A bacteriostatic composition containing a wood extract and a method for preparing the same

Abstract

The present application belongs to the field of biological pharmacy, and particularly relates to a bacteriostatic composition containing wood extract and a preparation method thereof. The bacteriostatic composition contains wood extract fine powder, polyethylene glycol 4000, glyceryl monostearate, lanolin, sorbitol, glycerol, triethanolamine, sodium thiosulfate and purified water. The wood extract fine powder prepared by the technical scheme of the present application is relatively friendly to the skin of pets, and experiments show that no erythema and edema phenomenon occurs. The cream prepared by using the wood extract meets the requirements of the Chinese Pharmacopoeia in viscosity and appearance performance, and can be further developed into a medicine for popularization and use.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biopharmaceuticals, and specifically relates to a bacteriostatic composition containing wood extract and a preparation method thereof. BACKGROUND

[0002] The wood extract contains a mixture of three monomer structural units, guaiacyl G, p-hydroxyphenyl H and syringyl S, and the effect is relatively complex. Although wood extract is currently used as a bactericide, there is less research on the type of preparation and effect.

[0003] For example, Chinese patent 202011287574.3 discloses a pet skin disease treatment agent containing wood vinegar, which is composed of wood vinegar, antioxidant, metal ion complexing agent and cosolvent. The wood vinegar prepared by a specific process has the best quality of bactericidal active ingredients, and the synergistic effect of the antioxidant, metal ion complexing agent and cosolvent further makes the bactericidal effect of the wood vinegar best, and also avoids the side effects of harmful ingredients on pet skin. Although the preparation and use of wood vinegar are disclosed, the preparation method and preparation of wood vinegar are not disclosed, which is difficult for universal use. SUMMARY

[0004] In view of the deficiencies of the prior art, the wood extract is prepared into a preparation, and a wood extract fine powder, polyethylene glycol 4000, glyceryl monostearate, lanolin, sorbitol, glycerol, triethanolamine, sodium thiosulfate and purified water are provided. The wood extract fine powder is friendly to the skin and does not cause erythema and edema; the final cream prepared from the wood extract has a viscosity and appearance performance meeting the requirements of the current edition of the Chinese Pharmacopoeia, and can be further developed into a cream and other drugs.

[0005] Specifically, the technical scheme of the present application is as follows:

[0006] The bacteriostatic composition contains, by weight ratio:

[0007]

[0008]

[0009] Further, the bacteriostatic composition contains, by weight ratio:

[0010]

[0011] The wood extract fine powder is prepared by the following steps, by weight ratio:

[0012] 1) Drying, grinding and preparing the material of broadleaf tree branches and trunks;

[0013] 2) Take the material of step 1), add buffer and cellulase, constant temperature water bath, filtrate, residue for standby;

[0014] 3) Take the residue and add appropriate amount of ethanol water, reflux extraction 2 times, combine the filtrate for standby;

[0015] 4) Combine the filtrate of step 2) and 3), filter, concentrate to get clear paste, add ethanol, static filtration, recover ethanol under reduced pressure and concentrate, get thick paste, vacuum drying, crush and sieve, get wood extract fine powder.

[0016] The wood extract fine powder preparation comprises the following steps:

[0017] 1) Dry the branches and trunks of broad-leaved trees, grind, and the material is standby;

[0018] 2) Take the material of step 1), add 200ml citric acid / sodium citrate with pH value of 4.0-5.5 and 5g cellulase,

[0019] 50-65 degrees constant temperature water bath for 24-48h, filtrate, residue for standby;

[0020] 3) Take the residue and add 75% above ethanol water, reflux extraction 2 times, combine the filtrate for standby;

[0021] 4) Combine the filtrate of step 2) and the filtrate obtained in step 3), filter, concentrate to clear paste with relative density of

[0022] 1.01-1.05, add ethanol to make the alcohol content reach 65%, static for 10-25 hours, filter, recover ethanol under reduced pressure and concentrate to relative density of 1.15-1.25, get thick paste, vacuum degree-0.05-1.4Mpa, drying temperature

[0023] 70-90℃, crush and sieve through 20-60 mesh screen under vacuum state, get wood extract fine powder.

