RU2440115C2 - Coformulated drugs containing 2-ethyl-3-(n,n-dimethylcarbamoyloxy)-6-methylpyridine salts with organic and inorganic acids and succinic acid showing antihypoxic, antiamnestic and anticonvulsant activity - Google Patents

Abstract

FIELD: medicine, pharmaceutics.

SUBSTANCE: what is offered is a coformulated drug for treating various ischemic pathologies containing succinic acid and 2-ethyl-3-(N,N-dimethylcarbamoyloxy)-6-methylpyridine salts with succinic or hydrochloric acid of general formula I

where HX is salt-forming succinic or hydrochloric acid, m + 0.1-3.0; showing antihypoxic, antiamnestic and anticonvulsant activity characterised by the fact the relation in I between 2-ethyl-3-(N,N-dimethylcarbamoyloxy)-6-methylpyridine salts and the second component providing a 'synergistic' (potentiating) pharmacological effect by succinic acid makes 1:>0.3. It is shown that succinic acid potentiates declared action of the compound of formula I. It is a reason to create the coformulated drugs exceeding common preparations of 3-oxypyridine groups in pharmacological activity: emoxypin and mexidol, used for treating ischemic pathologies, particularly in diseases accompanied by cerebral ischemia.

EFFECT: preparation of new pharmaceutical compositions for treating ischemic pathologies.

5 tbl

Description

The invention relates to the chemistry and pharmacology of derivatives of 3-hydroxypyridine and for the creation of combined drugs for the treatment of various types of ischemic pathologies consisting of succinic acid and salts of 2-ethyl-3- (N, N-dimethylcarbamoyloxy) -6-methylpyridine with organic (succinic ) or inorganic (hydrochloric) acid of the general formula (I)

Ia, HX = 0.5 HOOC-CH ₂ CH ₂ -COOH Ib, HX = HCl;

where HX is the salt-forming succinic or hydrochloric acid, m = 0.1-0.3.

Despite some recent successes in the development of drugs for the treatment of neurological diseases associated with cerebral ischemia and associated with impaired mnemonic functions, the majority of existing drugs, although they improve the neurological outcome, do not reduce the mortality of patients with these diseases (1 )

Antioxidants, in particular emoxipin and mexidol, which have antihypoxic effects, play an important role in the complex treatment of coronary artery disease of the brain (2).

HX = HCL, emoxipin

HX = 0.5 HC ₂ CCH ₂ CH ₂ CO ₂ H,

Mexidol, Mexico

HX = HCL, emoxipin Proxypine

HX = 0.5 HOOCH ₂ CH ₂ COOH

mexidol, mexicor

Endogenous succinic acid is the most important energy substrate involved in many recovery processes that occur in organs and tissues, including under conditions of various pathologies / 3 /. Succinic acid itself is practically not used as a medicine / 4 /. In Russia, only the diagnosticum Limontar is registered, which is a composition of citric and succinic acids used in the study of the secretory ability of the stomach; in addition, there is evidence of its use for the prevention and treatment of alcohol intoxication / 5 /. Succinic acid is mainly used in pharmaceuticals as a salt-forming component of a number of drugs - succinates (mexidol, metoprolol, etc.), which provides water-soluble forms of these drugs.

2-ethyl-3- (N, N-dimethylcarbamoyloxy) -6-methylpyridine succinate / 6,7 /, which is superior in antihypoxic activity to both emoxipin and mexidol, is a new structural analogue of emoxipin and mexidol. This compound, called proxypine, is currently in phase 1 clinical study as a neuroprotective agent for coronary artery disease.

In an in-depth study of the pharmacology of proxypine and its analogue in the form of hydrochloride, we found that succinic acid significantly enhances (potentiates) the antihypoxic activity of these compounds. This circumstance was the basis for the development of target compounds I.

Experimental chemical part

Target compounds I are synthesized according to the scheme

Example 1. Obtaining 2-ethyl-3- (N, N-dimethylcarbamoyloxy) -6-methylpyridine succinate (Ia).

To a suspension of 109.74 g (0.8 mol) of 2-ethyl-3-hydroxy-6-methylpyridine in 240 ml of 1,2-dichloroethane, 105.24 g (1.04) are gradually added with stirring at a temperature of 22 ± 2 ° C. mole) of triethylamine and 111.85 g (1.04 mol) of N, N-dimethylcarbamoyl chloride.

