HK1169826B - Azilsartan organic amine salts, process of preparing them and the use thereof - Google Patents

Description

Azilsartan organic amine salt and preparation method and application thereof

Technical Field

The invention relates to an azilsartan organic amine salt and a preparation method thereof, a pharmaceutical composition containing a therapeutically effective amount of the compound, and application of the azilsartan organic amine salt in preparation of antihypertensive drugs.

Background

Hypertension is a common cardiovascular disease, and a clinical syndrome mainly manifested by persistent rise of systemic arterial blood pressure often causes pathological changes of important organs such as heart, brain, kidney and the like and has corresponding consequences. China is one of the most serious countries in the world with hypertension, and in the past decades, the estimated number of adults with hypertension has increased from 3000 million in 1960 to 5900 million in 1980 to 9400 million in 1991, and currently exceeds 2 hundred million, and 50% of 300 million cardiovascular patients who die each year are associated with hypertension. In the united states, 1/3 adults also suffer from hypertension. The search for effective antihypertensive drugs with few adverse reactions is urgent.

The common antihypertensive agents are classified into central hypotensive agents, ganglion blocking agents, sympathetic nerve end inhibitory agents, adrenergic receptor blocking agents, vasodilating agents, diuretic agents, Angiotensin Converting Enzyme Inhibitors (ACEI), and angiotensin receptor antagonists according to their action sites. The Renin Angiotensin System (RAS) is a group of interacting and mutually regulating hormones or precursors secreted by the kidneys and liver, including renin, angiotensinogen, angiotensin i (ang i), angiotensin ii (ang ii), Angiotensin Converting Enzyme (ACE), angiotensin receptors, and the like. Of these Ang II is one of the strongest vasoconstrictors and possesses numerous biological activities.

Azilsartan medoxomil (structural formula A) is an angiotensin II receptor antagonist drug developed by Wutian pharmaceutical company in Japan and used for treating hypertension, and belongs to angiotensin II receptor antagonists (sartans) drugs. The potassium salt of azilsartan medoxomil 2 month in 2011 is approved by the U.S. FDA to be marketed under the trade name Edabi. The medicine is orally administered, and can be used alone or in combination with other blood pressure lowering medicines for treating hypertension and related complications. Azilsartan medoxomil has a remarkable curative effect on reducing blood pressure, and has a more efficient blood pressure reducing effect compared with losartan and olmesartan medoxomil. (WHITE W B. effects of the angiotens receiver block azilsartan and valsartan onealbum and clinical block compression in properties with states 1 and dhypertension [ J ]. Hypertension, 2011, 57 (3): 413-420.)

Azilsartan medoxomil is a prodrug which is rapidly hydrolyzed into azilsartan acid during gastrointestinal absorption and exerts medicinal effects. Azilsartan (English name: Azilsartan, structural formula shown in formula B) is chemically 1- [ [2 '- (4, 5-dihydro-5-oxo-1, 2, 4-oxadiazol-3-yl) [1, 1' -biphenyl ] -4-yl ] methyl ] -2-ethoxy-1H-benzimidazole-7-carboxylic acid, and can block the vasoconstriction effect of angiotensin II by selectively blocking the binding of angiotensin II to vascular smooth muscle AT1 receptor in vivo, thereby lowering blood pressure.

Formula A

Formula B

EP1992110668, US5243054A, US20050187269 disclose a process for the preparation of azilsartan and structurally similar compounds thereof; chinese patent CN100503605C discloses azilsartan medoxomil potassium salt and preparation and drug effect thereof; WO2010075347 discloses medical uses and pharmacological activities of azilsartan medoxomil and azilsartan medoxomil potassium salt; CN101381366B discloses azilsartan and potassium salt of ester thereof.

However, subsequent studies show that azilsartan, as a drug directly exerting efficacy, has carboxyl in the molecular structure, and is poorly absorbed in vivo, which affects the efficacy of the drug and is not conducive to being prepared into pharmaceutical dosage forms. In order to improve the bioavailability, the azilsartan medoxomil can be prepared into an active ester, namely the azilsartan medoxomil, by a chemical modification method, the bioavailability is greatly improved but is still not ideal, and the modification makes the molecular structure of the medicine complex, increases the synthesis difficulty and improves the production cost.

Disclosure of Invention

According to the invention, researches show that the azilsartan and the organic amine are salified, so that the pharmacokinetic characteristics of the azilsartan and the organic amine can be well improved, the bioavailability of the azilsartan and the organic amine are improved, the toxicity of the azilsartan and the organic amine is reduced, and the azilsartan and the organic amine are more suitable for conventional preparation processes.

The invention aims to provide an organic amine salt of azilsartan, wherein the proportion of azilsartan and organic amine is m: 1, m is 2-10, and the preferable proportion is 2.

