Pleuromutilin derivative oral solution for livestock and poultry and preparation method of pleuromutilin derivative oral solution

Abstract

The invention discloses a pleuromutilin derivative oral solution for livestock and poultry and a preparation method of the pleuromutilin derivative oral solution. The preparation method comprises the following steps: adding 2.5-10.0% (m / v) of pleuromutilin derivative raw material medicine into 2.5-10.0% (v / v) of cosolvent, and stirring until the pleuromutilin derivative raw material medicine is completely dissolved to obtain a solution 1; adding part of the diluent into the solution 1, uniformly stirring and mixing, adding 0.5-3.0% (m / v) of the dispersant and 0.01-0.1% (m / v) of the antioxidant, and stirring until complete dissolution to obtain a solution 2; and adding the rest of the diluent into the solution 2 for constant volume, and stirring until the mixture is completely and uniformly mixed to obtain the pleuromutilin derivative oral solution. The pleuromutilin derivative oral solution disclosed by the invention is used for efficiently preventing and treating the infection of sensitive pathogens such as gram-positive bacteria and mycoplasma of livestock and poultry, has good solubility and stability, is suitable for large-scale group drinking administration, and provides more convenience for clinical medication of veterinarians.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical formulation development technology, and in particular to an oral solution of truncated pleurotin derivatives for livestock and poultry and its preparation method. Background Technology

[0002] In recent years, my country's livestock industry has seen significant improvements in intensive and large-scale farming. However, this rapid development has also led to increased use of antibiotics and their overuse, resulting in increasingly serious antibiotic resistance in animal-derived bacteria. Therefore, the development of novel, highly active antibiotics with unique mechanisms of action against drug-resistant bacteria is urgently needed. Pleurotus truncatedis, with its unique mechanism of action, exhibits strong antibacterial activity against Gram-positive bacteria, mycoplasma, and some Gram-negative bacteria, and is less prone to cross-resistance with other antibiotics, making truncated pleurotus truncatedis drugs highly promising. A novel truncated pleurotus truncatedis derivative synthesized by the Lanzhou Institute of Animal Husbandry and Veterinary Medicine, Chinese Academy of Agricultural Sciences, is a candidate for Class I new veterinary drugs in China. Previous studies have demonstrated that truncated pleurotus truncatedis derivatives exhibit excellent in vitro antibacterial activity against standard strains, clinical strains, and drug-resistant Gram-positive bacteria, and possess good efficacy and drug-like properties.

[0003] Pleurotus truncated derivatives are almost insoluble in water, a characteristic that limits their clinical application. Traditional solid dosage forms such as powders, premixes, tablets, and granules cannot be administered via drinking water, while forced oral or injectable administration is impractical and stressful for large-scale farming. Therefore, developing a veterinary-specific oral solution that improves the solubility and stability of pleurotus truncated derivatives and is suitable for large-scale group administration via drinking water is crucial, providing greater convenience for veterinary clinical medication. Summary of the Invention

[0004] To overcome the shortcomings and deficiencies of the prior art, the purpose of this invention is to provide an oral solution of truncated pleurotin derivatives for livestock and poultry and its preparation method.

[0005] The technical solution provided by this invention is as follows:

[0006] An oral solution of truncated pleurotin derivatives for livestock and poultry, the solution comprising 2.5-10.0% (m / v) of the active ingredient truncated pleurotin derivative, 2.5-10.0% (v / v) of solubilizer, 0.5-3.0% (m / v) of dispersant, 0.01-0.1% (m / v) of antioxidant, and the balance being a diluent.

[0007] The chemical name of the truncated pleurotin derivative of this invention is (3aS,4R,5S,6S,8R,9R,9aR,10R)-6-vinyl-5-hydroxy-4,6,9,10-tetramethyl-1-oxododecanohydrogen-3a,9-propanol-3aH-cyclopentane[8]cycloen-8-yl 2-((1-(cyclobutanecarbamoyl)-2-methylpropyl-2-yl)thio)acetate, molecular weight: 547.80, molecular formula: C 31 H 49 NO5S has the following molecular structure as shown in formula (I):

[0008]

[0009] The preparation method of this truncated pleurotin derivative is described in detail in Chinese patent CN202311376279.9, entitled "Truncation of pleurotin derivatives containing cycloalkyl groups and their preparation methods and applications".

