RU2522980C1 - Biodegradable haemostatic therapeutic agent - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: what is described is a biodegradable haemostatic therapeutic agent for control of bleeding, which provides co-immobilising ε-aminocapronic acid 50 mg, lysozyme 5 mg in distilled water 6.5 l for 3 hours at room temperature for dialdehyde cellulose 1 g at a degree of oxidation 12%. The material is pressed out and dried to residual moisture no more than 10% in the air in darkness. After having dried, the material is milled in a fine mill to particles having a size of 20 to 50 mcm. A rate of control of bleeding is 102 seconds. A time of total resorption is 10 days.

EFFECT: agent provides a high degree of hydrolytic destruction and a good haemostatic activity.

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Description

The invention relates to pharmacy, and specifically to methods for producing hemostatic (hemostatic) preparations based on partially oxidized cellulose.

The drugs mentioned above are known. Thus, in EPO application No. 1153620, a hemostatic dressing made of oxidized cellulose SURGICEL (Johnson and Johnson company) containing 1 to 10,000 ppm of iron ions (3+) is described, and soluble hemostatic is known from EPO application No. 0468114 material in the form of a cellulose web oxidized with monochloracetic acid and sodium hypochlorite to introduce COOH carboxyl groups.

EPO application No. 0659440 describes a method for producing hemostatic based on oxidized cellulose containing 0.5-4.0% calcium, as well as thrombin, fibrinogen and / or antifibrinolytic. The disadvantages of this method include the use of cellulose, the mild oxidation state of which, with the conversion of CH ₂ OH groups to carboxylic (COOH), does not allow to obtain a material that provides the possibility of strong binding of ingredients to it: only Ca ^{2+ ions} are associated with COOH groups ionic forces, while the remaining components are in the form of a physical (mechanical) mixture. In addition, such materials are only difficult to grind to, for example, into a powder (analog).

A known method of producing a powdered material with a hemostatic effect, which involves mixing in an aqueous medium a carrier of partially oxidized cellulose to dialdehyde cellulose (DAC) with blood coagulation factors, for example, thrombin and fibrinogen, gelatin, ε-aminocaproic acid and lysozyme are additionally added to these substances and as partially oxidized cellulose, dialdehyde cellulose in the form of a web having an oxidation state, i.e. the content of aldehyde groups, from 4 to 6%, with the following ratios between the components:

- dialdehyde cellulose 1 g;

- fibrinogen 18/22 mg;

- gelatin 27/33 mg;

- ε-aminocaproic acid 45/55 mg;

- lysozyme 9.5 / 10.5 mg;

- thrombin 350 units;

- water 6.5 ml.

The components are maintained until the drugs are fully covalently bound to dialdehyde cellulose, followed by drying and grinding to powder. In order to prevent the interaction of thrombin and fibrinogen, the process of obtaining the drug is carried out in two stages. Separately, a solution of fibrinogen, ε-aminocaproic acid and half of the total amount of gelatin in half of the total amount of water and a solution of thrombin, lysozyme and the remaining amount of gelatin in the remaining amount of water are prepared separately; the resulting solutions are kept for 3-4 hours in half the amount of dialdehyde cellulose, intermediates are squeezed, dried in air and subjected to joint grinding. The time to stop bleeding with this drug in the experiment was 110 seconds, see, for example, RF patent No. 2235539, 2003 (prototype).

The specified technical solution is not without drawbacks. First, blood products - thrombin and fibrinogen - are very expensive and scarce. In addition, more and more patients in the world refuse to use drugs obtained from organs and tissues of animals or donated blood. Secondly, in order to avoid interaction between thrombin and fibrinogen in an aqueous solution, their immobilization is carried out separately, then the canvases are dried and co-milled to a powder. This complicates and increases the cost of the process. The third disadvantage is the low oxidation state of DAC, which leads to a slowdown in the rate of hydrolytic destruction of the drug.

The objective of the present invention is to remedy these shortcomings and obtain a powdered biodegradable hemostatic drug with a high degree of hydrolytic degradation (the ability to complete desorption) and good hemostatic activity.

To this end, the composition of the drug components was substantially changed, expensive scarce blood products and gelatin were excluded, the technological process for producing the drug was significantly simplified, the oxidation state of DAC was significantly increased, which ultimately led to an acceleration of hydrolytic destruction and, consequently, a decrease in the time of complete resorption during simultaneous increase in hemostatic activity.

Additional studies have shown that with an increase in the oxidation state of dialdehyde cellulose (DAC) and its protein derivatives, the rate of their hydrolytic destruction increases. In this case, proteins diffuse into the aqueous medium not in the form of native substances, but in the form of conjugates with DAC oligomers, which makes them more resistant to inactivating factors (heat, pH of the medium, inhibitors) compared to native biologically active substances (BAS), etc. e. exhibit a prolonged specific effect. The kinetics of hydrolytic destruction is described by a semi-logarithmic anamorphosis and in logarithmic coordinates is a straight line, the slope of which quantitatively expresses the rate constant of hydrolytic destruction as a constant of the first order reaction rate.

Knowing these constants, it is easy to calculate the half-life (half-resorption) of the drug according to the formula

K = 0.69 / T / 2,

where K is the destruction rate constant,

T / 2 - half-life of the drug.

The experimental data on the dependence of the rate constant of hydrolytic destruction on the degree of oxidation of the DAC are shown in table 1.

