WO2023236507A2

WO2023236507A2 - Highly stable chlortetracycline premix and preparation method therefor

Info

Publication number: WO2023236507A2
Application number: PCT/CN2022/141890
Authority: WO
Inventors: 宋玉忠; 张君启; 张向领; 陈洋; 吕向云; 吴新芝
Original assignee: 驻马店华中正大有限公司
Priority date: 2022-06-09
Filing date: 2022-12-26
Publication date: 2023-12-14
Also published as: CN114848599B; WO2023236507A3; CN114848599A

Abstract

The present invention belongs to the technical field of chlortetracycline production processes, and specifically relates to a highly stable chlortetracycline premix and a preparation method therefor. By means of combining and using different antioxidants, chlortetracycline degradation can be effectively slowed down, product utilization can be improved, and production costs can be reduced. The preparation method for the highly stable chlortetracycline premix comprises the pretreatment of a fermentation liquid, the addition of antioxidants, granulation of a filter cake after mixing, drying, etc. By means of improvement of process conditions, when sodium hydrogen sulfite and calcium chloride are used at a weight ratio of 1:1 as antioxidants to prepare the chlortetracycline premix, the degradation rate of the chlortetracycline is able to be controlled at 8% or less after storing the chlortetracycline premix at 50 °C for 90 days, effectively improving the stability of chlortetracycline.

Description

A kind of highly stable chlortetracycline premix and preparation method thereof

Technical field

The invention belongs to the technical field of chlortetracycline production technology, and specifically relates to a highly stable chlortetracycline premix and a preparation method thereof.

Background technique

Chlortetracycline is an active ingredient biosynthesized by Streptomyces aureofacieus and is a tetracycline antibiotic. In the industrial production process of chlortetracycline, the bacteria are mainly cultured through primary, secondary and tertiary fermentation, and then calcium salt is added to the fermentation liquid, followed by mixing, plate and frame filtration, and filter cake granulation and drying to obtain chlortetracycline. The chlortetracycline premix is a chlortetracycline fermentation mycelium mixture composed of hyphae and metabolites. It is generally brown or tan powder or granular, has a unique fermentation smell, and is slightly soluble in water and Alcohol, a dilute solution soluble in weak acid.

Chlortetracycline premix is a broad-spectrum antibiotic that has a wide range of antibacterial activity against most gram-positive and negative bacteria, rickettsiae, mycoplasma (mycoplasma), spirochetes, large viruses, etc. In the field of feeding, practice has proven that the use of chlortetracycline in feeding can effectively treat chicken orchid crown disease, chronic respiratory disease, infectious synovitis, coccidiosis, porcine leptospirosis, atrophic rhinitis, bacterial enteritis, swine dysentery, etc. Especially significant.

In the prior art, although methods for improving the production process of chlortetracycline premix have been disclosed, the stability of the produced chlortetracycline needs to be improved. For example, the Chinese patent with publication number CN102899377A discloses a method for preparing a chlortetracycline premix by strictly maintaining sterility during the entire culture process and maintaining a certain tank temperature and tank pressure, and using ammonia and supplementation. The method of feeding maintains a certain pH and nutrition, which is conducive to stable fermentation, thereby increasing the chlortetracycline content and chlortetracycline yield. For another example, the Chinese patent with publication number CN103284956A discloses a chlortetracycline premix, including chlortetracycline hydrochloride, calcium carbonate, corn starch, adhesive and enteric polyacrylic acid resin, and adopts a dry granulation process. , can significantly improve the one-time yield, increase the dispersion and sustained release properties of the product, and also ensure that chlortetracycline hydrochloride is not completely released in the gastric juice, improving the utilization of chlortetracycline hydrochloride.

Since the chlortetracycline premix is unstable to various oxidants, including oxygen, during storage, the storage environment can easily lead to the degradation of chlortetracycline, causing considerable economic losses to production companies.

Based on this, the inventor first used an antioxidant composition and adjusted the production process in order to slow down the degradation rate of chlortetracycline and improve product utilization.

Contents of the invention

The purpose of the present invention is to solve the problem in the prior art that chlortetracycline produced by fermentation is easily oxidized, and to provide a preparation method of a highly stable chlortetracycline premix, which can effectively slow down the oxidation of chlortetracycline by combining different antioxidants. The degradation of mycin increases product utilization and reduces production costs.