[0010] Preferably, the amount of the truncated pleurotin derivative is 2.5%, 5.0%, or 10.0%.

[0011] Preferably, the amount of the co-solvent is 2.5%, 5.0%, 7.5%, or 10.0%.

[0012] Preferably, the dispersant is 0.5%, 1.0%, 2.0%, or 3.0%.

[0013] Preferably, the amount of antioxidant used is 0.01%, 0.02%, 0.05%, or 0.1%.

[0014] Preferably, the co-solvent is at least one selected from benzyl alcohol, N-methylpyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide.

[0015] Preferably, the diluent is at least one of propylene glycol, glycerol, polyethylene glycol 200, and polyethylene glycol 300.

[0016] Preferably, the dispersant is at least one of sodium dodecyl sulfate, Tween 80, poloxamer 188, and Span 80.

[0017] Preferably, the antioxidant is at least one selected from butylated hydroxyanisole, tert-butylhydroquinone, propyl gallate, butylated hydroxytoluene, and vitamin C.

[0018] This invention further discloses a method for preparing the above-mentioned oral solution of truncated pleurotin derivatives for livestock and poultry, the method comprising the following steps:

[0019] (1) At room temperature, add the truncated pleurotin derivative raw material to the co-solvent and stir until completely dissolved to obtain solution 1;

[0020] (2) Add some diluent to solution 1, stir and mix well, then add dispersant and antioxidant, and stir until completely dissolved to obtain solution 2;

[0021] (3) Add diluent to solution 2 to make up the volume, stir until completely mixed, and obtain an oral solution of truncated pleurotin derivatives for livestock and poultry.

[0022] This invention overcomes the shortcomings of existing technologies and provides an oral solution of truncated pleurotin derivatives for livestock and poultry, and its preparation method. The method involves using benzyl alcohol or N,N-dimethylacetamide as a cosolvent to fully dissolve the truncated pleurotin derivatives, ensuring their existence in molecular form. Next, propylene glycol or glycerol is added as a diluent to ensure stable and uniform distribution of the drug molecules. Then, sodium dodecyl sulfate or Tween 80 is added as a dispersant to ensure the truncated pleurotin derivatives in the solvent exist in water as uniformly dispersed micelles, increasing their solubility in water. Finally, an antioxidant is added to maintain the stability of the truncated pleurotin derivatives, giving the oral solution a good shelf life. The main advantages of this invention are: compared with other solubilization technologies (such as β-cyclodextrin inclusion, nano-sizing, microencapsulation, self-emulsification, etc.), this invention solves the problem of poorly soluble drugs being insoluble in water by using a simple preparation process. By combining the effects of solubilizers, diluents, and dispersants, the truncated pleurotin derivatives in the solvent are uniformly dispersed in water in the form of micelles, which significantly improves the solubility of truncated pleurotin derivatives in water. This enables the oral solution of truncated pleurotin derivatives to be uniformly administered via drinking water in clinical applications, and is suitable for large-scale group administration in livestock and poultry.

[0023] The beneficial effects of this invention after adopting the above technical solution are as follows: Compared with traditional preparations (such as powders, premixes, tablets, etc.), the oral solution of truncated pleurotin derivatives for livestock and poultry of this invention solves the problem that truncated pleurotin derivatives are almost insoluble in water, greatly improves the solubility and dispersibility of the drug, and makes the drug exist in the form of molecules or tiny particles, which makes it easier to penetrate the gastrointestinal mucosa and enter the blood circulation. It significantly improves the bioavailability of the drug, enhances the convenience of administration, improves the stability of the raw material, accurately controls the dosage, and reduces drug resistance. It can be administered evenly through drinking water, which is more suitable for the needs of large-scale breeding and avoids the problem of uneven dosage caused by differences in feed intake in traditional feed mixing. Attached Figure Description

[0024] Figure 1 This is a morphological diagram of the oral solution of truncated pleurotin derivatives for livestock and poultry in Example 9 of the present invention;

[0025] Figure 2 This is a color diagram of the oral solution of truncated pleurotin derivatives for livestock and poultry in Example 9 of the present invention. Detailed Implementation

[0026] The technical solution of the present invention will be further described in detail below with reference to specific embodiments, but this does not constitute any limitation on the present invention.

