AU2021323853A1

AU2021323853A1 - Milbemycin oxime and praziquantel flavor tablets and preparation method therefor

Info

Publication number: AU2021323853A1
Application number: AU2021323853A
Authority: AU
Inventors: Guoqing Chen; Wei Ji; Ya LI; Chengjiang LUO; Yingfeng Wang; Yiyue WANG; Denglong XIE; Hongbo Xu; Huaying ZHANG; Yan Zhang; Qifeng Zhu
Original assignee: Zhejiang Hisun Animal Health Products Co Ltd
Current assignee: Zhejiang Hisun Animal Health Products Co Ltd
Priority date: 2020-08-13
Filing date: 2021-08-12
Publication date: 2023-03-09
Also published as: CN116249517A; WO2022033553A1; CN112220769A

Abstract

The present invention relates to a milbemycin oxime and praziquantel flavor tablet and a preparation method therefor. The milbemycin oxime and praziquantel flavor tablet of the present invention consists of a tablet core and a drug-free coating layer coated on the surface of the tablet core. One or more coating layers can be present. The coating layer contains at least one phagostimulant or corrigent. The tablet core consists of a pellet, a glidant, and a lubricant. The preparation process of the milbemycin oxime and praziquantel flavor tablet of the present invention comprises drug-containing powder→micropellet→tablet core→coating layer→flavor tablet. The preparation process is simple, and can uniformly mix a main drug and assistants together, so that the assistants can better function, the stability of the drug is improved, the taste of the drug is improved, and the flavor tablet is suitable for industrial production, and has wide application prospects.

Description

Milbemycin Oxime And Praziquantel Flavor Tablets And

Preparation Method Therefor

Field

The present invention belongs to the field of pet pharmaceutical technology, in

particular, the present invention relates to a Milbemycin Oxime and Praziquantel

flavor tablet and a preparation method thereof.

Background

The pet industry in China is developing rapidly, the number of people who keep

pets is increasing continuously, and pets are also increasing, wherein pets are mostly

cats and dogs. Pet cats and dogs are very susceptible to parasites, such as nematodes,

pinworms, flukes, etc., and most parasites can be transmitted to humans. Therefore,

anti-parasites for pets are very important. At present, there are tablets and topical

liquids for the prevention and control of parasites on the market, mainly oral tablets.

However, most drugs have a certain odor and bitter taste, pets' sense of smell and

taste are very sensitive. Therefore, the current commercial pet oral tablets have the

problem of difficult administration, because most tablets are not added with food

attractants, or food attractants have been added but cannot achieve the effect of

covering the drug odor and bitterness because many pets will chew the drug in the

mouth and crunch the tablets.

Milbemycin Oxime is a macrolide anti-parasitic drug in vitro and vivo, it is an

oxime derivative of Milbemycin A3 and A4, wherein the proportion of A4 accounts

for more than 80%. It mainly paralyzes the parasites to dead by enhancing the release

of the inhibitory neurotransmitter y-aminobutyric acid (GABA) of the parasites.

Specifically, it mainly acts as an agonist of the GABA neurotransmitter in nerve cells,

and also binds to glutamate-gated Cl-channels in nerve and muscle cells of

invertebrates. In both cases, it blocks the parasite's nerve signal transmission, and eventually the parasites are paralyzed, causing their muscles to lose ability to contract, stop feeding, and cause the parasites to die. It is commonly used to prevent dirofilariasis, control roundworms, hookworm and trichocephaliasis in dogs.

Praziquantel is a synthetic isoquinoline pyridine derivative that is effective against

most flukes in humans and animals, has repellent effects on all adult tapeworms in

livestock and companion animals, and has good effects on tapeworm larvae.

Milbemycin Oxime and Praziquantel flavor tablet is a broad-spectrum antiparasitic

drug with good repellent effect on parasites in vivo and vitro, especially nematodes

and arthropods. It can be used to treat multiple infections caused by juvenile and adult

nematodes and tapeworms, and can be used to prevent and treat nematode-induced

canine heartworm diseases.

Due to the bitter taste of Milbemycin Oxime and Praziquantel, pets often refuse

to eat or vomit after consumption during the clinical administration process, and

forced administration will have the risk of being scratched or bitten by pets, resulting

in inconvenient clinical administration or inaccurate dosage, which reduces the

therapeutic effect. Therefore, it is especially important to develop a new high-quality

Milbemycin Oxime and Praziquantel tablets.

Summary

Based on the above reasons, in order to solve the shortcomings of the prior art,

the present invention provides a Milbemycin Oxime and Praziquantel flavor tablet for

the treatment and prevention of parasites in vivo and vitro, which can not only solve

the problem of pet parasites, but also overcome the difficult administration defects of

commercial preparations, increase the willingness of pets to independently feed, avoid

the phenomenon of vomiting, and facilitate the administration of drugs by pet owners.

The present invention also provides the method for the preparation of the

Milbemycin Oxime and Praziquantel flavor tablet for pets, the preparation process is

as follows: medicinal powder--micropellet--tablet core->coating layer--flavor tablet,

which is simple and suitable for large-scale production.

In order to achieve the object of the present invention, the present invention adopts the following technical solution. The Milbemycin Oxime and Praziquantel flavor tablet according to the present invention consists of a tablet core and a coating layer which is coated on surface of the tablet core and does not contain a drug, the coating layer can be of one layer or multiple layers, the coating layer contains at least one flavoring agent (also known as a food attractant); the tablet core consists of micropellet, glidant and lubricating agent; wherein, the weight percentages of the micropellet, glidant and lubricating agent in the tablet core are micropellet 95.0%-98.0% glidant 1.0%-2.5% lubricating agent 1.0%-2.5%.

