RU2141964C1 - Method of preparing antiarthrosis medicinal preparation - glucosamine hydrochloride - Google Patents

Abstract

FIELD: pharmaceutical industry. SUBSTANCE: invention relates to a method of production of a medicinal preparation of an antiarthrosis effect from chitin. Chitin is hydrolyzed with concentrated hydrochloric acid (30-37%) and gaseous hydrogen chloride is bubbled in the reaction mixture. After hydrolysis of chitin the reaction mixture is cooled to the room temperature (10-20 C), kept at this temperature for crystallization, a precipitate is separated, washed out with a solvent, dissolved in water, solution is removed and evaporated. Ready product is washed out with a solvent and dried. Invention describes also a method of preparing glucosamine hydrochloride by hydrolysis of chitin with concentrated hydrochloric acid at heating involving crystallization of the ready product at cooling to the room temperature, separation of precipitate and its washing out with an organic solvent, dissolving in water, separation and evaporation of the solution and washing out and drying the end product. At hydrolysis the reaction mixture is bubbled with gaseous hydrogen chloride to avoid the decrease of hydrogen chloride concentration in solution. The proposed method ensures to decrease amount of hydrochloric acid solution used for hydrolysis, exclude the use of activated carbon to obtain D-glucosamine hydrochloride, to carry out the technological process without filtration of hot hydrochloric acid solutions and without the stage of evaporation of concentrated hydrochloric acid. EFFECT: increased yield of the end product, decreased consumption of reagents, simplified technology, decreased cost. 3 tbl, 2 ex

Description

 The invention relates to the pharmaceutical industry and relates to a method for the production of an anti-arthritic drug from chitin.

 A known method of producing an anti-arthritic agent D-glucosamine sulfate from the shell of crab and shrimp by treating the raw material with hydrochloric acid, converting the chloride to the base, treating the latter with concentrated sulfuric acid to form unstable, hygroscopic, easily oxidized D-glucosamine sulfate, which stabilize sodium chloride. As a result, the irritating effect on living tissues with intramuscular injection is enhanced, because the preparation contains a large amount (up to 13%) of sodium chloride (Patent No. 525861, Switzerland).

 There is also a known method for producing D-glucosamine hydrochloride by dissolving chitin in excess of hydrochloric acid and then evaporating the solution to form a slurry. The resulting suspension is diluted with water at a ratio of chitin and water of 1: 2.5. The resulting solution is decolorized with activated carbon for 4-5 minutes. The coal is separated by filtration under vacuum. The filtrate was evaporated in vacuo until crystallization began, cooled, and the precipitated crystals were washed with cold water, alcohol and dried. The yield of 70-74%. Further purification of D-glucosamine hydrochloride is carried out by recrystallization from hot 80% ethanol.

A known method of producing D-glucosamine hydrochloride, which consists in the hydrolysis of chitin in concentrated hydrochloric acid with stirring and heating in a boiling water bath for 2.5 hours. The ratio of the mass of chitin and the mass of hydrochloric acid with a specific gravity of 11.18 g / cm ³ is 1 : 5.9. At the end of hydrolysis, water (at a ratio of chitin: water - 1: 5) and activated carbon (at a ratio of 1: 0.1) are added to the solution. The mixture was decolorized with stirring at 60 ^° C. for 1 hour and filtered. If necessary, discoloration of the hydrolyzate is repeated. The purified hydrolyzate is evaporated in vacuo at 50 ^° C. to 2-4% of the initial solution of 10-15 ml. D-glucosamine hydrochloride crystals are washed with ethanol and then dried. Product yield 60-70%.

A known method of producing D-glucosamine hydrochloride, which consists in the hydrolysis of chitin at 75 ^o C for 2 hours, treatment with activated carbon and hot water in a ratio of 1: 0.5 (chitin-charcoal) and 1: 5 (chitin-water) also for 2 hours, evaporation of the hydrolyzate at 60 ^o C to 15% of the initial volume of the liquid phase, crystallization of the final product at 4 ^o C for 8 hours from the resulting hydrochloric acid solution (RF patent N 2038095).

 Obtaining D-glucosamine hydrochloride by the above method is associated with a high consumption of activated carbon.

 There is also known a method of producing D-glucosamine hydrochloride, excluding the use of activated carbon. It is as follows.

