RU2490016C1 - Parenteral composition containing carbamazepine in form of submicron emulsion possessing anticonvulsant activity - Google Patents

Abstract

FIELD: medicine, pharmaceutics.

SUBSTANCE: invention refers to medicine and pharmaceutical industry, particularly to creating a pharmaceutical composition of a submicron emulsion for parenteral administration, having anticonvulsant activity. The composition contains 5-carbamoyl-5H-dibenz-(b,f)-azepine, and additionally it contains soya been oil and sodium deoxycholate in the following proportions, wt %: 5-carbamoyl-5H-dibenz-(b,f)-azepine - 18.5-23.2, soya been oil - 2.1-2.3, sodium deoxycholate - 74.5-79.4. The composition has an average size of the deagglomerated microparticles of 108-132 nm.

EFFECT: composition enables the intravenous intraperitoneal administration of a low therapeutic dose with a high efficacy of the preparation, and reduction of dose-dependent adverse reactions, and extends the range of such preparations.

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Description

The invention relates to medicine and pharmacy, in particular to drugs used to treat epilepsy, in particular to the creation of a submicron emulsion containing 5-carbamoyl-5H-dibenz- (b, f) -azepine (carbamazepine), which has an anticonvulsant effect.

One of the main drugs used in the treatment of psychomotor disorders, trigeminal neuralgia, as well as for the relief of seizures, is carbamazepine. To date, the oral pharmaceutical forms of carbamazepine (tablets, capsules, suspensions) are widely represented on the pharmaceutical market.

However, the extremely poor solubility of carbamazepine in water (0.061 mg / ml) leads to slow and incomplete absorption in the gastrointestinal tract, which reduces the effectiveness of the drug. Creating a soluble form of the drug in the form of a submicron emulsion is very important, as it should lead to an increase in bioavailability. In addition, low solubility makes it difficult to create on its basis a form for parenteral administration (intravenous, subcutaneous, intraperitoneal). The form of the drug for parenteral administration into the body, in particular for intravenous administration, is urgently needed to provide emergency care to patients in case of seizures, as well as to patients who are in an unconscious state when it is impossible to administer the drug orally.

There are several ways to solubilize hydrophobic substances: complexation with amphiphilic polymers (most often, PEG, PVP), conclusion of the substance into particles (liposomes, emulsions, solid lipid particles, cochleates, micelles, polymer nanospheres, etc.), the use of cyclodextrins, etc. .

Emulsified oil-in-water dosage forms are used to administer a number of drug substances that are poorly soluble in water but can be solubilized by the oil phase of the emulsion.

A parenteral composition is currently known comprising 5H-dibenz (b, f) azepine-5-carboxamide and water or a water-based solvent, the composition not containing any other solubilizing additives (RU 2000110741, 02.27.2002). This source of information is considered by us as the closest analogue.

However, said parenteral composition containing carbamazepine is used in relatively large dosages for the treatment of epilepsy and has dose-dependent adverse reactions.

The technical result of our development in the form of a composition of a submicron emulsion of carbamazepine consists in its more complete absorption and the possibility of parenteral administration of small therapeutic doses with high drug efficacy, in reducing dose-dependent adverse reactions, as well as expanding the arsenal of such agents.

The technical result is achieved due to the fact that a pharmaceutical composition of a submicron emulsion for parenteral administration is developed, which has anticonvulsant activity and contains 5-carbamoyl-5H-dibenz- (b, f) -azepine and additionally soybean oil and sodium deoxycholate in the following ratio of components, wt .%:

5-carbamoyl-5H-dibenz- (b, f) -azepine - 18.5-23.2 soybean oil - 2.1-2.3 sodium deoxycholate - 74.5-79.4

and has an average size of disagglomerated microparticles of 108-132 nm.

The invention is illustrated by the following examples.

Preparation of a submicron emulsion for parenteral administration containing 5-carbamoyl-5H-dibenz- (b, f) -azepine and having an average deagglomerated microparticle size of 108-132 nm

Example 1

In a 1 L flask, 200 ml of a solution of sodium deoxycholate (DHN) with a concentration of 1 mg / ml in 0.04 M Tris buffer with a pH of 8.2, 6 mg of soybean oil and 58 mg of carbamazepine are mixed. The resulting dispersion is mixed and treated in an ultrasonic bath for 5-7 minutes. The result is an opalescent dispersion with an average particle size of 108-132 nm.