The suspension is heated to boiling and boiled with stirring for 4 hours. Upon completion of heating, the mixture is cooled to 22 ± 2 ° C, 120 ml of water are added, stirred for 10 minutes, the aqueous layer is separated, and the organic layer is washed with water (2 × 60 ml) from excess triethylamine and its hydrochloride, dried over anhydrous sodium sulfate. The desiccant is filtered off and the filtrate is evaporated in vacuo. A hot solution of 47.24 g (0.4 mol) of succinic acid in 300 ml of isopropyl alcohol is added to the residue after distillation of the solvent. The resulting solution was brought to a boil, boiled with activated carbon for 10 minutes, filtered and left at 5-10 ° C for 10-15 hours. After filtration and drying at 50-60 ° C, 151.8 g of 2-ethyl-3- (N, N-dimethylcarbamoyloxy) -6-methylpyridine (Ia) succinate are obtained in the form of a white crystalline powder, readily soluble in water, alcohols and acetone . An additional 23.7 g of product are obtained from the mother liquor after removal of the solvent and recrystallization of the residue from isopropyl alcohol. The total yield of Ia is 175.5 g (82% of theoretical).

T _pl. 84-86 ° C (from isopropyl alcohol).

Found,%: C 58.09; H, 7.24; N, 10.20.

C ₂₆ H ₃₈ N ₄ O ₈ .

Calculated,%: C 58.41; H 7.16; N, 10.48.

1 H-NMR spectrum (ppm): 1.20 (t, J = 7.5 Hz; 3 N, CH ₃ ethyl);

2.50 (C, 3 H, 6-CH ₃ ); 2.56 (C, 2 N, CH ₂ succinic acid);

2.72 (q, J = 7.5 Hz, 2 N, CH ₂ ethyl); 3.00 (C, 3 H, CH ₃ -N);

3.15 (C, 3 H, CH ₃ -N); 7.14 (g., J = 8.3 Hz, 1 H, H-5);

7.41 (g., J = 8.3 Hz, 1 H, H-4).

Example 2. Obtaining 2-ethyl-3- (N, N-dimethylcarbamoyloxy) -6-methylpyridine hydrochloride (IB).

To the residue after distillation of dichloroethane obtained from 109.74 g (0.8 mol) of 2-ethyl-6-methyl-3-hydroxypyridine and described in Example 1, 850 ml of ethyl acetate are added, treated with activated carbon at a temperature of 22 ± 2 ° C. , filter and isolate the product by adding an alcoholic solution of hydrogen chloride to pH 3.

135.3 g of 3- (N, N-dimethylcarbamoyloxy) -2-ethyl-6-methylpyridine (Ib) hydrochloride are obtained in the form of a white crystalline powder, readily soluble in water and alcohols, poorly soluble in ethyl acetate, ether and acetone.

An additional 33.1 g of product are obtained from the mother liquor after evaporation of the solvent and treatment of the residue with 180 ml of ethyl acetate.

The total yield of 2-ethyl-3- (N, N-dimethylcarbamoyloxy) -6-methylpyridine hydrochloride is 168.4 g (86% of theory).

T _pl. 181-183 ° C (from isopropyl alcohol).

Found,%: C 54.54; H, 7.00; Cl 14.60; N, 11.68.

C ₁₁ H ₁₇ ClN ₂ O ₂ .

Calculated,%: C 53.99; H, 7.00; Cl 14.49; N, 11.45.

PMR spectrum (SD3OD) ppm: 1.35 t. (CH ₃ CH ₂ ); 3.02 square meters

(CH ₃ CH ₂ ); 2.79 ears. from. (6-CH ₃ ); 3.04 and 3.19 s (NMe ₂ );

7.83 ears d. (C ⁵ N, JC ⁵ HC ⁶ H = 8.7 Hz); 8.30 d. (C ⁴ H)

The experimental pharmacological part.

Given the biological characteristics of succinic acid, including its antihypoxic properties / 8 /, as well as the pharmacological activity spectrum of 2-ethyl-3- (N, N-dimethyl-carbamoyloxy) -6-methylpyridine (base of compound I), it was of interest to study antihypoxic , antiamnestic and anticonvulsant activity of the latter in the form of succinate (compound Ia) and hydrochloride (compound Ib), as well as when they are combined with succinic acid.

In experiments on mice weighing 20-22 g, the effect of a single oral and intraperitoneal administration of compounds Ia, Ib and succinic acid was studied separately and together with compounds Ia and Ib on the survival time of animals on a model of hypobaric hypoxia using a flow-exhaust pressure chamber (animals were "raised" to a height of 11 km at a speed of 25-55 m / s) / 9 /.

