2, 4-dichlorobenzyl alcohol liposome, preparation method and aqueous solution

Abstract

The invention discloses a 2, 4-dichlorobenzyl alcohol liposome, a preparation method and an aqueous solution, and relates to the technical field of daily chemical preparations. The 2, 4-dichlorobenzyl alcohol liposome is prepared from the following raw materials in parts by mass: 8 to 15 parts of 2, 4-dichlorobenzyl alcohol, 20 to 60 parts of phospholipid and 5 to 12 parts of sterol. According to the 2, 4-dichlorobenzyl alcohol lipidosome provided by the invention, the encapsulation efficiency and the drug loading capacity of the lipidosome are improved through a preferable ratio and a preferable preparation process, so that the lipidosome is uniform in particle size, good in stability, improved in drug solubility and good in antibacterial activity. The water aqua further prepared by utilizing the liposome prepared by the invention has better stability and better application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of daily chemical preparations, and in particular to 2,4-dichlorobenzyl alcohol liposomes, a preparation method and an aqueous solution. Background Art

[0002] 2,4-dichlorobenzyl alcohol is a broad-spectrum and mild antibacterial agent developed by Boots in the 1850s. With its excellent antibacterial properties and safety, 2,4-dichlorobenzyl alcohol is widely used in a variety of products, such as throat lozenges, oral care products, cosmetics, disinfectants, and foot creams and lotions. Within a reasonable concentration range, 2,4-dichlorobenzyl alcohol is non-teratogenic, non-sensitizing, and non-irritating to the skin and mucous membranes, showing good safety. However, 2,4-dichlorobenzyl alcohol has low water solubility and is easily precipitated in aqueous solutions under low temperature conditions. This physicochemical property greatly limits its application in water-based preparations.

[0003] Liposomes, as tiny spherical structures composed of amphiphilic lipid molecules, have become widely used carriers in the field of drug delivery since they were first proposed by Bangham in 1965. The unique properties of liposomes enable them to encapsulate both water-soluble drugs and fat-soluble or amphiphilic drugs: the hydrophilic core can accommodate water-soluble drugs, while the lipid bilayer can embed fat-soluble or amphiphilic drugs. This encapsulation property can effectively improve the solubility and bioavailability of drugs, while providing the advantages of sustained release function and enhanced drug stability.

[0004] Although liposome technology is increasingly used in the field of drug delivery, there have been no reports on the research of 2,4-dichlorobenzyl alcohol liposomes. Based on the excellent antibacterial properties of 2,4-dichlorobenzyl alcohol, liposome encapsulation technology can significantly improve its low water solubility and low-temperature precipitation defects, further improving the stability and application breadth of its preparations. This strategy not only provides new ideas for the functional development of 2,4-dichlorobenzyl alcohol, but also helps promote its wider application in the fields of medicine and personal care. Therefore, studying the liposome preparation of 2,4-dichlorobenzyl alcohol and its related properties has important scientific significance and application value. Summary of the invention

[0005] The main purpose of the invention is to provide a 2,4-dichlorobenzyl alcohol liposome, broaden the application scope of 2,4-dichlorobenzyl alcohol and improve the utilization rate of 2,4-dichlorobenzyl alcohol.

[0006] To achieve the above object, the present invention provides a 2,4-dichlorobenzyl alcohol liposome, which comprises the following raw materials, calculated by mass: 8 to 15 parts of 2,4-dichlorobenzyl alcohol, 20 to 60 parts of phospholipids and 5 to 12 parts of sterols.

[0007] In one embodiment, the 2,4-dichlorobenzyl alcohol liposome is characterized in that the phospholipid is selected from one or more of soybean lecithin, egg yolk lecithin, phosphatidylinositol, and phosphatidylserine.

[0008] In one embodiment, the 2,4-dichlorobenzyl alcohol liposome is characterized in that the sterol is selected from one or more of cholesterol, sitosterol, brassicasterol, and ergosterol.

[0009] In one embodiment, the present invention provides a method for preparing 2,4-dichlorobenzyl alcohol liposomes, comprising the following steps:

[0010] S10, dissolving sterol, 2,4-dichlorobenzyl alcohol and phospholipid in a solvent, heating in a water bath, and evaporating under reduced pressure to obtain a film;

[0011] S20, subjecting the film to hydration reaction, ultrasonication, and extrusion to obtain 2,4-dichlorobenzyl alcohol liposomes.