Preferably, the glidant is a combination of one or more of calcium silicate,

colloidal silicon dioxide and silicon dioxide.

Preferably, the lubricating agent a combination of one or more of magnesium

stearate, talcum powder and glyceryl behenate.

Preferably, the particle size of the micropellets is 200~400 micron.

Wherein, the micropellet consists of Milbemycin Oxime, Praziquantel, filling

agent, disintegrating agent, and binding agent, wherein the weight percentages of

Milbemycin Oxime, Praziquantel, filling agent, disintegrating agent, and binding

agent are

Milbemycin Oxime 1.0%-10%

Praziquantel 4.0%-40%

filling agent 40%-80%

disintegrating agent 1.0%-5.0%

binding agent 1.0%-10%.

Milbemycin Oxime used in the present invention is a composite of Milbemycin

Oxime A3 and Milbemycin Oxime A4, calculated as anhydride, Milbemycin Oxime

(A3+ A4) should not be less than 95%; according to the method under the Content

Determination item, Milbemycin Oxime A4 should not be less than 80% of the sum of

Milbemycin OximeA3 and Milbemycin OximeA4.

Preferably, the filling agent is a combination of one or more of microcrystalline cellulose, maltodextrin, lactose monohydrate, saccharose, starch and dextrin. Preferably, the disintegrating agent is a combination of one or more of dry starch, sodium carboxymethyl starch, crosslinked polyvinylpyrrolidone and crosslinked sodium carboxymethylcellulose. The disintegrating agent can be used to make the micropellets disintegrated and broken after the drug contacting with water, to increase the surface area of the drug in contact with the dissolution medium and be beneficial to improve the dissolution degree of the drug. Preferably, the binding agent is a combination of one or more of povidone, sodium carboxymethylcellulose and hydroxypropyl methylcellulose. The method for preparing Milbemycin Oxime and Praziquantel flavor tablet is micropellet tableting, in order to ensure the fluidity of micropellet, and to ensure that the micropellets will not be crushed during tableting, the particle size of the micropellet needs to be controlled. The prepared particle size of the micropellet is controlled to be 200~400 micron. A Milbemycin Oxime and Praziquantel flavor tablet, it consists of tablet core and coating layer, the coating layer accounts for 2.0 %-8.0 % by weight of the tablet core, preferably 3.0%-5.0%.

The coating layer contains a coloring agent, a flavoring agent and a film-forming agent, wherein the weight percentages of the coloring agent, flavoring agent and film-forming agent are flavoring agent 10%-30%

coloring agent 1.0%-10%

film-forming agent 60%-90%. Furthermore, the coating layer contains a coloring agent, a flavoring agent and a film-forming agent, wherein the weight percentages of the coloring agent, flavoring agent and film-forming agent are flavoring agent 10%-30%

coloring agent 1.0%-10%

film-forming agent 60%-89%.

Preferably, the flavoring agent is a combination of one or more of chicken liver powder, beef flavor, beef extract and Luctarom©. The flavoring agent can increase the palatability of the drug, and is beneficial to drug administration.

Preferably, the coloring agent is a combination of one or more of sunset yellow,

sunset red, iron oxide red and iron oxide yellow. The coloring agent can be beneficial

to distinguish different specifications of drugs, prevent drug misuse, and also make

the products more recognizable, thereby enhancing the brand image.

Preferably, the film-forming agent is a combination of one or more of talcum

powder, polyethylene glycol 6000, and hydroxypropyl methylcellulose. The

film-forming agent can eliminate dust, make the surface appearance smoother, and

also prevent the tablet core from air, moisture and light, improve the stability of drugs,

and thus is beneficial to ensure the efficacy of drugs.

The invention also provides a method for the preparation of the Milbemycin

Oxime and Praziquantel flavor tablet for pets, comprising the following steps:

1) sieving a formula amount of Milbemycin Oxime, Praziquantel, a filling agent,

and a disintegrating agent through 50 mesh sieves, putting into a fluidized bed,

mixing well the drug and excipient in the lower fluidized bed under hot air flow of

°C-50°C, to obtain a mixture;

2) spraying a formula amount of binding agent solution into the mixture of step

1), the powder which absorbs the solution beginning to cohere to small particles, with

continuous addition of binding agent solution, small particles slowly aggregating to

form coarse micropellets;

3) continuing to dry off the coarse micropellets obtained in step 2) in a fluidized

bed under 40°C-50°C, sieving for two times, the sieve pore sizes of the two sievings

are 400 micron and 200 micron in turn, to obtain micropellets with particle size of

200-400 micron;

4) adding a formula amount of glidant and lubricating agent into the micropellets

obtained in step 3), mixing well, tableting, to obtain the tablet core;

5) slowly adding a formula amount of coating powder into the purified water,

and continuously stirring until homogeneous, to obtain a coating solution;

6) putting the tablet core obtained in step 4) into a coating machine, spaying even the coating solution of step 5) on surface of Milbemycin Oxime and Praziquantel tablet core, forming a coating layer; until tablet weight increases 2.0%-8.0%, to obtain the Milbemycin Oxime and Praziquantel flavor tablet.

The coating powder according to the present invention refers to the solid

component in the coating solution formulation, which does not contain water.

