ ═CR ¹² —CONH—Y—NHCO—CR ¹³
═CH ₂ (wherein R ¹² , R ¹³ and Y are represented by the above general formula [V]
As defined in Represents a divinyl compound having two radical polymerization active ethylenically unsaturated double bonds such as poly (meth) acrylamide. The cross-linking agent is an essential component for making the polymer water-insoluble, and an increase in the content of units derived from the cross-linking agent in the polymer causes a decrease in ion exchange capacity.

In general, the in vivo activity as a cholesterol lowering agent has a weak correlation with the ion exchange capacity. In order to express high in vivo activity, the resin should be designed to maximize the ion exchange capacity as much as possible. At the same time, in order to maintain a high ion exchange capacity and utilize the high in vivo activity of the resin, the resin must be swollen to some extent. The preferred degree of swelling is 3.5 ml / g-100 m
1 / g. If it is smaller than this range, the exclusion limit molecular weight of the resin becomes smaller than the molecular weight of the target bile acid, and the effect cannot be sufficiently exerted. On the other hand, if it is larger than this range, not only the in vivo activity is decreased, but also
There is a problem that the resin swells in the body and gives a feeling of fullness in the abdomen. From this point of view, the above general formula [III
], [IV] and / or [V] is contained in the repeating unit in an amount of 0.1 mol% to 40 mol%, and more preferably 0.4 mol% to 30 mol%.

The resin used in the present invention is essentially a repeating unit represented by the above general formula [I] and / or [II] and the above general formula [III], [IV] and / or
It is composed of a repeating unit represented by [V], and is usually composed of only this. However, if desired, it may further contain a third unit. This allows the resin to have various additional properties. However, when this unit is increased, the vinylamine unit is decreased and the adsorbability is adversely affected. Therefore, this unit is 40 mol% or less, more preferably 30 mol% or less. Examples of the other monomer copolymerizable with vinylamine include a styrene derivative, (meth) acrylic acid ester, (meth) acrylamide, and acrylonitrile.

As the polymerization reaction, any method such as solution polymerization, suspension polymerization, dispersion polymerization and emulsion polymerization can be adopted. In the present invention, the form of the resin used is not particularly limited. However, a suspension polymerization method can be mentioned as a method for easily obtaining an NVF copolymer. Examples of the substance that can be used as a polymerization bath during suspension polymerization include organic solvents that are sparingly soluble in NVF, such as aliphatic or aromatic hydrocarbons such as toluene, petroleum ether, and cyclohexane, halogeno compounds such as polychloroalkane, and chlorobenzene. Can be used. The ratio of such a polymerization bath is usually in the range of 1 to 5 volumes by volume with respect to the monomer phase composed of NVF and the crosslinking agent. As a method for dispersing the NVF phase in the polymerization bath, there can be used a continuous dropping method, a batch dropping method, an introducing method such as dropping or jetting a droplet into a solution by a nozzle.

The polymerization initiator must be soluble in the NVF phase. As such an initiator, for example, a water-soluble azo polymerization initiator such as 2,2-azobis-2-amidinopropane hydrochloride or 4,4-azobis-4-cyanovaleric acid is preferable, and the amount thereof is a monomer. Generally 0.
The range is from 02% by weight to 5.0% by weight. The polymerization temperature of the polymerization reaction is usually 30 to 120 ° C., and the polymerization time is usually 1
Hours to 15 hours.

In order to obtain a polyvinylamine copolymer, the crosslinked copolymer of NVF obtained by the above method must be hydrolyzed in an aqueous solution of hydrochloric acid, sulfuric acid, sodium hydroxide, potassium hydroxide or the like. I have to. The reaction temperature for the hydrolysis is 50 to 120 ° C., and the reaction time is usually 1 to 10
It is preferable to carry out in the range of time. Under the above reaction conditions, the formamide group is completely hydrolyzed, and a crosslinked copolymer having a primary amino group can be obtained.