In these experiments, it was found that succinic acid at doses of 7, 14 and 28 mg / kg orally, as well as compounds 1a and 1b at a dose of 25 mg / kg, have a moderate antihypoxic effect (Table 1). However, no significant differences were found in the effect of compounds Ia and Ib. In the case of simultaneous co-administration of compound Ia at a dose of 25 mg / kg and succinic acid at doses of 14, 28 and 56 mg / kg, there is an increase (potentiation) of antihypoxic effect compared with the effect observed when they are used separately, as well as in comparison with the effect of Mexidol at a dose of 100 mg / kg. Similar, but more pronounced results were obtained in the case of intraperitoneal administration of compounds Ia and Ib, on the one hand, and succinic acid, on the other. It should be noted that the effect of compound Ia was significantly less pronounced than compound Ib.

In experiments on mice weighing 18-20 g, the effect of a single oral administration of compound Ia and succinic acid was studied separately and together with compounds Ia and Ib on the survival time of animals on a model of hypoxic hypoxia with hypercapnia (pressure chamber) / 9 /.

In these experiments, it was found that compound Ia shows a moderate antihypoxic effect only in a high dose (150 mg / kg) (Table 2). Succinic acid when used separately at a dose of 168 mg / kg is not effective, and in combination with compound Ia it enhances (potentiates) the antihypoxic effect of the latter. It should also be noted that the combination of Ia and succinic acid is also superior in efficiency to Mexidol.

In experiments on rats weighing 200-250 g, we studied the effect of compounds Ia and IB, as well as succinic acid, separately and together with compounds Ia and IB on memory impairment and learning caused by scopolamine, using the active avoidance method (jump chamber) / 10 / .

It was shown that administration of scopolamine (60 minutes before training) for 5 days significantly disrupts the process of memorizing information (Table 3). Compounds 1a and 1b at a dose of 25 mg / kg, as well as succinic acid at a dose of 28 mg / kg, when administered separately, do not affect the memory impairment caused by scopolamine, whereas in the case of combined administration of succinic acid with compound 1b, but not on the 1st, and on the 5th day of the study, potentiation of their protective effect is noted. It should be noted that in this model, mexidol at a dose of 25 mg / kg was not effective.

In experiments on mice, the effect of a single oral and intraperitoneal administration of compounds Ia, Ib, and succinic acid separately in combination with compounds Ia and Ib on memory impairment and learning caused by electric shock was studied using the conditional passive avoidance reaction method / 10 /.

It was found that in intact animals, compounds Ia and Ib at a dose of 100 mg / kg and succinic acid at a dose of 25 mg / kg orally with separate and combined use do not significantly affect their learning ability (left column of Table 4). In mice that received electroshock after training (without administering the studied drugs), a significant deterioration in conditioned reflex activity was noted, which is manifested by a 4-fold decrease in the latent period of entry into the dark compartment of the chamber (right column of Table 4). Administration of compound 1a at a dose of 100 mg / kg orally and at doses of 2.5; 5, 10 and 25 mg / kg intraperitoneally, as well as succinic acid at a dose of 25 mg / kg intraperitoneally, leads to some (statistically insignificant) weakening of the amnestic effect of electroshock, which in the case of their combined use tends to more pronounced weakening of amnesia (right column of table 4).

In experiments in mice, the effect of preliminary (40 min) single intraperitoneal administration of compounds Ia and IB, as well as succinic acid separately and in combination with compounds Ia and IB on latent periods of clonus, tetanus, and deaths in response to subcutaneous administration of corazole at a dose was studied. 135 mg / kg / 11 /. In these experiments, it was shown that compound Ia at a dose of 25 mg / kg practically does not affect the convulsive effect of corazole, while compound Ib at the same dose increases the latent periods of tetanus and death (Table 5). Under similar conditions, succinic acid per se does not significantly alter the effect of corazole, whereas if it is administered in combination with compounds Ia and IB, the latent periods of tonic extension and death increase (moreover, when combined with compound Ib).

Thus, the claimed combination preparations containing compounds Ia and Ib, on the one hand, and succinic acid, on the other hand, have a more pronounced antihypoxic, antiamnestic and anticonvulsant effect in comparison with their separate use. Moreover, I HX = 0.5 moles of succinic acid, m at least 1 for tablets or capsules, and m at least 0.5 for injection, and in the case of I HX = HCL, m at least 1 for tablets or capsules and m not less than 0.5 for injection.

Our study of the pharmacological activity of drugs of the 3-hydroxypyridine group showed that their antihypoxic activity increases in the order: emoxipin <mexidol <proxypine <Ia + succinic acid <Ib + succinic acid.

The creation of the inventive combined preparations, in particular compounds Ia or Ib + succinic acid, will expand the range of drugs used to treat various ischemic diseases of the central nervous system.