[0012] In one embodiment, the solvent is selected from at least one of anhydrous ethanol, methanol, and chloroform.

[0013] In one embodiment, in step S10, the water bath heating temperature is 40° C. to 50° C., the water bath heating time is 1 h to 2 h; and / or the reduced pressure evaporation pressure is -0.08 Pa to -0.1 Pa.

[0014] In one embodiment, in step S20, the temperature of the hydration reaction is 45° C. to 55° C.; and / or,

[0015] The hydration reaction time is 45 min to 75 min.

[0016] In one embodiment, in step S20, the power of the ice bath ultrasound is 200W to 400W, and the time of the ice bath ultrasound is 5min to 15min.

[0017] The present invention also provides an aqueous solution, which comprises the 2,4-dichlorobenzyl alcohol liposomes as described in any one of the above items or the 2,4-dichlorobenzyl alcohol liposomes prepared by the preparation method of the 2,4-dichlorobenzyl alcohol liposomes as described above.

[0018] In the technical solution of the present invention, the 2,4-dichlorobenzyl alcohol liposomes include the following raw materials, by weight, 8 to 15 parts of 2,4-dichlorobenzyl alcohol, 20 to 60 parts of phospholipids and 5 to 12 parts of sterols. The 2,4-dichlorobenzyl alcohol liposomes provided by the present invention improve the encapsulation rate and drug loading of the liposomes through the optimal ratio and preparation process, make the particle size uniform, have good stability, improve the solubility of the drug, and have good antibacterial activity, and the aqueous preparation prepared by using the 2,4-dichlorobenzyl alcohol liposomes has good stability, further broadens its scope of use, and has good application prospects. DETAILED DESCRIPTION

[0019] To make the purpose, technical scheme and advantages of the embodiment of the present invention clearer, the technical scheme in the embodiment of the present invention will be clearly and completely described below. If the specific conditions are not specified in the embodiment, it is carried out according to the normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used, they are all conventional products that can be purchased commercially. In addition, the technical schemes between the various embodiments can be combined with each other, but must be based on the ability of ordinary technicians in the field to achieve. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that the combination of such technical solutions does not exist, and is not within the scope of protection required by the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present invention.

[0020] 2,4-Dichlorobenzyl alcohol, also known as 2,4-dichlorobenzyl alcohol, has a molecular formula of C7H6Cl2O. Since the 1850s, Boots has developed it as a broad-spectrum and mild antibacterial agent. Due to its excellent antibacterial properties, 2,4-dichlorobenzyl alcohol is widely used as an active ingredient or preservative in a variety of products such as throat lozenges, cosmetics, disinfectants, oral care products, and foot creams / lotions. 2,4-Dichlorobenzyl alcohol is non-teratogenic, non-sensitizing, and has no irritation to the skin and mucous membranes within a certain concentration, and has good safety. However, despite its many advantages, 2,4-dichlorobenzyl alcohol has low water solubility and is easily precipitated in aqueous products under low temperature conditions. This defect greatly limits its application in preparation of preparations.

[0021] Liposomes, as tiny spherical structures composed of amphiphilic lipids, have become the most widely used antimicrobial drug delivery vehicle due to their unique properties since they were first introduced by Bangham in 1965. The structural characteristics of liposomes enable them to encapsulate both water-soluble drugs and fat-soluble or amphiphilic drugs: the hydrophilic part of the core can accommodate water-soluble drugs, while the lipophilic part or lipid bilayer on the membrane can embed fat-soluble or amphiphilic drugs. This encapsulation promotes the dissolution of drugs and improves the bioavailability of drugs.

[0022] Although liposomes have been widely used in the field of drug delivery, there are no reports on 2,4-dichlorobenzyl alcohol liposomes. By preparing 2,4-dichlorobenzyl alcohol into liposomes, it is expected to overcome its low water solubility and low-temperature precipitation defects and further expand its application range.

[0023] In view of this, the present invention provides a 2,4-dichlorobenzyl alcohol liposome, which comprises the following raw materials, calculated by mass: 8 to 15 parts of 2,4-dichlorobenzyl alcohol, 20 to 60 parts of phospholipids and 5 to 12 parts of sterols.