[0024] The application also provides a preparation containing wood extract fine powder, and the preparation is one of cream, paste, film and gel; and the cream is further preferred.

[0025] The third object of the application provides a preparation process of the cream, specifically:

[0026] 1) Mix the wood extract fine powder obtained by the technical solution of the application with propylene glycol to form paste, standby;

[0027] 2) Take polyethylene glycol 4000, glyceryl monostearate and lanolin, heat to 60-85℃ to get oil phase;

[0028] 3) Take sorbitol, glycerol, triethanolamine, sodium thiosulfate and purified water, mix uniformly, heat to 60-85 DEG C, emulsified into the oil phase of step 2), and cool to semi-solid, then add the paste of step 1), and the cream is obtained.

[0029] Further, the weight ratio of the wood extract fine powder to propylene glycol is 1:0.5.

[0030] Further, the cream preparation process is:

[0031] 1) The wood extract fine powder obtained from the technical solutions 4-5 of the application is ground into paste with propylene glycol, and is used for standby;

[0032] 2) Take polyethylene glycol 4000, glyceryl monostearate and lanolin, heat to 70 DEG C to melt, and obtain the oil phase;

[0033] 3) Take sorbitol, glycerol, triethanolamine, sodium thiosulfate and purified water, mix uniformly, heat to 70 DEG C, emulsified into the oil phase of step 2), and cool to semi-solid, then add the paste of step 1), and the cream is obtained.

[0034] The use of the bacteriostatic composition containing the wood extract or its preparation in the preparation of the therapeutic agent for treating pet skin diseases.

[0035] The above technical solutions are adopted, and the beneficial effects of the application are:

[0036] 1) The wood is extracted by using the preferred buffer, and the wood extract obtained by screening the key technology is more mild to the skin and other tissues, and does not produce adverse feelings through pharmacological experiments.

[0037] 2) For the preparation of the preparation, especially the preparation of the cream, the appearance performance, viscosity and pH value are improved to different degrees. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 : Skin allergy test of wood extract;

[0039] Figure 2 : Viscosity test results of the cream of each embodiment of the application at the 0th / 6th month;

[0040] Figure 3 : Matrix uniformity score of the cream of each embodiment of the application at the 0th / 6th month;

[0041] Figure 4 : Matrix extensibility score of the cream of each embodiment of the application at the 0th / 6th month. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical scheme of the present application more clear, the present application is further explained below in combination with examples, but the protection scope of the present application is not limited to these examples, and the examples are only used for explaining the present application. It should be understood by those skilled in the art that any change or equivalent replacement without departing from the concept of the present application is included in the protection scope of the present application.

[0043] Example 1: Preparation of wood extract and its paste

[0044] 1) Drying and grinding the branches of broad-leaved trees, and preparing the materials;

[0045] 2) Taking the materials of step 1), adding 200ml citric acid / sodium citrate with pH value of 4.5 and 5g cellulase, and placing in a constant temperature water bath at 50-65 degrees for 36 hours, and then preparing the filtrate and residue;

[0046] 3) Taking the residue, adding 75% or more ethanol water, and refluxing for extraction twice, and then preparing the combined filtrate;

[0047] 4) Combining the filtrate of step 2) and the filtrate obtained in step 3), filtering, concentrating to clear paste with relative density of 1.03, adding ethanol to make the alcohol content reach 65%, and then standing for 15 hours, filtering, recovering ethanol under reduced pressure and concentrating to relative density of 1.20, obtaining thick paste, drying at vacuum degree of-0.05-1.4Mpa and drying temperature of 70-90℃, and then crushing through 60 mesh sieve under vacuum state, obtaining fine powder;

[0048] 5) Preparing the fine powder of step 4) into paste with propylene glycol; wherein the weight ratio of the two is 1:0.5.

