JPH01121284A - Bile acid salt of tocopherol, n,n-dialkylaminoalkylcarboxylic acid ester - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I (R<1> and R<2> are lower alkyl; R<3> and R<4> are H or methyl; n is 0-3; BA is bile acid). EXAMPLE:dl-alpha-Tocopherol N,N-dimethylaminoacetate taurocholate. USE:An eye drop and injection. PREPARATION:A tocopherol N,N-dialkylaminoalkylcarboxylate expressed by formula II is reacted with bile acid expressed by the formula BA using a lower alcohol based solvent, e.g. methanol. After completing the reaction, the solvent is distilled away under reduced pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to bile salts of tocopherol N,N-dialkylaminoalkylcarboxylic acid esters which have excellent effects as pharmaceuticals.

[Conventional technology and technical problems]

As tocopherol preparations, tocopherol esters such as acetate ester and nicotinic acid ester, which are stable against oxidation, are used for medical purposes. These esters, like free tocopherol, are oily or solid compounds that are insoluble in water.

Therefore, for the preparation of water-soluble formulations of tocopherol or its esters, a method of solubilization by addition of large amounts of nonionic surfactants is commonly used. However, the use of a large amount of surfactant causes undesirable problems such as siltation or hemolysis, making it unsuitable for injections and eye drops.

Therefore, solubilization using prodrugs is being considered.

That is, in general, promoiety (pro+woie)
Various attempts have been made to introduce polar groups as ty), but in order to obtain high solubility, it is necessary to use promo, which has a very high degree of dissociation.
iety is required. However, in the case of tocopherol, due to its chemical structure, it has an extremely large hydrophobic group (isoprene chain) at the 2-position of the chroman bone nucleus, so it is difficult to introduce a polar group by esterification, whether it is a cationic group or an anionic group. , the water solubility can be improved, but this results in imparting ionic surfactant function to tocopherol itself. This physicochemical property causes hemolysis, which is fatal when administered by injection.
It may cause pain.

Therefore, there is an urgent need to develop a water-soluble preparation of tocopherol that overcomes hemolytic properties, and research and development is progressing from various directions.

Conventionally, as aminoalkylcarboxylic acid esters of tocopherol, for example, amino acid esters of tocopherol have been known (Japanese Patent Laid-Open No. 58-203982). However, these compounds are oily or waxy at room temperature and, from the above-mentioned viewpoint, are not suitable for medical injections.

Bile salts of tocopherol nicotinic acid esters are also known (Japanese Unexamined Patent Publication No. 59-225184), but these compounds do not have much of a problem in terms of water solubility, but have the disadvantage of causing hemolysis at low concentrations. .

[Structure and effects of the invention]

Therefore, the present inventors have conducted various exploratory research over many years with the aim of developing low hemolytic and water-soluble tocopherol derivatives, and have finally found a new tocopherol derivative that satisfies the above objectives. Completed the invention.

The object compound of the present invention is a bile salt of tocopherol N,N-dialkylaminoalkylcarboxylic acid ester represented by the following general formula (1).

(In the formula, R1 and R2 mean the same or different lower alkyl groups. R3 and R4 mean a hydrogen atom or a methyl group. n means an integer of O to 3. BA means a bile acid. .) R1 in general formula (I). The lower alkyl group seen in the definition of R2 includes a straight chain or branched alkyl group having 1 to 6 carbon atoms, such as methyl, ethyl, n-propyl, n-butyl, isopropyl, isobutyl, 1-methylpropyl, ter t-butyl, n-pentyl, 1-
Examples include ethylpropyl, isoamyl, n-hexyl, and the most preferred are methyl and ethyl groups.

Specifically, the bile acids include, for example, taurocholic acid,
Glycocholic acid, cholic acid, taurodeoxycholic acid,
Examples include glycodeoxycholic acid, deoxycholic acid, taurochenodeoxycholic acid, glycochenodeoxycholic acid, ursodeoxycholic acid, and the like.

- The tocopherol derivative represented by formula ('I) has an asymmetric carbon at the 2-position of the chromanol ring, so d, R1
Although stereoisomers such as isomers exist, it goes without saying that the present invention includes any of these isomers.

Although various methods for producing the compound of the present invention can be considered, typical methods are as follows.