Table 1 Antihypoxia action 2-ETHYL-3- (N, N-dimethylcarbamoyloxy) -6-methylpyridine (as succinate - HYDROCHLORIDE AND Ia - Ib) and succinic acid alone and in combination a single oral and intraperitoneal administration hypobaric hypoxia MODEL IN MICE A drug Doses, mg / kg Life span, min Effect, % Control, inward (n = 72) - 43.2 ± 2.1 - Compound Ia inward (n = 16) 25 80.3 ± 11.5 + 86% * Compound Ib inward (n = 16) 25 63.1 ± 6.4 + 46% * Succinic acid inside (n = 8) 7 70.0 ± 13.8 + 62% * Succinic acid inside (n = 29) fourteen 65.0 ± 5.6 + 51% * Succinic acid inside (n = 8) 28 63.1 ± 10.5 + 46% * Compound Ia + 25 85.0 ± 10.2 + 97% * + succinic acid inside (n = 16) 7 Compound Ia + 25 123.8 ± 13.5 + 187% * + succinic acid inside (n = 56) fourteen Compound Ia + 25 133.9 ± 30.1 + 210% * + succinic acid inside (n = 24) 28 Compound Ia + 25 100.3 ± 18.2 + 132% * + succinic acid inside (n = 16) 56 Mexidol inside (n = 16) one hundred 72.5 ± 7.8 + 41% * Control (n = 16) 51.3 ± 2.1 Control b / w (n = 24) - 45.6 ± 1.7 - Compound Ia / abdominal. (n = 8) 25 72.5 ± 5.7 + 59% * Compound Ib / abdomen. (n = 8) 25 161.9 ± 36.4 + 255% * Succinic acid in / abdominal. (n = 8) fourteen 58.8 ± 8.4 + 28% * Compound Ia + 25 305.4 ± 39.2 + 570% * + succinic acid in / abdominal. (n = 24) fourteen Compound IB + 25 354.0 ± 47.0 + 676% + succinic acid in / abdominal. (n = 24) fourteen P <0.05 compared with control

table 2 Antihypoxia action 2-ETHYL-3- (N, N-dimethylcarbamoyloxy) -6-methylpyridine (as succinate - HYDROCHLORIDE AND Ia - Ib) and succinic acid alone and in combination a single oral and intraperitoneal administration in a Model of hypoxic hypoxia (GERMOKAMERA) In mice A drug Doses, mg / kg Life span, min Effect, % Control (n = 23) - 23.6 ± 0.83 - Compound Ia inward (n = 5) 25 23.4 ± 0.85 0% Compound Ia inward (n = 7) 150 30.8 ± 1.6 + 36% * Succinic acid inside (n = 7) 168 22.4 ± 2.4 0% Compound Ia + 25 22.3 ± 1.28 0% + succinic acid inside (n = 6) fourteen Compound Ia + 150 36.6 ± 1.2 + 55% * + succinic acid inside (n = 14) 168 Mexidol inside (n = 9) 500 31.0 ± 2.3 + 31% * Compound Ia / abdominal. (n = 9) 25 30.6 ± 1.3 + 37% * Compound Ia / abdominal. (n = 5) 40 32.8 + 2.1 + 39% * Compound Ib / abdomen. (n = 9) 25 29.8 ± 1.7 + 26% * Compound Ib / abdomen. (n = 6) 40 31.8 ± 1.28 + 35% * Succinic acid in / abdominal. (n = 5) 28 27.3 ± 2.2 + 15% Compound Ia + 25 33.0 ± 1.0 + 40% * + succinic acid in / abdominal. (n = 6) 28 Compound Ia + 40 33.0 ± 1.2 + 40% * + succinic acid (n = 5) 28 Compound IB + 25 30.0 ± 1.5 + 27% * + succinic acid in / abdominal. (n = 5) 28 Compound IB + 40 33.5 ± 1.23 + 42% * + succinic acid in / abdominal. (n = 6) 28 * P <0.05 compared with control