Preferably, the organic amine salt of azilsartan is present in a single molecule form or a complex form. The complex form is a molecular existence state understood by those skilled in the art, and generally, but not limited to, refers to a bonding state formed by intermolecular interaction, such as a complex state formed by intermolecular interaction of a hydrogen bond type, an ionic type, a charge transfer type and a van der waals force type, a complex state formed by a coordinate bond, and a covalent bond formed by a covalent bond.

Preferably, the organic amine is selected from methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethanolamine, piperazine, dibenzylethylenediamine, meglumine, tromethamine, tetramethylquaternary ammonium, tetraethylquaternary ammonium, or choline.

Preferably, the azilsartan organic amine salt has a structure shown in formula (I) or (II), wherein M is an organic amine, and M is selected from methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethanolamine, piperazine, dibenzylethylenediamine, meglumine, tromethamine, tetramethylquaternary ammonium, tetraethylquaternary ammonium or choline.

(n is an integer greater than 1)

(II)。

Preferably, the organic amine salt of azilsartan has a structure shown as formula (III) or (IV):

(n is an integer greater than 1)

(IV)。

Another object of the present invention is to provide a process for preparing the above compound, which comprises adding azilsartan acid and an organic amine into an alcoholic organic solvent, respectively, and salifying them at room temperature or under heating, preferably the process is carried out in an anhydrous environment.

When the organic amine is selected from choline, a choline alcohol solution is preferably added in the preparation of the corresponding azilsartan choline salt, more preferably a 45% choline methanol solution is added, and particularly preferably, the molar ratio of azilsartan acid to choline is 1: 1-2: 1.

When the organic amine is selected from methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethanolamine, piperazine, dibenzylethylenediamine, meglumine, tromethamine, tetramethylquaternary ammonium or tetraethylquaternary ammonium, preferably, the molar ratio of azilsartan acid and organic amine added in the alcohol organic solvent is 2:1 when preparing the corresponding organic amine salt of azilsartan.

Wherein the alcohol solvent is selected from methanol, ethanol, propanol or isopropanol.

Another object of the present invention is to provide a pharmaceutical composition for treating hypertension, which comprises a therapeutically effective amount of organic amine salts of azilsartan according to the present invention as an effective ingredient and a pharmaceutically acceptable carrier.

Further, the invention provides the use of the azilsartan organic amine salt and the pharmaceutical composition containing the azilsartan organic amine salt in the preparation of antihypertensive drugs.

In the formulation of pharmaceutical compositions, it is important that the drug substance be in a form that is convenient to handle and handle. This is important not only from the point of view of obtaining a commercially viable process for the preparation, but also from the point of subsequent preparation of pharmaceutical preparations containing the active compound.

Furthermore, in the preparation of pharmaceutical compositions, it is important that a reliable, reproducible and constant plasma concentration profile of the drug is provided after administration to a patient.

Chemical stability, solid state stability and "shelf life" of the active ingredient are also very important factors. The drug substance, and compositions containing it, should preferably be capable of being effectively stored for a considerable period of time without exhibiting significant changes in the physicochemical properties of the active ingredient (e.g. its chemical composition, density, hygroscopicity and solubility).

Furthermore, it is also very important to provide the drug in as chemically pure a form as possible.

It will be appreciated by those skilled in the art that typically if a drug is readily available in a stable form, the following advantages are provided: easy handling, easy preparation of suitable pharmaceutical formulations and reliable dissolution characteristics.

The effective amount of the active ingredient is an effective nontoxic dose, preferably in the range of 0.001 to 100mg/kg of the total weight, more preferably 0.001 to 50 mg/kg. When treating patients in need of treatment with the organic amine salt of azilsartan, oral or parenteral administration including topical, rectal, transdermal, injection or continuous infusion is preferred. The dosage for oral administration to human preferably comprises 0.05-3500 mg of active ingredient, most preferably 0.5-1000 mg of active ingredient. Oral administration forms using lower doses are preferred. However, high doses may also be administered parenterally where safe and convenient for the patient. The above dosages relate to the preferred amount of active ingredient expressed as the free acid.

It will be appreciated by those skilled in the art that the optimum number and spacing of individual doses of the active ingredient will depend upon the nature and extent of the condition being treated, the form, route and site of administration, and the particular patient being treated, and that such optimum will be determined by conventional techniques. It will also be appreciated by those skilled in the art that the optimal course of treatment, i.e. the number of doses of active ingredient administered per day over a given period of time, can be determined by those skilled in the art using routine tests for determining the course of treatment.