[0024] Liposomes are micro-nano particles with a special molecular structure. Their molecules are composed of a hydrophilic part at the head and a hydrophobic part at the tail, which are connected by a molecular skeleton. After entering the physiological fluid environment, the liposome molecules spontaneously arrange themselves to form double-layer closed vesicles due to their amphiphilic properties, with diameters ranging from 25 to 1000 nm. This bilayer structure not only gives the liposomes a high degree of structural stability, but also enables them to encapsulate poorly soluble drugs in the phospholipid bilayer membrane to form a tiny and stable water-soluble vesicle. Through this encapsulation effect, liposomes can significantly improve the water solubility of drugs that are originally poorly soluble in water, allowing them to exist at higher concentrations in aqueous solutions.

[0025] In addition, the encapsulation ability of liposomes can effectively disperse drug molecules into aqueous solutions to form smaller particles or molecular clusters, thereby increasing the contact area between drugs and water molecules. This structural characteristic not only accelerates the dissolution process of drugs, but also significantly improves the solubility and bioavailability of drugs. Therefore, liposomes, as drug delivery systems, can overcome the solubility limitations of poorly soluble drugs and provide important technical support for the development and application of drugs. The preparation of 2,4-dichlorobenzyl alcohol liposomes within the above mass range can solve the problem of poor solubility of 2,4-dichlorobenzyl alcohol and improve the encapsulation rate and drug loading of liposomes.

[0026] In some embodiments of the present invention, the phospholipid is selected from one or more of soybean lecithin, egg yolk lecithin, phosphatidylinositol, and phosphatidylserine. The phospholipid can be understood to exist in many animals and plants. The phospholipids commonly used to make artificial films need to have both flexibility and stability, so as to effectively encapsulate drugs and prevent drug leakage.

[0027] In some embodiments of the present invention, the sterol is selected from one or more of cholesterol, sitosterol, brassicasterol, and ergosterol.

[0028] The sterol is a class of organic compounds with a steroidal structure, which is widely present in the cell membranes of animals and plants. Sterol has strong membrane stability, can improve the fluidity and density of the phospholipid bilayer membrane, and further enhance the mechanical strength and durability of the film. In the drug delivery system, the addition of sterol helps to improve the stability of the drug carrier membrane and avoid premature release or leakage of drugs.

[0029] The present invention also provides a method for preparing 2,4-dichlorobenzyl alcohol liposomes, comprising the following steps:

[0030] S10, dissolving sterol, 2,4-dichlorobenzyl alcohol and phospholipid in a solvent, heating in a water bath, and evaporating under reduced pressure to obtain a film;

[0031] S20, subjecting the film to hydration reaction, ultrasonication, and extrusion to obtain 2,4-dichlorobenzyl alcohol liposomes.

[0032] In the technical scheme of the present invention, step S10 uses phospholipids, sterols and 2,4-dichlorobenzyl alcohol, and dissolves them together in an organic solvent through hydrophobic interactions between molecules to form a uniform mixed solution. Subsequently, the solvent is gradually evaporated by heating in a water bath and decompression treatment to concentrate the solute in the solution. When the solvent is completely evaporated, the solute is evenly deposited at the bottom of the container to form a uniform film with lipid bilayer characteristics. The film structure has the characteristics of hydrophilicity and hydrophobicity, which lays the foundation for the formation of liposomes in subsequent steps. In step S20, the dispersion behavior of phospholipids in water is activated by adding an appropriate amount of water to the film for hydration reaction. Since phospholipid molecules have the amphiphilic properties of hydrophilic heads and hydrophobic tails, a spherical stable bilayer structure will spontaneously form in the aqueous phase. The hydrophobic tails of sterol molecules are stacked with phospholipid tails and embedded in the phospholipid bilayer, further enhancing the stability of the bilayer membrane. Water molecules bind to the hydrophilic head of phospholipids, driving the reorganization process of the phospholipid membrane, effectively encapsulating 2,4-dichlorobenzyl alcohol in the bilayer or inner water phase of the liposome, and finally forming a closed liposome (vesicle structure). During this process, the film gradually dissolves and falls off the container wall. In order to further improve the uniformity and particle size distribution of the liposomes, the generated liposomes are dispersed and refined by ultrasonic treatment to break up larger particles and eliminate the aggregation effect. Finally, the liposome solution is processed by an extrusion device to form a liposome system with uniform particle size and stable distribution. This process achieves efficient encapsulation of 2,4-dichlorobenzyl alcohol, significantly improves its stability and dispersibility in aqueous solution, and optimizes the quality and delivery efficiency of the liposomes.

