RU224838U1 - Installation for the purification of poly-N-vinylpyrrolidone to obtain a pharmaceutical substance for the preparation of injection and infusion preparations - Google Patents

Abstract

The utility model relates to the field of equipment for chemical technology. Installation for purification of dry poly-N-vinylpyrrolidone with an average molecular weight (8000–12600) ± 2000 Yes, containing a source of initial dry poly-N-vinylpyrrolidone connected by pipelines, a conical thermal cleaning apparatus, a condenser and a collection of volatile impurities and their decomposition products , nitrogen source, vacuum source, while the conical thermal cleaning apparatus is equipped with a spiral mixing device and connected to a collection of dry purified poly-N-vinylpyrrolidone.

Description

Field of technology

The utility model relates to the field of equipment for chemical technology. More specifically, it offers a plant for the purification of dry poly-N-vinylpyrrolidone with an average molecular weight (8000-12600) ± 2000 Da from impurities of N-vinylpyrrolidone, 2-pyrrolidone, hydrazine and peroxide compounds, to obtain a pharmaceutical substance for the manufacture of injectable drugs and infusion use, incl. drugs used as a substitute for human blood plasma and detoxification agents "Hemodez-N" and "Hemodez".

State of the art

The pharmaceutical substance of low molecular weight poly-N-vinylpyrrolidone with an average molecular weight of 8000 ± 2000 Da, intended for the manufacture of drugs for injection and infusion use, is subject to requirements in accordance with FSP 42-0345-4367-03, presented in Table 1.

Table 1. Quality standards for poly-N-vinylpyrrolidone, with an average molecular weight of 8000 ± 2000 Da.

No. Indicator name Norm 1 Description Powder is white or white with a slightly yellowish tint with a slight specific odor. Hygroscopic. 2 Solubility Easily soluble in water, alcohol, chloroform, practically insoluble in ether 3 Authenticity red-brown color with iodine solution 4 pH from 3.0 to 7.0 5 Solution transparency 5 ml of solution A must be comparable to standard solution I 6 Solution color The color intensity of the preparation should not exceed the color intensity of standard No. 5b 7 Average molecular weight 8000±2000 8 Test for the absence of fractions with a molecular weight greater than 30,000 None 9 Water, %, no more 5.0 10 2-pyrrolidone, %, no more 4.0 eleven N-vinylpyrrolidone, %, no more 0.3 12 Aldehydes, %, no more 0.3 13 Sulphate ash, %, no more 0.05 14 Heavy metals, %, no more 0.0005 15 Hydrazine, %, no more 0.0005 16 Peroxide compounds, %, no more 0.04 17 Microbiological purity Category 1.2 18 Pyrogenicity The drug must be non-pyrogenic 19 Toxicity The drug must be non-toxic

The pharmaceutical substance of low molecular weight poly-N-vinylpyrrolidone with an average molecular weight of 12600 ± 2000 Da, intended for the manufacture of drugs for injection and infusion use, is subject to requirements in accordance with FSP 42-0345-4368-03, presented in Table 2.

Table 2. Quality standards for poly-N-vinylpyrrolidone, with an average molecular weight of 12600 ± 2000 Da.

No. Indicator name Norm 1 Description Powder is white or white with a slightly yellowish tint with a slight specific odor. Hygroscopic. 2 Solubility Easily soluble in water, alcohol, chloroform, practically insoluble in ether 3 Authenticity red-brown color with iodine solution 4 pH from 3.0 to 7.0 5 Solution transparency 5 ml of solution A must be comparable to standard solution I 6 Solution color The color intensity of the preparation should not exceed the color intensity of standard No. 5b 7 Average molecular weight 12600±2000 8 Test for the absence of fractions with a molecular weight greater than 45000 None 9 Water, %, no more 5.0 10 2-pyrrolidone, %, no more 3.0 eleven N-vinylpyrrolidone, %, no more 0.2 12 Aldehydes, %, no more 0.3 13 Sulphate ash, %, no more 0.05 14 Heavy metals, %, no more 0.0005 15 Hydrazine, %, no more 0.0005 16 Peroxide compounds, %, no more 0.04 17 Microbiological purity Category 1.2 18 Pyrogenicity The drug must be non-pyrogenic 19 Toxicity The drug must be non-toxic

It is known from the current state of the art that poly-N-vinylpyrrolidone is produced by radical polymerization of N-vinylpyrrolidone in water or organic solvents in the presence of a reaction initiator.