The compounds of the invention may be administered orally or parenterally, and may be formulated for various routes of administration, including tablets, pills, powders, and granules. In these solid formulations, the active ingredient is mixed with at least one inert diluent. Oral formulations may also include substances other than inert diluents, such as lubricants, glidants, and antioxidants, in accordance with conventional practice. In the form of capsule, tablet or pill, the preparation contains buffering agent. The tablet and pill can also be made into sustained release dosage form.

The parenteral formulations of the present invention include sterile aqueous solutions, although non-aqueous solutions of emulsions may also be employed. These dosage forms may also include adjuvants such as preserving, wetting, penetrating, buffering, emulsifying, and dispersing agents. The sterilization may be performed by filtering with a bacteria retaining filter (bacterio retaining filter), adding a sterilizing agent to the composition, irradiating the composition or heating the composition.

Compared with azilsartan and its esters, the azilsartan organic amine salt of the invention has the following main advantages:

(1) the salt of the invention has obviously increased solubility in conventional solvents and is suitable for conventional formulations.

(2) The salt of the invention has better preparation application value.

(3) The salt of the invention has better bioavailability and better treatment effect.

(4) The salts of the present invention are less toxic.

(5) The salt of the invention is prepared with high yield, high purity, rapidness, convenience and low cost, wherein, the ethanolamine salt and the choline salt have advantages in the process route and can directly separate out crystals.

Drawings

FIG. 1 is a graph of the exposure level of azilsartan acid after rats are administered 3.0mg/kg of the example two compounds (A) and 3.58mg/kg of azilsartan medoxomil (B);

FIG. 2 is a graph of the exposure level of M1 after administration of 3.0mg/kg of the example two compounds (A) and 3.58mg/kg of azilsartan medoxomil (B) to rats;

FIG. 3 is a graph of the exposure level of M2 after administration of 3.0mg/kg of the example two compounds (A) and 3.58mg/kg of azilsartan medoxomil (B) to rats;

FIG. 4 is a graph showing the effect of example two compounds on blood pressure in SHR rats after 2 weeks of continuous administration.

Detailed Description

EXAMPLE A1: 1 salt formation of Azilsartan acid and choline

Adding azilsartan acid (20.00g, 0.0439mol) into methanol (600.0ml), adding 46% choline aqueous solution (11.80g, 0.0439mol), stirring, dissolving, concentrating under reduced pressure, adding isopropyl ether (100.0ml), stirring, crystallizing, filtering, and vacuum drying to obtain 18g of white solid.

¹H NMR(DMSO-d6)δ：1.32(t，3H，CH₃)，3.30(s，9H)，3.43(t，2H，CH₂)，3.97(t，2H，CH₂)，4.29(q，2H，CH₂)，5.46(s，2H，CH₂)，7.29～7.87(m，11H)，11.21(br，2H，NH，OH)。

Elemental analysis (%): c, 64.30; h, 6.02; n, 12.49.

EXAMPLE Diazisartan acid and choline salified at 2:1

Adding azilsartan acid (10.00g, 0.022mol) and ethanol (100.0ml) into a reaction bottle, heating to reflux, adding 45% choline methanol solution (5.90g, 0.022mol), gradually dissolving, reacting for 3 hours under heat preservation, cooling to room temperature, stirring, crystallizing, filtering, and drying in vacuum to obtain 6.80g of white solid.

¹H NMR(DMSO-d6)δ：1.38(t，6H，CH₃)，3.09(s，9H)，3.39(t，2H，CH₂)，3.82(t，2H，CH₂)，4.58(q，4H，CH₂)，5.69(s，4H，CH₂)，7.05～7.61(m，22H)，11.07(br，4H，NH，OH，CO₂H)。

Elemental analysis (%): c, 65.22; h, 5.42; n, 12.23.

EXAMPLE Triazilsartan acid and Ethanolamine salified 1: 1

Adding azilsartan acid (10.00g, 0.0219mol) into methanol (300.0ml), adding ethanolamine (1.34g, 0.0219mol), stirring to dissolve, concentrating under reduced pressure, adding isopropyl ether (100ml), stirring to crystallize, filtering, and vacuum drying to obtain white solid (10.30 g).

¹H NMR(DMSO-d6)δ：1.30(t，3H，CH₃)，3.52(t，2H，CH₂)，4.27(t，2H，CH₂)，4.29(q，2H，CH₂)，5.52(s，2H，CH₂)，7.26～7.89(m，11H)，11.32(br，5H，NH，OH，NH₃)。

Elemental analysis (%): c, 62.59; h, 5.32; n, 13.54.

EXAMPLE Tetraazilsartan acid and Ethanolamine salified at 2:1

Azilsartan acid (10.0g, 0.0219mol) was added to methanol (300.0ml), ethanolamine (0.67g, 0.0110mol) was added, and the mixture was stirred to dissolve. Concentrating under reduced pressure to dryness, adding isopropyl ether (100ml), stirring, crystallizing, filtering, and vacuum drying to obtain white solid 8.93 g.