[0033] In some embodiments of the present invention, in step S10, the solvent is selected from at least one of anhydrous ethanol, methanol, and chloroform, preferably anhydrous ethanol. Anhydrous ethanol can dissolve sterols, 2,4-dichlorobenzyl alcohol, and phospholipids. These substances can be evenly dispersed in the entire solution in ethanol, facilitating the formation of a bilayer structure.

[0034] In some embodiments of the present invention, in step S10, the water bath heating temperature is 40°C to 50°C; the water bath heating time is 1h-2h. The reduced pressure evaporation is performed in a water bath at 40°C to 50°C. This temperature range can remove the solvent without destroying sensitive biomolecules. The liposome membrane formed in the pressure range of -0.08Pa to -0.1Pa is more uniform, and reducing the pressure can reduce the boiling point of ethanol, thereby evaporating the solvent at a lower temperature.

[0035] In some embodiments of the present invention, in step S20, the temperature of the hydration reaction is 45° C. to 55° C., and the time of the hydration reaction is 45 min to 75 min.

[0036] As water molecules bind to the hydrophilic head of phospholipids, the phospholipid membrane can be reorganized to form closed liposomes (vesicle structures). Hydration can induce phospholipid molecules to self-assemble into lipid bilayer structures.

[0037] In some embodiments of the present invention, in step S20, the power of the ice bath ultrasound is 200W to 400W, and the time of the ice bath ultrasound is 5min to 15min, wherein the specific steps of the ice bath ultrasound include: loading the hydrated liposomes into a centrifuge tube, inserting the centrifuge tube into a beaker filled with crushed ice, adjusting the position of the beaker so that the ultrasonic probe is in a suitable position, setting the power of the ultrasonic cell disruptor to 200W to 400W, and setting the whole time to 5min to 15min. After the parameter setting is completed, press the start button to start ultrasound, and take out the sample after completion. The mechanical shear force of the ultrasound further breaks up the large lipid vesicles, making them uniform and reducing the particle size, reorganizing the phospholipid molecules, forming stable liposomes, and encapsulating 2,4-dichlorobenzyl alcohol in the liposomes.

[0038] The present invention also provides an aqueous solution, which includes the 2,4-dichlorobenzyl alcohol liposomes as described in any one of the above items or the 2,4-dichlorobenzyl alcohol liposomes prepared by the preparation method of the 2,4-dichlorobenzyl alcohol liposomes as described above. The 2,4-dichlorobenzyl alcohol liposomes have all the above beneficial effects, which will not be repeated here one by one.

[0039] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0040] Example 1

[0041] A 2,4-dichlorobenzyl alcohol liposome, comprising the following raw materials: 8 parts of cholesterol, 10 parts of 2,4-dichlorobenzyl alcohol and 30 parts of soybean lecithin, wherein each part is 1 g;

[0042] Wherein, the preparation method of the 2,4-dichlorobenzyl alcohol liposome comprises the following steps:

[0043] (1) Cholesterol, 2,4-dichlorobenzyl alcohol and soybean lecithin were dissolved in anhydrous ethanol, and the organic solvent was evaporated under reduced pressure in a 40°C water bath until a uniform film was formed at the bottom of the bottle;

[0044] (2) adding pure water to the film prepared in step (1) for hydration, hydrating at 50° C. for 60 min to dissolve the film, performing ice bath ultrasound at a power of 200 W for 15 min, and extruding to obtain 2,4-dichlorobenzyl alcohol liposomes.

[0045] Example 2

[0046] A 2,4-dichlorobenzyl alcohol liposome, comprising the following raw materials: 10 parts of cholesterol, 10 parts of 2,4-dichlorobenzyl alcohol and 30 parts of soybean lecithin, wherein each part is 1 g;

[0047] Wherein, the preparation method of the 2,4-dichlorobenzyl alcohol liposome comprises the following steps:

[0048] (1) Cholesterol, 2,4-dichlorobenzyl alcohol and soybean lecithin were dissolved in anhydrous ethanol, and the organic solvent was evaporated under reduced pressure in a 40°C water bath until a uniform film formed at the bottom of the bottle;

[0049] (2) adding pure water to the film prepared in step (1) for hydration, hydrating at 50° C. for 60 min to dissolve the film, performing ice bath ultrasound at a power of 200 W for 5 min, and extruding to obtain 2,4-dichlorobenzyl alcohol liposomes.

