JP2007091688A - Method for producing fine powder for coating of solid preparation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an industrial method for the mass-production of fine powder for the coating of a solid preparation to enable dense coating even by a dry process. <P>SOLUTION: Agglomerated particles of fine polymer powder produced massively by spray drying and having an average particle diameter of ≤1μm is disintegrated and classified by a jet mill furnished with an air stream classifier. The fine powder for the coating of a solid preparation, having an average particle diameter of ≤1μm and enabling dense coating even by a dry process can be produced in a mass on an industrial scale by efficiently disintegrating the agglomerated particles of fine polymer powder producible in a mass by spray drying. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a fine powder for coating a solid preparation for coating a solid preparation.

  The solid preparation is coated with various bases in accordance with the purpose of adjusting the timing and speed at which the drug works or protecting a specific site from the drug. As the coating base, a polymer powder such as cellulose, acrylic or biodegradable is often used, and is coated on a solid preparation by a wet method or a dry method. In the wet method, a coating method in which a liquid in which a coating base is dissolved or suspended is sprayed on a solid preparation and then the liquid is evaporated is generally used. In the dry method, the coating base and the binder are combined with the solid preparation. In general, a coating method is used in which the coating base is adhered to a solid preparation by a binder.

  The polymer powder as the coating base is desirably a polymer fine powder having an average particle diameter of 1 μm or less in order to perform dense coating. As a method for producing such a coating base of a polymer fine powder having an average particle diameter of 1 μm or less, a cellulose polymer is dissolved in a solvent containing an organic solvent that can be mixed with water at an arbitrary ratio. There has been proposed a method of spray-drying a concentrated solution obtained by forming a molecular solution and mixing the polymer solution with water and then removing the organic solvent (see, for example, Patent Document 1). In Patent Document 1, a polymer powder having an average particle size of about 10 μm is obtained by spray drying, and the average of the polymer fine powder in the dispersion obtained by re-injecting the polymer powder into water and dispersing it. It is described that the particle diameter was 1 μm or less. That is, the polymer powder of about 10 μm obtained by this spray drying is a bonded particle of polymer fine powder having an average particle size of 1 μm or less.

  The granulation method by spray drying is a method in which a liquid is dispersed in a high-temperature air stream and dried, and by greatly increasing the specific surface area of the liquid, it can be dried in seconds to obtain a large amount of powder. This spray drying granulation method is composed of four stages of atomization, contact between hot air and droplets, evaporation of moisture, and separation and recovery of products from the hot air (for example, see Non-Patent Document 1). In addition, there are three methods of contact between hot air and droplets: cocurrent, countercurrent, and mixed flow. In the cocurrent flow method, the droplet contacts the hot air at a stage where the water content is high, and as the drying proceeds, This is suitable for drying heat-sensitive materials.

JP-A-8-109124 “Granulation Handbook”, edited by Japan Powder Industrial Technology Association, Ohm, 1991, p. 249-254

  In the method for producing a polymer powder as a coating base by spray drying described in Patent Document 1, the average particle size of the polymer powder obtained by spray drying is about 10 μm. When coating with, there is a problem that a dense coating cannot be performed. When the coating base is coated by a wet method, the coating base is dissolved or suspended in the liquid, and the polymer powder of about 10 μm is dispersed as a polymer fine powder having an average particle diameter of 1 μm or less. However, if the dispersion is insufficient, the average particle diameter may exceed 1 μm and the denseness of the coating may be impaired.

  In order to be able to coat the polymer powder of about 10 μm obtained by spray drying with a dry method, the polymer powder, which is a bonded particle of polymer fine powder, is crushed with a mortar or the like. However, the polymer powder obtained in a large amount by spray drying cannot be fully processed, and cannot sufficiently cope with the production of a coating base that is in great demand and is desired to be mass-produced on an industrial scale.

  Therefore, an object of the present invention is to enable mass production of fine powder for coating a solid preparation that can be densely coated by a dry method on an industrial scale.

  In order to solve the above problems, the method for producing a fine powder for coating a solid preparation of the present invention is obtained by spray-drying a dispersion of polymer fine powder having an average particle size of 1 μm or less and performing this spray-drying. A method of producing a fine powder for solid formulation coating by pulverizing and classifying the bonded fine particles of the polymer fine powder with a jet mill equipped with an airflow classifier was adopted.

  That is, a high molecular weight powder obtained by spray drying is obtained by pulverizing and classifying bonded fine particles of polymer fine powder having an average particle size of 1 μm or less obtained by spray drying in a jet mill equipped with an airflow classifier. The fine particles for coating a solid preparation having an average particle size of 1 μm or less that can be finely coated even by a dry method can be mass-produced on an industrial scale.