¹H NMR(DMSO-d6)δ：1.33(t，6H，CH₃)，3.09(t，2H，CH₂)，3.60(t，2H，CH₂)，4.30(q，4H，CH₂)，5.46(s，4H，CH₂)，7.28～7.93(m，22H)，11.0-13.0(br，7H，NH，CO₂H，OH)。

Elemental analysis (%): c, 64.07; h, 4.79; and N, 13.12.

EXAMPLE pentaazilsartan acid and piperazine salified 2:1

Azilsartan acid (10.0g, 0.0219mol) was added to methanol (300.0ml), piperazine (0.94g, 0.0109mol) was added, and the mixture was stirred to dissolve. Concentrating under reduced pressure to dryness, adding isopropyl ether (100ml), stirring, crystallizing, filtering, and vacuum drying to obtain white solid 9.45 g.

¹H NMR(DMSO-d6)δ：1.34(t，6H，CH₃)，2.68(s，8H，CH₂)，4.31(q，4H，CH₂)，5.47(s，4H，CH₂)，7.27～7.92(m，22H)，11.20(br，6H，NH，CO₂H)。

Elemental analysis (%): c, 64.79; h, 5.12; n, 14.15.

Test example-solubility test

And (4) test conclusion: the example one compound is comparable in solubility to the example two compounds.

Wherein "1: 40" means that 1g of the test sample is dissolved in 40ml of methanol at room temperature, and "1: 80" means the same; "1: 120" means that 1g of the sample is dissolved in 120ml of ethanol at room temperature, and "1: 200" means the same.

Test example two hygroscopicity test

The experimental method comprises the following steps:

1. placing a dry glass weighing bottle with a plug (outer diameter of 50nm and height of 15nm) in a climatic chamber with temperature of 25 deg.C + -1 deg.C and relative humidity of 80% + -2% in the previous day, and precisely weighing (m)₁)。

2. Taking a proper amount of the test sample, placing the test sample into the weighing bottle, spreading the test sample in the weighing bottle, precisely weighing the test sample (m) with the thickness of about 1mm₂)。

3. The weighing bottle is opened and is placed under the constant temperature and humidity condition for 24 hours together with the bottle cap.

4. The weighing bottle cap is closed, and precision weighing is carried out (m)₃)。

Calculating the formula: percent weight gain (m)₃-m₂)/(m₂-m₁)*100％

5. Definition of hygroscopicity increase

Deliquescence: absorb sufficient water to form liquid

Has the characteristics of moisture absorption: the moisture-drawing weight gain is not less than 15 percent

Moisture absorption: the moisture-drawing weight gain is less than 15 percent but not less than 2 percent

Slightly hygroscopic: the moisture-drawing weight gain is less than 2 percent but not less than 0.2 percent

No or almost no hygroscopicity: the moisture-drawing weight gain is less than 0.2 percent.

6. Testing results;

test sample	Moisture-wicking property	Conclusion (moisture-inducing property)
			EXAMPLES A Compound	10.51％	Is provided with
EXAMPLES two Compounds	0.02％	Is free of
			EXAMPLES III Compounds	5.66％	Is provided with
EXAMPLE four Compounds	0.08	Is free of

And (4) test conclusion: the second compound and the fourth compound have no hygroscopicity, are suitable for preparing pharmaceutical preparations, and are beneficial to the stability of the preparations.

Experimental example three SD rat drug test after administration

12 SD rats with the weight of 200-250g, the male and female halves, were randomly divided into 2 groups according to the weight, 6 rats in each group, and the male and female halves. Two groups were each administered a single oral dose of an equimolar amount of either Azilsartan Choline salt (Choline Azilsartan)3mg/kg or Azilsartan medoxomil (API of Edarbi) 3.58mg/kg of the compound of example (Azilsartan Choline salt, Choline Azilsartan). The detection of the levels of azilsartan acid (TAK-536), metabolites M1 (azilsartan decarboxylation product) and M2 (O-dealkylation product) in plasma was performed by taking 0.5ml of blood from the orbit before and at 0.5, 1.0, 2.0, 3.0, 4.0, 5.0, 7.0, 10, 24 and 48h after administration, and the results of the study are shown in the following tables and FIGS. 1-3.

The experimental results show that compared with the administration of equimolar azilsartan medoxomil, the Cmax and AUC of the azilsartan medoxomil in the blood plasma after the administration of the compound in the example are respectively improved by 98% and 70%, and the difference has statistical significance. The results show that the exposure level of the azilsartan acid can be greatly improved after the azilsartan medoxomil is changed into the choline salt.