Example 2

In a 1 L flask, 197.2 ml of a 1 mg / ml solution of DHN in a 0.04 M Tris buffer with pH 8.2, 5.5 mg of soybean oil and 61.3 mg of carbamazepine are mixed. The resulting dispersion is mixed and treated in an ultrasonic bath for 5-7 minutes. The result is an opalescent dispersion with an average particle size of 108-132 nm.

The optimal ratio of components and the resulting particle sizes are presented in table 1.

Table 1. Particle size in samples containing soybean oil and DHN. The content of soybean oil and DHN in the dispersion,% Particle size, nm Share% The average particle size, nm Oil - 1, DHN-70,0 155 97 983.4 3 569.2 Oil -2.1, DHN-74.5 132 one hundred 132 Oil - 2.2, DHN - 76.5 90 65 127 35 108,5 Oil - 2.3, DHN - 79.4 132 one hundred 132 Oil - 4, DHN - 90.0 136 98 960 2 548

The morphology of the particles in the dispersion was studied using transmission electron microscopy.

The determination of the degree of incorporation of carbamazepine into submicron particles according to example 1 and 2 was carried out as follows.

The loaded submicron particles were separated from unincorporated carbamazepine by gel filtration on a Sephadex G-25 column (NAP5), with a chromatographic layer volume of 10 ml. The volume of the applied dispersion of submicron particles on a NAP5 column is 0.5 ml (initial sample). Tris buffer (0.04 M, pH 8.2) was used as an eluent. The fraction of submicron particles with carbamazepine leaving the column was taken in a volume of 1 ml (fraction 1). In parallel, the initial sample in the amount of 0.5 ml without applying to the column was diluted twice by adding 1 ml of Tris buffer. In this case, a fraction containing unincorporated carbamazepine was obtained (fraction 2). The concentration of carbamazepine in the submicron dispersion and the degree of incorporation of substances into them were calculated according to the optical density measurements at 286 nm after adding to the 100 μl dispersion fraction 1 and fraction 2 in 2 ml of tetrahydrofuran (THF).

Settlement formula:

% inclusion of carbamazepine in the particles = fraction 1 / fraction 2 * 100%,

where fraction 1 is the optical absorption of the fraction of particles with carbamazepine after adding THF, fraction 2 is the optical absorption of a doubly diluted initial dispersion after adding THF.

The degree of inclusion of carbamazepine in the submicron emulsion oil / DHN 2.1-2.3 was 91%, the ratio of carbamazepine / carrier (soybean oil and DHN) was 0.24-0.28.

Lyophilization of the submicron emulsion was carried out as follows.

To the resulting submicron emulsion, sucrose was added as a cryoprotectant based on 10 parts by weight of sucrose per 1 part by weight of the total weight of carbamazepine and excipients. Then the samples were poured into 1 ml vials, frozen, lyophilized and sealed. Submicron emulsion is ready for use. Rehydration of the submicron emulsion before use was carried out by adding distilled water or a solution of sodium chloride so as to obtain an emulsion with the desired concentration of carbamazepine for parenteral administration.

The anticonvulsant activity of the 5-carbamoyl-5H-dibenz- (b, f) -azepine submicron emulsion is presented in the examples below.

We worked with laboratory animals in accordance with the current "Rules for the use of experimental animals" and the "International guidelines for biomedical research using animals" [International guidelines for biomedical research using animals. // Chronicle of the WHO. - 1985. - T. 39, No. 3. - C.3-9]. All animals were kept in a vivarium under the same living and feeding conditions (standard briquetted food). Our submicron oil-in-water emulsion drug composition was used for parenteral administration of carbamazepine. Carbamazepine is well soluble in the oil phase of emulsions, represented by long-chain triglycerides - soybean oil. This allows you to solubilize this drug without the use of organic solvents, as well as without the use of synthetic solubilizers, which can potentially cause side effects. To stabilize the submicron emulsion, a surfactant, represented by sodium deoxycholate, is used. Steroid micelle-forming surfactant-DHN is a part of bile and is involved in the process of fat assimilation in the gastrointestinal tract.