Chitin is dissolved in concentrated hydrochloric acid (30-37%), heated in a boiling water bath for 45-120 minutes at a ratio of the mass of chitin and the mass of hydrochloric acid from 1: 2 to 1: 4. Then the solution is kept until the chitin is completely hydrolyzed. After hydrolysis is complete, the reaction mixture is cooled to room temperature from 10 to 20 ^o C and left at this room temperature to crystallize D-glucosamine hydrochloride for 8-48 hours. The precipitate formed is separated by decantation, filtration or centrifugation at room temperature; washed with an organic solvent (for example, ethyl or isopropyl alcohol, acetone, etc.) with a mass ratio of chitin and solvent from 1: 5 to 1: 3; the washed precipitate is dissolved in water with a temperature of from 50 to 80 ^o C. (The mass ratio of chitin and water from 1: 2 to 1: 3). The solution is filtered through filter paper or centrifuged. The precipitate is washed with a little water. The resulting solution was evaporated in vacuo at a temperature not exceeding 60 ^° C. The crystals of D-glucazamine hydrochloride were separated and washed with a solvent (ethyl or isopropyl alcohol, acetone, etc.) to a pH of the washing solution of at least 2-3.

The washed crystals of D-glucosamine hydrochloride are dried in air at room temperature for 8-24 hours, and then in a drying device at a temperature not exceeding 60 ^o C.

 The yield of D-glucosamine hydrochloride is 70-76% (RF Patent N 2042785).

 The described method is close to the claimed and selected for the prototype.

From our point of view, this method has several disadvantages;
- a significant part of the product is lost at the stage of crystallization from the hydrolyzate, because part of the glucosamine remains in a saturated solution above the precipitate and is removed when it is separated.

 A decrease in these losses is possible with a decrease in the mass ratio of chitin and hydrochloric acid and with a decrease in the solubility of glucosamine hydrochloride in solution. But the decrease in the amount of hydrochloric acid is limited by the features of the chemical process: when the mass ratio of chitin and concentrated hydrochloric is greater than 1: 1.5, the hydrolysis reaction is slowed down due to the lack of hydrogen chloride in the solution, because he binds to the final product.

 All these factors lead to a sharp drop in the concentration of hydrogen chloride in solution (table 1). When the initial mass ratio of chitin and concentrated hydrochloric acid (36%) is more than 1: 1.5, the hydrolysis reaction practically stops, the dissolved chitin saturates the solution and new portions of the added chitin no longer dissolve in the reaction mixture.

 With a decrease in the concentration of hydrogen chloride in the solution, the solubility of the resulting D (+) - glucosamide hydrochloride significantly increases (table 2). As a result, product losses during separation of the solution after crystallization also increase.

 The aim of the invention is to increase the yield of the target product and the change in the amount of hydrochloric acid for hydrolysis.

 The proposed method for producing D-glucosamine hydrochloride is as follows: chitin obtained from the shell of crustaceans (shrimp, crab, crayfish, etc.) is loaded into a flask and pour concentrated hydrochloric acid (30-37%). The resulting mixture is heated in a boiling water bath until the chitin is completely dissolved. The remaining amount of chitin is then portioned into the solution, and gaseous hydrogen chloride is bubbled with constant stirring. The mass ratio of chitin and concentrated hydrochloric acid is from 1: 0.5 to 1: 2. Hydrogen chloride gas is supplied until the entire amount of chitin is completely dissolved, after which hydrolysis is continued with stirring and heating in a boiling water bath for 30 to 120 minutes.

 For the generation of hydrogen chloride, various devices are used, based on the displacement of gaseous hydrogen chloride from concentrated hydrochloric acid or chlorides (Zakharov L.N. Safety precautions in chemical laboratories: Ref. Ed. - L .: Chemistry, 1991. - P. 140-141 )

After hydrolysis, the reaction mixture is cooled to room temperature from 10 to 20 ^o C and left at this temperature to crystallize D-glucosamine hydrochloride for a period of time from 8 to 72 hours.

 The precipitated dirty product is separated by decantation, filtration or centrifugation at room temperature.

 After separation of the dark brown solution, the precipitate is purged with a stream of air to remove residual hydrochloric acid solution and washed with an organic solvent (for example, ethyl or isopropyl alcohol, acetone, etc.). The mass ratio of chitin and solvent is from 1: 0.5 to 1: 3.

The washed precipitate is dissolved with stirring in water with a temperature of from 20 to 80 ^o C (The mass ratio of chitin and water from 1: 2 to 1: 3). The solution is filtered through filter paper or centrifuged. The precipitate is washed with a little water. The resulting solution should be colorless or have a faint yellow or yellowish green hue.