[0027] The truncated pleurotin derivatives used in the following examples are chemically named (3aS,4R,5S,6S,8R,9R,9aR,10R)-6-vinyl-5-hydroxy-4,6,9,10-tetramethyl-1-oxododecanohydrogen-3a,9-propanol-3aH-cyclopentane[8]cycloen-8-yl 2-((1-(cyclobutanecarbamoyl)-2-methylpropyl-2-yl)thio)acetate, molecular weight: 547.80, molecular formula: C 31 H 49 NO5S has the following molecular structure as shown in formula (I):

[0028]

[0029] The preparation method of the truncated pleurotin derivative is described in detail in Examples 1, 7, and 9 of Chinese Patent Specification CN202311376279.9, entitled "Truncation of Pleurotin Derivatives Containing Cycloalkyl Groups and Their Preparation Methods and Applications" (i.e., "Derivative 2 (with added cyclobutylformyl chloride)" prepared in Example 9).

[0030] Example 1 Solubility Test

[0031] Solubility is one of the fundamental physical properties of active pharmaceutical ingredients (APIs). According to Item 16 of the General Rules in Part I of the 2020 edition of the *Pharmacopoeia of the People's Republic of China for Veterinary Medicine*, the solubility of truncated pleurotin derivatives in different solvents was determined.

[0032] As shown in Table 1, truncated pleurotin derivatives are almost insoluble in water, highly soluble in methanol, anhydrous ethanol, acetonitrile, dimethyl sulfoxide, and dichloromethane, readily soluble in ethyl acetate, n-octanol, and isopropanol, and slightly soluble in diethyl ether. To address the problem of the poor water solubility of truncated pleurotin derivatives, this invention aims to develop an oral solution to overcome this water insolubility issue and enable large-scale administration of medication to livestock and poultry via drinking water.

[0033] Table 1. Solubility of truncated pleurotin derivatives in different solvents

[0034]

[0035] Example 2: Screening of Co-solvents

[0036] Benzyl alcohol, N-methylpyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide were selected as co-solvents. The optimal co-solvent was chosen based on the dissolution time of truncated pleurotin derivatives, solution clarity, and compatibility with raw materials and excipients. At least one of benzyl alcohol, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide was preferred as the optimal co-solvent (see Table 2).

[0037] Table 2. Results of Cosolvent Screening

[0038]

[0039]

[0040] Example 3: Diluent Screening

[0041] Propylene glycol, glycerol, polyethylene glycol 200, and polyethylene glycol 300 were selected as diluents. The dissolution time of truncated pleurotin derivatives, the clarity of the solution, and the compatibility of raw materials and excipients were used as evaluation indicators to select the optimal diluent. Propylene glycol or glycerol was preferred as the optimal diluent (see Table 3).

[0042] Table 3. Results of diluent screening

[0043]

[0044] Example 4: Dispersant Screening

[0045] Sodium dodecyl sulfate, Tween 80, Span 80, and poloxamer 188 were selected as dispersants. The optimal dispersant was chosen based on solution properties, clarity, and dilution status. As shown in Table 4, sodium dodecyl sulfate or Tween 80 were preferred as the optimal dispersants.

[0046] Table 4. Results of Dispersant Screening

[0047]

[0048] Example 5: Optimization of Prescription Composition

[0049] Based on the screening results of Examples 2, 3, and 4, the dosage of raw materials and excipients in the formulation was further optimized. The clarity, content, and dissolution time of the raw materials and excipients in the oral solution were used as evaluation indicators to optimize the formulation composition. As shown in Table 5, the solutions prepared by formulations 2, 3, 4, and 8 showed good clarity, met the content standards, and had short dissolution times for the raw materials and excipients, all being pale yellow clear solutions.