Example 3

Study of the anticonvulsant activity of a submicron emulsion of carbamazepine in comparison with carbamazepine in a substance for generalized convulsions caused by maximum electroshock. The experiments were performed on male white outbred mice. Generalized seizures were induced using the maximum electric shock technique using a certified Rodent Shockers installation (Harvard Apparatus, USA). An electrical stimulus (500 V, 145-147 mA, duration - 0.6 s) was applied through special eye electrodes pre-moistened in physiological saline. The presence of primary-generalized seizures was recorded - tonic extension of the fore and hind limbs, subsequent to this phase of clonic seizures of the whole body and the death of animals [Voronina TA, Nerobkova L.N. Guidelines for the study of the anticonvulsant activity of pharmacological substances. Guidance on the experimental (preclinical) study of new pharmacological substances, 2nd edition, ed. RU. Khabrieva, Moscow, 2005, p.277-294].

The submicron emulsion of carbamazepine obtained in example 1 was administered intraperitoneally (VNB) in three doses: 3.3; 5.0 and 8.3 mg / kg. As a comparison drug, carbamazepine was used in the substance (5-carbamoyl-5H-dibenz (b, f) azepine; Akrikhin) at doses of 5, 10 and 20 mg / kg ip in a volume similar to that of the carbamazepine submicron emulsion. Control animals were injected with distilled water in an equivalent volume. Maximum electroshock was performed 40 minutes after the introduction of substances.

It was established that the maximum electroshock caused the onset of primary generalized convulsions - tonic extension of the front and hind limbs, and subsequent clonic convulsions of the whole body in all animals of the studied groups. Under the influence of maximum electric shock, the death of animals in the control group was 85.7%.

The submicron emulsion of carbamazepine at a dose of 8.3 mg / kg completely prevented the death of animals. At a dose of 5 mg / kg, a submicron emulsion of carbamazepine prevented death in 66.7% of cases, and in a small dose of 3.3 mg / kg, a submicron emulsion of carbamazepine eliminated death in 57% of animals. Thus, the anticonvulsant effect of a submicron emulsion of carbamazepine has a clearly defined dose-dependent nature - with an increase in the dose of a substance, its anticonvulsant effect increases linearly. The activity of the carbamazepine submicron emulsion when using small doses in the conditions of the model of primary-generalized seizures caused by maximum electroshock significantly exceeded the activity of standard carbamazepine in the substance (see table 2).

Table 2. Anticonvulsant activity of a submicron emulsion of carbamazepine compared to carbamazepine in a substance on a model of seizures caused by maximum electroshock (500 V, 145 mA, 0.6 s) Group dose % surviving animals (number of survivors / total number of animals in the group) Control, distilled water 15.4 (2/13) Carbamazepine substance, 5 mg / kg 20 (2/10) Carbamazepine substance, 10 mg / kg 62.5 (5/8) * Carbamazepine substance, 20 mg / kg 91.7 (11/12) * Carbamazepine submicron emulsion, 3.3 mg / kg, vnb 57.2 (4/7) * Carbamazepine submicron emulsion, 5 mg / kg, vnb 64.3 (9/14) * Carbamazepine submicron emulsion, 8.3 mg / kg, vnb 91.7 (11/12) * * - p <0.05 significance of differences according to the Piersen criterion relative to control.

Example 4

The study of the anticonvulsant activity of the submicron emulsion of carbamazepine obtained in example 2, in comparison with carbamazepine in a substance for generalized convulsions caused by the introduction of picrotoxin.

The experiments were performed on male white outbred mice. Generalized convulsions were caused by the method of antagonism with the GABA-A receptor agonist, picrotoxin, in accordance with existing guidelines [Voronina TA, Nerobkova L.N. Guidelines for the study of the anticonvulsant activity of pharmacological substances. Guidance on the experimental (preclinical) study of new pharmacological substances, 2nd edition, ed. RU. Khabrieva, Moscow, 2005, p.277-294]. According to the method, picrotoxin was injected subcutaneously in the cervical region of the back of the mouse. The latent time of onset of seizures, the number of seizures (clonic convulsions of the front and / or hind limbs without loss of the overturning reflex lasting more than 3 seconds) and the percentage of animals with tonic-clonic seizures were recorded. The studied substances are a submicron emulsion of carbamazepine at doses of 5 and 8.3 mg / kg and carbamazepine in a substance at doses of 10 and 20 mg / kg, which were administered intraperitoneally 35 minutes before picrotoxin injection at a dose of 6 mg / kg. The onset of seizures in mice of the control group is recorded 7.4 minutes after administration of picrotoxin. The number of convulsive seizures (clonic convulsions of the front and / or hind limbs without loss of the overturning reflex lasting more than 3 seconds) in the control animals amounted to 6.9 seizures, the lifespan was 24.3 minutes, and the number of surviving animals was only 11% (see table 3 )

