阅读说明：本技术 一种低温稳定性好的含吡虫啉的复方制剂及其制备方法 (Imidacloprid-containing compound preparation with good low-temperature stability and preparation method thereof ) 是由 梁瑾 谢等龙 王以跃 冀伟 张燕 徐红波 王盈峰 闻亚 陈国庆 于 2021-09-04 设计创作，主要内容包括：本发明公开一种低温稳定性好的含吡虫啉的复方制剂,每100mL制剂中含有：吡虫啉3-7g,莫昔克丁2-5g,依西太尔10-15g,双甲脒0.05-0.1g,抗氧化剂0.05-0.25g,稳定剂10-20g,透皮剂5-10g。本发明公开上述低温稳定性好的含吡虫啉的复方制剂的制备方法。本发明所述含吡虫啉的复方制剂适用于宠物的体内外驱虫,施用于宠物体外局部皮肤。本发明所得复方制剂对寄生虫及虫卵的杀灭效果优于复方制剂中的任一单一组分,无药物的刺激性气味,能够清凉止痒并且具有良好的透皮效果。同时本发明中所含有的稳定剂,能保证制剂中吡虫啉在低温的条件下不会析出,使本产品在严寒地区使用时保证了产品的治疗效果。(The invention discloses a compound preparation containing imidacloprid with good low-temperature stability, wherein each 100mL of the preparation contains: 3-7g of imidacloprid, 2-5g of moxidectin, 10-15g of epsiprantel, 0.05-0.1g of amitraz, 0.05-0.25g of antioxidant, 10-20g of stabilizer and 5-10g of transdermal agent. The invention discloses a preparation method of the imidacloprid-containing compound preparation with good low-temperature stability. The compound preparation containing imidacloprid is suitable for expelling insects in vivo and in vitro of pets and is applied to local skin in vitro of pets. The compound preparation obtained by the invention has better killing effect on parasites and worm eggs than any single component in the compound preparation, has no irritant odor of the medicine, can cool and relieve itching and has good transdermal effect. Meanwhile, the stabilizing agent contained in the invention can ensure that the imidacloprid in the preparation can not be separated out under the low temperature condition, so that the product can ensure the treatment effect when being used in severe cold areas.)

1. The imidacloprid-containing compound preparation with good low-temperature stability is characterized in that each 100mL of the preparation contains: 3-7g of imidacloprid, 2-5g of moxidectin, 10-15g of epsiprantel, 0.05-0.1g of amitraz, 0.05-0.25g of antioxidant, 10-20g of stabilizer and 5-10g of transdermal agent.

2. The imidacloprid-containing compound preparation with good low-temperature stability according to claim 1, which is characterized in that each 100mL of the preparation contains: 5-7g of imidacloprid, 2-5g of moxidectin, 10-13g of epsiprantel, 0.05-0.1g of amitraz, 0.05-0.2g of antioxidant, 12-20g of stabilizer and 5-8g of transdermal agent.

3. The imidacloprid-containing compound preparation with good low-temperature stability according to claim 1, wherein the antioxidant is at least one of butyl hydroxy anisole, dibutyl hydroxy toluene, thiodipropionic acid and propyl gallate.

4. The imidacloprid-containing compound preparation with good low-temperature stability according to claim 1 or 3, characterized in that the antioxidant is butylated hydroxyanisole.

5. The imidacloprid-containing compound preparation with good low-temperature stability according to claim 1, wherein the stabilizer is at least one of isopropyl myristate, diethylene glycol monoethyl ether, Miglyol 812 and Miglyol 840.

6. The imidacloprid-containing compound preparation with good low-temperature stability according to claim 1 or 5, which is characterized in that the stabilizer is isopropyl myristate.

7. The imidacloprid-containing compound preparation with good low-temperature stability according to claim 1, which is characterized in that the solvent is at least one of benzyl alcohol, dimethyl sulfoxide, dimethylformamide, dimethylacetamide and N-methylpyrrolidone.

