CN117442702A

CN117442702A - Antibacterial liquid with controllable-size protein-based nanoparticles

Info

Publication number: CN117442702A
Application number: CN202311404388.7A
Authority: CN
Inventors: 杨鹏; 李玲
Original assignee: Shaanxi Normal University
Current assignee: Shaanxi Normal University
Priority date: 2022-01-26
Filing date: 2022-01-26
Publication date: 2024-01-26
Also published as: CN114470149A; CN114470149B

Abstract

The invention discloses an antibacterial solution with controllable-size protein-based nano particles, which is prepared by dissolving protein and a modifier in water, regulating pH to 3-8 by NaOH, and reacting for 5-10 hours at room temperature to obtain a dispersion with controllable-size protein-based nano particles. According to the invention, the antibacterial property of the natural proteins such as lysozyme is utilized, and the antibacterial property of the natural proteins is improved by modifying the natural proteins with the modifier. The antibacterial solution can also inhibit formation of bacterial biofilm, and remove formed biofilm. The antibacterial liquid can be prepared in a large volume, has high biocompatibility and simple preparation method, and can not generate drug resistance. The composition can also be made into various antibacterial agents such as antibacterial coatings, gel, powder, tabletting and the like, and the use modes of the composition are relatively diversified, including oral administration, intramuscular injection, intravenous injection, patch, microneedle, aerosol inhalation, spraying, gargle, toothpaste, food additives and the like, so that bacterial drug resistance caused by improper use of antibiotics can be effectively avoided.

Description

Antibacterial liquid with controllable-size protein-based nanoparticles

The present application is a divisional application of chinese patent application with application number 202210095697.X, application date 2022, month 01, 26, and name "an antibacterial liquid with protein-based nanoparticles of controllable size".

Technical Field

The invention belongs to the technical field of medical materials, and particularly relates to an antibacterial liquid with protein-based nano particles with controllable sizes, which has strong bactericidal capacity for bacteria and fungi and strong antiviral capacity.

Background

Bacterial infections are one of the ten causes of death worldwide, threatening the lives of countless people. The discovery of penicillin in the 20 th century opens up a new chapter for antibiotic resistance, and is the biggest invention in the 20 th century. But subsequent abuse of antibiotics also greatly promotes the development of bacterial resistance. Each new antibiotic is clinically used to bring new drug-resistant strains and even generate multi-drug-resistant super drug-resistant bacteria. Antibiotic resistance is an increasingly serious problem worldwide. According to the statistics of world health organization, death caused by infection in global patients, wherein more than 85% of the deaths are caused by infection of drug-resistant bacteria, and the malignant result brings great burden to life health and economy of human beings. More than 70 tens of thousands of people die annually from drug resistant disease. The threat of the "post antibiotic era" is the urgent need for new antimicrobial materials and methods to replace antibiotics to address this crisis.

Antibacterial enzymes such as lysozyme, lysostaphin and the like have gained increasing attention in recent years due to their high biocompatibility. But its limitations in antimicrobial ability also limit its development. Therefore, whether to modify the antibacterial agent, the biocompatibility of the antibacterial agent can be maintained, and the antibacterial performance of the antibacterial agent can be further improved, so that the antibacterial agent becomes a great challenge.

Disclosure of Invention

The invention aims to overcome the defect of antibiotic drug resistance, and provides a multifunctional antibacterial liquid which is simple to prepare, is biologically safe, does not cause bacterial drug resistance and can effectively remove bacterial biomembrane.

The antibacterial solution adopted by the invention is a dispersion solution with controllable-size protein-based nano particles, which is obtained by dissolving a modifier and protein in water, adjusting the pH to 3-8 by NaOH, and reacting for 5-10 hours at room temperature.

The protein is one or more of lysozyme, lactalbumin, insulin, beta-lactoglobulin, bovine serum albumin, human serum albumin, alpha-lactalbumin, fibrinogen, beta-amyloid, transferrin, collagen, gastric protein, keratin, myoglobin, hemoglobin, soybean protein, lactoferrin, albumin, thyrolactoglobulin, prion protein, abeta peptide, alpha-synuclein, alpha-amylase, pepsin, horseradish peroxidase, ribonuclease A, cytochrome c, cystatin C, DNA polymerase, casein, huntingtin, immunoglobulin light chain.