A micropellet refers to a spherical entity composed of drug powder and excipient,

generally the diameter thereof is less than 2.5mm, a micropellet dosage is a multi-unit

dose dispersion dosage form, that is, a dose often consists of multiple dispersed units,

usually a dose consists of tens to hundreds of micropellets. At present, micropellet is

commonly used in human sustained controlled release preparations or

immediate-release preparations, considering the current problem of clinical

administration of pet tablets, the present invention firstly applies the micropellet

technology to Milbemycin Oxime and Praziquantel flavor tablet products, as a taste

masking technology, so that pets can effectively delay the release of peculiar odor and

bitter taste in the mouth when biting tablets, thereby solving the problem of vomiting

phenomenon in pets.

In order to solve the problem of pets' chewing tablets, the drug is made into

micropellets, and then the micropellets are subjected to tableting, and the tablet core is

coated again to mask the taste. In this way, whether the pets swallow directly or bitten

off the tablets, an effect of masking taste can be achieved, and the active feeding ratio

of pets increases; at the same time, the Milbemycin Oxime and Praziquantel flavor

tablets according to the present invention play an isolation and moisture-proof effect

through the film-forming agent in the coating layer, the protection of the product is

strengthen, and the dissolution and curative effects of drug are not influenced,

furthermore the taste is covered, the active feeding ratio of pets is increased, and the

problem of difficult administration in pet is solved.

The process of the method for the preparation of the Milbemycin Oxime and

Praziquantel flavor tablet according to the present invention is simple, it can evenly

mix the main drug and auxiliaries together, so that the auxiliaries can play a better

role, improve the stability of the drug and improve the taste of the drug, and the preparing method is suitable for industrial production and has a broad application prospect.

Embodiments The following is a detailed description of the present invention in combination of the embodiments, it should be noted that the following embodiments are only used to illustrate the present invention, and do not constitute a limitation of the present invention. Milbemycin Oxime used in the present invention (A3+A4=97.5%; A4/(A3+A4)=83.3%) was purchased from Zhejiang Hisun Pharmaceutical Co., Ltd.; Praziquantel was purchased from Hisun Pharmaceutical (Nantong) Co., Ltd.; iron oxide red, sunset yellow were purchased from Shanghai Yipin Pigment Co., Ltd.; Polyethylene Glycol 6000 was purchased from Shanghai MAHON Biotechnology Co., Ltd.; Chicken Liver Powder was purchased from Qingdao Longhai Foodstuffs Co., Ltd.; Saccharose was purchased from Nanning Sugar Industry Co., Ltd.; Crosslinked polyvinylpyrrolidone was purchased from Huangshan Bonsun Pharmaceuticals Co., Ltd.; Povidone, colloidal silicon dioxide were purchased in Huzhou Prospect Pharmaceutical Co., Ltd.; Lactose Monohydrate was purchased by the MEGGLE GmbH & Co.KG; magnesium stearate, sodium carboxymethylcellulose, hydroxypropyl methylcellulose, talcum powder, dextrin were purchased from Anhui Shanhe Pharmaceutical Excipient Co., Ltd.; beef extract was purchased from PF, Inc.; and crosslinked sodium carboxymethylcellulose was purchased by DuPont Corporation. The coating machine involved in the present invention was XiaoLun high-efficiency film-coating machine, Model BG-100. The coating parameters were: the revolution speed was 10rpm, the inlet air temperature was 60°C, and the bed temperature was 40°C, until the tablet weight increased by 2.0%-8.0%. The fluidized bed involved in the present invention was a multifunctional granulating/pelletizing pill fluidized bed, Model DPL-II. The fluidized bed fan frequency was 20Hz, the inlet air temperature was 55°C, the drying temperature was

°C, the material temperature was controlled to 35°C, and the turntable speed was

400rpm.

Example 1

Tablet core formulation:

Table 1

No. Drug and excipient Weight (g)

1 Milbemycin Oxime 16

2 Praziquantel 40

3 saccharose 754

crosslinked sodium 4 45 carboxymethylcellulose

5 povidone 95

6 colloidal silicon dioxide 25

7 magnesium stearate 25

Total 1000

Coating solution formulation:

Table 2

No. Coating solution (g)

1 hydroxypropyl methylcellulose 20

2 iron oxide red 10

3 polyethylene glycol 6000 40

4 beefextract 15

5 chicken liver powder 15

6 purified water 2000

Note: purified water was dried off during the preparation of coating, and the

amount of purified water was not calculated in the formulation of the coating.

Preparation methods:

1) a formula amount of Milbemycin Oxime, Praziquantel and the filling agent saccharose, the disintegrating agent crosslinked sodium carboxymethylcellulose were sieved through 50 mesh sieves, put into a fluidized bed, the drug and excipient were mixed well in the lower fluidized bed under hot air flow of 45°C, mixed well, to obtain a mixture;

2) a formula amount of the binding agent 15% povidone water solution was

sprayed into the mixture of step 1), the powder which absorbed the solution began to

cohere to small particles, with continuous addition of binding agent povidone water

solution, small particles were slowly aggregated to form coarse micropellets;

3) the coarse micropellets obtained in step 2) was continued to be dried off in the

fluidized bed under 45°C, sieved for two times, the sieve pore sizes of the sievings

were 400 micron and 200 micron in turn, micropellets with particle size of 200-400

micron were obtained;

4) a formula amount of the glidant colloidal silicon dioxide and the lubricating

agent magnesium stearate were added into the micropellets obtained in step 3), mixed

well, tableted, to obtain the tablet core;

5) a formula amount of coating powder was added into the purified water slowly,

and stirred continuously until homogeneous, to obtain a coating solution;

6) the tablet core obtained in step 4) was put into the coating machine, the

coating solution obtained in step 5) was spayed even on the core surface of

Milbemycin Oxime and Praziquantel tablet to form the coating layer, and the

Milbemycin Oxime and Praziquantel tablets with different coating proportions were

prepared. The results are specifically shown in Table 3.