8. The imidacloprid-containing compound preparation with good low-temperature stability according to claim 1 or 7, characterized in that the solvent is dimethyl sulfoxide.

9. The imidacloprid-containing compound preparation with good low-temperature stability according to claim 1 or 7, which is characterized in that the transdermal agent is L-menthol.

10. The imidacloprid-containing compound preparation with good low-temperature stability as claimed in any one of claims 1 to 9, which is characterized by comprising the following steps:

a. sequentially dissolving imidacloprid, moxidectin, epsiprantel and amitraz in a solvent to obtain a solution A;

b. dissolving an antioxidant and a transdermal agent in a solvent to obtain a solution B;

c. mixing the solution A and the solution B, adding a stabilizer, uniformly mixing, fixing the volume and filtering.

Technical Field

The invention relates to the technical field of pet insect repellents, in particular to a compound preparation containing imidacloprid with good low-temperature stability and a preparation method thereof.

Background

With the development of social economy, the living standard of people is continuously improved, more and more pets enter families of people, and play a positive role in the life of people, mainly dogs and cats. However, as the number of pets increases, the pets and the contact process of the pets and the external environment are inevitably infected with parasites, and the parasitic diseases become one of the important factors influencing the health of small animals, wherein some human beings and animals have the parasitic diseases together and directly harm the health of human beings.

When pets are infected with parasites, particularly ectoparasites, the pets are often unbearable in itching, irritated and sometimes even continuously bitten to cause depilation and skin injury. And the symptoms of itching in pets are not alleviated until the period of time after the application of the antiparasitic drug has taken effect. Antiparasitic topical formulations currently on the market basically only consider the antiparasitic effect of the drug, but do not consider the comfort of the pet before the drug takes effect.

Chemical anthelmintics have long been an important means of controlling animal parasites, but because of their long-term and frequent use, they have developed significant resistance to certain drugs. The problem of drug resistance of parasites is a great challenge to the prevention and treatment of parasites, and the problem not only harms the health of animals, but also threatens the health and ecological environment of human beings. The combined medication is one of the existing methods for solving the drug resistance of the parasites, namely two or more drugs are used together for treatment, so that the curative effect can be improved, the dosage can be reduced, the sensitivity of the parasites to the drugs can be maintained, and the generation of the drug resistance can be prevented and delayed.

Imidacloprid, which is an approved insecticide for agricultural cereals and for repelling fleas from dogs and cats, is a new generation of chloronicotinyl insecticides. At the end of the 80 s, Bayer AG in Germany succeeded in synthesizing such highly active compounds as represented by imidacloprid. Imidacloprid has high affinity to postsynaptic nicotinic acetylcholine receptors of central nervous system of insects, and can inhibit acetylcholine activity, resulting in paralysis and death of parasite. Imidacloprid is a relatively widely applied antiparasitic drug for pets at present, but imidacloprid is unstable at low temperature and is easy to separate out, so that the use of the product in cold regions is limited, and the use effect of the product is influenced.

In conclusion, the development of an antiparasitic compound preparation which has the advantages of wide pest-resistant spectrum, good stability, no pungent smell, good cooling, itching-relieving and transdermal effects is very necessary.

Disclosure of Invention

The invention aims to solve the defects in the prior art, and provides a compound preparation containing imidacloprid with good low-temperature stability and a preparation method thereof.

One of the technical schemes of the invention is as follows: the imidacloprid-containing compound preparation with good low-temperature stability is provided, and the mass (g) and total volume (mL) of the raw materials are as follows: 3-7% of imidacloprid, 2-5% of moxidectin, 10-15% of epsiprantel, 0.05-0.1% of amitraz, 0.05-0.25% of antioxidant, 10-20% of stabilizer, 5-10% of transdermal agent and solvent added to 100%.