[0050] Prescription 1: At room temperature, add 5.0% (w / v) of truncated pleurotin derivatives to 2.5% (v / v) of benzyl alcohol as a cosolvent and stir to dissolve to obtain solution 1; add a certain amount of propylene glycol as a diluent to solution 1, stir to mix well, then add 0.5% SDS (w / v) as dispersant and 0.01% BHT (w / v) as antioxidant, stir to dissolve to obtain solution 2; add the remaining diluent to solution 2 and make up the volume, stir until completely mixed to obtain an oral solution of truncated pleurotin derivatives.

[0051] Prescription 2: At room temperature, add 5.0% (w / v) of truncated pleurotin derivatives to 5.0% (v / v) of benzyl alcohol as a cosolvent and stir to dissolve to obtain solution 1; add a certain amount of propylene glycol as a diluent to solution 1, stir to mix well, then add 1.0% SDS (w / v) as dispersant and 0.01% BHT (w / v) as antioxidant, stir to dissolve to obtain solution 2; add the remaining diluent to solution 2 and make up the volume, stir until completely mixed to obtain an oral solution of truncated pleurotin derivatives.

[0052] Prescription 3: At room temperature, 5.0% (w / v) of truncated pleurotin derivatives are added to 7.5% (v / v) of benzyl alcohol as a cosolvent and stirred to dissolve, thus obtaining solution 1; a certain amount of propylene glycol as a diluent is added to solution 1, and after stirring and mixing, 0.5% of Tween 80 (v / v) as a dispersant and 0.01% of BHT (w / v) as an antioxidant are added and stirred to dissolve, thus obtaining solution 2; the remaining diluent is added to solution 2 and the volume is adjusted, and the mixture is stirred until completely mixed to obtain an oral solution of truncated pleurotin derivatives.

[0053] Prescription 4: At room temperature, add 5.0% (w / v) of truncated pleurotin derivatives to 10.0% (v / v) of benzyl alcohol as a cosolvent and stir to dissolve to obtain solution 1; add a certain amount of propylene glycol as a diluent to solution 1, stir to mix well, then add 1.0% of Tween 80 (v / v) as a dispersant and 0.01% of BHT (w / v) as an antioxidant, stir to dissolve to obtain solution 2; add the remaining diluent to solution 2 and make up the volume, stir until completely mixed to obtain an oral solution of truncated pleurotin derivatives.

[0054] Prescription 5: At room temperature, add 2.5% (w / v) of truncated pleurotin derivatives to 2.5% (v / v) of the solubilizer N,N-dimethylacetamide and stir to dissolve to obtain solution 1; add a certain amount of propylene glycol as a diluent to solution 1, stir to mix well, then add 0.5% of the dispersant Tween 80 (v / v) and 0.01% of the antioxidant BHT (w / v), stir to dissolve to obtain solution 2; add the remaining diluent to solution 2 and make up the volume, stir until completely mixed to obtain an oral solution of truncated pleurotin derivatives.

[0055] Prescription 6: At room temperature, add 2.5% (w / v) of truncated pleurotin derivatives to 5.0% (v / v) of the solubilizer N,N-dimethylacetamide and stir to dissolve to obtain solution 1; add a certain amount of propylene glycol as a diluent to solution 1, stir to mix well, then add 1.0% of the dispersant Tween 80 (v / v) and 0.01% of the antioxidant BHT (w / v), stir to dissolve to obtain solution 2; add the remaining diluent to solution 2 and make up the volume, stir until completely mixed to obtain an oral solution of truncated pleurotin derivatives.

[0056] Prescription 7: At room temperature, add 2.5% (w / v) of truncated pleurotin derivatives to 7.5% (v / v) of solubilizer N,N-dimethylacetamide and stir to dissolve to obtain solution 1; add a certain amount of diluent propylene glycol to solution 1, stir to mix well, then add 0.5% dispersant SDS (w / v) and 0.01% antioxidant BHT (w / v), stir to dissolve to obtain solution 2; add the remaining diluent to solution 2 and make up to volume, stir until completely mixed to obtain oral solution of truncated pleurotin derivatives.