[0049] Example 2: Preparation of wood extract and its paste

[0050] 1) Drying and grinding the branches of broad-leaved trees, and preparing the materials;

[0051] 2) Taking the materials of step 1), adding 200ml citric acid / sodium citrate with pH value of 4.0 and 5g cellulase, and placing in a constant temperature water bath at 50 degrees for 24 hours, and then preparing the filtrate and residue;

[0052] 3) Taking the residue, adding 75% or more ethanol water, and refluxing for extraction twice, and then preparing the combined filtrate;

[0053] 4) Combining the filtrate of step 2) and the filtrate obtained in step 3), filtering, concentrating to clear paste with relative density of 1.01, adding ethanol to make the alcohol content reach 65%, and then standing for 10 hours, filtering, recovering ethanol under reduced pressure and concentrating to relative density of 1.15-1.25, obtaining thick paste, drying at vacuum degree of-0.05Mpa and drying temperature of 70℃, and then crushing through 20 mesh sieve under vacuum state, obtaining fine powder;

[0054] 5) The fine powder of step 4) is mixed with propylene glycol to form a paste; wherein the weight ratio of the two is 1:0.5.

[0055] Example 3: Preparation of wood extract and its paste

[0056] 1) The branches of broad-leaved trees are dried and ground, and the material is prepared for use;

[0057] 2) The material of step 1) is taken, 200 ml of citric acid / sodium citrate with a pH value of 5.5 and 5 g of cellulase are added, and it is kept in a constant temperature water bath at 65 degrees for 48 hours. The filtrate and residue are prepared for use;

[0058] 3) The residue is taken and extracted with more than 75% ethanol water for 2 times, and the combined filtrate is prepared for use;

[0059] 4) The filtrate of step 2) and the filtrate obtained in step 3) are combined, filtered, concentrated to a clear paste with a relative density of 1.05, ethanol is added to make the alcohol content reach 65%, and it is kept still for 25 hours. After filtration, ethanol is recovered under reduced pressure and concentrated to a relative density of 1.15-1.25 to obtain a thick paste. The vacuum degree is -0.05-1.4 Mpa, the drying temperature is 70-90°C, and the thick paste is crushed to pass through a 60 mesh sieve under vacuum to obtain a fine powder;

[0060] 5) The fine powder of step 4) is mixed with propylene glycol to form a paste; wherein the weight ratio of the two is 1:0.5.

[0061] 1) The branches of broad-leaved trees are dried and ground, and the material is prepared for use;

[0062] 2) The material of step 1) is taken, 200 ml of citric acid / sodium citrate with a pH value of 6.6 and 5 g of cellulase are added, and it is kept in a constant temperature water bath at 65 degrees for 48 hours. The filtrate and residue are prepared for use;

[0063] 3) The residue is taken and extracted with water for 2 times, and the combined filtrate is prepared for use;

[0064] 4) The filtrate of step 2) and the filtrate obtained in step 3) are combined, filtered, concentrated to a clear paste with a relative density of 1.05, ethanol is added to make the alcohol content reach 65%, and it is kept still for 25 hours. After filtration, ethanol is recovered under reduced pressure and concentrated to a relative density of 1.15-1.25 to obtain a thick paste. The vacuum degree is -0.05-1.4 Mpa, the drying temperature is 70-90°C, and the thick paste is crushed to pass through a 60 mesh sieve under vacuum to obtain a fine powder;

[0065] 5) The fine powder of step 4) is mixed with propylene glycol to form a paste; wherein the weight ratio of the two is 1:0.5.

