RU98672U1 - INSTALLATION FOR SUBLIMATION DRYING BIOLOGICALLY ACTIVE SUBSTANCES - Google Patents

Abstract

 Installation for freeze-drying biologically active substances at atmospheric pressure, characterized in that it contains a separate chamber with a nozzle for dispersing a solution of biologically active substances and freezing in liquid nitrogen by direct contact with the solution, a freeze-drying chamber for dehydration in a gushing layer; additionally contains a non-contact shell-and-tube heat exchanger for cooling the air supplied to the sublimation chamber for dehydration biologically active substances, and in front of the heat exchanger there is a drying column.

Description

The proposed invention relates to the field of pharmaceutical industry, in particular, to an installation for freeze-drying of biologically active substances at atmospheric pressure.

The closest in technical essence and the achieved result is a unit for freeze-drying of biologically active substances, including a drying chamber, nozzle, cooling system, air injection unit, filter (WO 03/072016 A2, class A61K from 09/04/03).

The disadvantage of this installation is the gradual freezing in the air stream, which leads to the appearance of a coarse-grained structure of particles of the frozen solution with segregation of the dissolved substance, which negatively affects the properties of the final product, makes the freezing process longer.

The technical result of the invention is to obtain high-quality drugs with the full preservation of their biological activity, reducing the time of the process.

The proposed technical result is achieved using an installation containing a separate chamber with a nozzle for dispersing a solution of biologically active substances and freezing in liquid nitrogen by direct contact with the solution and a sublimation chamber for dehydration in a gushing layer. The installation further comprises a non-contact shell-and-tube heat exchanger for cooling the air supplied to the sublimation chamber for dehydration of biologically active substances, and a drying column is located in front of the heat exchanger.

Installation for freeze drying shown in figure 1 includes:

1. freezing chamber;

2. ultrasonic nozzle;

3. sublimation chamber;

4. shell and tube heat exchanger;

5. drainage tower;

6. compressor;

7. 2 thermocouples;

8. hygrometer;

9. anemometer;

10. air recycling line.

Installation for freeze-drying biologically active substances works as follows.

The initial solution is dispersed in liquid nitrogen (T = -196 ° C) into a cylindrical freezing chamber (1) for instant freezing by direct contact with the solution using an ultrasonic nozzle (2) with a productivity of 5 ml / min to 20 ml / min. In this case, the possible size of the resulting particles is from 18 microns to 300 microns, depending on the frequency of operation of the nozzle. The nozzle gives a narrow particle size distribution. Other common types of nozzles are also effective for producing particles of the appropriate size, including dual-stream, pneumatic, and vibration. Then, frozen particles of a spherical shape material are transferred to a freeze-drying chamber (3), where freeze-drying occurs in a flowing layer, which is created by a stream of cold, dried air (Т _air = -24.5 ° C, Т _{dew point} = -35 ° C) supplied to the camera from below. Air is pumped by compressor (6), then dried in a drying column. The drying agent used in this installation is silica gel of the KSMG state standard specification 3956-76 brand. Technical silica gel is a dried porous silicic acid gel with a highly developed inner surface and is a glassy transparent or glassy opaque grains of oval, spherical or irregular shape with color from colorless to light-colored, 4-7 mm in size, bulk density not less than 400-760 g / dm ³ . After drying in a drying column, the air enters a non-contact shell-and-tube heat exchanger (4); a mixture of dry ice with alcohol, which is located in the annulus, is used as a refrigerant.

Example.

The starting material is a 15% mass solution of a protein preparation in water. The mass of loading is 100 g. The range of initial velocities of the air supplied to the chamber was regulated during drying in the range from 0.03 m / s to 0.06 m / s. The duration of the process is from 130 minutes to 200 minutes. The residual moisture content of the dried particles ranged from 1.2% to 1.9%. Particles of the resulting product have a low density and high porosity. No adhesion of particles during the process was observed, the product has good flowability. Also, the particles retained the correct spherical shape and initial size.

Table of process parameters and analytical research results Process parameters Material characteristics Stage of freezing Drying stage Cooling temperature, ° С Working frequency, kHz The average diameter of the frozen particles, microns The initial speed of the drying agent, m / s Drying time, min Residual moisture content,% Preservation of protein activity,% The average particle diameter, microns The average pore diameter, microns -196 ° C 48 35 0.03 200 1.9 81.6 33.6 0.31 0.06 140 1.6 82.0 120 fifteen 0.03 165 1.5 84.4 14.2 0.29 0.06 130 1.2 86.2

Claims (1)

Installation for freeze-drying of biologically active substances at atmospheric pressure, characterized in that it contains a separate chamber with a nozzle for dispersing a solution of biologically active substances and freezing in liquid nitrogen by direct contact with the solution, a freeze-drying chamber for dehydration in a gushing layer, while installing additionally contains a non-contact shell-and-tube heat exchanger for cooling the air supplied to the sublimation chamber for dehydration biologically active substances, and in front of the heat exchanger there is a drying column.