The alkylation reaction of the amino group of the primary amine resin may be carried out by a known method. For example, dimethylsulfate, diethylsulfate, methyl halide, ethyl halide and the like are allowed to act on the primary amino group. The quaternary ammonium resin of polyvinylamine resin can be obtained by thoroughly alkylating an amino group. Alternatively, by reacting in the coexistence of formic acid and formalin to synthesize a weakly basic anion exchange resin of tertiary amine type, alkylation may be carried out by a known method such as further reaction with an alkyl halide to obtain a strong basic anion. Ion exchange resins can be manufactured.

The ion exchange capacity of a NVF homopolymer having a trimethylammonium group is theoretically C.
It is 8.2 meq / g for l type. As a result, as described above, the styrene-based resin having the same functional group is a Cl type 4.
Compared with 7 meq / g, the exchange capacity per unit weight is 1.7 times, and a resin having a high ion exchange capacity can be obtained. In the case of tertiary amine resin, vinyl amine resin is 14.
1 meq / g, while styrene resin is 6.2
In meq / g, the exchange capacity ratio is 2-3 times. The ion exchange capacity was measured according to the method described in the example and calculated as the equivalent weight per dry resin. In the present invention, in the case of a strongly basic resin, the content of the quaternary ammonium salt unit is preferably 30 mol% or more in all monomers. Of course, strong and weak mixed type anion exchange resins may be used.

The anion exchange resin thus produced is
It has at least one functional group selected from primary to tertiary amino groups and quaternary ammonium groups. In the resin used in the present invention, the functional group having the highest molar fraction is (a) 1
The resin having a primary amino group has a weak base exchange capacity of 8 to 22.
The resin having a meq / g, (b) secondary to tertiary amino group has a weak base exchange capacity of 3.0 to 16 meq / g, or (c) the resin having a quaternary ammonium group has a weak base exchange capacity. The exchange capacity is preferably 1.5 to 85 meq / g.

The counter ion in the strongly basic vinylamine resin is, for example, a halide ion such as a hydroxide ion, a basic substance ion, a bromide ion, a sulfate ion, a nitrate ion, an acetate ion, an oxalate ion, a citrate ion and the like. Can be mentioned. However, for a divalent anion such as a sulfate ion, one anion is coordinated with two molecules of vinylamine structural unit. However, the counterion must be physiologically acceptable. Therefore, it is usually used in the form of chloride ion. In the case of tertiary amine resins, it is possible to use various salt forms and free amines (OH type). When it is used in a salt form, it may be the above-mentioned counter ion, though it varies depending on the pH electrolyte of the solution and its selectivity coefficient.

The cholesterol-reducing agent of the present invention includes
Not only the spherical polymer but also various shapes of resin such as crushed products can be adopted. The crushed product can be crushed to a desired size by a conventionally known method after obtaining a lump resin by solution polymerization or the like. The resin has an average particle size of 1 in the wet state.
It is preferable that it is μm to 2 mm. In the case of the present invention, it is preferable that the particle size of the resin be as small as possible within the range that can be handled, in order to make the physical movement by food as small as possible and make it stay in the body for a long time. More preferably, it is 5 to 250 μm in the wet state.

Oral administration is usually used to administer the cholesterol-reducing agent of the present invention to the human body. In the case of oral administration, it is preferable to take a preparation such as tablets, fine granules and granules before or after a meal. Also, it may be taken in a state of being suspended in water or another solution.

[0031]

EXAMPLES The present invention will be specifically described below with reference to production examples and examples, but the present invention is not limited to the following production examples and examples as long as the gist thereof is not exceeded. In the following Production Examples and Examples, meq / g represents milliequivalent per dry resin weight. The ion exchange capacity was measured according to the Diaion Manual (published by Mitsubishi Kasei Co., Ltd.).

Production Example 1 Polymerization reaction: A 1000 ml 4-necked flask was charged with 400 ml of cyclohexane and 800 mg of ethyl cellulose to prepare a polymerization bath. On the other hand, N-vinylformamide (purity 94%, impurities are mainly formic acid) 176 g, civinylbenzene (purity> 80%) 24.0 g, demineralized water 4.5.
g, and V-50 (azo polymerization initiator, trade name, manufactured by Wako Pure Chemical Industries, Ltd.) 400 mg were mixed to prepare a monomer solution. Both solutions were bubbled with nitrogen before being subjected to the reaction,
The polymerization reaction was performed under a nitrogen atmosphere. Polymerization bath 100 rp
The monomer solution was gradually added dropwise while stirring at m. Thirty
After stirring for 1 minute, the temperature was raised and polymerization was carried out at 65 ° C. for 8 hours. After heating, the monomer solution gelled in about 15 minutes. After the polymerization was completed, the crosslinked copolymer produced was collected by filtration, washed with methanol and then washed with water. The polymerization yield was 81% based on the raw material monomers. The resulting crosslinked copolymer was white in appearance, but was slightly opaque when observed under a microscope. The specific surface area was 0 m ² / g.