In order to achieve the above objects, the present invention adopts the following technical solutions:

A preparation method of highly stable chlortetracycline premix, including the following steps:

(1) Fermentation broth pretreatment: Add calcium salt according to the chlortetracycline titer and the amount of dry matter in the chlortetracycline fermentation broth, and press filter to obtain a wet filter cake;

(2) Add antioxidants: Add antioxidants to the wet filter cake obtained in step (1) to obtain a mixture. The amount of antioxidants added is 0.5% to 5% of the weight of the wet filter cake;

(3) Granulation and drying of the mixed filter cake: Sieve and granulate the mixture obtained in step (2), and then dry it at a temperature of <200°C for 30 to 60 minutes to obtain the product.

Specifically, the chlortetracycline titer of the chlortetracycline fermentation broth in step (1) is 10,000 to 30,000 U/mL; the dry matter content (mass percentage) is 5% to 15%.

Specifically, the calcium salt in step (1) is calcium carbonate; the amount of calcium carbonate added is 1 to 12g/100mL chlortetracycline fermentation broth.

Specifically, the antioxidant described in step (2) is any one of sodium bisulfite, VC, citric acid, magnesium chloride, calcium chloride or a combination of two or more in any proportion.

Preferably, the antioxidant in step (2) is sodium bisulfite, or a composition of sodium bisulfite and calcium chloride in any proportion, or a composition of sodium bisulfite and magnesium chloride in any proportion.

Further preferably, the weight ratio of sodium bisulfite and calcium chloride in the composition is 1:1-3; the weight ratio of sodium bisulfite and magnesium chloride is 1:1-3.

Furthermore, based on a general inventive concept, the present invention also provides a method for improving the stability of chlortetracycline premix. The specific method adopts the steps in the above preparation method.

Further, based on a general inventive concept, the present invention also includes a chlortetracycline premix prepared by the above method.

Preferably, the content (mass percentage) of chlortetracycline in the chlortetracycline premix is 15% to 25%.

Further, the present invention also provides the use of the chlortetracycline premix as a feed additive to improve feed utilization.

Chlortetracycline premix is a broad-spectrum antibiotic and has a wide range of antibacterial activity against most gram-positive and negative bacteria, rickettsiae, mycoplasma (mycoplasma), spirochetes, large viruses, etc. Practice has proven that Chlortetracycline premix is particularly effective against chicken orchid disease, chronic respiratory diseases, infectious synovitis, coccidiosis, porcine leptospirosis, atrophic rhinitis, bacterial enteritis, swine dysentery, etc.

Specifically, during application, it is added to pig feed to treat pig leptospirosis or swine dysentery.

Specifically, when the chlortetracycline content (mass percentage) in the chlortetracycline premix is 15%, the amount added to the pig feed is 2.67-4kg/ton, and is used for 7 consecutive days; When the chlortetracycline content (mass percentage) in the chlortetracycline premix is 20%, the amount added to the pig feed is 2 to 3 kg/ton and used for 7 days in mixed feeding.

Compared with the prior art, the beneficial effects of the present invention are:

1. The preparation method of the present invention can effectively improve the stability of chlortetracycline and slow down its degradation rate during storage by adding antioxidants during the preparation process of chlortetracycline premix.

2. The present invention optimizes the process conditions. When sodium bisulfite and calcium chloride with a weight ratio of 1:1 are used as antioxidants to prepare chlortetracycline premix, the obtained chlortetracycline premix is stored at 50°C. After 90 days, the degradation rate of chlortetracycline can be controlled at 7.92%, which effectively improves the stability of chlortetracycline.

3. The amount of the chlortetracycline premix obtained by the present invention added to the feed is less than that of the commonly used premix in the prior art, thereby improving the utilization rate of the chlortetracycline product and reducing the production cost of the enterprise.

Detailed ways

The technical solution of the present application is clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

Experimental methods without specifying specific conditions in the following examples are usually performed according to conventional conditions or conditions recommended by the manufacturer. The raw materials and reagents used are conventional commercially available products unless otherwise specified. Unless otherwise stated, all parts are by weight and all percentages are by weight.

Example

A method for preparing a highly stable chlortetracycline premix. The specific steps are as follows;

(1) Pretreatment of fermentation broth: Place the chlortetracycline fermentation broth in a pretreatment tank. According to the titer in the tank (specifically 20000U/mL in this embodiment) and the dry matter content (the solid content after drying of the fermentation broth in this embodiment) substance content is 7%), add calcium carbonate in an amount of 12g/100mL chlortetracycline fermentation broth, mix evenly, filter with plates and frames, and squeeze to obtain a wet filter cake;

(2) Add antioxidant: Mix the solid antioxidant and the wet filter cake obtained in step (1) thoroughly to obtain a mixture; the antioxidant used is one of sodium bisulfite, VC, citric acid, magnesium chloride, and calcium chloride. or more; the addition amount is 0.5% to 5%;

(3) Granulation and drying of the mixed filter cake: Granulate the mixture obtained in step (2) with a 20-40 mesh screen, and then dry it at a temperature of <200°C for 30-60 minutes to obtain the finished product.