The method of radical polymerization in aqueous solutions initiated by hydrogen peroxide in the presence of ammonia as a promoter has become widespread. The rate of polymerization of N-vinylpyrrolidone, the structure and quality of the resulting poly-N-vinylpyrrolidone are practically impossible to regulate, and radical polymerization occurs spontaneously, with an increase in temperature and the production of a polymer with a wide molecular weight distribution (MWD), the content of impurities of unknown structure (Yu.E Kirsch “Poly-N-vinylpyrrolidone and other poly-N-vinyl amides” - M.: Nauka, 1998). The quality of poly-N-vinylpyrrolidone used for medical purposes is subject to increased requirements: it must contain a minimum amount of by-products and starting substances.

Invention EP 0258854 (published 03/09/1988) discloses a method for purifying solutions of poly-N-vinylpyrrolidone from N-vinylpyrrolidone, which consists of treating them with sorbents, zeolites or ion-exchange resins. The disadvantages of the disclosed method are that it is applicable only for solutions, as well as the impossibility of purifying poly-N-vinylpyrrolidone from other impurities of hydrazine, aldehydes and 2-pyrrolidone. In addition, the invention does not disclose information about the installation for implementing the proposed method.

Patent RU 2057144 (published on March 27, 1996) discloses a method for purifying dilute aqueous solutions of poly-N-vinylpyrrolidone with a concentration of 7.5-8.5% from unwanted impurities (2-pyrrolidone, N-vinylpyrrolidone), which consists of in passing solutions first through an ion exchange resin of a macroporous structure based on a copolymer of styrene with divinylbenzene containing sulfo groups, in Na ⁺ form at pH 6-7.5, and then through an ion exchange resin of a macroporous structure based on a copolymer of styrene with divinylbenzene containing benzyltrimethylammonium groups, in OH ^{- -} form at pH 8.5-9.5. The invention states that from the resulting solutions it is possible to prepare dosage forms for injections and infusions. However, the invention does not disclose the residual content of peroxide compounds and hydrazine in a solution of poly-N-vinylpyrrolidone. The disadvantage of the proposed method is the impossibility of purifying dry poly-N-vinylpyrrolidone, as well as removing impurities of hydrazine and aldehydes. The invention does not contain information about the installation for implementing the proposed method.

The utility model patent RU 110744 (published on November 27, 2011) discloses a device for concentrating reaction masses containing copolymers of N-vinylpyrrolidone with 2-methyl-5-vinyltetrazole or 2-methyl-5-vinylpyridine and reducing the content of impurities in them, which contains an apparatus for cleaning the reaction mass, connected on one side by a liquid supply line to a reservoir for water supply, and on the other side, the apparatus is connected by a liquid supply line to a pump, which is connected to an ultrafiltration installation, while the apparatus, pump and ultrafiltration installation are combined into a liquid circuit with the possibility of liquid circulation, in which there is a line for draining the filtrate, a line for transferring the product to the dryer with storage and a line for washing the entire liquid circuit. The disadvantage of the known installation is the purification of polymers in the form of solutions and the impossibility of purifying dry polymers.

Thus, from the analysis of the existing level of technology it follows that there is a need to develop a plant for the effective purification of dry poly-N-vinylpyrrolidone with an average molecular weight (8000-12600) ± 2000 Da from impurities of N-vinylpyrrolidone, 2-pyrrolidone, hydrazine and peroxide compounds in order to obtain a substance for the preparation of injection and infusion solutions that meets the requirements of the State Pharmacopoeia.

Disclosure of the essence of the utility model.

To overcome the disadvantages of the known level of technology, the authors of this utility model propose a purification installation, which contains a source of initial dry poly-N-vinylpyrrolidone, a conical thermal cleaning apparatus, a condenser and a collector of volatile impurities and their decomposition products, a nitrogen source, a vacuum source, connected by pipelines. , wherein the conical thermal cleaning apparatus is equipped with a spiral mixing device and is connected to a collection of dry purified poly-N-vinylpyrrolidone.

The technical result of using the utility model is the effective purification of dry poly-N-vinylpyrrolidone with an average molecular weight (8000-12600) ± 2000 Da from impurities of N-vinylpyrrolidone, 2-pyrrolidone, hydrazine and peroxide compounds, obtaining a substance for the preparation of injection and infusion preparations .