The modifier is one or more of cysteine, tris (2-carboxyethyl) phosphine hydrochloride, glutathione, mercaptoethanol, dithiothreitol, dimercaptosuccinic acid, sodium sulfite, beta-mercaptoethanol, hydrogen peroxide, ozone, sodium ferrate, trivalent cobalt salt, chlorate, potassium permanganate, persulfate, potassium dichromate, concentrated sulfuric acid, hydrochloric acid, nitric acid, hydrobromic acid, hydroiodic acid, perchloric acid, fluorine gas, chlorine gas, sodium bismuthate, periodic acid, lead dichloride, guanidine hydrochloride, urea, trifluoroethanol, hexafluoroisopropanol and trifluoroacetic acid.

The mass ratio of the protein to the modifier in the antibacterial liquid is preferably 1:0.5 to 2.

The concentration of the protein dissolved in water is preferably 1 to 50mg/mL, and the concentration of the modifier is preferably 1 to 50mg/mL.

In the antibacterial solution, the size of the protein-based nanoparticles is 10-200 nm.

And spin-coating or spray-coating the antibacterial liquid on the surfaces of different substrates to be modified to obtain the antibacterial coating. The substrate to be modified may be any existing material for film formation, and is hardly limited to shape and material. Specifically, the method comprises the following steps: (1) a metallic material: stainless steel, titanium and alloys thereof, cobalt-based alloys, nickel-titanium alloys, magnesium and alloys thereof, zinc and alloys thereof, iron and alloys thereof, and the like; (2) inorganic material: inorganic materials such as silica, titania, carbon materials, silicon, and titanium nitride; (3) high molecular material: polyester (PET), polyvinyl alcohol (PVALC), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), polystyrene (PS), polyurethane (PU), polypropylene (PP), polyamide, polycarbonate (PC), polyacrylonitrile, polyacrylic acid (PAA) and derivatives thereof, polyetheretherketone, silicone rubber, polylactic acid, polyglycolide, polylactide, polycaprolactone, and the like; (4) natural biological material: plastic starch-based materials (PSM), sodium alginate, collagen, fibrin, sodium hyaluronate, gelatin, etc.; (5) artificially synthesizing polypeptide hydrogel materials: poly L-glutamic acid, poly L-lysine, and the like. The kind of the base material is not limited to the above materials, and may be a mixed material of the above materials.

And dissolving a high molecular compound with the mass fraction of 5-30% in the antibacterial liquid to obtain the antibacterial gel. Wherein the polymer compound comprises one or more of starch, cellulose, gelatin, pectin, konjac gum, carrageenan, acacia, agar, seaweed gel, alginic acid, hyaluronic acid, chitosan, carrageenan, polysaccharide derivative, collagen, poly-L-lysine and poly-L-glutamic acid.

Dialyzing the antibacterial solution for 1 day, and lyophilizing to obtain antibacterial powder preparation; tabletting the powder preparation in a tabletting machine to obtain the antibacterial tablet preparation.

The beneficial effects of the invention are as follows:

1. the antibacterial liquid provided by the invention has an antibacterial effect without adding antibiotics, can effectively avoid bacterial drug resistance caused by improper use of antibiotics, and can not cause bacterial drug resistance.

2. The antibacterial liquid has net positive charge, good biocompatibility and high bactericidal performance of nano materials, and has high antibacterial effect on bacteria and fungi and high antiviral performance.

3. The antibacterial liquid can effectively inhibit the formation of the biological film, and has good cleaning effect on the formed biological film.

4. The antibacterial liquid can inhibit mildew of rice, traditional Chinese medicines and the like in a humid environment.

5. The antibacterial liquid has the advantages of simple preparation method, biological safety and controllable nanoparticle size, can be prepared into various antibacterial agents such as antibacterial coatings, gel, powder, tabletting and the like, and has various use modes including various use modes such as oral administration, intramuscular injection, intravenous injection, patch, microneedle, aerosol inhalation, spraying, gargle, toothpaste, food additive and the like.

Drawings

FIG. 1 is a distribution diagram of the size of nanoparticles in the antibacterial solution of example 1.

FIG. 2 is a graph showing the size distribution of nanoparticles in the antibacterial solution of example 2.