Hydrolysis reaction: 1 cross-linking copolymer
The mixture was placed in a liter flask and 700 ml of 2N-sodium hydroxide aqueous solution was added. Warm the solution to 4 ° C at 85 ° C.
Hydrolyzed for hours. The degree of swelling of the obtained cross-linked copolymer was 7.33 ml / g and the water content was 78.9%.
The weak base exchange capacity was 18.0 meq / g. From the results of IR spectrum and ¹³ C-NMR (CP-MAS method), the formyl group (164 ppm) was completely disappeared.

Production Example 2 Hydrolysis-Methylation reaction: 1000 ml of 100 ml of the wet weakly basic resin obtained in Production Example 1 and 100 ml of demineralized water were used.
Place in a ml flask, sodium formate 40g, 37%
81 g of aqueous formaldehyde solution was added. Further, hydrochloric acid was added to adjust the pH to 5. Gradually raise the temperature to 5 at 90 ° C
Reacted for hours. Carbon dioxide gas was generated violently in the initial stage,
At the end of the reaction, it almost disappeared. After completion of the reaction, the resin was washed with water, and then made into an OH type with 0.1N-sodium hydroxide aqueous solution. The obtained resin had a weak base exchange capacity of 9.3 meq / g and an average particle size of about 340 μm.
The degree of methylation of amino groups was determined by ¹³ C-NMR (CP / MAS
The degree of methylation is 1.8
Met. It is considered that 80% or more of the amino groups are produced as tertiary amino groups or secondary amino groups.

Production Example 3 A copolymer was synthesized and hydrolyzed in the same manner as in Example 1 except that 160 g of N-vinylformamide and 42 g of divinylbenzene in the monomer solution were used. Further, the amino group was made tertiary by the same method as in Production Example 2. The weak base exchange capacity of the obtained resin is 8.5.
It was meq / g and the average particle size was about 390 μm. The methylation degree of the amino group was 1.7. 80 of the amino groups
% Or more is a tertiary amino group, and it is considered that a part thereof remains as a primary amino group or a secondary amino group.

Production Example 4 Methylation reaction: In a 500 ml four-necked flask, 50 ml of the wet weak basic resin obtained in Production Example 1 and 50% were added.
150 ml of aqueous methanol solution was added. An aqueous solution containing 30 ml of methyl iodide, 50 ml of 50% aqueous methanol solution, and 28 g of sodium carbonate was slowly added dropwise thereto. After the reaction, the resin was collected by filtration and washed with methanol and demineralized water. The obtained resin has a neutral salt decomposition capacity of 6.3 m.
eq / g, average particle size was about 340 μm.

Example 1 In Vivo Pharmacological Test 6-week-old male Wistar rats were used as a control group, and Examples 1 to 4 were used.
And imidazole-based gel type resins of Comparative Examples (JP-A-60
No. 209523, resin described in Production Example-1), 3 animals each, and a control group was fed with a standard powder food, and
The standard powdered diet containing 0.25% of each resin was given to the Comparative Examples for 10 days. After 10 days, the livers were removed from the rats, the livers of each group were collected, the microsome fractions were separated, and the activities of HMG-CoA reductase and cholesterol 7α-hydroxylase were measured.

The bile acid adsorbing resin adsorbs and fixes the bile acid in the intestinal tract and suppresses the absorption of bile acid from the intestinal tract, thereby synthesizing cholesterol as a precursor of bile acid in the liver and bile acid from cholesterol. Promotes synthetic systems. This effect is particularly remarkable in rats, and the effectiveness of the resin in vivo was evaluated by measuring the activities of the rate-controlling enzymes HMG-CoA reductase and cholesterol 7α-hydroxylase of each synthetic system.