Preferably, the mass (g) and total volume (mL) of each raw material of the compound preparation are as follows: 5-7% of imidacloprid, 2-5% of moxidectin, 10-13% of epsiprantel, 0.05-0.1% of amitraz, 0.05-0.2% of antioxidant, 12-20% of stabilizer, 5-8% of transdermal agent and solvent added to 100%.

In a preferred embodiment of the present invention, the antioxidant is selected from one or more of Butyl Hydroxyanisole (BHA), dibutyl hydroxytoluene (BHT), thiodipropionic acid, and propyl gallate, and further may be butyl hydroxyanisole.

In a preferred embodiment of the present invention, the stabilizer is selected from one or more of isopropyl myristate, diethylene glycol monoethyl ether, Miglyol 812, Miglyol 840, and further isopropyl myristate.

In a preferred embodiment of the present invention, the solvent is selected from the group consisting of benzyl alcohol, dimethyl sulfoxide (DMSO), dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and further may be dimethyl sulfoxide.

In a preferred scheme of the invention, the transdermal agent has the function of cooling and relieving itching, and the cooling and relieving itching transdermal agent is L-menthol. The menthol has the effects of cooling, relieving itching and masking taste, so that the animal can greatly relieve itching after taking the medicine, and the menthol has good medication comfort. Meanwhile, the traditional Chinese medicine transdermal enhancer is a common traditional Chinese medicine transdermal enhancer and has a remarkable transdermal enhancing effect on a plurality of medicines.

The second technical scheme of the invention is as follows: a method for preparing a compound preparation containing imidacloprid with good low-temperature stability is provided, which comprises the following steps:

a. sequentially dissolving imidacloprid, moxidectin, epsiprantel and amitraz in a proper amount of solvent to prepare a solution A;

b. dissolving the antioxidant and the transdermal agent in a prescription amount in a proper amount of solvent to prepare solution B;

c. mixing the solution A and the solution B, adding a formula amount of stabilizer, uniformly stirring, and fixing the volume by using a solvent;

d. filtering the obtained solution with microporous membrane, and bottling to obtain the final product.

The technical scheme of the invention has the following advantages:

1. the invention adopts the drug effect components of imidacloprid, moxidectin, epsiprantel, amitraz and the like to be compounded for use, can simultaneously repel and kill acarids, fleas, ticks, worms, tapeworms and the like, has wide repellent spectrum, and improves the curative effect of the drugs by compounding a plurality of drugs.

2. The invention adds the stabilizer, thereby leading the imidacloprid to be stable under the low temperature condition and not to be separated out, and ensuring the use effect of the product in severe cold areas.

3. The L-menthol with the effects of cooling, relieving itching and promoting transdermal penetration is added, so that the medicine can play a better role while the medicine using comfort degree of pets is increased.

4. The product has simple preparation process and no special requirement on equipment, and is suitable for industrial production.

Detailed Description

The present invention will be further illustrated with reference to the following specific examples.

The following procedures, reagents and instruments used are not specified by manufacturers, and are all conventional products commercially available.

Example 1

The compound preparation of the embodiment comprises the following components (unit: mass (g) and volume (ml)%):

1L of compound imidacloprid drops is prepared according to the following method:

a. sequentially dissolving imidacloprid, moxidectin, epsiprantel and amitraz in 500mL of benzyl alcohol to prepare a solution A;

b. dissolving BHT and L-menthol with the prescription amount in 200mL of benzyl alcohol to prepare solution B;

c. mixing the solution A and the solution B, adding the isopropyl myristate with the prescription amount, uniformly stirring, and fixing the volume by using benzyl alcohol;

d. filtering the obtained solution with microporous membrane, and bottling to obtain the final product.

Example 2

The compound preparation of the embodiment comprises the following components (unit: mass (g) and volume (ml)%):

1L of compound imidacloprid drops is prepared according to the following method:

a. sequentially dissolving imidacloprid, moxidectin, epsiprantel and amitraz in 500mL of DMSO to prepare a solution A;

b. dissolving BHA and L-menthol with the prescribed amount in 200mL DMSO to prepare a solution B;

c. mixing the solution A and the solution B, adding a prescription amount of Miglyol 840, uniformly stirring, and fixing the volume by DMSO;

d. filtering the obtained solution with microporous membrane, and bottling to obtain the final product.