[0066] 1) The branches of broad-leaved trees are dried and ground, and the material is prepared for use;

[0067] 2) Take the material of step 1), add 200 ml of acetic acid / sodium acetate buffer with pH value of 4.5 and 5 g of cellulase, and keep in constant temperature water bath at 50-65 degrees for 36 hours. The filtrate and residue are reserved for use;

[0068] 3) Take the residue and add more than 75% ethanol water to reflux and extract twice. The combined filtrate is reserved for use;

[0069] 4) Combine the filtrate of step 2) and the filtrate obtained in step 3), filter, concentrate to a clear paste with relative density of 1.03, add ethanol to make the alcohol content reach 65%, stand for 15 hours, filter, recover ethanol under reduced pressure and concentrate to a relative density of 1.20 to obtain a thick paste. Dry under vacuum at a vacuum degree of -0.05-1.4 Mpa and a drying temperature of 70-90℃, and then crush the dried product through a 60 mesh sieve to obtain a fine powder;

[0070] 5) Mix the fine powder of step 4) with propylene glycol to form a paste; the weight ratio of the two is 1:0.5.

[0071] 1) Use steam gas mixture derived from dry distillation pyrolysis of branches and trunks of broad-leaved trees grown at a latitude of 46° north and with a growth period of more than 100 years to obtain a red-brown liquid after condensation separation;

[0072] 2) Pour the red-brown liquid obtained in step 1) into a container and stand for aging separation for 3-5 years. Collect the intermediate clear part to obtain a crude wood extract;

[0073] 3) Distill the crude wood vinegar obtained in step 2) again under normal pressure, and collect the fraction at 98-103℃ to obtain the desired wood extract;

[0074] 4) Mix the wood extract of step 3) with propylene glycol, and the volume ratio of the two is 1:0.5.

[0075] Animal experiment: skin irritation experiment

[0076] 1.1 Animals

[0077] 35 healthy adult Japanese big-eared rabbits with a weight of 2.0-3.0 kg were provided by Lu'nan Pharmaceutical Group Co., Ltd.

[0078] 1.2 Materials

[0079] The pastes of examples 1-3 and comparative examples 1-3, and propylene glycol (Jiujia Biological Technology Co., Ltd. of Jiangsu).

[0080] 2 Method

[0081] 2.1 Rabbit skin irritation experiment

[0082] 2.1.1 Grouping and administration, 35 rabbits were taken, all female, and randomly divided into 7 groups, respectively, examples 1-3, comparative examples 1-3 group, blank control group, 5 in each. Before administration, skin integrity check, skin damage shall not be included in the complete skin group. 24h before administration, the back hair on both sides was removed with scissors, the range was 3cm*3cm, and then 6% sodium sulfide solution was used for depilation, the cream required for the experiment was directly applied to the left side of the depilated skin, the thickness was about 0.1mm, then two layers of gauze (2.5cm*2.5cm) and a layer of kraft paper were covered, and then non-irritating adhesive tape and bandage were used for fixation; the right side was coated with propylene glycol as a control, and the coating time was 4h. After the coating was finished, the drug was removed and the administration site was cleaned with warm water. Administration or coating was performed once a day at 8am, and the administration was continued for 7d.

[0083] 2.1.2 Skin irritation reaction score, the skin irritation evaluation was carried out according to the skin irritation reaction score standard in the Technical Guidelines for Drug Irritation, Allergy and Hemolysis Research. The specific score and situation are as follows:

[0084] Table 1 Skin irritation reaction score standard

[0085]

[0086] 2.1.3 Observation index, before each coating and 1h after removing the drug, the administration site was observed for erythema and edema, whether the administration site had pigmentation, bleeding points, rough skin or thin skin, and the occurrence time and subsidence time, and the erythema and edema were scored.

[0087] Score=(edema score+erythema score) / 2

[0088] 2.1.4 Statistical analysis, the irritation score of rabbits was evaluated every day, SPSS16.0 or Graphad Prism was used, P<0.05 indicated that the difference was statistically significant, and the specific results were as follows: Figure 1 From Figure 1 It can be seen that the score of examples 1-3 of the application is significantly higher than that of the comparative example group. It can be seen that the combination of material selection and dosage screening is not random and needs to be explored through experiments to find the most suitable preparation process.