[0057] Prescription 8: At room temperature, add 2.5% (w / v) of truncated pleurotin derivatives to 10.0% (v / v) of solubilizer N,N-dimethylacetamide and stir to dissolve to obtain solution 1; add a certain amount of diluent propylene glycol to solution 1, stir to mix well, then add 1.0% dispersant SDS (w / v) and 0.01% antioxidant BHT (w / v), stir to dissolve to obtain solution 2; add the remaining diluent to solution 2 and make up the volume, stir until completely mixed to obtain oral solution of truncated pleurotin derivatives.

[0058] Table 5 Results of Prescription Composition Examination

[0059]

[0060]

[0061] Example 6: Process Optimization

[0062] Based on the optimization of the prescription composition, a single-factor study was conducted to optimize the preparation process of oral solutions containing truncated pleurotin derivatives, and a stable, reliable and feasible production process was established to prepare safe, effective and quality-controllable oral solutions containing truncated pleurotin derivatives.

[0063] (1) Examination of the order of addition of raw and auxiliary materials

[0064] Regarding the order of adding raw materials and excipients, this invention designed five process routes, using solution properties, clarity, and content as evaluation indicators, and combined with phenomena observed during the preparation process, to screen for a suitable order of adding raw materials and excipients. As shown in Table 6, process 1 is the most suitable preparation process for oral solutions containing truncated pleurotin derivatives.

[0065] Process 1: At room temperature, 5.0% (w / v) of truncated pleurotin derivatives are added to 5.0% (v / v) of solubilizer and stirred to dissolve, thus obtaining solution 1; a certain amount of diluent is added to solution 1, and after stirring and mixing, 1.0% dispersant (w / v) and 0.01% antioxidant (w / v) are added and stirred to dissolve, thus obtaining solution 2; the remaining diluent is added to solution 2 and the volume is adjusted, and the mixture is stirred until completely mixed to obtain an oral solution of truncated pleurotin derivatives.

[0066] Process 2: At room temperature, 5.0% (v / v) of solubilizer and a certain amount of diluent are stirred and mixed, and then 5.0% (w / v) of truncated pleurotin derivative is added and stirred to dissolve to obtain solution 1; 1.0% of dispersant (w / v) and 0.01% of antioxidant (w / v) are added to solution 1 and stirred to dissolve to obtain solution 2; the remaining diluent is added to solution 2 and the volume is adjusted, and stirred until completely mixed to obtain oral solution of truncated pleurotin derivative.

[0067] Process 3: At room temperature, 5.0% (w / v) of truncated pleurotin derivative, 1.0% (w / v) of dispersant and 0.01% (w / v) of antioxidant are mixed and then added to 5.0% (v / v) of solubilizer. After stirring and dissolving, solution 1 is obtained. Diluent is added to solution 1 and the volume is adjusted. The mixture is stirred until completely mixed to obtain oral solution of truncated pleurotin derivative.

[0068] Process 4: At room temperature, 5.0% (v / v) of solubilizer and a certain amount of diluent are stirred and mixed to obtain solution 1; 5.0% (w / v) of truncated pleurotin derivative, 1.0% of dispersant (w / v) and 0.01% of antioxidant (w / v) are added to solution 1, and stirred and dissolved to obtain solution 2; the remaining diluent is added to solution 2 and the volume is adjusted, and stirred until completely mixed to obtain oral solution of truncated pleurotin derivative.

[0069] Process 5: At room temperature, 5.0% (v / v) of solubilizer and a certain amount of diluent are stirred and mixed, then 1.0% (w / v) of dispersant and 0.01% (w / v) of antioxidant are added and stirred to dissolve to obtain solution 1; 5.0% (w / v) of truncated pleurotin derivative is added to solution 1 and stirred to dissolve to obtain solution 2; the remaining diluent is added to solution 2 and the volume is adjusted, and stirred until completely mixed to obtain oral solution of truncated pleurotin derivative.