Example 3

The compound preparation of the embodiment comprises the following components (unit: mass (g) and volume (ml)%):

1L of compound imidacloprid drops is prepared according to the following method:

a. sequentially dissolving imidacloprid, moxidectin, epsiprantel and amitraz in 500mL of dimethylformamide according to the prescription amount to prepare a solution A;

b. dissolving propyl gallate and L-menthol with the prescription amount in 200mL of dimethylformamide to prepare a solution B;

c. mixing the solution A and the solution B, adding the isopropyl myristate with the prescription amount, uniformly stirring, and fixing the volume by using dimethylformamide;

d. filtering the obtained solution with microporous membrane, and bottling to obtain the final product.

Example 4

The compound preparation of the embodiment comprises the following components (unit: mass (g) and volume (ml)%):

1L of compound imidacloprid drops is prepared according to the following method:

a. sequentially dissolving imidacloprid, moxidectin, epsiprantel and amitraz in 500mL of N-methylpyrrolidone to prepare a solution A;

b. dissolving thiodipropionic acid and L-menthol with the prescription amount in 200mL of N-methylpyrrolidone to prepare a solution B;

c. mixing the solution A and the solution B, adding the diethylene glycol monoethyl ether with the formula amount, uniformly stirring, and fixing the volume by using N-methylpyrrolidone;

d. filtering the obtained solution with microporous membrane, and bottling to obtain the final product.

Example 5

The compound preparation of the embodiment comprises the following components (unit: mass (g) and volume (ml)%):

1L of compound imidacloprid drops is prepared according to the following method:

a. sequentially dissolving imidacloprid, moxidectin, epsiprantel and amitraz in 500mL of dimethylacetamide to prepare a solution A;

b. dissolving thiodipropionic acid and L-menthol with the prescription amount in 200mL of dimethylacetamide to prepare a solution B;

c. mixing the solution A and the solution B, adding a prescription amount of Miglyol 812, uniformly stirring, and fixing the volume with dimethyl acetamide;

d. filtering the obtained solution with microporous membrane, and bottling to obtain the final product.

Comparative example 1

The compound preparation of the embodiment comprises the following components (unit: mass (g) and volume (ml)%):

1L of compound imidacloprid drops is prepared according to the following method:

a. sequentially dissolving imidacloprid, moxidectin, epsiprantel and amitraz in 500mLDMSO according to the prescription amount to prepare a solution A;

b. dissolving BHA and L-menthol with the prescription amount in 200mLDMSO to prepare solution B;

c. mixing the solution A and the solution B, and fixing the volume by DMSO;

d. filtering the obtained solution with microporous membrane, and bottling to obtain product comparative example 1

Comparative example 2

The compound preparation of the embodiment comprises the following components (unit: mass (g) and volume (ml)%):

1L of compound imidacloprid drops is prepared according to the following method:

a. sequentially dissolving imidacloprid, moxidectin, epsiprantel and amitraz in 500mLDMSO according to the prescription amount to prepare a solution A;

b. dissolving BHA and L-menthol with the prescription amount in 200mLDMSO to prepare solution B;

c. mixing the solution A and the solution B, adding a prescription amount of Miglyol 840, uniformly stirring, and fixing the volume by using DMSO;

d. filtering the obtained solution with microporous membrane, and bottling to obtain the final product.

Comparative example 3

The compound preparation of the embodiment comprises the following components (unit: mass (g) and volume (ml)%):

1L of compound imidacloprid drops is prepared according to the following method:

a. sequentially dissolving imidacloprid, moxidectin, epsiprantel and amitraz in 500mL of benzyl alcohol to prepare a solution A;

b. dissolving BHT with the prescription amount in 200mL of benzyl alcohol to prepare a solution B;

c. mixing the solution A and the solution B, adding the isopropyl myristate with the prescription amount, uniformly stirring, and fixing the volume by using benzyl alcohol;

d. filtering the obtained solution with microporous membrane, and bottling to obtain the final product.