[0089] Selection of preparation process, in order to further study the wood extract, the inventors have studied the cream, gel and film prepared therefrom, and through further experiments, it is found that the wood extract prepared into cream is more acceptable to modern people, and the materials required for preparing cream are easy to obtain, and similar experiments on pet skin and even human skin have also achieved certain technical effects. The specific process is as follows:

[0090] Table 2: Example and content of adjuvants

[0091]

[0092] Example 1: The preparation process of the cream is as follows:

[0093] 1) Take an appropriate amount of the paste prepared by the present application for standby;

[0094] 2) Take polyethylene glycol 4000, glyceryl monostearate, lanolin, paste, heat to 60°C to melt, and obtain an oil phase;

[0095] 3) Take sorbitol, glycerol, triethanolamine, sodium thiosulfate, and mix them with purified water (the weight ratio of the aqueous base to purified water is 1:1), heat to 60°C, add to the oil phase of step 2) for emulsification, and when it becomes semi-solid after cooling, add the paste of step 1), and obtain the cream.

[0096] Example 2: The preparation process of the cream is as follows:

[0097] 1) Take an appropriate amount of the paste prepared by the present application for standby;

[0098] 2) Take polyethylene glycol 4000, glyceryl monostearate, lanolin, paste, heat to 85°C to melt, and obtain an oil phase;

[0099] 3) Take sorbitol, glycerol, triethanolamine, sodium thiosulfate, and mix them with purified water (the weight ratio of the aqueous base to purified water is 1:1), heat to 85°C, add to the oil phase of step 2) for emulsification, and when it becomes semi-solid after cooling, add the paste of step 1), and obtain the cream.

[0100] Example 3: The preparation process of the cream is as follows:

[0101] 1) Take an appropriate amount of the paste prepared by the present application for standby;

[0102] 2) Take polyethylene glycol 4000, glyceryl monostearate, lanolin, paste, heat to 70°C to melt, and obtain an oil phase;

[0103] 3) Take sorbitol, glycerol, triethanolamine, sodium thiosulfate, and mix them with purified water (the weight ratio of the aqueous base to purified water is 1:1), heat to 70°C, add to the oil phase of step 2) for emulsification, and when it becomes semi-solid after cooling, add the paste of step 1), and obtain the cream.

[0104] Comparative Example 1: The preparation process of the cream is as follows:

[0105] The ingredients are the same, the content is shown in Table 1, and the preparation process is shown in Example 3.

[0106] Comparative Example 2: A cream and its preparation process are as follows:

[0107] 1) Take an appropriate amount of paste obtained by the preparation of the present application for standby;

[0108] 2) Take stearic alcohol, glycerin monostearate, lanolin, paste and heat to 70℃ to melt, get oil phase;

[0109] 3) Take sorbitol, glycerol, triethanolamine, sodium thiosulfate and purified water and mix evenly (wherein the weight amount ratio of aqueous matrix and purified water is 1:1), heat to 70℃, add to the oil phase of step 2) emulsification, cold to semi-solid, add the paste of step 1), get the cream.

[0110] Among them, the amount of stearic alcohol is 40g, and the others are the same as shown in Example 1.

[0111] Comparative Example 3: A cream and its preparation process are as follows:

[0112] 1) Take an appropriate amount of paste obtained by the preparation of the present application for standby;

[0113] 2) Take polyethylene glycol 4000, glycerin monostearate, liquid paraffin, paste and heat to 70℃ to melt, get oil phase;

[0114] 3) Take sorbitol, glycerol, triethanolamine, sodium thiosulfate and purified water and mix evenly (wherein the weight amount ratio of aqueous matrix and purified water is 1:1), heat to 70℃, add to the oil phase of step 2) emulsification, cold to semi-solid, add the paste of step 1), get the cream.

[0115] Among them, the amount of liquid paraffin is 30g, and the others are the same as shown in Example 1.