Test example four SHR (spontaneous hypertension) rat antihypertensive effect test

38 SHR male rats of 25 weeks of age were randomly divided into 4 groups based on the initial blood pressure, and 8 rats were added to each group except for 6 rats in the solvent control group. 10mg/kg of the compound of example (Azilsartan Choline salt, Choline Azilsartan), the compound of example (Azilsartan ethanolamine salt) and the control drug (Azilsartan medoxomil potassium salt) were administered sequentially, respectively, and the vehicle was administered to the solvent control group. The administration volume was 5ml/kg and the administration period was 2 weeks.

As can be seen from FIG. 4, after 1 or 2 weeks of continuous administration, the compounds of example two and four significantly reduced the blood pressure of SHR rats (p < 0.01) as compared with the solvent control group; under the same dosage (10mg/kg), the second compound of the example has the best blood pressure reducing effect, and the fourth compound of the example has the second best blood pressure reducing effect than the control drug.

Test example five effects on angiotensin II-induced hypertension in rats

1. Laboratory instruments and other materials:

(1) instrument for measuring the position of a moving object

DSI remote sensing pressure measurement system

Blood pressure implant model: TA11PA-C40, Data Sciences International.

Blood pressure data analysis software: ponemah Software 5.0, Data sciences International.

Model of Alzet micro osmotic pump: alzet, model 2002, Alzet corporation, USA.

(2) Test drugs and reagents

Test compound code number: HS-10149 (example two compounds); batch number: 20110324, respectively; offered by Jiangsu Hoisen pharmaceutical Co., Ltd; purity: 99.5 percent; physical state: a white powder; storage conditions are as follows: sealing, drying at 4-8 deg.C, and protecting from light.

Solvent: ceolus; batch number: b063; physical state: a white powder; storage conditions are as follows: sealing, room temperature and drying.

Angiotensin II; batch number: 041M 5062V; purity: more than or equal to 93 percent; storage conditions are as follows: -20 ℃ in the absence of light;

the supplier: Sigma-Aldrich, Inc.

2. Compound preparation

(1) Angiotensin II

The modeled dose of angiotensin II was determined according to literature reports (Harrison-Bernard LM, Zhuo J, Kobori H, Ohishi M, Navar LG. Intra AT (1) receptor binding in ANG II-induced hypertension. am J physiological recovery. 2002 Jan; 282(1) F19-25; Diz DI, Baer PG, NasjlettiA. angiotensin II-induced hypertension in the effects on the plasma center, nal exposure, and tissue release of behaviour. J ClinInv. 1983 g; 72(2) 466-77). Accurately weighing the required angiotensin II, adding sterile physiological saline to prepare into a concentration of 14.4mg/mL, and gently mixing until the mixture is clear. Stored at-20 ℃ in the dark.

(2) Test agent

HS-10149 suspension: accurately weighing the required compound, diluting with 2% Ceolus suspension in gradient to three concentrations of 0.20mg/ml, 0.06mg/ml and 0.02mg/ml, stirring to dissolve uniformly, storing at 4 deg.C in dark place, preheating to room temperature before administration, and mixing well.

3. Laboratory animal

Sprague-Dawley rats 37 (supplied by Shanghai Sprague laboratory animals Co., Ltd.), female 17, male 20, animal certification numbers: 2007000524884, 2007000525715, 2007000526632.

4. Procedure of the test

(1) Hypertension induction and blood pressure implant implantation

After one week of acclimation, animals meeting the weight requirement (female: 230-. Male mice were anesthetized with ketamine (44mg/kg, im.) in combination with 2% pentobarbital sodium solution (30mg/kg, ip.) and female mice were anesthetized with 2% pentobarbital sodium solution (40mg/kg, ip); and (3) performing implant implantation operation on the test day 0, implanting a micro osmotic pump for the day 7, continuously monitoring the blood pressure for 24 hours, screening animals by taking the average systolic pressure for 24 hours as the standard of reaching 140mmHg, performing the test on qualified animals, and removing the unqualified animals.

(2) Grouping

The animals selected for the test are divided into groups according to the average blood pressure of 24 hours, wherein 8 animals in each group are averagely divided into half and half, and the number of the 8 animals in each group meets the requirements of statistical test and pharmacodynamic guidance principle.

(3) Administration of drugs

After grouping, solvent control group, test drug low, medium and high dose group are respectively administrated with 2% Ceolus, 0.1mg/kg, 0.3mg/kg and 1.0mg/kg HS-10149 by single gavage. The administration time of the test is 10 to 10 am and 30 minutes, and the intragastric volume is 5 mL/kg.