Weight increment proportions of the coatings:

Table 3

Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 Sample 7

Tablet Proportion Proportion Proportion Proportion Proportion Proportion

core 1% 2% 3% 5% 8% 10%

Note: The proportion of coating weight increment refers to the ratio of the added

weight of the tablet core by the coating process to the weight of the tablet core.

Example 2

Tablet core formulation:

Table 4

No. Drug and excipient Weight (g)

1 Milbemycin Oxime 90

2 Praziquantel 360

3 lactose monohydrate 450

crosslinked 4 40 polyvinylpyrrolidone

5 povidone 40

6 colloidal silicon dioxide 10

7 magnesium stearate 10

Total 1000

Coating solution formulation:

Table 5

No. Coating solution (g)

1 hydroxypropyl methylcellulose 49

2 iron oxide red 0.5

3 sunset yellow FCF 0.5

4 talcum powder 40

5 chicken liver powder 10

6 purified water 2000

The preparation method is the same as that in Example 1, wherein the weight

increment by the coating processing is 3%.

Note: purified water was dried off during the preparation of coating, and the

amount of purified water was not calculated in the formulation of the coating.

Example 3

Tablet core formulation:

Table 6

No. Drug and excipient Weight (g)

1 Milbemycin Oxime 50

2 Praziquantel 200

3 saccharose 400

4 dextrin 265

crosslinked 5 25 polyvinylpyrrolidone

sodium 6 25 carboxymethylcellulose

7 colloidalsilicon dioxide 10

8 magnesium stearate 25

Total 1000

Coating solution formulation:

Table 7

No. Coating solution (g)

1 hydroxypropyl methylcellulose 40

2 sunset yellow FCF 2.5

3 iron oxide red 2.5

4 talcum powder 40

5 chicken liver powder 7.5

6 beef flavor 7.5

7 purified water 2000

Note: purified water was dried off during the preparation of coating, and the

amount of purified water was not calculated in the formulation of the coating.

The preparation method is the same as that in Example 1, wherein the weight

increment by the coating processing is 3%.

Example 4

Tablet core formulation:

Table 8

No. Drug and excipient Weight (g)

1 Milbemycin Oxime 90

2 Praziquantel 200

3 maltodextrin 300

4 microcrystalline cellulose 225

crosslinked sodium 5 45 carboxymethylcellulose

6 povidone 90

7 colloidalsilicon dioxide 25

8 magnesium stearate 25

Total 1000

Coating solution formulation:

Table 9

No. Coating solution(g)

1 hydroxypropyl methylcellulose 50.5

2 iron oxide yellow 1.0

3 iron oxide red 1.5

4 talcum powder 32

5 beefflavor 10

6 beef extract 5.0

7 purified water 2000

Note: purified water was dried off during the preparation of coating, and the

amount of purified water was not calculated in the formulation of the coating.

The preparation method is the same as that in Example 1, wherein the weight

increment by the coating processing is 3%.

Assay 1:

Before the drug in the solid preparation was absorbed, it must be disintegrated

and dissolved and then converted into a solution to be absorbed, so dissolving

experiments in vitro were carried out to simulate the process of drug dissolution and

release in pet's body. Seven samples prepared in Example 1 were assayed for

dissolving detection. The limit requirement is that the dissolution within 30 minutes

should not be less than 80% of the labeled amount. The dissolution medium was 0.4%

SDS water solution under 37C, the revolution speed was 100rpm, 5ml sample was

taken at 30min, filtered, the continued filtrate was taken as a test solution, and the

dissolution of Milbemycin Oxime and Praziquantel was determined. The test results

are shown in Table 10.

Table 10

No. Dissolution of Milbemycin Dissolution of

Oxime (%) Praziquantel(%)

Sample 1 (tablet core) 99.9 91.6

Sample 2 (1% proportion) 99.8 91.5

Sample 3 (2% proportion) 99.2 90.1

Sample 4 (3% proportion) 98.5 89.5

Sample 5 (5% proportion) 97.5 89.1

Sample 6 (8% proportion) 95.6 85.4

Sample 7 (10% proportion) 72.5 73.4

It can be seen from the data of Table 10 that Sample 7 (the proportion accounting

for 10%) failed the test, and the dissolution of the drug slowed down, which affected

the release of the drug in pet's body, thereby reducing the efficacy of the product.

Therefore, the weight proportion of the coating layer in the tablet core should not

exceed 8%.

Assay 2:

Seven samples of Milbemycin Oxime and Praziquantel flavor tablets for pets

prepared in Example 1 were compared with the tablets prepared by conventional

process (Milbemycin Oxime and Praziquantel tablets not prepared by micropellet

tableting technology) for active feeding of pet cats, and the test site was Hangzhou

stray pet shelter.

Wherein, the specific formula and preparation method of the tablets prepared by

a conventional process were as follows:

Tablet core formulation:

Table 11

No. Drug and excipient Weight (g)

1 Milbemycin Oxime 16

2 Praziquantel 40

3 saccharose 754

4 crosslinked sodium carboxymethylcellulose 45

5 povidone 95

6 colloidal silicon dioxide 25

7 magnesium stearate 25

Total 1000

Coating solution formulation:

Table 12

No. Coating solution (g)

1 hydroxypropyl methylcellulose 20

2 iron oxide red 10

3 polyethylene glycol 6000 40

4 beefextract 15

5 chicken liver powder 15

6 purified water 2000

Note: The amounts of drug and excipient in the formulation of the tablets prepared by conventional process are the same as those in Example 1, and the proportion of coating weight increment accounts for 3%.