  The jet mill is preferably a fluidized bed type having a plurality of jet nozzles and causing the bonded fine particles of the polymer fine powder to collide with each other near the center of the crushing chamber.

  The method for producing a fine powder for coating a solid preparation according to the present invention comprises pulverizing and classifying bonded fine particles of a polymer fine powder having an average particle size of 1 μm or less obtained by spray drying in a jet mill equipped with an airflow classifier. As a result, fine particles for solid pharmaceutical coatings with an average particle size of 1 μm or less that can be efficiently pulverized from fine particles of polymer fine powder obtained in large quantities by spray-drying and can be densely coated by a dry method. Can be made on an industrial scale.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a production process of a method for producing a fine powder for coating a solid preparation according to the present invention. First, a dispersion in which fine polymer powder for solid preparation coating is dispersed is prepared, and this dispersion is spray-dried. Thereafter, the polymer powder obtained by spray drying is pulverized and classified with a jet mill equipped with an airflow classifier to produce a fine powder for solid preparation coating having an average particle size of 1 μm or less.

  The dispersion in which the polymer fine powder is dispersed can be prepared by a known method. For example, a polymer material can be dissolved in a solvent containing an organic solvent to form a polymer solution, and the polymer solution is mixed with water, and then the organic solvent is removed to prepare a dispersion. In addition to this method, it can be prepared by an emulsion polymerization method known as a method for preparing an acrylic polymer solution.

  FIG. 2 shows the spray drying granulator used for the spray drying. This spray-drying granulator is a co-current type in which a dispersion A and hot air B in which polymer fine powder is dispersed are jetted from the top of the drying chamber 1 in the same direction. After being agitated and the polymer in the solution is atomized, it is sprayed into the drying chamber 1. The polymer powder C dried by contact with the hot air B is separated from the hot air B by the collector 3 and collected.

  FIG. 3 shows a jet mill used for crushing and classifying the polymer powder C. This jet mill is a fluidized bed type in which a plurality of jet nozzles 12 are provided in a vertical cylindrical casing 11 and polymer powder C supplied from a supply pipe 13 collides with each other near the center of the casing 11. The polymer fine powder D crushed by this collision is classified by a classifying rotor 14a that rotates at high speed of an airflow classifier 14 provided on the upper portion of the casing 11, and is collected from the discharge pipe 14b to the collector 15. Sent. The polymer fine powder D that has been classified and collected by the collector 15 is collected in the collection container 16 as a product of the fine powder E for solid formulation coating.

  4A and 4B show electron micrographs of the polymer powder C obtained by spray drying using the spray drying granulator. In FIG. 4A, the magnification is 800 times, and the particle diameter of the polymer powder C is 10 to several tens of μm. FIG. 4 (b) shows an enlargement of the magnification to 10,000 times, and it can be seen that the polymer powder C is a large number of fine particles of bonded particles having a particle diameter of 1 μm or less.

  FIG. 5 shows an electron micrograph of the polymer fine powder D obtained by crushing and classifying the polymer powder C with a jet mill. The magnification of this photograph is 13000 times, and the polymer fine powder D is a spherical fine powder having a particle diameter of about 0.1 to 0.2 μm. The average particle diameter of the polymer fine powder D is smaller than the average particle diameter of the fine powder of the bonded granule before pulverization shown in FIG. The reason for this is not clear, but may be due to the polishing action caused by the collision between the polymer fine powders D in the fluidized bed of the jet mill or between the polymer fine powder D and the polymer powder C.

Process drawing which shows the manufacturing process of the manufacturing method of the fine powder for solid formulation coating which concerns on this invention 1 is a schematic longitudinal sectional view showing a spray drying granulator used in the spray drying process of FIG. 1 is a schematic longitudinal sectional view showing a jet mill used in the crushing and classification process of FIG. a and b are electron micrographs of polymer powder C obtained by the spray-drying granulator shown in FIG. Electron micrograph of fine polymer powder D obtained by crushing and classifying with the jet mill of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drying chamber 2 Atomizer 3 Collector 11 Casing 12 Jet nozzle 13 Supply pipe 14 Airflow classifier 14a Classification rotor 14b Drain pipe 15 Collector 16 Collection container

Claims (2)

  The dispersion of polymer fine powder having an average particle size of 1 μm or less is spray-dried, and the polymer fine powder-bound particles obtained by spray drying are crushed with a jet mill equipped with an airflow classifier. A method for producing a fine powder for solid preparation coating, wherein the fine powder for solid preparation coating is produced by classification.   2. The solid formulation coating according to claim 1, wherein the jet mill is a fluidized bed type having a plurality of jet nozzles and causing the bonded fine particles of the polymer fine powder to collide with each other in the vicinity of the center of the crushing chamber. Production method of fine powder.