[0050] Example 3

[0051] A 2,4-dichlorobenzyl alcohol liposome, comprising the following raw materials: 5 parts of cholesterol, 8 parts of 2,4-dichlorobenzyl alcohol and 20 parts of soybean lecithin, wherein each part is 1 g;

[0052] Wherein, the preparation method of the 2,4-dichlorobenzyl alcohol liposome comprises the following steps:

[0053] (1) Cholesterol, 2,4-dichlorobenzyl alcohol and soybean lecithin were dissolved in anhydrous ethanol, and the organic solvent was evaporated under reduced pressure in a 40°C water bath until a uniform film was formed at the bottom of the bottle;

[0054] (2) adding pure water to the film prepared in step (1) for hydration, hydrating at 50° C. for 60 min to dissolve the film, performing ice bath ultrasound at a power of 200 W for 15 min, and extruding to obtain 2,4-dichlorobenzyl alcohol liposomes.

[0055] Example 4

[0056] A 2,4-dichlorobenzyl alcohol liposome, the 2,4-dichlorobenzyl alcohol liposome comprises the following raw materials: 12 parts of cholesterol, 15 parts of 2,4-dichlorobenzyl alcohol and 60 parts of soybean lecithin, wherein each part is 1g; wherein the preparation method of the 2,4-dichlorobenzyl alcohol liposome comprises the following steps:

[0057] (1) Cholesterol, 2,4-dichlorobenzyl alcohol and soybean lecithin were dissolved in anhydrous ethanol, and the organic solvent was evaporated under reduced pressure in a 40°C water bath until a uniform film was formed at the bottom of the bottle;

[0058] (2) adding pure water to the film prepared in step (1) for hydration, hydrating at 50° C. for 75 min to dissolve the film, performing ice bath ultrasound at a power of 200 W for 15 min, and extruding to obtain 2,4-dichlorobenzyl alcohol liposomes.

[0059] Example 5

[0060] A water preparation method comprises: adding 5% propylene glycol, 5% glycerol, 2% hyaluronic acid, 0.10% 2,4-dichlorobenzyl alcohol liposome prepared in Example 1, and 0.1% hydroxyethyl cellulose into pure water and dispersing them uniformly, adding 0.1% flavor, adding pure water to 100%, stirring uniformly, adjusting the pH to 6.8-7.2 with triethanolamine, and filtering through a 0.22 μm filter membrane to obtain the water preparation.

[0061] Comparative Example 1

[0062] A 2,4-dichlorobenzyl alcohol liposome, comprising the following raw materials: 20 parts of cholesterol, 10 parts of 2,4-dichlorobenzyl alcohol and 80 parts of soybean lecithin, wherein each part is 1 g;

[0063] Wherein, the preparation method of the 2,4-dichlorobenzyl alcohol liposome comprises the following steps:

[0064] (1) Cholesterol, 2,4-dichlorobenzyl alcohol and soybean lecithin were dissolved in anhydrous ethanol, and the organic solvent was evaporated under reduced pressure in a 40°C water bath until a uniform film was formed at the bottom of the bottle;

[0065] (2) adding pure water to the film prepared in step (1) for hydration, hydrating at 50° C. for 60 min to dissolve the film, performing ice bath ultrasound at a power of 200 W for 5 min, and extruding to obtain 2,4-dichlorobenzyl alcohol liposomes.

[0066] Comparative Example 2

[0067] A 2,4-dichlorobenzyl alcohol liposome, comprising the following raw materials: 10 parts of cholesterol, 5 parts of 2,4-dichlorobenzyl alcohol and 30 parts of soybean lecithin, wherein each part is 1 g;

[0068] Wherein, the preparation method of the 2,4-dichlorobenzyl alcohol liposome comprises the following steps:

[0069] (1) Cholesterol, 2,4-dichlorobenzyl alcohol and soybean lecithin were dissolved in anhydrous ethanol, and the organic solvent was evaporated under reduced pressure in a 40°C water bath until a uniform film was formed at the bottom of the bottle;

[0070] (2) adding pure water to the film prepared in step (1) for hydration, hydrating at 50° C. for 60 min to dissolve the film, performing ice bath ultrasound at a power of 200 W for 5 min, and extruding to obtain 2,4-dichlorobenzyl alcohol liposomes.