[0116] Comparative Example 4: A cream and its preparation process are as follows:

[0117] 1) Take an appropriate amount of paste obtained by the preparation of the present application for standby;

[0118] 2) Take polyethylene glycol 4000, lanolin, paste and heat to 70℃ to melt, get oil phase;

[0119] 3) Take sorbitol, glycerol, triethanolamine, sodium thiosulfate and purified water and mix evenly (wherein the weight amount ratio of aqueous matrix and purified water is 1:1), heat to 70℃, add to the oil phase of step 2) emulsification, cold to semi-solid, add the paste of step 1), get the cream.

[0120] Among them, the oil matrix does not contain glycerin monostearate, and the others are the same as shown in Example 1.

[0121] Comparative Example 5: A cream and its preparation process are as follows:

[0122] 1) Take an appropriate amount of paste obtained by the preparation of the present application for standby;

[0123] 2) Take polyethylene glycol 4000, glyceryl monostearate, lanolin, paste, heat to 70℃ to melt, get oil phase;

[0124] 3) Take polysorbate-80, glycerol, triethanolamine, sodium thiosulfate and purified water, mix evenly (the weight ratio of aqueous base to purified water is 1:1), heat to 70℃, add to the oil phase of step 2) for emulsification, and cool to semi-solid, then add the paste of step 1), and get the cream.

[0125] The amount of polysorbate-80 in the aqueous base is 10g, and the others are the same as shown in Example 1.

[0126] Comparative Example 6: A cream and its preparation process are as follows:

[0127] 1) Take an appropriate amount of paste obtained by the preparation of the present application for standby;

[0128] 2) Take polyethylene glycol 4000, glyceryl monostearate, lanolin, paste, heat to 70℃ to melt, get oil phase;

[0129] 3) Take sorbitol, glycerol, triethanolamine and purified water, mix evenly (the weight ratio of aqueous base to purified water is 1:1), heat to 70℃, add to the oil phase of step 2) for emulsification, and cool to semi-solid, then add the standby paste, and get the cream.

[0130] The aqueous base does not contain sodium thiosulfate, and the others are the same as shown in Example 1.

[0131] Comparative Example 7: A cream and its preparation process are as follows:

[0132] 1) Take an appropriate amount of paste obtained by the preparation of the present application for standby;

[0133] 2) Take polyethylene glycol 4000, glyceryl monostearate, lanolin, paste, heat to 70℃ to melt, get oil phase;

[0134] 3) Take sorbitol, glycerol, triethanolamine, vitamin C and purified water, mix evenly (the weight ratio of aqueous base to purified water is 1:1), heat to 70℃, add to the oil phase of step 2) for emulsification, and cool to semi-solid, then add the standby paste, and get the cream.

[0135] The amount of vitamin C in the aqueous base is 2g, and the others are the same as shown in Example 1.

[0136] Verification of the physical properties of the cream:

[0137] 1) pH detection: 2g of the cream of Examples 1-3 and Comparative Examples 1-7 was taken at 0, 1, 2, 3, 6 months, respectively, and then dispersed uniformly with 5g of water, and measured with a pH meter. The specific values are shown in Table 3:

[0138] Table 3 pH detection of each example

[0139]

[0140] 2) Viscosity determination

[0141] According to the method of Chinese Pharmacopoeia 2020 edition, the specific values are Figure 2 Viscosity is an important indicator for measuring the cream, although it is required to be within 10-100 (Pa·s) to meet the requirements, but it is generally believed that the effect is the best when the viscosity is between 30-60 (Pa·s). Through comparative experiments, it is not difficult to find that the viscosity of Comparative Examples 5-7 is lower than 10, which does not meet the requirements of the Pharmacopoeia; while the viscosity of Comparative Examples 1-4 is more than 60, even 80, and the viscosity effect is significantly lower than that of the present application.