Preparation methods:

1) a formula amount of Milbemycin Oxime, Praziquantel and the filling agent

saccharose, the disintegrating agent crosslinked sodium carboxymethylcellulose were

sieved though 50 mesh sieves, put into a wet type granulator, mixed well, to obtain a

mixture;

2) a formula amount of the binding agent 15% povidone water solution was

added to the mixture obtained in step 1), and put into the shear machine for

granulation, to obtain wet particles;

3) the wet particles obtained in step 2) were transferred to an oven to be dried off,

the drying temperature was 45°C, the particles were sieved through 24 mesh sieves, to

obtain dried particles;

4) the dried particles obtained in step 3) were put into a mixer, a formula amount

of the glidant colloidal silicon dioxide and the lubricating agent magnesium stearate

were added, mixed well, tableted, to obtain the tablet core;

5) a formula amount of coating powder was added into purified water slowly,

and stirred continuously until homogeneous, to obtain a coating solution;

6) the tablet core obtained in step 4) was put into the coating machine, the

coating solution obtained in step 5) was spayed evenly on the surface of the

Milbemycin Oxime and Praziquantel tablet core to form the coating layer, and the

Milbemycin Oxime and Praziquantel tablets prepared by a conventional process were

obtained.

Test methods: 160 pet cats were randomly selected and divided into 8 groups,

each group of 20 cats, numbered as A, B, C, D, E, F, G and H, and two tests were

carried out: (1) the 7 samples prepared in Example 1 and samples of the tablets

prepared by a conventional process were fed separately, and the active feeding ratio of

each group was calculated; and (2) the 7 samples prepared in Example 1 and the

samples of the tablets prepared by a conventional process were fed into the pets'

mouths, and the number of untaken spit out of each group of pets was calculated. The test results are shown in Table 13.

Table 13

Active feeding Active feeding Vomit Vomit No. Samples Pet number number ratio number ratio

A Sample 1 20 5 25% 6 30% (tablet core)

B Sample 2 20 8 40% 2 10% (1% proportion)

C Sample 3 20 16 80% 1 5% (2% proportion)

D Sample 4 20 18 90% 1 5% (3% proportion)

E Sample 5 20 19 95% 1 5% (5% proportion)

F Sample 6 20 19 95% 1 5% (8% proportion)

G Sample 7 20 20 100% 1 5% (10% proportion) Tablets prepared H by a conventional 20 14 70% 8 40% process It can be seen from the results of Table 13 that the active feeding ratio of pets

with the Milbemycin Oxime and Praziquantel flavor tablet samples prepared by the

coating according to the present invention is significantly increased, much higher than

that of the tablet core samples, and the Milbemycin Oxime and Praziquantel flavor

tablets according to the present invention can solve the problem of pet drug

administration. The active feeding ratio of Sample 3 reached 80%, so the weight

proportion of the coating layer should not be less than 2% of the tablet core.

The vomiting number is the amount that the drug is fed into the pet's mouth and

the pet does not take but vomit. It can be seen from the results of vomiting ratio

(Table 13) that the vomiting ratio of Milbemycin Oxime and Praziquantel flavor

tablets using micropellet tableting technology was greatly reduced, and the

phenomenon of anti-vomiting in pets were solved.

The Milbemycin Oxime and Praziquantel flavor tablets for pets should not only

meet the quality requirements without affecting the efficacy of drugs, but also improve the active feeding ratio of pets, reduce the pets' vomiting ratio, and solve the problem of difficult drug administration. The results of Assay 1 and Assay 2 show that the Milbemycin Oxime and Praziquantel flavor tablets using the micropellet tableting technology and tablet core treated by coating can significantly improve the active feeding ratio of pets and reduce the vomiting ratio of pets.

Assay 3:

The obtained samples prepared in Example 1 to Example 4 were detected for

micropellet fluidity, tablet surface appearance, brittleness and disintegration time.

The detection index of micropellet fluidity is that the angle of repose is of< 40°.

The detection indicators of tablet surface appearance are that the tablet surface is

smooth by naked eye observation.

The detection index of brittleness is that the weight loss should not exceed 0.8%,

and the fracture, cracking and crushed pieces should not be detected.

The detection index of disintegration time is that the disintegration time should

not exceed 15 minutes. The detection results are shown in Table 14.

Table 14

micropellet Tablet surface Disintegration No. Brittleness fluidity appearance time

Example 1 5 minutes 28 35.60 Surface smooth 0.05% (Sample 4) seconds

4 minutes 30 Example 2 34.30 Surface smooth 0.04% seconds

5 minutes 20 Example 3 35.10 Surface smooth 0.06% seconds

5 minutes 15 Example 4 33.20 Surface smooth 0.04% seconds

It can be seen from the data in Table 14 that the Milbemycin Oxime and

Praziquantel flavor tablets provided according to the present invention were prepared by micropellet tableting and coating treatment, and the tablets prepared have aesthetic appearance, good particle fluidity, robust wear resistance and fast disintegration; through the optimization of formulation and processing, the stability of drug in the production process is guaranteed, and the product quality is improved.