[0071] Comparative Example 3

[0072] A 2,4-dichlorobenzyl alcohol liposome, comprising the following raw materials: 8 parts of cholesterol, 10 parts of 2,4-dichlorobenzyl alcohol and 80 parts of soybean lecithin, wherein each part is 1 g;

[0073] Wherein, the preparation method of the 2,4-dichlorobenzyl alcohol liposome comprises the following steps:

[0074] (1) Cholesterol, 2,4-dichlorobenzyl alcohol and soybean lecithin were dissolved in anhydrous ethanol, and the organic solvent was evaporated under reduced pressure in a 40°C water bath until a uniform film was formed at the bottom of the bottle;

[0075] (2) adding pure water to the film prepared in step (1) for hydration, hydrating at 50° C. for 60 min to dissolve the film, performing ice bath ultrasound at a power of 200 W for 5 min, and extruding to obtain 2,4-dichlorobenzyl alcohol liposomes.

[0076] Comparative Example 4

[0077] A 2,4-dichlorobenzyl alcohol liposome, comprising the following raw materials: 10 parts of cholesterol, 20 parts of 2,4-dichlorobenzyl alcohol and 100 parts of soybean lecithin, wherein each part is 1 g;

[0078] Wherein, the preparation method of the 2,4-dichlorobenzyl alcohol liposome comprises the following steps:

[0079] (1) Cholesterol, 2,4-dichlorobenzyl alcohol and soybean lecithin were dissolved in anhydrous ethanol, and the organic solvent was evaporated under reduced pressure in a 40°C water bath until a uniform film was formed at the bottom of the bottle;

[0080] (2) adding pure water to the film prepared in step (1) for hydration, hydrating at 50° C. for 60 min to dissolve the film, performing ice bath ultrasound at a power of 200 W for 15 min, and extruding to obtain 2,4-dichlorobenzyl alcohol liposomes.

[0081] Comparative Example 5

[0082] The 2,4-dichlorobenzyl alcohol liposomes of Example 1 used in Example 5 were replaced with the raw material of 2,4-dichlorobenzyl alcohol, and the rest were the same as Example 5.

[0083] Performance test (quality evaluation of 2,4-dichlorobenzyl alcohol liposomes)

[0084] 1. Liposome encapsulation efficiency and drug loading

[0085] Test method: Use methanol to prepare 0.05 mg / mL 2,4-dichlorobenzyl alcohol reference solution and blank liposome demulsification solution, and perform full wavelength scan in the range of 200-400 nm. The results show that 2,4-dichlorobenzyl alcohol has a large characteristic absorption at 272 nm and no interference, so 272 nm is selected as the measurement wavelength.

[0086] Accurately weigh 50 mg of 2,4-dichlorobenzyl alcohol reference substance and prepare a series of reference substance solutions with methanol at concentrations of 0.05, 0.10, 0.20, 0.40, 0.60, and 0.80 mg / mL. Measure the absorbance at 272 nm and plot a standard curve with concentration as the abscissa (C) and absorbance (A) as the ordinate. The regression equation is A=1.2021C-0.0038, R 2 =0.9998, indicating that 2,4-dichlorobenzyl alcohol has a good linear relationship in the range of 0.05-0.80 mg / mL.

[0087] Take 1.5mL of 2,4-dichlorobenzyl alcohol liposomes in a 10mL volumetric flask, dilute to the mark with methanol, measure the absorbance, and substitute into the standard curve to calculate the total drug content W1. Take another 0.5mL of 2,4-dichlorobenzyl alcohol liposomes into an ultrafiltration tube, centrifuge at 5000r / min for 10min, take the filtrate and dilute to 1mL with methanol, measure the absorbance, and calculate the free drug content W2. Calculate the encapsulation efficiency and drug loading according to the following formula.