FIG. 3 is a graph showing the bactericidal activity profile of the antibacterial liquid of example 1 against Staphylococcus aureus, escherichia coli and Candida tropicalis.

FIG. 4 is a graph showing the antiviral effect of the antibacterial solution of example 1 on adenovirus.

FIG. 5 shows the results of a hemolysis test of the antibacterial liquid of example 1.

FIG. 6 shows the results of an experiment for resistance of Staphylococcus aureus to the antibacterial liquid of example 1.

FIG. 7 shows the test results of the rice mildew resistance of the antibacterial liquid of example 1.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples, but the scope of the present invention is not limited to these examples.

Example 1

After 5 mg/mLL-cysteine aqueous solution and 5mg/mL lysozyme aqueous solution were mixed in equal volumes at room temperature, pH was adjusted to 6.5, 7.0 and 7.5 with 1mol/L sodium hydroxide aqueous solution, respectively, and the mixture was reacted at room temperature for 8 hours to obtain an antibacterial solution. As can be seen from FIG. 1, the nanoparticles of the obtained antibacterial liquid can be controlled from 10nm to 100 nm.

Example 2

After mixing 10mg/mL of glutathione aqueous solution and 10mg/mL of lysozyme aqueous solution in equal volumes at room temperature, pH was adjusted to 6.5, 7.0 and 7.5 by 1mol/L of sodium hydroxide aqueous solution, respectively, and the mixture was reacted at room temperature for 8 hours to obtain an antibacterial solution. As can be seen from fig. 2, the nanoparticles in the resulting antimicrobial solution are also controllable from 10nm to 200nm.

Example 3

At room temperature, 5mg/mL bovine serum albumin aqueous solution and 5mg/mL tris (2-carboxyethyl) phosphine hydrochloride aqueous solution are mixed according to the volume ratio of 2:1, respectively regulating the pH to 7.0, 7.5 and 8.0 by using 1mol/L sodium hydroxide aqueous solution, and reacting for 5 hours at room temperature to obtain the antibacterial liquid.

Example 4

At room temperature, 5mg/mL glutathione aqueous solution and 5mg/mL lysozyme aqueous solution are mixed according to the volume ratio of 1:2, regulating the pH value to 7.0 by using 1mol/L sodium hydroxide aqueous solution, and reacting for 8 hours at room temperature to obtain the antibacterial liquid.

Example 5

At room temperature, 15mg/mL of aqueous solution of tris (2-carboxyethyl) phosphine hydrochloride and 15mg/mL of aqueous solution of lactalbumin are mixed according to the volume ratio of 1:2, regulating the pH value to 8.0 by using 1mol/L sodium hydroxide aqueous solution, and reacting for 8 hours at room temperature to obtain the antibacterial liquid.

Example 6

After mixing 10 mg/mLL-cysteine aqueous solution and 10mg/mL lysozyme aqueous solution in equal volume at room temperature, pH was adjusted to 6.5 with 1mol/L sodium hydroxide aqueous solution, and the mixture was reacted at room temperature for 8 hours to obtain an antibacterial solution. The antibacterial liquid is spin-coated on a quartz plate, and the antibacterial coating can be obtained.

Example 7

After mixing 10mg/mL of glutathione aqueous solution and 10mg/mL of lysozyme aqueous solution in equal volumes at room temperature, the pH was adjusted to 7.0 with 1mol/L of sodium hydroxide aqueous solution, and the mixture was reacted at room temperature for 8 hours to obtain an antibacterial solution. Spraying the antibacterial liquid on the surface of PP to obtain the antibacterial coating.

Example 8

After 5mg/mL of tris (2-carboxyethyl) phosphine hydrochloride aqueous solution and 5mg/mL of insulin aqueous solution were mixed in equal volumes at room temperature, the pH was adjusted to 8.0 with 1mol/L of sodium hydroxide aqueous solution, and the mixture was reacted at room temperature for 8 hours to obtain an antibacterial solution. Spraying the antibacterial liquid onto the surface of stainless steel to obtain the antibacterial coating.

Example 9

At room temperature, 5mg/mL dithiothreitol aqueous solution and 5mg/mL human serum albumin aqueous solution are mixed according to the volume ratio of 2:1, and adjusting the pH value to 8.0 by using 1mol/L sodium hydroxide aqueous solution, and reacting for 8 hours at room temperature to obtain the antibacterial liquid. 0.15g of gelatin is dissolved in 1mL of antibacterial liquid to obtain antibacterial gel.