[0070] Table 6 Results of screening for the order of adding raw and auxiliary materials

[0071]

[0072] (2) Investigation of stirring speed

[0073] Stirring speed is one of the core process parameters in solution preparation, directly affecting the production process. Controlling it within a suitable range is crucial. The optimal stirring speed was screened using the dissolution time of truncated pleurotin derivatives, the dissolution time, content, properties, and clarity of dispersants and antioxidants as evaluation indicators.

[0074] As shown in Table 7, stirring at 300 r / min results in slow dissolution, stirring at 700 r / min produces a large number of bubbles, and stirring at 500 r / min results in fast dissolution without producing bubbles, but with the lowest clarity. Therefore, 500 r / min is selected as the optimal stirring speed.

[0075] Table 7 Results of Stirring Speed ​​Screening

[0076]

[0077] (3) Investigation of stirring temperature

[0078] Stirring temperature and stirring speed complement each other, jointly affecting the dissolution rate of solid materials and the stability of the solution. The optimal stirring temperature was screened using the dissolution time of truncated pleurotin derivatives, the dissolution time, content, properties, and clarity of dispersants and antioxidants as evaluation indicators.

[0079] As shown in Table 8, the dissolution times at 25℃, 35℃, and 45℃ are not significantly different, and the content, properties, and clarity all meet the requirements. However, considering factors such as equipment operating costs in large-scale production, production at 25℃ is preferable.

[0080] Table 8 Results of Stirring Temperature Screening

[0081]

[0082]

[0083] Example 7: Formulation and Process Determination

[0084] (1) Based on the optimization results of Examples 2, 3, 4 and 5, the final formulation of the oral solution of truncated pleurotin derivatives for livestock and poultry was determined (see Table 9).

[0085] Table 9. Formulation of oral solutions containing truncated pleurotin derivatives

[0086]

[0087] (2) Based on the results of Example 6, the optimal preparation process for the oral solution of truncated pleurotin derivatives was determined, specifically as follows:

[0088] A. At room temperature, add 2.5% or 5.0% (w / v) of truncated pleurotin derivatives to 5.0% or 10.0% (v / v) of co-solvent and stir at 500 r / min to dissolve and obtain solution 1.

[0089] B. Add a certain amount of diluent to solution 1, stir at 500 r / min to mix well, then add 1.0% (w / v) dispersant and 0.01% (w / v) antioxidant, stir at 500 r / min to dissolve and obtain solution 2.

[0090] C. Add the remaining diluent to solution 2 and make up the volume. Stir at 500 r / min until completely mixed to obtain an oral solution of truncated pleurotin derivatives for livestock and poultry.

[0091] Example 8: Stability Study of Oral Solution of Pleurotus ostreatus Derivatives for Livestock and Poultry

[0092] Stability determines the quality, efficacy, and safety of drugs, and is often used to determine the shelf life of drugs and provide a scientific basis for determining the production, packaging, storage, and transportation conditions of drugs. In accordance with the 2020 edition of the *Pharmacopoeia of the People's Republic of China*, Part I, General Chapter 9001, "Guiding Principles for Stability Testing of Raw Materials and Preparations," influencing factor tests (strong light irradiation, high temperature, and high humidity) and accelerated testing studies were conducted on oral solutions of truncated pleurotin derivatives to provide experimental basis for the further development of oral solutions of truncated pleurotin derivatives.

[0093] (1) Influencing Factors Experiment

[0094] Three batches (batch numbers 20240601, 20240602, and 20240603) of small-scale truncated pleurotin derivative oral solutions were prepared according to Example 7. These solutions were placed under high temperature (60°C), high humidity (90% ± 5%), and strong light irradiation (4500 ± 500 lx) conditions, respectively. Samples were taken on days 0, 5, and 10, and the stability of the solutions was evaluated using the content as the evaluation index, as shown in Table 10.