Implementation of a utility model

In the preferred embodiment of the utility model (Fig. 1), the cleaning installation includes connected by pipelines 1, a source of initial dry poly-N-vinylpyrrolidone 2, a conical thermal cleaning apparatus 3, heated by a coolant, a condenser 4, cooled by a coolant, and a collection of volatile impurities and products their decomposition 5, a nitrogen source 6, a vacuum source 7, and the conical thermal cleaning apparatus is equipped with a spiral mixing device 8 installed on the top cover while maintaining tightness, and connected to a collection of purified dry poly-N-vinylpyrrolidone 9.

The source of inert gas 6 can be a cylinder with compressed inert gas with suitable technical characteristics or an inert gas line, which is usually available in industries of the corresponding profile.

The source of vacuum 7 can be a vacuum pump with suitable technical characteristics or a vacuum line, which is usually available in production facilities of the corresponding profile.

A specialist in the field of equipment for chemical technology is aware of all the changes that can be made to the design of the proposed installation without going beyond the scope of the utility model formula.

Achieving a technical result in the implementation of a utility model will be further illustrated with examples that will contribute to an accurate and complete understanding of its essence.

Example 1 (auxiliary).

A reactor equipped with a jacket, a bottom drain, a top-drive mixer, a bubbler for supplying inert nitrogen gas, pipes for supplying starting materials, a temperature sensor and a reflux condenser is loaded with 70 liters of demineralized water. Turn on the mixing device and load 42 ml of a 25% aqueous ammonia solution into the reactor, then load 27 ml of a 0.1% solution of sodium pyrophosphate (Na ₄ P ₂ O ₇ ) and 27 ml of a 0.01% solution of copper dichloride (CuCl ₂ ). Then 28 liters of N-vinylpyrrolidone are loaded into the reactor and the contents of the reactor are heated to 70 °C, kept with stirring for 5 minutes and 1.0 liters of 30% hydrogen peroxide are loaded into the reactor at such a rate that the temperature does not exceed 75 °C. Then an additional 75 g of 25% ammonia solution is charged into the reactor. Then the remaining 2.4 liters of 30% hydrogen peroxide are loaded at such a rate that the temperature does not exceed 75 °C. Then the remaining 163 ml of a 25% ammonia solution is introduced into the reactor, stirred at a temperature of 75 ° C for 2 hours. The resulting aqueous solution of poly-N-vinylpyrrolidone is dried on a spray dryer and dry poly-N-vinylpyrrolidone containing impurities of N-vinylpyrrolidone, 2 is obtained. -pyrrolidone, hydrazine and peroxide compounds.

The characteristics of three batches of the resulting dry poly-N-vinylpyrrolidone with an average molecular weight of 8000 ± 2000 Da are shown in Table 3.

Table 3. Characteristics of poly-N-vinylpyrrolidone according to example 1.

No. Indicator name Norm Meaning/
Compliance with the Global Fund Batch 1 Batch 2 Batch 3 1 Description Powder is white or white with a slightly yellowish tint with a slight specific odor. Hygroscopic. Resp. Resp. Resp. 2 Solubility Easily soluble in water, alcohol, chloroform, practically insoluble in ether Resp. Resp. Resp. 3 Authenticity red-brown color with iodine solution Resp. Resp. Resp. 4 pH from 3.0 to 7.0 5.6 5.9 5.9 5 Solution transparency 5 ml of solution A must be comparable to standard solution I Resp. Resp. Resp. 6 Solution color The color intensity of the preparation should not exceed the color intensity of standard No. 5b Resp. Resp. Resp. 7 Average molecular weight 8000±2000 Resp. Resp. Resp. 8 Test for the absence of fractions with a molecular weight greater than 30,000 None Resp. Resp. Resp. 9 Water, %, no more 5.0 6.2
(not corresponding) 6.1
(not corresponding) 6.9
(not corresponding) 10 2-pyrrolidone, %, no more 4.0 5.9
(not corresponding) 5.5
(not corresponding) 5.1
(not corresponding) eleven N-vinylpyrrolidone, %, no more 0.3 0.65
(not corresponding) 0.45
(not corresponding) 0.47
(not corresponding) 12 Aldehydes, %, no more 0.3 0.5
(not corresponding) 0.5
(not corresponding) 0.5
(not corresponding) 13 Sulphate ash, %, no more 0.05 Resp. Resp. Resp. 14 Heavy metals, %, no more 0.0005 Resp. Resp. Resp. 15 Hydrazine, %, no more 0.0005 0.0010
(not corresponding) 0.0015
(not corresponding) 0.0015
(not corresponding) 16 Peroxide compounds, %, no more 0.04 0.20
(not corresponding) 0.21
(not corresponding) 0.29
(not corresponding)

Example 2 (auxiliary).