A submicron emulsion of carbamazepine at a dose of 8.3 mg / kg significantly and statistically significantly increased the latent time of onset of picrotoxin-induced seizures 1.5 times, decreased the number of convulsive seizures by 1.97 times and increased the life expectancy and percentage of surviving animals (up to 50%) .

A submicron emulsion of carbamazepine at a dose of 5 mg / kg had a less anticonvulsant effect against seizures caused by picrotoxin and was comparable to the activity of standard carbamazepine at a dose of 20 mg / kg.

The effect of a submicron emulsion of carbamazepine at a dose of 8.3 mg / kg in the conditions of this model significantly exceeds the indicators obtained against the background of standard carbamazepine at a dose of 20 mg / kg (see table 3).

The data presented in table 3 indicate that the proposed composition of a submicron emulsion of carbamazepine objectively weakens the performance of recorded seizures in the presented models. In addition, the new composition is more preferable than the known dosage forms of carbamazepine, since it is used in much lower doses, has optimal delivery routes in the body, and therefore does not have a number of side effects characteristic of a standard preparation.

Thus, a 10 mg / kg submicron emulsion carbamazepine had a significant anticonvulsant effect in the picrotoxin antagonism test. Thus, the composition of a submicron emulsion of carbamazepine increased the latent time of onset of seizures caused by picrotoxin, reduced the number of convulsive seizures (clonic convulsions of the front and / or hind limbs without losing the inverted reflex for more than 3 seconds) and completely prevented the appearance of clonic-tonic convulsions.

The composition of the submicron emulsion of carbamazepine at a dose of 10 mg / kg is superior to carbamazepine in the substance (20 mg / kg) in anticonvulsant activity in the test of antagonism with picrotoxin (small dose of toxin 2.5 mg / kg).

The composition of the submicron emulsion of carbamazepine in doses of 3.3, 5.0 and 8.3 mg / kg has a pronounced anticonvulsant activity in the maximum electric shock test.

The composition of the submicron emulsion of carbamazepine at a dose of 8.3 mg / kg has a pronounced anticonvulsant effect on primary generalized convulsions caused by picrotoxin.

The anticonvulsant effect of the composition of the submicron emulsion of carbamazepine has a pronounced dose-dependent nature and increases linearly with increasing dose of the substance.

The composition of the submicron emulsion of carbamazepine in anticonvulsant activity significantly exceeds carbamazepine in substance. In the maximum electric shock test, the composition of the submicron emulsion of carbamazepine has an anticonvulsant effect in doses 3-4 times lower (3.3, 5.0 and 8.3 mg / kg), and in the test of antagonism with picrotoxin in doses 2 times lower (8 3 mg / kg) than carbamazepine in substance (20 mg / kg).

Thus, the composition of the submicron emulsion of carbamazepine in doses of 3.3, 5.0 and 8.3 mg / kg has a clear anticonvulsant activity in the tests of maximum electroshock and antagonism with picrotoxin, with the most pronounced effect in the test of maximum electroshock.

The invention can be used in practical medicine.

Claims (1)

A pharmaceutical composition of a submicron emulsion for parenteral administration, having anticonvulsant activity, containing 5-carbamoyl-5H-dibenz- (b, f) -azepine, characterized in that it additionally contains soybean oil and sodium deoxycholate in the following ratio, wt.%:
5-carbamoyl-5H-dibenz- (b, f) -azepna 18.5-23.2 soybean oil 2.1-2.3 sodium deoxycholate 74.5-79.4
and has an average disagglomerated microparticle size of 108-132 nm.