Assay 4:

The absorption rate of drug in vivo is often determined by the speed of

dissolution, if the dissolution ratio is too fast, obvious adverse reactions may be

produced, and the time of maintaining efficacy can also be shortened; while if the

dissolution is too slow, the drug cannot be absorbed, the blood concentration of the

therapeutic effect cannot be reached; therefore, the dissolution rate of the drug should

be controlled. The samples of Example 1 to Example 4 were taken for dissolution

detection, and the limit requirement is that the dissolution within 30 minutes should

not be less than 80% of the labeled amount. The dissolution medium was 0.4% SDS

water solution under 37°C, the revolution speed was 100rpm, 5ml sample was taken

at 30min, filtered, the continued filtrate was taken as a test solution, and the

dissolution of Milbemycin Oxime and Praziquantel dissolution was determined. The

dissolution results were shown in Table 15 and Table 16.

Table 15 Dissolution of Milbemycin Oxime

Time 30 (min)

Example 1 (Sample 4) 98.5%

Example 2 96.2%

Example 3 93.1%

Example 4 93.9%

Table 16 Dissolution of Praziquantel

Time 30 (min)

Example 1 (Sample 4) 89.5%

Example 2 94.1%

Example 3 96.1%

Example 4 96.9%

It can be seen from the above dissolution data that the dissolution within 30

minutes of the samples prepared and obtained in Example 1 to Example 4 exceeded

%, therefore all of the samples meet the requirements of quality standards.

Assay 5:

The products produced by the preparation method according to the present

invention were tested for influencing factors, and aliquots of Sample 4 prepared in

Example 1 were placed respectively under the conditions of high temperatures of

°C and 40 °C, high humidity of RH75% and R192.5% and strong illumination of

4500Lx50Lx, sampled and tested on Day 5 and Day 10, and compared with the

sample on Day 0. The results are shown in Table 17 to Table 19 below.

The detection of the related substances complies with the relevant provisions

under the issue of tablet of the Appendix 5 of the "Chinese Veterinary

Pharmacopoeia", and the content determination were carried out according to the

determination by high performance liquid chromatography on page 36 of the

Appendix of the "Chinese Veterinary Pharmacopoeia".

Related substances: Praziquantel impurities A, B, and C should not exceed 0.5%,

Milbemycin Oxime impurity D should not exceed 1.5%, other impurities should not

exceed 1.0%, and total impurities should not exceed 6.0%.

Contents: all the contents of Milbemycin Oxime and Praziquantel should be

90.0%-110.0% of the labeled amount.

Dissolution: The limit requirement is that the dissolution within 30 minutes is not

less than 80% of the labeled amount.

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By analyzing the data of influencing factors in Table 17 to Table 19 above, the

formulation provided according to the present invention and product prepared and

obtained by the preparation method according to the present invention have good

stability under high temperature, high humidity and illumination conditions.

Assay 6:

The clinical trials of the product prepared by the preparation methods according

to the present invention were carried out to observe the clinical effects of Milbemycin

Oxime and Praziquantel flavor tablets (Sample 4 in Example 1) on parasites in cats,

and to observe the adverse reactions that may occur during the administration at the

same time.

Test animals: domestic cats, aged 1.5 months to adulthood. The cats were

transported to the laboratory and then kept in different cages for 7 to 10 days, so that

the cats could adapt to the environment and be tame, and the cat's mental state and

appetite and the like were observed. At the same time, the newly excreted feces by the

cats were collected one by one, and the worm eggs were examined by saturated saline

floating method and water washing precipitation method respectively. Among them,

the cats with at least one positive egg of Toxocara cati, Capillaria, Hookworm,

Clonorchis sinensis, Echinostomes, Pharyngo-stomum, Spirometra mansoni and

Dipylidium, and with good mental state and appetite were used in the test.

Test grouping:

The animals were randomly divided into 3 groups as follows:

Group I: Milbemycin Oxime and Praziquantel flavor tablet low-dosage group,

Milbemycin Oxime 1mg/kg + Praziquantel 2.5mg/kg;

Group II: Milbemycin Oxime and Praziquantel flavor tablet medium-dosage

group, Milbemycin Oxime 2mg/kg + Praziquantel 5mg/kg; and

Group III: Milbemycin Oxime and Praziquantel flavor tablet high-dosage group,

Milbemycin Oxime 4mg/kg + Praziquantel 10mg/kg.

Each group of 35 cats, the species of the infected eggs in the cats were similar

among the groups, as shown in Table 20 below:

Table 20 The species of worms infected cats and the number of cats in each test

group

The species of worms and the number of positive cats

Group Clonorchis Pharyngo-stomum or Spirometra Toxocara Dipylidium Hookworm Capillaria sinensis Echinostomes mansoni cati

I 16 18 12 3 10 2 10

II 16 18 12 3 12 3 10

III 14 18 10 3 10 2 10

Administration regimen:

Milbemycin Oxime and Praziquantel flavor tablet medium-dosage group was

administered orally once. The administration regimens in the low-dosage group and

high-dosage group were similar to that in the medium-dosage group, but the dosage

was halved or doubled.

Clinical observations:

After administration, the following items were observed on the administered cats

once a day in the morning and once a day in the afternoon: mental state, appetite, and

activity of the cats; elimination of worms, and the excreted worm bodies or segments

were collected for species identification to understand the excretion condition and

peaks of excretion.

Feces egg counting:

Fresh feces of cats infected with Capillaria were collected on one day before

administration and Day 7 and Day 14 after administration, respectively, and the fecal

eggs per gram was calculated by McMaster's Method.

Parasitological autopsy:

On Day 15 after administration, all the test cats were euthanized. Then, the worm

bodies in the digestive tract, liver, trachea, lungs, and bladder of each cat were collected according to the parasitological complete autopsy method to identify the species and count according to the species respectively.