A reactor equipped with a jacket, a bottom drain, a top-drive mixer, a bubbler for supplying inert nitrogen gas, pipes for supplying starting materials, a temperature sensor and a reflux condenser is loaded with 75 liters of demineralized water. Turn on the mixing device and load 200 ml of a 25% aqueous ammonia solution into the reactor, then load 32 ml of a 0.1% solution of sodium pyrophosphate (Na ₄ P ₂ O ₇ ) and 32 ml of a 0.01% solution of copper dichloride (CuCl ₂ ). Then 30 liters of N-vinylpyrrolidone are loaded into the reactor and the contents of the reactor are heated to 70 °C, kept with stirring for 5 minutes and 1.7 liters of 30% hydrogen peroxide are loaded into the reactor at such a rate that the temperature does not exceed 73 °C. Then an additional 0.94 liters of 25% ammonia solution is charged into the reactor. Then the remaining 2.4 liters of 30% hydrogen peroxide are loaded at such a rate that the temperature does not exceed 75 °C. Then the remaining 320 ml of 25% ammonia solution is introduced into the reactor and stirred at a temperature of 75 °C for 2 hours. Then add 0.51 l of hydrogen peroxide and 0.5 l of aqueous ammonia solution, after which the reaction mixture is left for 1 hour. The resulting aqueous solution of poly-N-vinylpyrrolidone is dried in a spray dryer to obtain dry poly-N-vinylpyrrolidone powder containing impurities of N-vinylpyrrolidone, 2-pyrrolidone, hydrazine and peroxide compounds. The characteristics of three batches (Batch 4, 5 and 6) of the resulting dry poly-N-vinylpyrrolidone with a molecular weight of 12600 ± 2000 Da are shown in Table 4.

Table 4. Characteristics of poly-N-vinylpyrrolidone according to example 2.

No. Indicator name Norm Meaning/
Compliance with the Global Fund Batch 4 Batch 5 Batch 6 1 Description Powder is white or white with a slightly yellowish tint with a slight specific odor. Hygroscopic. Resp. Resp. Resp. 2 Solubility Easily soluble in water, alcohol, chloroform, practically insoluble in ether Resp. Resp. Resp. 3 Authenticity red-brown color with iodine solution Resp. Resp. Resp. 4 pH from 3.0 to 7.0 5.6 5.9 5.9 5 Solution transparency 5 ml of solution A must be comparable to standard solution I Resp. Resp. Resp. 6 Solution color The color intensity of the preparation should not exceed the color intensity of standard No. 5b Resp. Resp. Resp. 7 Average molecular weight 12600±2000 Resp. Resp. Resp. 8 Test for the absence of fractions with a molecular weight greater than 30,000 None Resp. Resp. Resp. 9 Water No more than 5.0% 7.2
(not corresponding) 6.6
(not corresponding) 6.5
(not corresponding) 10 2-pyrrolidone No more than 3.0% 5.7
(not corresponding) 5.2
(not corresponding) 5.9
(not corresponding) eleven N-vinylpyrrolidone No more than 0.2% 0.59
(not corresponding) 0.49
(not corresponding) 0.41
(not corresponding) 12 Aldehydes No more than 0.2% 0.6
(not corresponding) 0.5
(not corresponding) 0.5
(not corresponding) 13 Sulfated ash No more than 0.05% Resp. Resp. Resp. 14 Heavy metals No more than 0.0005% Resp. Resp. Resp. 15 Hydrazine No more than 0.0005% 0.0015
(not corresponding) 0.0013
(not corresponding) 0.0010
(not corresponding) 16 Peroxide compounds No more than 0.04% 0.29
(not corresponding) 0.26
(not corresponding) 0.22
(not corresponding)

Example 3.