Design of experiments

Solvent control was a suspension of 2% Ceolus

(4) Experimental procedure

Healthy animals are selected to implant the implant on the 0 th day of the experiment, a micro osmotic pump is subcutaneously implanted on the 8 th day, and the blood pressure is monitored for 24 hours on the 15 th day, and the animals with qualified blood pressure are selected to enter the experiment. A single administration of either the positive or test drug was administered 10 am on day 16 of the experiment and the blood pressure was monitored 24 hours after administration. After the test was completed, the animals were euthanized by excessive carbon dioxide inhalation.

5. Data processing and analysis

The DSI remote sensing pressure measuring device automatically records data every 5 seconds, and the average value with hours as a time unit is calculated by software to serve as original data. P is less than 0.05, which indicates that the administration group has significant difference compared with the solvent control group; p < 0.01, indicating that the administered group had a very significant difference compared to the solvent control group.

6. Results of the experiment

(1) Blood pressure raising action of angiotensin II

On the 6 th day after the micro osmotic pump filled with angiotensin II is implanted, monitoring the dynamic blood pressure of the animal for 24 hours, taking the condition that the average systolic pressure of 24 hours is increased to 140mmHg as the standard for successful molding, leading the animal with qualified blood pressure to enter the test, and removing the animal with unqualified blood pressure. A total of 5 animals (4 males and 1 female) were culled in this trial. The mean of the 24 hour mean systolic blood pressure for all animals entering the test was 167 mmHg.

(2) Effect of HS-10149 on blood pressure of model animals

The data show that the solvent has no effect on the blood pressure levels of the animals. After administration, the mean blood pressure (mean value within 23 hours after administration) of animals in three dose groups of HS-10149(0.1mg/kg, 0.3mg/kg, 1.0mg/kg) is significantly reduced (p < 0.01) compared with that in the solvent group, the mean reduction percentage is respectively 24.7%, 39.3% and 44.9%, and HS-10149 shows positive correlation of dose-effect in the range of the tested dose; the mean blood pressure at 23, 13 and 3 hours before and 1 hour after the administration of the drug among the experimental groups has no significant difference among the groups (P is more than 0.05); compared with a solvent control group, the average blood pressure of the HS-10149 groups with low, medium and high doses at 2, 7, 13, 18 and 23 hours after the administration has very significant difference (P is less than 0.01); the low, medium and high dose groups of HS-10149 have larger reduction of the average blood pressure compared with the solvent control group at 23 hours after the administration. It follows that the pharmacodynamic action of HS-10149 can last about 23 hours after a single administration.

Comparison of the mean MBP 23 hours before and 23 hours after dosing

(Mean±S.E.，N＝8)

Note: p < 0.05, P < 0.01vs. solvent control

7. Conclusion

The test result shows that HS-10149 shows obvious blood pressure lowering effect in a rat hypertension model induced by angiotensin II, the drug effect and the dosage are in positive correlation between the dosage of 0.1mg/kg to 1.0mg/kg, the lowest effective dosage is 0.1mg/kg, and three dosages still show strong blood pressure lowering effect 23hr after administration.

Experimental example six Beagle dog acute toxicity experimental study

The purpose is as follows: the experiment aims to adopt an approximate lethal dose method, administer the two compounds or azilsartan medoxomil potassium salt in the embodiment through the stomach gavage of Beagle dogs, observe the acute toxic reaction of animals, study the toxicity condition of the two compounds in the embodiment after administration, and compare the toxicity of the two compounds in the embodiment with the azilsartan medoxomil potassium salt, thereby providing reference information for the toxicity evaluation of the two compounds in the embodiment.

The method comprises the following steps: a total of 6 Beagle dogs, example two compounds and 3 animals each of the azilsartan medoxomil potassium salt groups were used as determined by the near lethal dose method. The dosage is 0.09, 0.13, 0.19, 0.28, 0.42, 0.63, 0.95, 1.42, 2.13, 3.20 g/kg^-110 dose sequences of which 3.20 g.kg^-1The dose was already at the maximum dose administered (corresponding to 1081 times the dose intended for clinical humans). Simultaneously collecting blood before administration, on the 2 nd day, on the 7 th day and on the 14 th day after administration, and performing corresponding blood biochemical index determination; electrocardiography, body weight, and body temperature were measured before administration, on the 7 th day, and on the 14 th day after administration.

Results of the experiment

Azilsartan medoxomil potassium salt group: 3.20 g.kg^-1The animals in the dose group have vomit, salivation and hypokinesia on the day of administration, the activity is reduced on the 2 nd to 8 th days, the animals lie prostrate on the 5 th to 8 th days and die on the 9 th day. 2.13 g.kg^-1The animals in the dose group had vomiting, salivation and reduced activity on the day of administration. After the administration, the activity decreased on day 2, and the activity returned to normal on day 3, after which no abnormality was observed by cage side observation. 1.42 g.kg^-1The animals in the dose group showed vomiting and restlessness on the day of administration. After the administration, the activity decreased on day 2, and the activity returned to normal on day 3, after which no abnormality was observed by cage side observation.