Effect evaluation:

According to the change of the number of feces worm eggs, the results of clinical

efficacy test of each animal were evaluated according to the following criteria:

(1) Cured: the reduction ratio of worm eggs in feces is of >90%, and the signs of

the test animals return to normal.

(2) Effective: the reduction ratio of worm eggs in feces is of>60%, and the signs

of the test animals improve but do not completely return to normal.

(3) Ineffective: the reduction ratio of worm eggs in feces is of < 60%, the

condition of animals is not significantly relieved, and there are still clinical

manifestations such as diarrhea and vomiting.

The clinical observation results are shown in Table 21 to Table 27.

Throughout the trial period, all the test cats had normal mental states, appetite,

and defecation. The time of excreting worm bodies after administrating the tested

drug to cat was as early as 1 h after administration and at the latest on Day 6 after

administration, but the peak of excretion was 48-72 h after administration. The worm

bodies that can be detected in feces with the naked eye were mainly Toxocara cati and

tapeworms.

Expelling efficiency:

According to the numbers of various worms detected in cats, the expelling ratios

of various worms in each tested drug dosage group and drug control group were

calculated according to the following formula.

Average number of residual Average number of residual

Expelling ratio= worms in the control group worms in the test group x100 %

Average number of residual worms in the control group

According to the changes of Capillariaeggs in cat feces at different times before and after administration, the reduction ratio and egg negative conversion ratio of

Capillaria eggs in each tested drug dosage group and drug control group were calculated according to the following formula. EPG before expelling-EPG after expelling Egg reduction ratio= X100

% EPG before expelling

Cat number of egg negative conversion Egg negative conversion ratio= x100

% Cat number of expelling

The average number of EPG before and after administration and the reduction

ratio of egg between groups at different periods were descriptively calculated by

SPSS software, and the multiple comparisons for average value between groups were

calculated by Duncan's new complex range method (P<0.05).

Table 21 Expelling efficiency on Clonorchissinensis

No. Drug Cat Average value of live worms Expelling number remaining in the body (range) rate (%)

Milbemycin Oxime and Praziquantel 16 34.0(0-26) 88.0 flavor tablet low-dosage group

Milbemycin Oxime and Praziquantel 16 18.1(0-70) 93.6 flavor tablet medium-dosage group

Milbemycin Oxime and Praziquantel 14 5.1 (0-91) 98.2 flavor tablet high-dosage group

Table 22 Expelling efficiency on Echinostomes and Pharyngo-stomum

Autopsy results Average value of Cat live worms Expelling No. Drug number Worm species Positive cat remaining in the rate (%) body (range)

Milbemycin Oxime and Echinostomes 0 0 100.0 I Praziquantel flavor tablet 18 low-dosage group Pharyngo-stomum 1 0.3(0-4) 99.7

Echinostomes 0 0 100.0 Milbemycin Oxime and II Praziquantel flavor tablet 18 medium-dosage group Pharyngo-stomum 0 0 100.0

III Milbemycin Oxime and 18 Echinostomes 0 0 100.0 Praziquantel flavor tablet high-dosage group Pharyngo-stomum 0 0 100.0

Table 23 Expelling efficiency on Spirometra mansoni

Milbemycin Oxime and Praziquantel flavor 12 1.7(0~10) 67.9 tablet low-dosage group

Milbemycin Oxime and Praziquantel flavor 12 1.1 (0-5) 81.1 tablet medium-dosage group

Milbemycin Oxime and Praziquantel flavor 10 0.6(0-4) 88.7 tablet high-dosage group

Table 24 Expelling efficiency on Dipylidium

Drug Cat Average value of live worms Expelling No. number remaining in the body (range) rate (%)

Milbemycin Oxime and Praziquantel 3 1.7(0-3) 84.1 flavor tablet low-dosage group

Milbemycin Oxime and Praziquantel 3 0 100.0 flavor tablet medium-dosage group

Milbemycin Oxime and Praziquantel 3 0 100.0 flavor tablet high-dosage group

Table 25 Expelling efficiency on Toxocara cati

Milbemycin Oxime and Praziquantel 10 0.5 (0O2) 93.9 flavor tablet low-dosage group Milbemycin Oxime and Praziquantel 12 0 100.0 flavor tablet medium-dosage group

Milbemycin Oxime and Praziquantel 10 0 100.0 flavor tablet high-dosage group

Table 26 Expelling efficiency on Hookworm

Milbemycin Oxime and Praziquantel 2 3.5 (0~7) 70.1 flavor tablet low-dosage group

Milbemycin Oxime and Praziquantel 3 0 100.0 flavor tablet medium-dosage group

Milbemycin Oxime and Praziquantel 2 0 100.0 flavor tablet high-dosage group

Table 27 Expelling efficiency on Capillaria

Number of worm eggs (EPG), reduction ratio of worm eggs (%), negative conversion ratio of worm egg(%)

Od 7d 14d No. Drug number Number Number of Number of Negatm ofdworm Negative worm eggs worm eggs Reduction conversion eggs n conversion (Xi SD (X SD) (X±S) ratio (XSD)(X± ratio SD) ( ratio ratio

Milbemycin Oxime and Praziquantel 10 880+728.8' 2 8 2 1 2 8 2 .4b 67.9 0 9 5 1 13 0 .1b 89.2 0 low-dosage group

Milbemycin Oxime and Praziquantel 10 770+691.7a 0.0 b 100.0 70.0 0 1 10 1 0.0b 98.7 80.0 flavor tablet medium-dosage group

Milbemycin Oxime and S Praziquantel 10 810+648.8' 0 1 0.0 b 100.0 100.0 0+0.0b 100.0 100.0 high-dosage group

Note: different alphabets a and b marked in the upper right corner in the same

line indicate significant differences between values (P < 0.05).