Dry poly-N-vinylpyrrolidone powder obtained according to examples 1 and 2 is purified in the installation shown in Fig. 1. The dry poly-N-vinylpyrrolidone powder to be cleaned is loaded through an intermediate container (2) through a pipeline (1) into a conical apparatus (3) equipped with a spiral mixing device (8), connected to sources of inert gas (6) and vacuum (7) , a collection of dry powder of purified poly-N-vinylpyrrolidone (9), a condenser (4) connected to a collection of volatile impurities and their decomposition products (5). The conical apparatus is evacuated, the poly-N-vinylpyrrolidone to be purified is heated and stirred in a vacuum at a given temperature for several hours, the volatile impurities separated and their decomposition products are collected in a collection (5). After this, the conical apparatus (3) is filled with inert gas, the temperature of the contents of the conical apparatus is increased to a given value, and stirring of the poly-N-vinylpyrrolidone is continued in an atmosphere of inert gas at a given temperature for several hours. Then the conical apparatus is cooled to a temperature of 20-25 °C and the dry powder of purified poly-N-vinylpyrrolidone is unloaded into the appropriate container (9). The conditions for the purification process are indicated in table 5 for poly-N-vinylpyrrolidone obtained according to example 1 and in table 6 for poly-N-vinylpyrrolidone obtained according to example 2. The content of impurities of N-vinylpyrrolidone, 2-pyrrolidone, hydrazine, peroxide compounds and water in dry powder of purified poly-N-vinylpyrrolidone, shown in tables 7-12. The remaining characteristics of purified poly-N-vinylpyrrolidone correspond to the standards specified in Table 1 for a polymer with an average molecular weight of 8000 ± 2000 Da and in Table 2 for a polymer with an average molecular weight of 12600 ± 2000 Da.

Table 5. Process conditions for poly-N-vinylpyrrolidone according to Example 1

No. Process parameters Meaning 1 Batch of dry powder being purified
poly-N-vinylpyr-rolidone 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 2 Heating temperature in vacuum 80 85 90 95 100 80 85 90 95 100 80 85 90 95 100 3 Heating time in vacuum 6 5 4 3 4 6 5 4 3 4 6 5 4 3 4 4 Heating temperature in inert gas 85 90 100 105 110 85 90 100 105 110 85 90 100 105 110 5 Heating time in inert gas 6 5 4 3 4 6 5 4 3 4 6 5 4 3 4 6 Batch of purified poly-N-vinylpyrrolidone 1.1 1.2 1.3 1.4 1.5 2.1 2.2 2.3 2.4 2.5 3.1 3.2 3.3 3.4 3.5

Table 6. Process conditions for poly-N-vinylpyrrolidone according to Example 2

No. Process parameters Meaning 1 Batch of dry powder being purified
poly-N-vinylpyrrolidone 4 4 4 4 4 5 5 5 5 5 6 6 6 6 6 2 Heating temperature in vacuum 80 85 90 95 100 80 85 90 95 100 80 85 90 95 100 3 Heating time in vacuum 6 5 4 3 4 6 5 4 3 4 6 5 4 3 4 4 Heating temperature in inert gas 85 90 100 105 110 85 90 100 105 110 85 90 100 105 110 5 Heating time in inert gas 6 5 4 3 4 6 5 4 3 4 6 5 4 3 4 6 Batch of purified poly-N-vinylpyrrolidone 4.1 4.2 4.3 4.4 4.5 5.1 5.2 5.3 5.4 5.5 6.1 6.2 6.3 6.4 6.5

Table 7. Characteristics of poly-N-vinylpyrrolidone (lot 1) purified

No. Indicator name Norm Meaning Part. 1.1 Part. 1.2 Part. 1.3 Part. 1.4 Part. 1.5 1 Water no more than 5.0% 0.2 0.1 0.9 0.1 0.9 2 2-pyrrolidone no more than 4.0 0.7 0.7 1.1 0.7 1.1 3 N-vinylpyr-rolidone no more than 0.3% 0.35 0.16 0.15 0.1 0.1 4 Aldehydes no more than 0.3% 0.5 0.2 0.1 0.1 0.1 5 Hydrazine no more
0.0005% 0.0006 0.0002 0.0002 0.0001 0.0001 6 Peroxide compounds no more than 0.04% 0.10 0.03 0.02 0.02 0.02