Method for Measuring Enzyme Activity After the experiment was completed, the liver was extracted from the control group and the rats to which the cholesterol-reducing agent was administered. The microsome fraction was separated and its enzymatic activity was measured. HMG-CoA reductase activity is HMG-C labeled with isotopes
oA was added, and the amount of mevalonic acid produced was quantified by TLC (thin layer chromatography). On the other hand, for cholesterol 7α-hydroxylase activity, cholesterol labeled with an isotope was added, and the produced 7α-hydroxycholesterol was quantified by TLC. The relative intensity is shown in Table-1. The weakly basic resin was used in the OH type and the strong basic resin was used in the CI type. Numbers are% of control group
It is represented by.

[0040]

[Table 1] Table 1 ────────────────────────────────── Anion exchange resin HMG-CoA Cholesterol 7α reductase -Hydroxylase ────────────────────────────────── Control group 100 100 Production example-1 156.8 106. 8 Production Example-2 155.3 143.4 Production Example-3 153.9 143.0 Production Example-4 95.8 174.8 Comparative Example 162.7 105.9 ──────────── ────────────────────────

As is clear from these examples, the resin of the present invention is almost equivalent to HMG-CoA reductase in comparison with the comparative example, but has excellent enzyme activity against cholesterol 7α-hydroxylase. It showed a rising effect.

[0042]

The cholesterol-reducing agent of the present invention is excellent in cholesterol-reducing action and chemical stability.
Therefore, the dose can be reduced and it can be taken as a tablet.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masayuki Mitsuya, Masayuki Mitsuya 1000 Kamoshida-cho, Midori-ku, Yokohama, Kanagawa Sanryo Kasei Co., Ltd. (72) Inventor Go Ito 3-43-11 Minamiotsuka, Toshima-ku, Tokyo Issue Mitsubishi Kasei Co., Ltd. Tokyo branch office

Claims (3)

[Claims] 1. The following general formula [I]:(In the above formula, R¹And R²Are independent hydrogen
Child or C₁~ C₃Represents an alkyl group. ) And / or
Or the following general formula [II](In the above formula, R³, R^FourAnd R^FiveEach independently
Hydrogen atom or C₁~ C₃Represents an alkyl group of^-Is
It represents a counterion coordinated to an ammonium salt. )
Repeating unit and the following general formula [III](In the above formula, R⁶, R⁷, R⁸And R⁹Each is German
It stands to represent a hydrogen atom or a methyl group. ), The following general formula
[IV] [Chemical 4][In the above formula, R^TenAnd R¹¹Are independent hydrogen
Or a methyl group, and Y is C₁~ C_FiveAlkylene group
Or- (CH₂CH₂-O)_n-CH₂-CH ₂−
(N represents an integer of 1 to 5). ] And / or
Is the following general formula [V][In the above formula, R¹²And R¹³Are each independently hydrogen
Represents an atom or a methyl group, and Y is defined in the above general formula [IV].
Just as I meant it. ) And the repeating unit represented by
The main component is a cross-linked copolymer having the structure
Cholesterol reducer. 2. The general formula [I] and / or in the cross-linked copolymer
Alternatively, the repeating unit represented by [II] is 30 to 99.9.
Mol%, general formula [III], [IV] and / or [V]
0.1 to 40 mol% of the repeating unit represented by the following general formulas [I] and [II], which can bond with these repeating units:
The cholesterol-reducing agent according to claim 1, wherein the repeating unit other than the repeating units represented by [III], [IV] and [V] is composed of 0 to 40 mol%. 3. R of the general formula [I]¹And R²Is that
Independently represent a hydrogen atom, a methyl group or an ethyl group,
And R¹And R²At least one of the
Or represents an ethyl group, and R in the general formula [II]³, R^Fourand
R^FiveAre each independently a hydrogen atom, a methyl group or an ethyl group.
Represents a radical and R³, R^FourAnd R ^FiveAt least
The other one is characterized by representing a methyl group or an ethyl group.
The cholesterol-reducing agent according to claim 2.