[0088] Encapsulation efficiency = (W1-W2) / W1×100%

[0089] Drug loading = (W1-W2) / W 总 ×100%

[0090] Where W1 is the total drug content in the liposome; W2 is the free drug content; W 总is the total mass of the liposomes, the encapsulation efficiency and drug loading of Examples 1 to 4 and Comparative Examples 1 to 4 were calculated, and the test results are shown in Table 1:

[0091] Table 1 Encapsulation efficiency and drug loading of Examples 1 to 4 and Comparative Examples 1 to 4

[0092] Encapsulation rate (%) Drug loading (%) Example 1 83.26 17.16 Example 2 77.67 15.17 Example 3 68.19 16.53 Example 4 62.48 10.77 Comparative Example 1 40.87 3.71 Comparative Example 2 53.52 5.95 Comparative Example 3 48.32 4.93 Comparative Example 4 33.80 2.82

[0093] Table 1 shows the encapsulation efficiency and drug loading of the liposomes of Examples 1 to 4 and Comparative Examples 1 to 4. The results show that since the amounts of Comparative Examples 1 to 4 are not within the range, the effects are worse than those of Examples 1 to 4. This is because a better ratio is used in the examples. When the phospholipid content exceeds the appropriate amount, the system is unstable; and excess cholesterol increases the rigidity of the liposomes and destroys the structure of the liposomes. In addition, the liposome membrane has a limited loading capacity for drugs. After reaching saturation, excess drugs precipitate and the encapsulation efficiency decreases. Therefore, the preferred formulation of the embodiments of the present invention has a higher encapsulation efficiency and drug loading.

[0094] 2. Liposome particle size, Zeta potential and polydispersity coefficient

[0095] Determination of the liposomes prepared in Example 1: 1 mL of 2,4-dichlorobenzyl alcohol liposomes was taken, diluted with pure water by an appropriate multiple, and the average particle size, polydispersity index and Zeta potential of the liposomes were determined using a Malvern laser particle size analyzer. The results showed that the average particle size of the liposomes prepared in Example 1 was 103.03±0.32 nm, and the polydispersity index PDI was 0.105±0.023, indicating that the particle size distribution of 2,4-dichlorobenzyl alcohol liposomes was uniform; the Zeta potential of 2,4-dichlorobenzyl alcohol liposomes was -13.6±0.85 mV, indicating that the liposomes had good stability.

[0096] 3. Storage stability of liposomes

[0097] The liposomes prepared in Example 1 were stored at 4° C. for 0, 10, 20 and 30 days, and the encapsulation efficiency and drug loading of the liposomes were measured to evaluate their stability. The test results are shown in Table 2.

[0098] Table 2 Storage stability results at 4℃

[0099] Days (d) Encapsulation rate (%) Drug loading (%) 0 83.26 17.16 10 81.50 16.96 20 81.31 16.83 30 80.89 16.58

[0100] As can be seen from Table 2, during the 30-day storage time, the encapsulation efficiency of 2,4-dichlorobenzyl alcohol liposomes decreased by 2.37%, and the drug loading amount only decreased by 0.58%, indicating that 2,4-dichlorobenzyl alcohol liposomes have good stability at 4°C. This is because the use of phospholipids and sterols to encapsulate the 2,4-dichlorobenzyl alcohol liposomes can improve their stability and drug loading amount.

[0101] 4. Solubility Determination

[0102] 5 mL of pure water was added to a 10 mL centrifuge tube, and the 2,4-dichlorobenzyl alcohol bulk drug and the 2,4-dichlorobenzyl alcohol liposome powder prepared in Example 1 were added respectively. The mixture was shaken in a constant temperature oscillator at 37° C. for 48 h and then taken out. During the shaking process, solids were always present at the bottom of the centrifuge tube. The tube was centrifuged at 13000 rpm for 10 min, and the supernatant was taken to determine the 2,4-dichlorobenzyl alcohol content. The results are shown in Table 3.

[0103] Table 3 Solubility test results

[0104] sample Solubility (mg / mL) 2,4-Dichlorobenzyl alcohol API 1.04 2,4-Dichlorobenzyl alcohol liposomes 1.52

[0105] It can be seen from the data in the table that after 2,4-dichlorobenzyl alcohol is prepared into liposomes according to the method of embodiment 1 of the present invention, the solubility of the drug in water can be improved, the utilization rate of 2,4-dichlorobenzyl alcohol can be greatly increased, and the scope of use can be broadened.