Table 3 EFFECTS antiamnesic 2-ETHYL-3- (N, N-dimethylcarbamoyloxy) -6-methylpyridine (as succinate - HYDROCHLORIDE AND Ia - Ib) and succinic acid alone and in combination MODEL amnesia, scopolamine causes, in REACTION TEST CONDITIONAL active avoidance (JUMP CAMERA) IN RATS Training day The control Scopolamine, 2 mg / kg iv. Compound Ia, 25 mg / kg orally Compound IB, 25 mg / kg orally Succinic acid, 28 mg / kg orally Compound Ia, 25 mg / kg + succinic acid, 28 mg / kg orally Compound IB, 25 mg / kg + succinic acid, 28 mg / kg orally one 1.2 ± 0.4 0.1 ± 0.1 * 0 0.8 ± 0.4 0 0 0.7 ± 0.4 2 4.7 ± 0.7 0.5 ± 0.3 * 0 2.0 ± 1.0 0.4 ± 0.3 0.2 ± 0.2 2.3 ± 1.2 3 7.2 ± 0.5 1.6 ± 0.9 * 0.8 ± 0.5 3.3 ± 1.3 2.0 ± 0.8 1.3 ± 0.9 3.3 ± 1.3 four 7.8 ± 0.7 2.2 ± 0.9 * 1.0 ± 1.0 4,5 ± 1,6 1.5 ± 0.5 1.8 ± 1.4 4,5 ± 1,6 5 8.3 ± 0.6 2.3 ± 0.9 * 1.7 + 1.1 4.3 ± 1.6 2.8 ± 1.0 2.5 ± 1.4 6.3 + 1.2 ** * P <0.05 compared with the control, ** P <0.05 compared with scopolamine

Table 4 EFFECTS antiamnesic 2-ETHYL-3- (N, N-dimethylcarbamoyloxy) -6-methylpyridine (as succinate - HYDROCHLORIDE AND Ia - Ib) and succinic acid alone and in combination a single oral and intraperitoneal administration in mice of amnesia, causes Electroshock , BY THE METHOD OF THE CONDITIONAL REACTION OF PASSIVE AVOIDANCE A drug Doses, mg / kg The latent period of stay of mice in a light chamber (s) after: training after 24 hours and subsequent electroshock (amnesia) Control (n = 12) - 103 ± 10 Compound Ia inward (n = 12) one hundred 81 ± 13 Compound Ib inward (n = 12) one hundred 79 ± 13 Succinic acid inside, (n = 12) 25 90 ± 13 Compound Ia + one hundred 95 ± 11 + succinic acid inside (n = 11) 25 Compound IB + one hundred 117 ± 19 + succinic acid inside (n = 12) 25 Control (n = 12) - 25 ± 5 Compound Ia inward (n = 12) one hundred 29 ± 5 Compound Ia + one hundred 42 ± 5 + succinic acid inside (n = 12) 25 Control (n = 12) - 25 ± 5 Compound Ia / abdominal. (n = 2) 2.5 30 + 7 Compound Ia / abdominal. (n = 11) 5 50 ± 9 Compound Ia / abdominal. (n = 11) 10 59 ± 10 Compound Ia 25 75 ± 11 Succinic acid in / abdominal. (n = 12) 25 50 ± 8 Compound Ia + 2.5 48 ± 6 + succinic acid in / abdominal. (n = 12) 25 Compound Ia + 5 60 ± 7 + succinic acid in / abdominal. (n = 12) 25 Compound Ia + 10 69 ± 8 + succinic acid in / abdominal. (n = 15) 25 Compound Ia + 25 70 ± 9 + succinic acid in / abdominal. (n = 14) 25

Table 5 The anti-seizure effect of 2-ethyl-3- (N, N-dimethyl-carbamoyloxy) -6-methyl-pyridine (in the form of succinate - Ia and hydrochloride - Ib) and sodium is very much complete. A drug Doses, mg / kg Latent periods (c) caused by corazole: clonus tetanus of death Control (n = 15) - 180 ± 22 380 ± 40 420 ± 5 Compound Ia (n = 12) 25 179 ± 21 385 ± 60 415 ± 60 Compound IB (n = 12) 25 172 ± 19 570 ± 36 * 609 ± 40 * Succinic acid (n = 10) 25 305 + 70 439 ± 50 490 ± 60 Compound Ia + Succinic Acid (n = 13) 25 25 180 + 19 590 ± 35 * 710 ± 50 * ** Compound IB + succinic acid (n = 13) 25 25 166 + 7 645 ± 50 * 989 ± 80 * ** * P <0.05 compared with the control, ** P <0.05 compared with scopolamine

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Claims (1)

1. The combined drug for the treatment of various types of ischemic pathologies, consisting of succinic acid and salts of 2-ethyl-3- (N, N-dimethylcarbamoyloxy) -6-methylpyridine with succinic or hydrochloric acid, the general formula I

where HX is salt-forming succinic or hydrochloric acid, m = 0.1-3.0, with antihypoxic, antiamnestic and anticonvulsant activity, characterized in that the ratio in I between the salt of 2-ethyl-3- (N, N-dimethylcarbamoyloxy) - 6-methylpyridine and the second component, providing a "synergistic" (potentiating) pharmacological effect of succinic acid, is 1:> 0.3.