[0095] Table 10. Experimental Results of Influencing Factors

[0096]

[0097] (2) Accelerated testing

[0098] Three batches of oral solutions containing truncated pleurotin derivatives were placed in a drug stability test chamber at a temperature of (40±2)℃ and a relative humidity of (75±5)% for 3 months. Samples were taken in the 0th, 1st, 2nd and 3rd months of the test period, and the content was used as the evaluation index to evaluate the stability of the solution, as shown in Table 11.

[0099] Table 11 Accelerated Test Results

[0100]

[0101] Example 9: Quality Evaluation of Oral Solution of Pleurotus ostreatus Derivatives for Livestock and Poultry

[0102] Three batches of small-scale oral solutions of truncated pleurotin derivatives were prepared according to Example 7. The properties, color, clarity, pH, content, related substances, and microbial limits of the solutions were investigated according to the 2020 edition of the Pharmacopoeia of the People's Republic of China.

[0103] 1. Characteristics

[0104] Three samples of truncated pleurotin derivative oral solutions were taken and their properties were observed visually. The truncated pleurotin derivative oral solutions were pale yellow and clear solutions (see...). Figure 1 ).

[0105] 2. Color

[0106] According to the Solution Color Test Method (Method I) of Part I (Appendix 0901) of the 2020 edition of the *Pharmacopoeia of the People's Republic of China for Veterinary Medicine*, the oral solution of truncated pleurotin derivatives was compared with a yellow standard colorimetric solution to determine the solution color. For example... Figure 2 As shown, the color of the oral solution of truncated pleurotin derivatives should not be darker than that of the yellow standard colorimetric solution No. 3.

[0107] 3. Clarity

[0108] Clarity Test Method (Method II) of Part I (Appendix 0902) of the 2020 edition of the *Veterinary Pharmacopoeia of the People's Republic of China* was used to determine the clarity of oral solutions containing truncated pleurotin derivatives using a turbidimeter. The turbidity of the solution was considered clear if it did not exceed 0.5 of the turbidity standard. The turbidity value of the oral solutions containing truncated pleurotin derivatives was between 2 and 5 NTU.

[0109] 4. pH

[0110] The pH of truncated pleurotin derivative oral solutions was determined using a pH meter according to the pH determination method in Appendix 0631 of the 2020 edition of the Veterinary Pharmacopoeia of the People's Republic of China. The pH of truncated pleurotin derivative oral solutions is between 5.0 and 8.0.

[0111] 5. Content

[0112] The content of truncated pleurotin derivatives in oral solutions was determined by high performance liquid chromatography (HPLC) according to the 2020 edition of the *Veterinary Pharmacopoeia of the People's Republic of China*, Part I (Appendix 0512). The content of truncated pleurotin derivatives in oral solutions should be 90.0%–110.0% of the labeled amount.

[0113] Chromatographic conditions: An Inertsil ODS-3 column (4.6 × 250 mm, 5 μm) was used as the packing material, with 0.1% phosphoric acid aqueous solution-acetonitrile (30:70) as the mobile phase; the flow rate was 1.0 mL / min; the detection wavelength was 200 nm; the column temperature was 30 °C; and the injection volume was 10 μL. The theoretical plate number, calculated based on the truncated pleurotin derivative peaks, was not less than 5000, and the tailing factor was not greater than 2.0.

[0114] 6. Related substances

[0115] According to the high performance liquid chromatography method in Part I (Appendix 0512) of the 2020 edition of the Pharmacopoeia of the People's Republic of China for Veterinary Medicine, the relevant substances in oral solutions of truncated pleurotin derivatives were determined.

[0116] Chromatographic conditions: A Poroshell 120EC-C18 column (4.6 × 150 mm, 4.0 μm) was used as the stationary phase; 0.1% phosphoric acid aqueous solution was used as mobile phase A, acetonitrile as mobile phase B, and the flow rate was 1.0 mL / min. Gradient elution was performed according to Table 12. The detection wavelength was 200 nm; the column temperature was 30 °C; and the injection volume was 10 μL.

[0117] If there are impurity peaks in the chromatogram of the test solution, the peak area of ​​a single impurity shall not exceed the peak area of ​​the main peak of the control solution (0.5%), and the sum of the peak areas of all impurities shall not exceed twice the peak area of ​​the main peak of the control solution (2.0%).