Comparative example 4

The formulation of this example comprises the following components (in units of mass (g) and volume (ml)):

1L imidacloprid drops were prepared as follows:

a. dissolving imidacloprid with the prescription amount in 500mL of benzyl alcohol to prepare solution A;

b. dissolving BHT and L-menthol with the prescription amount in 200mL of benzyl alcohol to prepare solution B;

c. mixing the solution A and the solution B, adding the isopropyl myristate with the prescription amount, uniformly stirring, and fixing the volume by using benzyl alcohol;

d. filtering the obtained solution with microporous membrane, and bottling to obtain the final product.

Comparative example 5

The formulation of this example comprises the following components (in units of mass (g) and volume (ml)):

1L moxidectin drop was prepared as follows:

a. dissolving the moxidectin with the prescription amount in 500mL of benzyl alcohol in sequence to prepare a solution A;

b. dissolving BHT and L-menthol with the prescription amount in 200mL of benzyl alcohol to prepare solution B;

c. mixing the solution A and the solution B, adding the isopropyl myristate with the prescription amount, uniformly stirring, and fixing the volume by using benzyl alcohol;

d. filtering the obtained solution with microporous membrane, and bottling to obtain the final product.

Comparative example 6

The formulation of this example comprises the following components (in units of mass (g) and volume (ml)):

1L of epsiprantel drops were prepared as follows:

a. dissolving the prescribed quantity of epsiprantel in 500mL of benzyl alcohol in turn to prepare a solution A;

b. dissolving BHT and L-menthol with the prescription amount in 200mL of benzyl alcohol to prepare solution B;

c. mixing the solution A and the solution B, adding the isopropyl myristate with the prescription amount, uniformly stirring, and fixing the volume by using benzyl alcohol;

d. filtering the obtained solution with microporous membrane, and bottling to obtain the final product.

Comparative example 7

The compound preparation of the embodiment comprises the following components (unit: mass (g) and volume (ml)%)

1L drop of amitraz was prepared as follows:

a. dissolving the amitraz with the prescription amount into 500mL of benzyl alcohol in sequence to prepare a solution A;

b. dissolving BHT and L-menthol with the prescription amount in 200mL of benzyl alcohol to prepare solution B;

c. mixing the solution A and the solution B, adding the isopropyl myristate with the prescription amount, uniformly stirring, and fixing the volume by using benzyl alcohol;

d. filtering the obtained solution with microporous membrane, and bottling to obtain the final product.

EXAMPLE 1 Low temperature stability test (Freeze-thaw test)

Test drugs: the imidacloprid-containing compound preparation obtained in example 1-5 and the insect repellent obtained in comparative example 1-2 were used.

The test method comprises the following steps: taking the above groups of samples, and performing freeze-thaw test according to the technical guide principle of chemical drug stability research, namely that the freeze-thaw test comprises three cycles, wherein each cycle is performed for 2 days at-10 to-20 ℃, and then the samples are tested for 2 days under the acceleration condition of 40 ℃. The behavior of the sample after two phases of each cycle was observed, and the imidacloprid content was detected after the experiment was completed.

The test results are shown below:

in the above table, the operation A was carried out at-10 to-20 ℃ for 2 days to observe the presence or absence of precipitation, and the operation B was carried out at 40 ℃ for 2 days to observe the presence or absence of precipitation.

As can be seen from the results in the above table, the imidacloprid-containing compound preparation (examples 1-5) obtained by the invention has good stability at low temperature, and the imidacloprid is not precipitated. The imidacloprid-containing compound preparation containing the low-dose stabilizer (comparative example 2) is slightly precipitated under the low-temperature condition, the precipitated imidacloprid is dissolved once the temperature rises, and the imidacloprid is precipitated under the low-temperature condition in the control test (comparative example 1) and cannot be dissolved again even if the temperature rises.