[0106] 5. Antibacterial Activity Determination

[0107] Dilute the 2,4-dichlorobenzyl alcohol API and liposomes to the same concentration and soak the sterile filter paper in them for 2 h. Dilute the suspension of Escherichia coli, Staphylococcus aureus and Candida albicans to 1×10 6 CFU / mL, take the bacterial solution to plate, place the filter paper containing the drug on the coated bacterial plate, and observe and measure the diameter of the inhibition zone after culturing at 37℃ for 24 hours. The filter paper soaked in sterile water was used as the blank control, and the filter paper soaked in blank liposomes was used as the negative control. The test was repeated 3 times and the average value was taken.

[0108] Table 4 Antibacterial activity of 2,4-dichlorobenzyl alcohol and 2,4-dichlorobenzyl alcohol liposomes

[0109]

[0110] As shown in Table 4, no inhibition zone appeared around the blank liposomes, while obvious inhibition zone appeared around 2,4-dichlorobenzyl alcohol and its liposome solution, indicating that 2,4-dichlorobenzyl alcohol still had obvious antibacterial effect on Escherichia coli, Staphylococcus aureus and Candida albicans after being encapsulated by liposomes.

[0111] 6. Evaluation of the physical and chemical indicators of 2,4-dichlorobenzyl alcohol liposome lotion

[0112] With reference to the current Chinese cosmetics implementation standard QB / T 2660-2004, the above Example 5 and Comparative Example 5 were placed at (5±1)°C and (40±1)°C for 24 hours, respectively. After returning to room temperature, the appearance of the solution before and after the placement was observed and its stability was compared. There should be no obvious difference in properties before and after the test. The results are shown in Table 5.

[0113] Table 5 Appearance changes of 2,4-dichlorobenzyl alcohol lotion

[0114]

[0115] As shown in Table 5, the preparation prepared by 2,4-dichlorobenzyl alcohol liposomes has better stability, and the disadvantage of easy precipitation at low temperature is improved.

[0116] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A 2,4-dichlorobenzyl alcohol liposome, characterized in that: The 2,4-dichlorobenzyl alcohol liposome comprises the following raw materials, calculated by weight: 8-15 parts of 2,4-dichlorobenzyl alcohol, 20-60 parts of phospholipids and 5-12 parts of sterols.

2. The 2,4-dichlorobenzyl alcohol liposome according to claim 1, characterized in that The phospholipid is selected from one or more of soybean lecithin, egg yolk lecithin, phosphatidylinositol, and phosphatidylserine.

3. The 2,4-dichlorobenzyl alcohol liposome according to claim 1, characterized in that The sterol is selected from one or more of cholesterol, sitosterol, brassicasterol and ergosterol.

4. A method for preparing 2,4-dichlorobenzyl alcohol liposomes as claimed in claims 1 to 3, characterized in that: The following steps are involved: S10, dissolving sterol, 2,4-dichlorobenzyl alcohol and phospholipid in a solvent, heating in a water bath, and evaporating under reduced pressure to obtain a film; S20, subjecting the film to a hydration reaction, performing ice bath ultrasonication, and extruding to obtain 2,4-dichlorobenzyl alcohol liposomes.

5. The method for preparing 2,4-dichlorobenzyl alcohol liposomes as claimed in claim 4, characterized in that: In step S10, the solvent is selected from at least one of anhydrous ethanol, methanol, and chloroform.

6. The method for preparing 2,4-dichlorobenzyl alcohol liposomes as claimed in claim 4, characterized in that: In step S10, the water bath heating temperature is 40° C. to 50° C., and the water bath heating time is 1 h to 2 h; and / or, The reduced pressure evaporation pressure is -0.08Pa to -0.1Pa.

7. The method for preparing 2,4-dichlorobenzyl alcohol liposomes as claimed in claim 4, characterized in that: In step S20, the temperature of the hydration reaction is 45° C. to 55° C.; and / or, The hydration reaction time is 45 min to 75 min.

8. The method for preparing 2,4-dichlorobenzyl alcohol liposomes as claimed in claim 4, characterized in that: In step S20, the power of the ice bath ultrasound is 200W to 400W, and the time of the ice bath ultrasound is 5min to 15min.

9. An aqueous solution, characterized in that The aqueous solution comprises the 2,4-dichlorobenzyl alcohol liposomes as claimed in any one of claims 1 to 3 or the 2,4-dichlorobenzyl alcohol liposomes prepared by the preparation method of the 2,4-dichlorobenzyl alcohol liposomes as claimed in claims 4 to 8.

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