Table 8. Characteristics of poly-N-vinylpyrrolidone (lot 2) purified

No. Indicator name Norm Meaning Part. 2.1 Part. 2.2 Part. 2.3 Part. 2.4 Part. 2.5 1 Water no more than 5.0% 0.2 0.1 0.1 0.1 0.1 2 2-pyrrolidone no more than 4.0 0.9 0.6 0.6 0.7 0.7 3 N-vinylpyr-rolidone no more than 0.3% 0.35 0.16 0.15 0.1 0.1 4 Aldehydes no more than 0.3% 0.5 0.2 0.1 0.1 0.1 5 Hydrazine no more
0.0005% 0.0006 0.0002 0.0002 0.0001 0.0001 6 Peroxide compounds no more than 0.04% 0.10 0.03 0.02 0.02 0.02

Table 9. Characteristics of poly-N-vinylpyrrolidone (part 3) purified

No. Indicator name Norm Meaning Part. 3.1 Part. 3.2 Part. 3.3 Part. 3.4 Part. 3.5 1 Water no more than 5.0% 0.3 0.1 0.1 0.1 0.1 2 2-pyrrolidone no more than 4.0 0.8 0.6 0.6 0.5 0.5 3 N-vinylpyr-rolidone no more than 0.3% 0.39 0.17 0.14 0.10 0.10 4 Aldehydes no more than 0.3% 0.4 0.2 0.1 0.1 0.1 5 Hydrazine no more
0.0005% 0.0007 0.0003 0.0003 0.0001 0.0001 6 Peroxide compounds no more than 0.04% 0.09 0.03 0.02 0.02 0.02

Table 10. Characteristics of poly-N-vinylpyrrolidone (part 4) purified

No. Indicator name Norm Meaning Part. 4.1 Part. 4.2 Part. 4.3 Part. 4.4 Part. 4.5 1 Water, %, no more 5.0 0.2 0.1 0.9 0.1 0.9 2 2-pyrrolidone, %, no more 4.0 0.7 0.7 1.1 0.7 1.1 3 N-vinylpyrrolidone, %, no more 0.3 0.35 0.16 0.15 0.1 0.1 4 Aldehydes, %, no more 0.3 0.5 0.2 0.1 0.1 0.1 5 Hydrazine, %, no more 0.0005 0.0006 0.0002 0.0002 0.0001 0.0001 6 Peroxide compounds, %, no more 0.04 0.10 0.03 0.02 0.02 0.02

Table 11. Characteristics of poly-N-vinylpyrrolidone (lot 5) purified

No. Indicator name Norm Meaning Part. 5.1 Part. 5.2 Part. 5.3 Part. 5.4 Part. 5.5 1 Water, %, no more 5.0 0.2 0.1 0.1 0.1 0.1 2 2-pyrrolidone, %, no more 4.0 0.9 0.6 0.6 0.7 0.7 3 N-vinylpyrrolidone, %, no more 0.3 0.35 0.16 0.15 0.1 0.1 4 Aldehydes, %, no more 0.3 0.5 0.2 0.1 0.1 0.1 5 Hydrazine, %, no more 0.0005 0.0006 0.0002 0.0002 0.0001 0.0001 6 Peroxide compounds, %, no more 0.04 0.10 0.03 0.02 0.02 0.02

Table 12. Characteristics of poly-N-vinylpyrrolidone (part 6) purified

No. Indicator name Norm Meaning Part. 6.1 Part. 6.2 Part. 6.3 Part. 6.4 Part. 6.5 1 Water, %, no more 5.0 0.3 0.1 0.1 0.1 0.1 2 2-pyrrolidone,%, no more 4.0 0.8 0.6 0.6 0.5 0.5 3 N-vinylpyrrolidone, %, no more 0.3 0.39 0.17 0.14 0.10 0.10 4 Aldehydes, %, no more 0.3 0.4 0.2 0.1 0.1 0.1 5 Hydrazine, %, no more 0.0005 0.0007 0.0003 0.0003 0.0001 0.0001 6 Peroxide compounds, %, no more 0.04 0.09 0.03 0.02 0.02 0.02

Brief description of drawings

In FIG. 1 schematically shows the installation in accordance with the utility model.

Claims (1)

Installation for purification of dry poly-N-vinylpyrrolidone with an average molecular weight (8000–12600) ±2000 Yes, containing a source of initial dry poly-N-vinylpyrrolidone connected by pipelines, a conical thermal cleaning apparatus, a condenser and a collection of volatile impurities and their decomposition products , nitrogen source, vacuum source, while the conical thermal cleaning apparatus is equipped with a spiral mixing device and connected to a collection of dry purified poly-N-vinylpyrrolidone.