The chlortetracycline fermentation broth described in step (1) is obtained by the following steps:

a. Streptomyces aureus goes through the sandy soil spore tube, the mother slope, the daughter slope, the first-level seed tank, and the second-level seed tank to obtain the second-level seed;

b. First disinfect the fermentation tank, then pour in a compound medium composed of corn liquor, soybean cake powder, starch, glucose, etc., and then perform high-temperature sterilization;

c. Then move the secondary seeds into the fermentation tank, and add the compound culture medium in step b for fermentation and culture; during the fermentation and culture process, the tank temperature should be controlled at 26-33°C, the tank pressure at 0.001-0.040Mpa, and the pH at 5.5- 6.0 and other indicators, the fermentation cycle is 90-124 hours, and the fermentation liquid is obtained at the end of the fermentation. The main component of the fermentation liquid is chlortetracycline.

All other process parameters in the preparation method of chlortetracycline fermentation broth can adopt conventional settings in the prior art, and the preparation method is not the point of invention of the present invention, so it will not be described again.

Specifically, in order to verify the impact of antioxidants on the stability of chlortetracycline premix, in this test, the chlortetracycline premix prepared by adding the above single antioxidant was placed at 50°C and stored for different times. The content changes of chlortetracycline and the degradation rate of chlortetracycline in the chlortetracycline premix product were measured. The results are shown in Tables 1 to 3. Table 1, Table 2, and Table 3 respectively show the dosage of different antioxidants. The test results are 0.5%, 1% and 5% respectively.

Table 1 Comparison of changes in chlortetracycline content when 0.5% antioxidant is added and stored at 50°C.

Table 2 Comparison of changes in chlortetracycline content when 1% antioxidant is added and stored at 50°C

Table 3: Comparison of changes in chlortetracycline content after adding 5% antioxidants and storing at 50°C

It can be seen from the data in Tables 1 to 3 that after adding different types of antioxidants, the degradation rate of chlortetracycline decreased compared with the blank group; comparing the effects of different antioxidants on the degradation rate of chlortetracycline, it can be seen that adding The degradation rate of chlortetracycline was the lowest after sodium bisulfite, followed by calcium chloride and magnesium chloride.

It can be seen from the above test that after using a single antioxidant, the prepared chlortetracycline premix has a certain stability and the degradation rate of chlortetracycline has decreased. On this basis, in order to further reduce the degradation rate of chlortetracycline Regarding the degradation rate, the inventor used sodium bisulfite, calcium chloride, and magnesium chloride as objects to examine the effects of different antioxidant combinations on the degradation rate of chlortetracycline.

Prepare the mixed preparations of sodium bisulfite and calcium chloride, and sodium bisulfite and magnesium chloride according to the weight ratio of 1:1, 1:2, and 1:3 respectively. Add the mixed preparation to step (1) with reference to the above preparation process. into the wet filter cake, and then place the prepared chlortetracycline premix at 50°C for different times, and analyze the changes in chlortetracycline content and the degradation rate of chlortetracycline in the chlortetracycline premix product. The measurement was carried out and the results are shown in Tables 4 to 6. Table 4, Table 5 and Table 6 are the test results when the dosage is 0.5%, 1% and 5% respectively.

Table 4 Results of chlortetracycline content in samples stored at 50°C after adding 0.5% antioxidant combination

Table 5 Results of chlortetracycline content in samples stored at 50°C after adding 1% antioxidant combination

Table 6: Results of chlortetracycline content in samples stored at 50°C after adding 5% antioxidant combination

Comparing the effects of different addition amounts on chlortetracycline degradation, it can be seen that the degradation rate of chlortetracycline premix is the lowest when the addition amount of antioxidant combination is 0.5%, indicating that the more addition amount of antioxidant combination is not better. Comparing the antioxidant effects of different ratios of sodium bisulfite and calcium chloride, as well as sodium bisulfite and magnesium chloride, it can be seen that when the ratio of sodium bisulfite and magnesium chloride, or sodium bisulfite and calcium chloride is 1 When the composition is added in :1 or 1:2, the degradation rate of chlortetracycline premix is lower than that of using a single antioxidant under the same conditions. Among them, adding an antioxidant combination of sodium bisulfite and calcium chloride in a ratio of 1:1 and storing it at 50°C for 90 days, the degradation rate of chlortetracycline can be controlled at 7.92%, indicating that the composition is stable to chlortetracycline. The improvement effect is the most significant.