Example two compound groups: 3.20 g.kg^-1The animals in the dose group showed loose stool, watery stool and salivation on the day of administration, and the process was continued until the observation was finished. Watery stool and reduced activity can be seen on the 2 nd day after administration, watery stool and normal activity can be seen on the 3 rd day, and stool characters can be recovered to normal on the 4 th day, and no abnormality is seen by cage side observation. 2.13 g.kg^-1The animals in the dose group have no abnormality on the day of administration, vomit and reduced activity on the 2 nd day after administration, loose stool and normal activity on the 3 rd day, and fecal characters recover on the 4 th dayNormal, no abnormalities were observed by cage side observation thereafter. 1.42 g.kg^-1Water-sampling stool and hypomotility appear on the day of dosing of animals in the dose group. After the administration, the activity decreased on day 2, and the activity returned to normal on day 3, after which no abnormality was observed by cage side observation.

The body weight of all animals in the azilsartan medoxomil potassium salt group and the example two compound group was reduced after the administration of the drug by day 7 and increased after the administration of the drug by day 14 in all the surviving animals.

The body temperature of all animals in the azilsartan medoxomil potassium salt group and the two compound groups in the examples is not obviously abnormal on the 7 th day after the administration, and the body temperature of all the surviving animals is not obviously abnormal on the 14 th day after the administration.

The electrocardiogram and hematological index examination of all animals in the azilsartan medoxomil potassium salt group and the compound group in the example on the 2 nd and 7 th days after the administration of the drug has no obvious abnormality, and the electrocardiogram and hematological index examination related to all the surviving animals on the 14 th day after the administration of the drug has no obvious abnormality.

The systolic pressure and the diastolic pressure of 5 animals in the azilsartan medoxomil potassium salt group and the compound group of example two are reduced to different degrees on the 2 nd day after the administration, and no obvious abnormality is found in the systolic pressure and the diastolic pressure of 14 th day after the administration of all the survival animals.

Azilsartan medoxomil potassium salt group: the administration dose is 3.20 g/kg^-1ALT, AST, CK, CRE, UREA, UA were significantly elevated on days 2 and 7 after administration to dogs, and died on day 9. The dosage of the drug is 2.13 g/kg^-1After the administration of the composition to dogs, the ALT, CRE, UREA and UA values are obviously increased on the 2 nd day, the ALT, CK, CRE and UA values are obviously increased on the 7 th day, the ALT, CK, CRE and UA values are recovered to be normal on the 14 th day, and other obvious abnormalities are not found. The administration dose is 1.42 g/kg^-1After the administration of the composition to dogs, ALT, CRE and UA are obviously increased on day 2, CRE and UA are obviously increased on day 7, the composition returns to normal on day 14, and other compositions have no obvious abnormality.

Example two compound groups: CRE, UREA and UA values are obviously increased on the 2 nd day, CRE and UA values are obviously increased on the 7 th day and normal recovery is realized on the 14 th day after all dogs are dosed(ii) a Wherein the administration dose is 3.20 g/kg^-1ALT is increased on day 2 after the administration of the drug to dogs, and the ALT returns to normal on day 7, and no obvious abnormality is found in others.

The PT values after administration of all animals in the azilsartan medoxomil potassium salt group and the example two compound group were significantly decreased compared to those before the administration. Azilsartan medoxomil potassium salt group administration dosage of 3.20 g.kg^-1Fib values were significantly elevated on day 2 and day 7 after canine dosing; the dosage of the drug is 2.13 g/kg^-1The Fib values were significantly elevated on day 2 after dog dosing. EXAMPLES two compounds were administered in a dose of 3.20 g.kg^-1The Fib values increased significantly on day 2 after dosing. No obvious abnormality was found in others.

Azilsartan medoxomil potassium salt group: 3.20 g.kg^-1Animals died on day 9 after dosing. The animal is roughly dissected to see perianal filth and bloody excrement; the left lung lobes are black and red (suspected to be caused by the posture of left lying on the left after death), and the right lung lobes are not obviously abnormal; the stomach bottom can be seen with gray wart, the small intestine is red brown from the middle part of jejunum to colon intestine, the color gradually deepens with the downward advancing of the intestinal tract section, no obvious ulcer is seen on the mucosa surface, and the mucosa surface of the intestinal tract section is scattered in dark red area; no obvious abnormality was observed in the other organs. 2.13 g.kg^-1The animals in the dose group are anesthetized and dissected on the 15 th day, the gross dissection of the animals can show that the fundus stomach and the cardia are scattered on small red spots, the mucous membrane surface is red, a small amount of chylomicron-like food can be seen in the stomach, and other organs are not abnormal. 1.42 g.kg^-1The animals in the dose group are anesthetized and dissected on the 15 th day, the general dissection of the animals can show that the mucosa of the stomach body is scattered in a red area, a small amount of chyme-like food can be seen in the stomach, and other organs are not abnormal.