Example 10

After 10mg/mL of an aqueous mercaptoethanol solution and 10mg/mL of an aqueous lysozyme solution were mixed in equal volumes at room temperature, the pH was adjusted to 7.0 with 1mol/L of an aqueous sodium hydroxide solution, and the mixture was reacted at room temperature for 8 hours to obtain an antibacterial solution. 0.2g of chitosan is dissolved in 1mL of antibacterial liquid, and the antibacterial gel is obtained.

To demonstrate the beneficial effects of the present invention, the inventors conducted various performance tests on the antibacterial liquid of example 1, and specific experiments were as follows:

1. antibacterial Activity test

The antibacterial activity of the above antibacterial liquid was evaluated based on colony counting, using two bacteria (staphylococcus adamantine ATCC6538 and escherichia coli ATCC 25922) and one fungus (candida tropicalis ATCC 1369). Before performing the in vitro antimicrobial test, the bacterial solutions were incubated overnight at 37℃in a centrifuge tube of 50mL MHB medium with shaking at 70 rpm. The bacteria or fungi are placed in the logarithmic growth phase. Centrifuging to collect bacteria, washing with PBS buffer solution three times to remove residual culture medium, and adding 10 times ⁸ Concentration of CFU/mLResuspended in PBS buffer. 100. Mu.L of the resuspended bacterial suspension was added to 900. Mu.L of the antibacterial solution and incubated at 37℃for 8 hours, and the bacterial or fungal suspension was serially diluted and plated onto MHA plates. After incubation of these MHA plates for 24 hours at 37 ℃, colony counts were recorded. The antibacterial activity is represented by the sterilization rate, which is calculated according to the following formula:

wherein C0 represents the number of colonies in the blank PBS, and C represents the number of colonies in the antibacterial solution. The experimental results are shown in FIG. 3. The result shows that the antibacterial liquid has high sterilization rate for gram-positive bacteria, gram-negative bacteria and candida tropicalis.

2. Antiviral properties

Preparation of 2mL of the complete culture medium with the density of 3-5 multiplied by 10 ⁴ The 293T cell suspension of each mL is inoculated into a 6-hole plate and cultured for 16 to 24 hours at 37 ℃ until the cell confluence reaches 30 percent, the supernatant liquid in the hole plate is removed, 1mL of complete culture medium is added, and then adenovirus solution is added (adenovirus is diluted to uniform titer of 1 multiplied by 10 by basic culture medium) ⁸ TU/mL) of which 10. Mu.L of LPBS buffer was added to three wells and 10. Mu.L of antibacterial solution was added to the other three wells. Mixing, and culturing. After 48 hours, photographs were taken under a fluorescence microscope and the number of GFP-positive cells was counted to calculate the infection rate. The results in FIG. 4 show that 10. Mu.L of the antibacterial solution added to the cells was not infected with the virus, indicating that the antibacterial solution had excellent antiviral ability.

3. Hemolysis experiment

Fresh blood was centrifuged and red blood cells were collected and washed three times with PBS buffer. Red blood cells were dispersed at 5% (v/v) in PBS buffer. After the antibacterial solution was diluted to different concentrations, 100. Mu.L of the red blood cell dispersion was added to 900. Mu.L of the antibacterial solution at different concentrations, and incubated at 37℃for 1 hour. 100. Mu.L of red blood cell dispersion was added to 900. Mu.L of PBS buffer as a blank group, and 100. Mu.L of red blood cell dispersion was added to 900. Mu.L of secondary water as a positive control group. After centrifugation, the supernatant was taken to determine the OD ₅₄₀ . The calculation formula of the hemolysis rate is as follows:

the results in FIG. 5 show that when the antibacterial solution reaches 10mg/mL, the hemolysis rate is still low, and thus the blood compatibility of the antibacterial solution is good.