[0118] Table 12 Gradient elution experiment

[0119]

[0120] 7. Microbial limits

[0121] Take 10 mL of the oral solution of truncated pleurotin derivatives, place it in a sterile conical flask, add sterile sodium chloride-peptone buffer at pH 7.0 to dilute to 100 mL, mix well, and use as a 1:10 test solution.

[0122] Total aerobic bacteria count: Take 0.1 mL of the 1:10 test solution and add it to 100 mL of sterile sodium chloride-peptone buffer containing 0.5% polysorbate 80 at pH 7.0 and keep warm at 45℃. Filter through a membrane and rinse the filter membrane 8 times with the above buffer solution, 100 mL each time, as a test for aerobic bacteria.

[0123] Total mold and yeast count: Add 1 mL of a 1:10 test solution to 100 mL of sterile sodium chloride-peptone buffer (pH 7.0) containing 0.5% polysorbate 80, incubated at 45°C. Filter through a membrane, rinsing the membrane 8 times with the above buffer solution (100 mL each time). This rinse is used for mold and yeast testing. Take separate samples of the above membranes and perform microbial limit testing for non-sterile products using the microbial count method, according to the 2020 edition of the *Veterinary Pharmacopoeia of the People's Republic of China*, Part I (Appendix 1105)).

[0124] Escherichia coli: Add 10 mL of a 1:10 test solution to 200 mL of tryptic soy broth and test according to the non-sterile product microbial limit test: control bacteria test method (according to the 2020 edition of the Pharmacopoeia of the People's Republic of China, Part I (Appendix 1106)).

[0125] The test results showed that the total number of aerobic bacteria per 1 mL of the test sample did not exceed 10. 2 CFU, total number of molds and yeasts not exceeding 10 1 CFU was not detected, and Escherichia coli was not found. The results showed that the oral solutions of the truncated pleurotin derivatives of the present invention met the requirements.

[0126] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A livestock and poultry use of pleuromutilin derivative oral solution, characterized in that, The solution comprises 2.5-10.0% (m / v) of active ingredient pleuromutilin derivative, 2.5-10.0% (v / v) of cosolvent, 0.5-3.0% (m / v) of dispersing agent, 0.01-0.1% (m / v) of antioxidant, and the rest of diluent.

2. The oral solution of claim 1, wherein, The pleuromutilin derivative is used in an amount of 2.5%, 5.0% or 10.0%.

3. The oral solution of claim 1, wherein The cosolvent is used in an amount of 2.5%, 5.0%, 7.5% or 10.0%.

4. The oral solution of claim 1, wherein The dispersing agent is 0.5%, 1.0%, 2.0% or 3.0%.

5. The oral solution of claim 1, wherein The antioxidant is used in an amount of 0.01%, 0.02%, 0.05% or 0.1%.

6. The oral solution of claim 1, wherein, The cosolvent is at least one of benzyl alcohol, N-methylpyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide and dimethyl sulfoxide.

7. The oral solution of claim 1, wherein The diluent is at least one of propylene glycol, glycerol, polyethylene glycol 200 and polyethylene glycol 300.

8. The oral solution of claim 1, wherein, The dispersing agent is at least one of sodium dodecyl sulfate, Tween 80, poloxamer 188 and Span 80.

9. The oral solution of claim 1, wherein, The antioxidant is at least one of butylated hydroxyanisole, tert-butyl hydroquinone, propyl gallate, dibutyl hydroxytoluene and vitamin C.

10. A method for preparing the oral solution of a pleuromutilin derivative for livestock and poultry according to any one of claims 1 to 9, characterized in that, The method comprises the following steps: (1) adding pleuromutilin derivative raw material to cosolvent, stirring until completely dissolved to obtain solution 1; (2) adding part of diluent to solution 1, stirring until completely dissolved, then adding dispersing agent and antioxidant, stirring until completely dissolved to obtain solution 2; (3) adding diluent to solution 2 to constant volume, stirring until completely mixed to obtain oral solution of pleuromutilin derivative for livestock and poultry.

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