(In the formula, H1, RZ, pz, R, a and n have the above-mentioned meanings) (,1) That is, -tocopherol represented by formula (II)
Bile salt (I) is obtained by reacting an N,N-dialkylaminoalkylcarboxylic acid ester with a bile acid. Although this method is a conventional method, for example, the reaction is carried out using a lower alcohol solvent such as methanol, ethanol, propatool, etc. After the reaction is completed, the target substance can be obtained by distilling off the solvent under reduced pressure.

↓ Alkali metal salts of bile acids, i.e., the method comprises - formula A bile salt (1) is obtained in the presence of a hydrohalide salt of tocopherol N,N-dialkylaminoalkylcarboxylic acid ester represented by (I [I) and an alkali metal salt of a bile acid. This method is carried out in a conventional manner, but the target substance can be obtained by carrying out the reaction in a lower alcohol solvent such as methanol, ethanol, propatool, etc., desalting after the completion of the reaction, and then distilling off the solvent.

Hydrogen halide specifically means HCI, )IBr.

Examples of the alkali metal salts of bile acids include sodium salts, potassium salts, and calcium salts of bile acids, and sodium salts are most preferred. Specifically, sodium taurocholate, sodium glycocholate, sodium cholate, sodium taurodeoxycholate,
Sodium glycodeoxycholate, sodium deoxycholate, sodium taurochenodeoxycholate,
Examples include sodium glycochenodeoxycholate and sodium ursodeoxycholate.

Next, we will show the methods and results of hemolytic experiments and animal experiments to prove the usefulness of the target compounds of the present invention.

I) Red blood cells from a male deaf Wistar rat were used to prepare a 10% (v/v) red blood cell solution with isotonic phosphate buffer (pH 7, 4, 0, 15M). di-α-tocopherol N.

N-dimethylaminoacetic acid ester taurocholate (
dl-a-tocopheryl N, N-dimet
hyl-aminoacetate taurocho
iate, hereinafter abbreviated as dl-rx-TDMAATC 2, was dissolved in distilled water to prepare a test solution. Test liquid 0.2 m
Add 0.4 ml of isotonic phosphate buffer to 7 and leave at 37°C for 5 minutes, then add 0.2 ml of 10% red blood cell solution and 37°C 13
After shaking for 0 minutes, centrifuge at 3000 rpm for 10 minutes. The supernatant was diluted 6 times with distilled water, and the absorbance at 540 nm was measured. For the control, 10% red blood cell fluid was added to isotonic phosphate buffer (0.6-), and for the 100% hemolyzed specimen, distilled water (0.6-) was added.
- to which 0.2 m/10% red blood cell fluid was added, and the absorbance was measured according to the above method.

ii)! fJL The results are shown in Figure 1.

In addition, FIG. 1 shows the hemolytic property of di-α-TDMAATC against rat red blood cells, and the horizontal axis is dl-tx-TD.
It represents the concentration of MAATC (mol/l), and the vertical axis is
Represents hemolysis rate (%).

As is clear from FIG. 1, the compound of the present invention di-α
-The hemolytic property of TDMAATC is extremely low, and dl -α-
The hemolysis rate is 5% or less when the TDMAATC concentration is in the range of 0.15 to 7.6 mM.

iii) In addition, dl-α-TDMA, which is a compound of the present invention
In addition to ATC, 3-di-α-
Taurocholate of tocopherylcacarnyl-1-methylpyridinium ester (JP-A-59-225184 >
When a similar experiment was conducted with 0.2 mM concentration, 100% hemolysis occurred. However, surprisingly, as shown in FIG.
There was no change in the concentration range of 1 to 10 mM, indicating low hemolysis.

[Narrow i) Method: Wistar male rats weighing 360-380 g.
Used in one group of animals, dl was injected into the left femoral vein of the rat under ether anesthesia.
- Administer a single dose of α-TDMAATC aqueous solution (90 mM). The dose was 5°nag equivalent of α-tocopherol. Blood was collected from the human jugular vein at 0.25, 1, 2, 4, and 8 degrees 24 hours after administration, and the amount of tocopherol in the serum and di-
α-tocopheryl N, N-dimethylaminoacetate (di-α-tocopheryl N, N-diI
Ilethylaminoacetate.

(hereinafter abbreviated as dl-α-TDMAA) was determined by high performance liquid chromatography (HPLC).

HPLC conditions: Column is shimpack CN, solvent is acetonitrile/acetic acid buffer (pH 5, 0, 1M)
, 65:35, flow rate l, 5 mZ/min, detection was performed at 283 nm.

i)! ! ! The results are shown in Figure 2.