Experimental example 2 in vivo insecticidal Effect test

Test drugs: the imidacloprid-containing compound preparation obtained in example 1-3 and the insect repellent obtained in comparative example 5-6 were used.

The test method comprises the following steps: 90 dogs which are naturally infected with roundworms, hookworms and whipworms are selected from the wandering dog base through excrement examination, each dog is infected with 2 or 3 kinds of parasites of roundworms, hookworms and whipworms, and no anthelmintic is used in 3 months before the test;

the 90 dogs were divided into 6 groups of 15 dogs each based on the principle that the infected insects were distributed as evenly as possible. The group 1 is a drug-free control group, the group 2 is a self-made sample group of the example 1, the group 3 is a self-made sample group of the example 2, the group 4 is a self-made sample group of the example 3, the group 5 is a sample group of the comparative example 5, and the group 6 is a sample group of the comparative example 6;

0.1mL of the medicine is administrated per kg of body weight, and the medicine is dripped between two scapulae on the back of a dog when the body weight is less than 25 kg; when the weight is more than or equal to 25kg, the medicine is dripped on the skin from the shoulder blade to the tail base part of the back of the dog, and the medicine is equally applied at 3-4 points.

Feces of each dog were collected on the day of administration (day 0, before administration) and 7 days, 14 days, 21 days, and 28 days after administration, and after the feces were mixed uniformly, eggs of each dog in the feces were counted, and the reduction rate and the relative reduction rate of each egg were calculated.

The test results are shown below:

TABLE 2 dog feces roundworm egg count results of each test group

Group/time	Day 0	7 days	14 days	21 days	28 days
						Medicine-free set	289	295	285	305	310
EXAMPLE 1 group	275	23	0	0	0
						EXAMPLE 2 group	297	28	0	0	0
EXAMPLE 3 group	302	30	0	0	0
						Comparative example 5 group	288	77	40	38	49
Comparative example 6 group	291	102	56	36	35

TABLE 3 counting results of hookworm eggs in feces of dogs in each test group

Group/time	Day 0	7 days	14 days	21 days	28 days
						Medicine-free set	178	183	180	198	202
EXAMPLE 1 group	186	10	0	0	0
						EXAMPLE 2 group	176	15	0	0	0
EXAMPLE 3 group	181	13	0	0	0
						Comparative example 5 group	179	79	25	20	25
Comparative example 6 group	184	98	31	23	22

TABLE 4 reduction of ova after 7 and 14 days of the test

As can be seen from table 2, the reduction rates of the roundworm eggs and hookworm eggs in the examples 1, 2 and 3 reached 90% or more 7 days after the administration, and no worm egg was detected 14 days after the administration. In contrast, in the groups of comparative examples 5 and 6, the reduction rate of the roundworm eggs and hookworm eggs is more than 80% after 14 days of administration, and the reduction rate of the roundworm eggs and hookworm eggs reaches about 85% after 28 days of administration. No decrease of worm eggs in the drug-administration group.

Therefore, for expelling the insects in vivo, the insect expelling effect and the insect expelling time of the compound preparation are better than those of the single preparation of moxidectin and epsiprantel.

Experimental example 3 in vitro insecticidal Effect test

Test drugs: the imidacloprid-containing compound preparation obtained in examples 1-3 and the anthelmintics obtained in comparative examples 4, 5 and 7 were used.