Table 1 The degree of oxidation of the DAC,% The rate constant of hydrolytic degradation, min ^-1 4-6 18 × 10 ^-5 6.5 21 × 10 ^-5 12 33 × 10 ^-5 eighteen 39 × 10 ^-5

On the other hand, with an increase in the oxidation state of DAC, its mechanical strength sharply decreases. The effect of the degree of oxidation of cellulose (medical gauze) to DAC on the strength characteristics of the material are presented in table 2.

table 2 The degree of oxidation,% Breaking load (on the basis), daN Sustaining breaking load,% - 33,4 100.0 3.0 22.0 65,2 5,0 21.6 64.6 8.0 20.5 61,4 12.0 18.3 56.6 15.0 16,2 49.0 26.0 45.0 45.0

From the data given in tables 1 and 2, it follows that an increase in the degree of oxidation over 12% is irrational, because with a slight increase in the rate constant of hydrolytic destruction, there is a significant drop in the mechanical strength of the DAC by more than 50%. It should also be noted that when grinding DAC of high oxidation states, a dusty fraction of the powder is formed.

Comparative characteristics of the hemostatic properties of materials and their relationship with the oxidation state of DAC, the composition and time of complete resorption are shown in table 3.

Table 3 The degree of oxidation of the DAC,% Coagulation factors, mg per 1 g of DAC The rate constant of hydrolytic degradation Time to stop bleeding, sec Full resorb time
tion, days According to the patent of the Russian Federation No. 2235539 4-6%, prototype Fibrinogen 18-22 gelatin 27-23 aminocaproic acid 45-55 lysozyme 9.5-10.5 thrombin 350 units 18 × 10 ^-5 min ^-1 110 twenty By the proposed solution 12% Aminocaproic acid is administered in an amount of 50 mg / g, lysozyme - 5 mg / g 33 × 10 ^-5 min ^-1 102 10

Thus, the proposed new biodegradable hemostatic drug in the form of a powder with particle sizes from 20 to 50 microns has the following characteristics:

DAC with oxidation states of 12% - 1.0 g;

ε-aminocaproic acid - 50.0 ± 0.25 mg / g;

lysozyme - 5.0 ± 0.25 mg / g.

A drug composition in this composition provides a high rate of stopping bleeding, long-term preservation of the sterility of the material and the minimum time for complete resorption.

The time to stop bleeding is 102 seconds.

Complete resorption time is 10 days.

Therefore, the proposed technical solution meets all the requirements for the invention: novelty, utility and prior art.

The novelty consists, firstly, in the use of DAC with an oxidation state of 12% to immobilize hemostatic agents as a carrier. Secondly, ε-aminocaproic acid (without fibrinogen, thrombin and gelatin) is used as a specific hemostatic agent. Thirdly, the proposed composition is a fine powder with particle sizes from 20 to 50 microns. Fourthly, the time of complete resorption is 10 days.

The usefulness is obvious: the rate of stopping bleeding is 102 seconds, which is less, but comparable to the time for stopping bleeding of the prototype - 110 seconds, but given that this result is achieved by a simple and minimal composition of medicinal components, especially with biodegradation (resorption) property, usefulness This development is undeniable.

 State of the art

A pharmacopeia article and other documents necessary for inclusion in the pharmacopeia of the Russian Federation are drawn up for the drug. Not a single product on the basis of DAC, previously approved for medical use, has such a status.

The invention is illustrated by examples.

Example 1

6.5 L of distilled water is poured into the reactor, a stirrer is turned on, and 185 g of sodium periodate are added. The solution is stirred until the reagent is completely dissolved. In the resulting sodium periodate solution, 1 kg of cellulose (medical cotton gauze) is placed in the form of a web and kept at room temperature in the dark for 14 hours. After activation, the web is squeezed, washed 4 times with 10 l of distilled water, squeezed again and dried in air in the dark to a residual moisture content of not more than 10% at room temperature. The oxidation state of cellulose to DAC is 12%.

Example 2

50 g of ε-aminocaproic acid, 5 g of lysozyme are dissolved in 6.5 l of distilled water, the reaction mixture is stirred, the pH of the solution is 5.5-6.0. 1 kg of DAC with an oxidation state of 12% is placed in the solution, kept for 3 hours at room temperature in the dark, squeezed out, dried in air in the dark to a residual moisture content of not more than 10% and ground in a superfine grinding mill to particles ranging in size from 20 to 50 microns.

Under experimental conditions, adult rabbits caused bleeding with the intravenous administration of 500 IU of heparin and 250 IU of fibrinolysin. Mechanically, bleeding stopped after 20-30 minutes.

Under thiopental anesthesia, superficial excision of a 1.4 cm ² liver fragment caused bleeding, a biodegradable hemostatic agent was applied to the wound, marking a stop of bleeding after 102 seconds.

Claims (4)

1. A biodegradable hemostatic drug in the form of microfibers, consisting of dialdehyde cellulose with chemically immobilized blood coagulation factor ε-aminocaproic acid and the bacteriolytic enzyme lysozyme, characterized in that it contains dialdehyde cellulose with an oxidation state of 12% with the following oxidation state of 12% content of components:
DAC with oxidation states of 12% - 1.0 g;
ε-aminocaproic acid 50.0 ± 0.25 mg / g;
lysozyme 5.0 ± 0.25 mg / g. 2. The biodegradable hemostatic drug according to claim 1, characterized in that the particle sizes of its microfiber form of partially oxidized cellulose with components immobilized on it are in the range from 20 to 50 microns. 3. The biodegradable hemostatic drug according to claim 1, characterized in that the time of complete hydrolytic destruction - complete biodegradation is not more than 10 days. 4. The biodegradable hemostatic drug according to claim 1, characterized in that the time for stopping the bleeding during its use is not more than 102 seconds.