The high-stability chlortetracycline premix of the present invention can be prepared into a premix product with a mass percentage of 10%, 15%, 20% or 30%. After adding a stabilizer to the chlortetracycline premix, the product stability is improved, and the CTC% content of the active ingredient is increased. Under the same prescription dosage, the premix dosage is reduced and the bioavailability is improved.

Application examples

In order to further illustrate the beneficial effects of the combination of different antioxidants and the specific dosage in the present invention on the degradation rate of the chlortetracycline premix product, the following is a re-verification with a specific example of scaled-up production.

Take a certain batch of wet filter cakes from the chlortetracycline production line (the content of chlortetracycline is about 20%, the wet cake weighs about 11,000kg, and the wet filter cake is prepared by using ^50m3 of fermentation broth), and add a weight ratio of 0.5% A mixed preparation, wherein sodium bisulfite: calcium chloride = 1:1, and the method in the embodiment is used to prepare the chlortetracycline premix, and the chlortetracycline premix without adding antioxidant combination is Control group; three parallels are set for each condition, and the test results are averaged.

Among them, the control group refers to the method in the examples to directly mix the fermentation broth and calcium carbonate, and then filters and squeezes through the plate and frame to obtain a wet filter cake; the test group refers to the methods in the examples to mix the fermentation broth and calcium carbonate After mixing evenly, filter through the plate and frame and squeeze to obtain a wet filter cake. Add solid antioxidants to the wet filter cake and mix evenly.

After different treatment groups have been placed for different times, the test results of the chlortetracycline content in the products are shown in Table 7 below.

Table 7: Test results of chlortetracycline content of production scale-up test samples stored at room temperature.

As can be seen from Table 7, with the addition of 0.5% sodium bisulfite and calcium chloride mixed preparation, the chlortetracycline degradation rate of the premix product is 5.43 percentage points lower than that of the control group, indicating that the addition of sodium bisulfite and calcium chloride The mixture improves the stability of chlortetracycline premix.

According to the national standard, when the chlortetracycline premix prepared by using existing technology (control group conditions) is added to pig therapeutic feed (used to treat porcine leptospirosis or swine dysentery, etc.), the added amount needs to be 2~ 3kg/ton (the content of chlortetracycline in the premix is 20%). When using the technical solution of the present application to prepare a chlortetracycline premix, the premix with a chlortetracycline content of 20% can reach the national standard when added to the feed in an amount of 1.9 to 2.8kg/ton (see "Veterinary Drug Quality Standards" 》 (2017 edition)), compared with the existing technology, the preparation method of the present application significantly improves product utilization and reduces production costs.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the foregoing embodiments. Modify the recorded technical solutions, or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

A method for preparing a highly stable chlortetracycline premix, which is characterized in that it includes the following steps:

(1) Fermentation broth pretreatment: Add calcium salt according to the chlortetracycline titer and the amount of dry matter in the chlortetracycline fermentation broth, and press filter to obtain a wet filter cake;

(2) Add antioxidants: Add antioxidants to the wet filter cake obtained in step (1) to obtain a mixture. The amount of antioxidants added is 0.5% to 5% of the weight of the wet filter cake;

(3) Granulation and drying of the mixed filter cake: Sieve and granulate the mixture obtained in step (2), and then dry it at a temperature of <200°C for 30 to 60 minutes to obtain the product.
The preparation method according to claim 1, characterized in that the chlortetracycline titer of the chlortetracycline fermentation broth in step (1) is 10,000-30,000 U/mL; the mass percentage of dry matter is 5%-15%.
The preparation method according to claim 1, wherein the calcium salt in step (1) is calcium carbonate; the amount of calcium carbonate added is 1 to 12 g/100 mL chlortetracycline fermentation broth.
The preparation method according to claim 1, wherein the antioxidant in step (2) is any one of sodium bisulfite, VC, citric acid, magnesium chloride, and calcium chloride or two or more in any proportion. Compositions.
The preparation method according to claim 1, characterized in that the antioxidant in step (2) is a composition with a weight ratio of sodium bisulfite and calcium chloride of 1: (1-3).
The preparation method according to claim 1, characterized in that the antioxidant in step (2) is a composition with a weight ratio of sodium bisulfite and magnesium chloride of 1: (1-3).
A chlortetracycline premix prepared by any method of claims 1-6.
The application of the chlortetracycline premix described in claim 7 in improving feed utilization.