[0142] 3) Evaluation index of ointment appearance

[0143] The appearance evaluation is evaluated from two aspects of the uniformity of the matrix and the ductility of the matrix, and the scores are shown in Table 4.

[0144] Table 4 Score standard of appearance performance

[0145]

[0146] From the scores of Figure 3 (matrix uniformity) and Figure 4 (matrix ductility), it can be seen that in terms of matrix uniformity, through the integration of 0-6 months, Examples 1-3 have significant difference (P<0.01) compared with Comparative Examples 1-7; in terms of matrix ductility, through the integration of 0-6 months, Examples 1-3 have significant difference (P<0.01) compared with Comparative Examples 1-7.

Claims

1. A preparation of an antimicrobial composition containing a wood extract solution, characterized by, The bacteriostatic composition comprises, by weight ratio: Wood extract fine powder 20 parts Polyethylene glycol 4000 20-68 parts Glyceryl monostearate 20-72 parts Lanolin 15-65 parts Sorbitol 5-20 parts Glycerin 20-60 parts Triethanolamine 2-6 parts Sodium thiosulfate 1-4 parts Purified water q.s. The wood extract fine powder is prepared by the following steps: 1) Dry and grind the branches of broad-leaved trees, and reserve the material; 2) Take the material of step 1), add 200 ml of citric acid / sodium citrate buffer with pH value of 4.0-5.5 and 5 g of cellulase, and keep in constant temperature water bath at 50-65 °C for 24-48 h, then filter the filtrate and residue for reserve; 3) Take the residue of step 2), add 75% or more of ethanol water, and reflux extract twice, then combine the filtrates for reserve; 4) Combine the filtrate of step 2) and the filtrate obtained in step 3), filter, concentrate to clear extract with relative density of 1.01-1.05, add ethanol to make the content of alcohol reach 65%, stand still for 10-25 h, filter, recover ethanol under reduced pressure and concentrate to relative density of 1.15-1.25, obtain thick extract, crush through 20-60 mesh screen under vacuum condition, dry at vacuum degree of -0.05-1.4 Mpa and drying temperature of 70-90 °C, and obtain wood extract fine powder; The preparation is cream.

2. The bacteriostatic composition of claim 1, wherein The bacteriostatic composition comprises, by weight ratio: Wood extract fine powder 20 parts Polyethylene glycol 4000 40 parts Glyceryl monostearate 40 parts Lanolin 30 parts Sorbitol 10 parts Glycerin 40 parts Triethanolamine 4 parts Sodium thiosulfate 2 parts Purified water q.s.

3. The bacteriostatic composition of claim 1, wherein The preparation process of the cream is: 1) Mix the wood extract fine powder and propylene glycol to prepare paste for reserve; 2) Heat polyethylene glycol 4000, glyceryl monostearate and lanolin to melt state at 60-85 °C to obtain oil phase; 3) Mix sorbitol, glycerin, triethanolamine and sodium thiosulfate with purified water, heat to 60-85 °C, add to the oil phase of step 2) for emulsification, and add the paste of step 1) when it becomes semi-solid after cooling, to obtain the cream.

4. The bacteriostatic composition of claim 3, wherein the composition is formulated as a gel. The weight ratio of the wood extract fine powder to propylene glycol is 1:0.

5.

5. The bacteriostatic composition of claim 3, wherein the composition is formulated as a tablet. The preparation process of the cream is: 1) Mix the wood extract fine powder and propylene glycol to prepare paste for reserve; 2) Heat polyethylene glycol 4000, glyceryl monostearate and lanolin to melt state at 70 °C to obtain oil phase; 3) Mix sorbitol, glycerin, triethanolamine and sodium thiosulfate with purified water, heat to 70 °C, add to the oil phase of step 2) for emulsification, and add the paste of step 1) when it becomes semi-solid after cooling, to obtain the cream.

6. Use of a preparation containing the bacteriostatic composition of any one of claims 1-2 in the preparation of a therapeutic agent for treating skin diseases of pets.

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