Example two compound groups: 3.20 g.kg^-1The animals in the dose group are anesthetized and dissected on the 15 th day, each organ sample is stained by hematoxylin-eosin (HE), and the examination is carried out under a light microscope, so that no obvious abnormality is seen in the gross dissection of the animals. 2.13 g.kg^-1The animals in the dose group are anesthetized and dissected on the 15 th day, the animals are roughly dissected to see that the stomach is full, the animals contain a large amount of granular food, the cardiac mucosa surface is red and is scattered on red dots, and other organs are not abnormal. 1.42g·kg^-1The animals in the dose group are anesthetized and dissected on the 15 th day, the animals are roughly dissected to see that the stomach is full, the animals contain a large amount of granular food, the cardia is scattered on the mucous membrane to turn red, and other organs are not abnormal.

Azilsartan medoxomil potassium salt 3.20 g.kg^-1Dose group animal dissection observation record: samples of each organ were stained with hematoxylin-eosin (HE) and examined under light microscopy. Diffuse hepatic sinus dilation congestion appears in the liver, and partial liver tissues are autolyzed; the red marrow and white marrow of the spleen have obviously reduced lymphocytes, and the fibrous tissues in the red marrow are proliferated; diffuse moderate extravasated edema of lung tissue; extravasated blood and autolysis of kidney tissues; necrosis of gastric mucosal epithelium, edema of submucosa, and proliferation of fibroblasts, and some new capillaries can be seen; focal necrosis of the epithelium of the duodenum, jejunum, ileum, colon, caecum and rectum mucosa or with extravasated blood bleeding.

Conclusion of the experiment

Under the test conditions, Beagle dogs are gavaged with the compound of the example or the azilsartan medoxomil potassium salt, and the approximate lethal dose of the compound of the example is more than 3.20 g.kg^-1The approximate lethal dose range of the azilsartan medoxomil potassium salt is 2.13-3.20 g.kg^-1Thus, the acute toxicity of the example two compounds is lower than that of the azilsartan medoxomil potassium salt.

Claims (10)

1. The organic amine salt of azilsartan is characterized in that the proportion of azilsartan to organic amine is 2:1, and the organic amine is selected from ethanolamine or choline.

2. The organic amine salt of azilsartan according to claim 1, wherein said organic amine salt of azilsartan is present in the form of a complex.

3. The organic amine salt of azilsartan according to claim 2, having the formula (I)As shown in the drawings, the above-described,being cations of choline or organic amines with H⁺A cation formed wherein the organic amine is selected from the group consisting of ethanolamine,

4. the organic amine salt of azilsartan according to claim 3, wherein said organic amine salt of azilsartan has the structure shown in formula (III):

5. a method for preparing the organic amine salt of azilsartan as claimed in any one of claims 1 to 4, which comprises adding azilsartan acid and organic amine respectively into an alcohol organic solvent, and salifying the azilsartan acid and the organic amine at room temperature or under heating, wherein the molar ratio of the azilsartan acid to the organic amine is 2: 1.

6. a method for preparing the organic amine salt of azilsartan according to any one of claims 1 to 4, which comprises adding azilsartan acid and an organic amine into an alcohol organic solvent respectively, and salifying the azilsartan acid and the organic amine at room temperature or under heating, wherein the azilsartan acid and the organic amine are reacted in an anhydrous environment, and the molar ratio of the azilsartan acid to the organic amine is 2: 1.

7. a process for preparing azilsartan choline salt represented by formula (III) according to claim 4, which comprises adding azilsartan acid and a choline alcohol solution in an alcoholic organic solvent, wherein the choline alcohol solution is a 45% choline methanol solution, and the molar ratio of azilsartan acid to choline is 2: 1.

8. The method according to any one of claims 5 to 7, wherein the alcoholic organic solvent is selected from methanol, ethanol, propanol or isopropanol.

9. A pharmaceutical composition for treating hypertension, which comprises a therapeutically effective amount of the organic amine salt of azilsartan according to any one of claims 1 to 4 as an effective ingredient and a pharmaceutically acceptable carrier.

10. Use of the organic amine salt of azilsartan according to any one of claims 1 to 4, or the pharmaceutical composition according to claim 9, for the preparation of antihypertensive drugs.