The solution is evaporated in vacuo at a temperature of not more than 60 ^o C to 5-10% of the original volume.

 D-glucosamine hydrochloride crystals are separated by decantation, filtration or centrifugation and washed with a solvent (ethyl or isopropyl alcohol, acetone, etc.) in portions, 2-4 times. Rinsing is carried out to a pH of the washing solution of at least 2-3 according to universal indicator paper.

 The mass ratio of chitin and solvent for washing is from 1: 0.5 to 1: 3.

 The filtrate is allowed to crystallize an additional amount of D (+) - glucosamine hydrochloride, which is then separated, washed with a solvent and attached to the main product (after washing the product, the filtrates are used to wash dirty D-glucosamine hydrochloride or sent for rectification).

The washed crystals of D-glucosamine hydrochloride are dried in air at room temperature for 3 to 24 hours, and then in a drying device at a temperature not exceeding 60 ^o C from 1 to 18 hours.

 The yield of D-glucosamine hydrochloride is 72-82%.

Examples of the method
Example 1. In a round-bottom flask with a capacity of 6 dm ^3, 700 g of chitin was charged, 3540 g (3 dm ³ ) of concentrated hydrochloric acid was poured at room temperature. A flask with a reflux condenser, a stirrer, and a hydrogen chloride gas supply tube was placed in a boiling water bath. After 5-10 minutes, chitin was completely dissolved in boiling acid. With stirring, 2840 g of chitin was added portionwise to the flask (total mass of chitin - 3540 g). After adding another portion of chitin, the flask was closed and hydrogen chloride was bubbled into the solution with stirring until the chitin was completely dissolved. After complete dissolution of the total amount of chitin, hydrolysis was carried out at the boiling point of the mixture (94-96) ^o C and stirring for 120 minutes.

 After hydrolysis, the flask with the reaction mixture was cooled to room temperature and left to crystallize for 48 hours.

 The precipitate of dirty glucosamine hydrochloride was separated from the solution under vacuum on a Buchner funnel through 3 layers of filter paper.

The precipitate was washed in portions (3 times) with ethyl alcohol. 7080 g (8.85 dm ³ ) of alcohol were used for washing.

The washed precipitate of the dirty product was dissolved in 7.0 dm ^{3 of} distilled water with a temperature of from 40 to 50 ^o C. The solution was filtered through 2 layers of filter paper on a Buchner funnel under vacuum.

The pure solution was evaporated in vacuo on an IR-10M rotary evaporator at a temperature in a water bath of 40 to 50 ^° C by 95% until a thick suspension formed. The suspension was cooled to room temperature.

The resulting crystals were washed with ethyl alcohol in portions 3 times. The total amount of alcohol per flushing 7080 g (8.85 DM ³ ).

The washed crystals were dried first in air at room temperature for 3 hours and then in an oven at 60 ^° C. for 10 hours.

 Received 2761 g of D (+) - glucosamine hydrochloride. The yield is 78%.

 Example 2. The same as in example 1, but isopropyl alcohol was used instead of ethyl alcohol. Received 2832 g of D (+) - glucosamine hydrochloride. The yield is 80%.

 The remaining data of examples of the method are shown in table 3.

Mass fraction of D (+) - glucosamine hydrochloride in the product obtained by the proposed method is 99.5-99.9%. The mass fraction of the main substance in the product was determined by two methods:
- titration of hydrogen chloride associated with the molecule D (+) - glucosamine, sodium hydroxide solution with registration of changes in pH or conductivity of the solution (TU 15-02 549-89 "D (+) - glucosamine hydrochloride for medical purposes");
- determination of the mass fraction of total nitrogen by the Kjeldahl method (GOST 7635-86 "Fish, marine mammals, marine invertebrates and their processed products. Analysis methods") using the Kjeltec Auto System 1040 automatic nitrogen / protein analyzer ('Tecator Sweden).

 These two methods gave the same results.

 The identity of the product D (+) - glucosamine hydrochloride is confirmed by the following methods.

 1. Determination of the mass fraction of total and amine nitrogen.

 The theoretical nitrogen content in the molecule of D (+) - glucosamine hydrochloride and its isomer D (+) - galactosamine hydrochloride N (theor) = 6.49%. Moreover, all nitrogen is contained in the amino group (Theoretical nitrogen content in the molecule of N-acetyl) -D-glucosamine is 6.33%).