The experimental method comprises the following steps: after diagnosis, the 105 healthy dogs are artificially infected with sarcoptidosis mites and are randomly divided into 7 groups, wherein each group comprises 15 dogs, the 1 st group is the self-made sample group of the example 1, the 2 nd group is the self-made sample group of the example 2, the 3 rd group is the self-made sample group of the example 3, the 4 th group is the sample group of the comparative example 4, the 5 th group is the sample group of the comparative example 5, the 6 th group is the sample group of the comparative example 7, and the 7 th group is a drug-free control group; 0.1mL of the medicine is administrated per kg of body weight, and the medicine is dripped between two scapulae on the back of a dog when the body weight is less than 25 kg; when the weight is more than or equal to 25kg, the medicine is dripped on the skin from the shoulder blade to the tail base part of the back of the dog, and the medicine is equally applied at 3-4 points. The control dogs were not dosed and observed for onset of disease.

The test lasts for 14 days, clinical symptoms of the test dogs are observed and recorded, and skin tissues at the junctions of all canine lesion sites and healthy skin are scraped for microscopic observation on 1 day, 7 days and 14 days of the test. And (3) adding a 10% NaOH solution into the mixture when the disease material of the polypide is not detected, centrifuging the mixture for 5min at 1500r/min, detecting the precipitate by a microscope, and detecting the polypide as negative and the polypide as positive.

The test results are shown below:

the experimental data show that the negative conversion rate of the groups of example 1, example 2 and example 3 reaches more than 85% after 7 days of administration, and the negative conversion rate is 100% after 14 days of administration. The negative conversion rate of the comparative example 4 group, the comparative example 5 group and the comparative example 7 group in 7 days is about 50 percent, the negative conversion rate of the comparative example 14 days is more than 60 percent, and the negative conversion rates of the control groups are all 0.

It can be seen from this that: for in vitro anthelmintic, the compound preparation has better anthelmintic effect and anthelmintic aging time than the single preparation of moxidectin, imidacloprid and amitraz.

Experimental example 4 transdermal effect test

Test drugs: the imidacloprid-containing compound preparation obtained in example 1 and the insect repellent obtained in comparative example 3 were used.

Test animals: SPF grade SD rats, male, weighing 250-300 g.

The experimental method comprises the following steps: the rats are killed after neck breakage, the abdominal hairs of the rats are shaved off by a trimmer immediately, the abdominal skin is cut off, the taken-off skin is laid on a clean glass plate, the horny layer faces downwards, the subcutaneous fat layer and the connective tissue are carefully wiped off by the glass plate, the skin is repeatedly washed clean by physiological saline, the rat is placed in the physiological saline and stored in a refrigerator at 4 ℃ for later use, and the experiment is carried out within 1 week. The integrity of the rat skin was checked visually before the experiment without any breakage.

The abdominal skin of the treated rat was fixed between a supply tank and a receiving tank with the horny layer facing the supply tank, 2.0mL each of the samples of example 1 and comparative example 3 preheated at 32 ℃ were added to the supply tank, and 6.5mL of a 50% ethanol solution was added to the receiving tank, followed by air-bleeding. Discharging bubbles at the contact position of the receiving liquid and the skin, sampling at the temperature of 32 +/-1 ℃ in a diffusion pool water bath, ensuring that an isotonic solution is uniformly distributed, sampling at 0.5, 1, 2, 4, 6, 8, 12 and 24 hours respectively, quantitatively absorbing 6.5mL of the receiving liquid every time, simultaneously supplementing the receiving liquid preheated at the equal volume of 32 ℃, stirring the receiving liquid in the receiving pool before sampling every time and in the middle of sampling, and plugging a supply pool and the receiving pool to prevent the solution from volatilizing. The obtained receiving liquid sample and the liquid medicine in the diffusion cell after the experiment are finished are filtered by a 0.45 mu m filter membrane, and the filtrate is stored at 4 ℃ for detection. And (4) determining the drug concentration of the imidacloprid according to a sample content determination method.

The results of the experiments are given in the following table

From the above table, it can be seen that: the invention proves that the L-menthol plays a great role in promoting the transdermal penetration of the medicine by adding the L-menthol (example 1) to the sample with the imidacloprid accumulated penetration amount of 526.34ug which is higher than that of the sample without adding the L-menthol (comparative example 3) within 24 h.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.