It is shown based on the above test results that the Milbemycin Oxime and

Praziquantel flavor tablets produced by the formulation and preparation method

according to the present invention have good repellent effects on Toxocara cati,

Capillaria, Hookworm, Clonorchis sinensis, Echinostomes, Pharyngo-stomum,

Spirometra mansoni, and Dipylidium infected cats. It is recommended that the clinical

dosage of the drug for Toxocara cati, Hookworm, Clonorchis sinensis, Echinostomes,

and Dipylidium is administered once by mouth in medium dose; the dosage of the

drug for Capillariais administered once by mouth in high dose; the dosage of the

drug for Spirometra mansoni is administered in high dose, and it is necessary to repeat the administration for two days, once a day.

Observation of adverse reactions:

After the cats in the test groups were administered, the mental state, appetite, and

activity of the cats before and after the administration were compared, and no

abnormal reactions related to the administration were found.

Claims

1. A Milbemycin Oxime and Praziquantel flavor tablet, characterized in that, the

Milbemycin Oxime and Praziquantel flavor tablet consists of a tablet core and a

coating layer which is coated on surface of the tablet core and does not contain a drug,

the coating layer is of one layer or multiple layers, the coating layer comprises at least

one flavoring agent; the tablet core consists of a micropellet, a glidant, and a

lubricating agent.

2. The Milbemycin Oxime and Praziquantel flavor tablet of Claim 1, characterized in that, the weight percentages of the micropellet, glidant, and

lubricating agent in the tablet core are

micropellet 95.0%-98.0%

glidant 1.0%-2.5%

lubricating agent 1.0%-2.5%.

3. The Milbemycin Oxime and Praziquantel flavor tablet of Claim 2,

characterized in that, the glidant is a combination of one or more of calcium silicate,

colloidal silicon dioxide and silicon dioxide; the lubricating agent is a combination of

one or more of magnesium stearate, talcum powder and glyceryl behenate.

4. The Milbemycin Oxime and Praziquantel flavor tablet of Claim 1 or 2,

characterized in that, the particle size of the micropellet is 200~400 micron.

5. The Milbemycin Oxime and Praziquantel flavor tablet of Claim 1 or 2,

characterized in that, the micropellet consists of Milbemycin Oxime, Praziquantel, a

filling agent, a disintegrating agent, and a binding agent, wherein the weight

percentages of Milbemycin Oxime, Praziquantel, filling agent, disintegrating agent,

and binding agent are

Milbemycin Oxime 1.0%-10%

Praziquantel 4.0%-40%

filling agent 40%-80%

disintegrating agent 1.0%-5.0%

binding agent 1.0%-10%.

6. The Milbemycin Oxime and Praziquantel flavor tablet of Claim 5,

characterized in that, the filling agent is a combination of one or more of

microcrystalline cellulose, maltodextrin, lactose monohydrate, saccharose, starch and

dextrin; the disintegrating agent is a combination of one or more of dry starch, sodium

carboxymethyl starch, crosslinked polyvinylpyrrolidone and crosslinked sodium

carboxymethylcellulose; and the binding agent is a combination of one or more of

povidone, sodium carboxymethylcellulose and hydroxypropyl methylcellulose.

7. The Milbemycin Oxime and Praziquantel flavor tablet of Claim 1, characterized in that, the coating layer accounts for 2.0 %-8.0 % by weight of the

tablet core, preferably 3.0%-5.0%.

8. The Milbemycin Oxime and Praziquantel flavor tablet of Claim 1, characterized in that, the coating layer contains a coloring agent, a flavoring agent and

a film-forming agent, wherein the weight percentages of the coloring agent, flavoring

agent and film-forming agent are

flavoring agent 10%-30%

coloring agent 1.0%-10%

film-forming agent 60%-89%.

9. The Milbemycin Oxime and Praziquantel flavor tablet of Claim 8,

characterized in that, the flavoring agent is a combination of one or more of chicken

combination of one or more of sunset yellow, sunset red, iron oxide red and iron oxide

yellow; the film-forming agent is a combination of one or more of talcum powder, polyethylene glycol 6000, and hydroxypropyl methylcellulose.

10. A method for the preparation of the Milbemycin Oxime and Praziquantel

flavor tablet of Claim 1, characterized in that, comprising the following steps:

1) sieving a formula amount of Milbemycin Oxime, Praziquantel, a filling agent,

°C-50°C, to obtain a mixture;

2) spraying a formula amount of binding agent solution into the mixture of step

form coarse micropellets;

bed under 40°C-50°C, sieving for two times, to obtain micropellets;

obtained in step 3), mixing well, tableting, to obtain the tablet core;

5) slowly adding a formula amount of coating powder into the purified water,

and continuously stirring until homogeneous, to obtain a coating solution;

6) putting the tablet core obtained in step 4) into a coating machine, spaying even

the coating solution of step 5) on surface of Milbemycin Oxime and Praziquantel

tablet core, forming a coating layer; until tablet weight increases 2.0%-8.0%, to obtain

the Milbemycin Oxime and Praziquantel flavor tablet.

11. The method for the preparation of the Milbemycin Oxime and Praziquantel

flavor tablet of Claim 10, characterized in that, the sieve pore sizes of the two sievings

in step 3) are 400 micron and 200 micron in turn.