 The mass fraction of total nitrogen determined by the Kjeldahl method in a product dried to constant weight was N (total) = (6.47 ± 0.03)%.

 The mass fraction of amine nitrogen, determined by potentiometric titration of the hydrochloric acid solution of the product with a NaOH solution, was N (amine) = (6.48 ± 0.06)%.

 Thus, in the product, all nitrogen is part of the amino group. According to the content of the amino group, the product coincides with D (+) - glucosamine hydrochloride or its isomer D (+) - galactosamine hydrochloride.

 2. Specific rotation of solutions.

According to the Aldrich catalog, the specific rotation of D (+) - glucosamine hydrochloride (98% of the basic substance) is [α] $\genfrac{}{}{0ex}{}{\text{26}}{\text{D}}$ = +82.4 ^o . For D (+) - galactosamine hydrochloride (98% of the basic substance) [α] $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = + 95 ^o .

For the product obtained by the proposed method, the specific rotation angle is equal to [α] $\genfrac{}{}{0ex}{}{\text{26}}{\text{D}}$ = + (82 ± 2) ^o , which corresponds to the specific rotation of D (+) - glucosamine hydrochloride.

 3. Thin layer chromatography.

The identification and purity of the finished product was determined by thin-layer chromatography in a solvent system butanol-1: acetic acid: water: pyridine in a ratio of 2: 1: 1: 1 on Silufol plates (TU 6-09-05-936-78 (+) -glucosamine hydrochloride qualification pure "). Detection was carried out with a 0.2% alcohol solution of ninhydrin. At the same time, H ₂ SO ₄ was used as a detecting agent.

Only one spot was found on the chromatogram with R _f = 0.51 - 0.54. Thus, only D (+) - glucosamine hydrochloride was present in the product.

 Additionally, chromatography was performed according to the method described in book. Chromatography: Practical application of the method: In 2 hours. Part 2. Trans. from English / Ed. E. Heftman. - M .: Mir, 1986.- 422 p. - on Silufol plates in the propanol-water system (7: 1). D (+) - glucosamine hydrochloride, D (+) - galactosamine hydrochloride, N-acetyl-D-glucosamine and D-glucose were used as witnesses. Detection was carried out with a solution of ninhydrin and sulfuric acid. Only one spot was present on the chromatogram of the product, corresponding to D (+) - glucosamine hydrochloride.

 An essential distinguishing feature of the proposed method for producing D-glucosamine hydrochloride is that in order to avoid lowering the concentration of hydrogen chloride in the solution during hydrolysis, the reaction mixture is bubbled with gaseous hydrogen chloride.

This method has several advantages over the known:
- decreases the amount used in the hydrolysis of hydrochloric acid;
- the yield of the purified product is 78-82%;
- excludes the use of activated carbon;
- excludes the filtration of hot hydrochloric acid solutions;
- eliminates the expensive operation of evaporation of concentrated hydrochloric acid.

 Thus, obtaining a drug - glucosamine hydrochloride according to the proposed method is less time consuming and more economical.

 The State Pharmacological Committee at its meeting of June 6, 1995 (protocol No. 14) decided on the recommendation for medical use of glucosamine hydrochloride as an anti-arthritic drug.

List of references
1. RF patent N 2038095.

 2. Switzerland patent N 525861.

 3. RF patent N 2042685.

 4. Decision of the FC of the Ministry of Health of the Ministry of Health of the Russian Federation on the recommendation for medical use of Glucosamine hydrochloride, a drug developed by the Pyatigorsk State Pharmaceutical Academy, JSC Sevrybtekhtsentr and JSC Sevryba, protocol N 14 of July 16, 1995. // Information on the decisions of the pharmacological committee of the Ministry of Health of the Russian Federation MP: New drugs. - M.: 1995, no. 5, p. 54 and 55. - (ISS N 0132-8603).

Claims (1)

 A method of producing D-glucosamine hydrochloride by hydrolysis of chitin with concentrated hydrochloric acid by heating, which includes crystallization of the target product upon cooling to room temperature, separating the precipitate, washing the precipitate with an organic solvent, dissolving the precipitate in water, separating and evaporating the solution, washing and drying the product, characterized in that during hydrolysis, the reaction mixture is bubbled with gaseous hydrogen chloride in order to avoid lowering the concentration of hydrogen chloride in the solution e.

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