4. Drug resistance test

10mL of Staphylococcus aureus in the logarithmic phase of MHB was taken and diluted to 10 with MHB ⁵ CFU/mL was used as working fluid. The antibacterial solution was dispersed in MHB at various concentrations, and then 100. Mu.L was mixed with 100. Mu.L of the working solution and then added to a 96-well plate. The well plate was placed in an enzyme-labeled instrument, the OD590 thereof was measured at 37℃and the bacterial growth was observed. Wherein the lowest concentration capable of inhibiting bacterial growth is the Minimum Inhibitory Concentration (MIC) of the antibacterial solution. The bacteria were then cultured at 0.125×mic. The above procedure was repeated again with bacteria in log phase. FIG. 6 is obtained. The results show that the obtained antibacterial liquid does not induce bacteria to develop drug resistance.

5. Rice mildew-proof experiment

Taking 10g of rice, equally dividing into two groups, and soaking one group of rice with deionized water for 0.5h to obtain a blank group; the other group was immersed in the antibacterial solution of example 1 at ph=7.0 for 0.5 hours, and was the experimental group. Two groups of rice were dried and placed in a constant temperature and humidity cabinet (25 ℃,99% RH) and two groups of rice were observed daily for mildew. The results are shown in fig. 7, where the white group rice had significantly mildewed on day 10, where there had been significant mildew spots on day 34, and by day 62 the white group rice had been completely covered with mold, while the experimental group rice remained consistent with the first day 62. Therefore, the antibacterial liquid can effectively inhibit mildew of rice.

The protein in the above embodiment may be any one or more of β -lactoglobulin, α -lactalbumin, fibrinogen, β -amyloid, transferrin, collagen, gastric protein, keratin, myoglobin, hemoglobin, soy protein, lactoferrin, albumin, thyrolactoglobulin, prion protein, aβ peptide, α -synuclein, α -amylase, pepsin, peroxidase, ribonuclease a, cytochrome c, cystatin C, DNA polymerase, casein, huntingtin, immunoglobulin light chain, and the modifier may be any one or more of dimercaptosuccinic acid, sodium sulfite, β -mercaptoethanol, hydrogen peroxide, ozone, sodium ferrate, trivalent cobalt salts, chlorate, potassium permanganate, persulfate, potassium dichromate, concentrated sulfuric acid, hydrochloric acid, nitric acid, hydrobromic acid, hydroiodic acid, perchloric acid, fluorine gas, chlorine gas, sodium bismuthate, periodic acid, lead dichloride, hydrochloric acid, urea, trifluoroethanol, hexafluoroisopropanol, and trifluoroacetic acid.

The antibacterial liquid can be spin-coated or sprayed on the surfaces of different substrates to obtain antibacterial coatings. The substrate may be any material currently used for film formation, and is hardly limited to shape and material. Specifically, the method comprises the following steps: (1) a metallic material: stainless steel, titanium and alloys thereof, cobalt-based alloys, nickel-titanium alloys, magnesium and alloys thereof, zinc and alloys thereof, iron and alloys thereof, and the like; (2) inorganic material: inorganic materials such as silica, titania, carbon materials, silicon, and titanium nitride; (3) high molecular material: polyester (PET), polyvinyl alcohol (PVALC), polyethylene (PE), polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), polystyrene (PS), polyurethane (PU), polypropylene (PP), polyamide, polycarbonate (PC), polyacrylonitrile, polyacrylic acid (PAA) and derivatives thereof, polyetheretherketone, silicone rubber, polylactic acid, polyglycolide, polylactide, polycaprolactone, and the like; (4) natural biological material: plastic starch-based materials (PSM), sodium alginate, collagen, fibrin, sodium hyaluronate, gelatin, etc.; (5) artificially synthesizing polypeptide hydrogel materials: poly L-glutamic acid, poly L-lysine, and the like. The kind of the base material is not limited to the above materials, and may be a mixed material of the above materials.

The antibacterial gel can be obtained by dissolving the high molecular compound with the mass fraction of 5-30% in the antibacterial liquid. Wherein the polymer compound comprises one or more of starch, cellulose, gelatin, pectin, konjac gum, carrageenan, acacia, agar, seaweed gel, alginic acid, hyaluronic acid, chitosan, carrageenan, polysaccharide derivative, collagen, poly-L-lysine and poly-L-glutamic acid.

Dialyzing the antibacterial solution for 1 day, and freeze-drying to obtain an antibacterial powder preparation; tabletting the powder preparation in a tabletting machine to obtain the antibacterial tablet preparation.

