RU2537250C1 - Method for fenbendazole encapsulation - Google Patents

Abstract

FIELD: medicine, pharmaceutics.

SUBSTANCE: invention refers to chemical-pharmaceutical industry and represents a method for drug encapsulation by non-solvent addition; the method is characterised by the fact that the above drug is presented by fenbendazole, while a coating is sodium carboxymethyl cellulose precipitated from a butanol solution by adding methylcarbinol as a non-solvent and water at 25°C.

EFFECT: invention provides simplifying and accelerating the microencapsulation process, reducing the microencapsulation loss (higher weight yield).

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Description

The invention relates to the field of encapsulation, and in particular, to the field of production of fenbendazole microcapsules.

Previously known methods for producing microcapsules of drugs. So, in US Pat. 2092155, IPC A61K 047/02, A61K 009/16 published on 10/10/1997, Russian Federation, a method for microencapsulation of drugs based on the use of ultraviolet radiation was proposed.

The disadvantages of this method are the duration of the process and the use of ultraviolet radiation, which can affect the process of formation of microcapsules.

In US Pat. 2091071, IPC A61K 35/10, Russian Federation, published 09/27/1997, a method for producing the preparation by dispersion in a ball mill to obtain microcapsules is proposed.

The disadvantage of this method is the use of a ball mill and the duration of the process.

In US Pat. 2101010, IPC A61K 9/52, A61K 9/50, A61K 9/22, A61K 9/20, A61K 31/19, Russian Federation, published 01/10/1998, a chewing form of the drug with a taste masking having the properties of a controlled release of the drug The preparation contains microcapsules with a size of 100-800 microns in diameter and consists of a pharmaceutical core with crystalline ibuprofen and a polymer coating, including a plasticizer, flexible enough to withstand chewing. The polymer coating is a methacrylic acid based copolymer.

The disadvantages of the invention: the use of a copolymer based on methacrylic acid, as these polymer coatings can cause cancerous tumors; complexity of execution; the duration of the process.

In US Pat. 2173140, IPC A61K 009/50, A61K 009/127, Russian Federation, published September 10, 2001. A method for producing silicon organolipid microcapsules using a rotary-cavitation unit with high shear forces and powerful sonar acoustic and ultrasonic dispersion ranges is proposed.

The disadvantage of this method is the use of special equipment - a rotary-quittance installation, which has an ultrasonic effect, which affects the formation of microcapsules and can cause adverse reactions due to the fact that ultrasound destructively affects polymers of a protein nature, therefore, the proposed method is applicable when work with polymers of synthetic origin.

In US Pat. 2359662, IPC A61K 009/56, A61J 003/07, B01J 013/02, A23L 001/00, published June 27, 2009, Russian Federation, a method for producing microcapsules using spray cooling in a Niro spray cooling tower under the following conditions: air temperature inlet 10 ° C; outlet air temperature 28 ° C; spray drum rotation speed 10,000 rpm. The microcapsules of the invention have improved stability and provide controlled and / or prolonged release of the active ingredient.

The disadvantages of the proposed method are the duration of the process and the use of special equipment, a set of certain conditions (air temperature at the inlet 10 ° C, air temperature at the outlet 28 ° C, rotation speed of the spray drum 10,000 rpm).

The closest method is the method proposed in US Pat. 2134967, IPC A01N5 3/00, A01N 25/28, published August 27, 1999, Russian Federation (1999). A solution of a mixture of natural lipids and a pyrethroid insecticide in a weight ratio of 2-4: 1 in an organic solvent is dispersed in water, which simplifies the microencapsulation method.

The disadvantage of this method is dispersion in an aqueous medium, which makes the proposed method inapplicable for producing microcapsules of water-soluble preparations in water-soluble polymers.

The technical task is to simplify and accelerate the process of obtaining microcapsules, reducing losses when receiving microcapsules (increase in yield by mass).

The solution to the technical problem is achieved by the method of encapsulation of phenbendazole, characterized in that sodium carboxymethyl cellulose is used as the shell of the microcapsules when they are obtained by the physicochemical precipitation with a non-solvent using two precipitators - methylcarbinol and butanol, the production process is carried out without special equipment.

A distinctive feature of the proposed method is the use of sodium carboxymethyl cellulose as the shell of fenbendazole microcapsules as their core, as well as the use of two precipitants - methylcarbinol and butanol.

The result of the proposed method is the production of fenbendazole microcapsules in sodium carboxymethyl cellulose at 25 ° C for 20 minutes. The output of microcapsules is more than 90%.

EXAMPLE 1. Obtaining microcapsules of fenbendazole with dissolution of the drug in dioxane, the ratio of core / polymer 1: 3

100 mg of fenbendazole is dissolved in 1 ml of dioxane and the resulting mixture is dispersed in a solution of sodium carboxymethyl cellulose in butanol containing the indicated 300 mg of polymer in the presence of 0.01 g of the preparation E472c with 1000 rpm stirring. Then pour 2 ml of a 95% solution of methylcarbinol and 1 ml of distilled water. The resulting suspension is filtered and dried at room temperature.

Received 0.396 g of a white with a yellowish tinge of powder. The yield was 99%.

EXAMPLE 2. Obtaining microcapsules of fenbendazole with dissolution of the drug in dimethyl sulfoxide (DMSO), the ratio of core / polymer 1: 3

100 mg of fenbendazole is dissolved in 1 ml of DMSO and the resulting mixture is dispersed in a solution of sodium carboxymethyl cellulose in butanol containing the indicated 300 mg of polymer in the presence of 0.01 g of the preparation E472c with 1000 rpm stirring. Then pour 2 ml of a 95% solution of methylcarbinol and 1 ml of distilled water. The resulting suspension is filtered and dried at room temperature.

Received 0.397 g of a white with a yellowish tinge of powder. The yield was 98%.

EXAMPLE 3. Obtaining microcapsules of fenbendazole with the dissolution of the drug in dimethylformamide (DMF), the ratio of core / polymer 1: 3

100 mg of fenbendazole is dissolved in 1 ml of DMF and the resulting mixture is dispersed in a solution of sodium carboxymethyl cellulose in butanol containing the indicated 300 mg of polymer in the presence of 0.01 g of the preparation E472c with 1000 rpm stirring. Then pour 2 ml of a 95% solution of methylcarbinol and 1 ml of distilled water. The resulting suspension is filtered and dried at room temperature.

Received 0.388 g of a white with a yellowish tinge of powder. The yield was 97%.

Fenbendazole microcapsules were obtained by the physicochemical non-solvent precipitation method using two precipitants, methylcarbinol and butanol, which increased the yield and accelerated the microencapsulation process. The process is simple to execute and lasts for 20 minutes, does not require special equipment.

The proposed technique is suitable for the veterinary industry due to minimal losses, speed, ease of obtaining and isolation of microcapsules.

Claims (1)

A method of encapsulating a drug with a non-solvent precipitation method, characterized in that phenbendazole is used as a drug, and carboxymethyl cellulose is used as a shell, which is precipitated from a solution in butanol by adding methyl carbinol and water as a solvent at 25 ° C.