FIG. 2 shows the results of examining the blood dynamics of the compound of the present invention and α-tocopherol, and the horizontal axis is di-α-TD.
The time after MAATC administration is represented, and the vertical axis represents the amount of tocopherol and dl-α-TDMAA in the serum.

The O mark indicates di-α-TDMAA, and the * mark indicates α-tocopherol.

As is clear from FIG. 2, the concentration of free tocopherol in the blood increases immediately after administration, reaching approximately 10 times the concentration within 4 hours after administration. di-α-TDMAA showed a biphasic disappearance. Therefore, it is clear that di-α-TDM^A is hydrolyzed in the rat body immediately after administration to produce free α-tocopherol.

The compound of the present invention is characterized by being easily soluble in water, capable of preparing a solution of 100 n+M or more, and having extremely low hemolytic properties, and is extremely valuable as a tocopherol derivative. Furthermore, in animal experiments using rats, this bile salt is rapidly hydrolyzed in the rat body after intravenous administration, increasing the concentration of free tocopherol in plasma.

Therefore, it is useful as an aqueous tocopherol injection or eye drops that can be administered intravenously, and since it is powdery, it is easy and convenient to handle in terms of formulation technology.

When preparing injections, infusions, eye drops, syrups, etc. using the compound of the present invention as a main ingredient, if necessary, by a conventional method,
A pH adjusting agent, a buffering agent, etc. are added to form a parenteral preparation by a conventional method, and the drug is administered once to several times a day.

〔Example〕

Examples of the present invention will be listed next, but it goes without saying that the present invention is not limited to these.

Examples 1 to 11 Various tocopherol N,N-dialkylaminoalkylcarboxylic acid ester bile salts shown in Table 1 were manufactured by the following manufacturing methods A and B.

Further, the 'H-NMR spectrum of the obtained substance is shown in Table 2.

Tocopherol N,N-dialkylaminoalkylcarboxylic acid esterlllllol and free bile acid l
ll1lllo1 was dissolved in methanol 100- and the solvent was distilled off under reduced pressure to obtain tocopherol N,N- as a white powder.
Bile salts of dialkylaminoalkyl carboxylic acid esters are obtained.

Preparation 1 Tocopherol N,N-dialkylaminoalkylcarboxylic acid ester hydrochloride IIIIIIlol and sodium bile acid 1 mmol were dissolved in a small amount of methanol,
The solvent was distilled off under reduced pressure, a small amount of ethanol was added to the residue, and insoluble NaCl was removed through a membrane filter (0.45 J!
After filtration, the solvent is distilled off under reduced pressure to obtain a white powder of bile salt of tocopherol N,N-dialkylaminoalkylcarboxylic acid ester.

Table 2 Table 2 (continued)

[Brief explanation of the drawing]

Figure 1 is a graph showing the hemolytic properties of dl-α-TDMAATC against rat red blood cells, and Figure 2 is a graph showing the hemolytic properties of dl-α-TDMAATC against rat red blood cells.
dl in serum after intravenous injection of MAATC aqueous solution to rats
Figure 2 shows changes over time in -α-TDMA^ and free α-tocopherol concentrations. In the figure, ○ indicates dl-α-TDMAA,
indicates α-tocopherol. Applicant's agent: Kaoru Dai Furuya 1 Figure 0.1 0.5 1
5 10α-α-TDMAAT
Concentration of C (Kari 0-5IIX: ll/l) 1, Indication of the case Japanese Patent Application No. 61280474 2, Name of the invention Bile salt of tocopherol N, N-dialkylaminoalkylcarboxylic acid ester 3, Person making the amendment Case Relationship with Patent applicant (021) Eisai Co., Ltd. 4, Agent 5, Detailed explanation of the invention and drawings in the specification subject to amendment 6, Contents of the amendment (1) End line of page 10, bottom of page 11 of the specification 6 lines from 1804
~ Corrected “serum” in line 5 as “plasma” (1) Corrected Figure 2 as shown in the attached sheet 7. List of attached documents [1) 1 drawing

Claims (1)

[Claims] 1 General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R^1 and R^2 mean the same or different lower alkyl groups. R^3 and R^4 are Means a hydrogen atom or a methyl group. n means an integer of 0 to 3. BA
means bile acid. ) A bile salt of tocopherol N,N-dialkylaminoalkylcarboxylic acid ester.