Claims

1. An antimicrobial solution having protein-based nanoparticles of controlled size, characterized by: the antibacterial solution is a dispersion solution of protein-based nano particles with controllable size, which is obtained by dissolving protein and a modifier in water, adjusting the pH to 3-8 by NaOH, and reacting for 5-10 hours at room temperature;

the protein is any one or more of lactalbumin, insulin, beta-lactoglobulin, bovine serum albumin, human serum albumin, alpha-lactalbumin, fibrinogen, beta-amyloid, transferrin, collagen, gastric protein, keratin, myoglobin, hemoglobin, soy protein, lactoferrin, albumin, thyrolactoglobulin, prion protein, A beta peptide, alpha-synuclein, alpha-amylase, pepsin, horseradish peroxidase, ribonuclease A, cytochrome c, cystatin C, DNA polymerase, casein, huntingtin, immunoglobulin light chain;

the modifier is any one or more of cysteine, tris (2-carboxyethyl) phosphine hydrochloride, glutathione, mercaptoethanol, dithiothreitol, dimercaptosuccinic acid, sodium sulfite, beta-mercaptoethanol, hydrogen peroxide, ozone, sodium ferrate, trivalent cobalt salt, chlorate, potassium permanganate, persulfate, potassium dichromate, concentrated sulfuric acid, hydrochloric acid, nitric acid, hydrobromic acid, hydroiodic acid, perchloric acid, fluorine gas, chlorine gas, sodium bismuthate, periodic acid, lead dichloride, guanidine hydrochloride, urea, trifluoroethanol, hexafluoroisopropanol and trifluoroacetic acid.

2. The antimicrobial liquid with controllable size protein-based nanoparticles of claim 1, wherein: the mass ratio of the protein to the modifier is 1:0.5 to 2.

3. The antimicrobial liquid with controllable size protein-based nanoparticles of claim 2, wherein: the modifier and the protein are dissolved in water, so that the protein concentration in the water is 1-50 mg/mL and the modifier concentration is 1-50 mg/mL.

4. The antimicrobial liquid with controllable size protein-based nanoparticles of claim 1, wherein: in the antibacterial solution, the size of the protein-based nano particles is 10-200 nm.

5. The antimicrobial liquid with controllable size protein-based nanoparticles of claim 1, wherein: and spin-coating or spray-coating the antibacterial liquid on the surface of the substrate to be modified to obtain the antibacterial coating.

6. The antimicrobial liquid with controllable size protein-based nanoparticles of claim 5, wherein the substrate to be modified comprises any one of the following materials:

(1) Metal material: stainless steel, titanium and alloys thereof, cobalt-based alloys, nickel-titanium alloys, magnesium and alloys thereof, zinc and alloys thereof, iron and alloys thereof;

(2) Inorganic material: inorganic materials such as silica, titania, carbon materials, silicon, titanium nitride, and the like;

(3) High molecular material: polyester, polyvinyl alcohol, polyethylene, polytetrafluoroethylene, polyvinyl chloride, polystyrene, polyurethane, polypropylene, polyamide, polycarbonate, polyacrylonitrile, polyacrylic acid and derivatives thereof, polyether ether ketone, silicone rubber, polylactic acid, polyglycolide, polylactide and polycaprolactone;

(4) Natural biological material: plastic starch-based material, sodium alginate, collagen, fibrin, sodium hyaluronate and gelatin;

(5) Artificially synthesized polypeptide hydrogel material: poly L-glutamic acid, poly L-lysine.

7. The antimicrobial liquid with controllable size protein-based nanoparticles of claim 1, wherein: dissolving a high molecular compound with the mass fraction of 5-30% in the antibacterial liquid to obtain antibacterial gel; the polymer compound comprises one or more of starch, cellulose, gelatin, pectin, konjac gum, carrageenan, acacia, agar, seaweed gel, alginic acid, hyaluronic acid, chitosan, carrageenan, polysaccharide derivative, collagen, poly-L-lysine and poly-L-glutamic acid.

8. The antimicrobial liquid with controllable size protein-based nanoparticles of claim 1, wherein: dialyzing the antibacterial solution, and freeze-drying to obtain an antibacterial powder preparation; tabletting the powder preparation in a tabletting machine to obtain the antibacterial tablet preparation.