JPS5941970B2 - Emulsion containing anticancer drugs - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an emulsion containing an anticancer agent using water as a dispersion medium, and particularly to an emulsion that can be used as a carrier to induce an anticancer agent to a local cancer site. be.

Although various chemical drugs, so-called anticancer drugs, have already been developed for chemotherapy against malignant tumors, most of them have not yet been put into full-scale practical use.

One of the reasons for this is that although various anticancer drugs have been confirmed to have remarkable anticancer effects, they still have too many side effects on living organisms to be used clinically as chemotherapy. This is because it cancels out the effects.

On the other hand, magnetic anticancer drugs are used to guide or hold the drug to the cancerous local area using a magnetic field, increasing the drug's efficacy by concentrating the drug's action locally, and preventing the generation of side effects by diffusing to other parts of the body. Several attempts have already been proposed.

For example, there is a method in which an anticancer drug is adsorbed to magnetite colloid, or a drug in which magnetite particles are adsorbed to anticancer drug particles is administered to a living body, and a magnet is placed or inserted locally.

Although such drugs are recognized to be effective when administered in the peritoneal cavity or digestive system, they are difficult to be applied when administering intravascularly, that is, when attempting to induce or retain the drug locally through the blood circulation system.

In the case of intravascular administration of drugs, the drug must be small enough to circulate within the blood vessel without hindrance and pass through the minute capillaries at the end. Even if a sufficiently small amount of material such as It will lead to death.

Of course, reaching local capillaries and occluding them to kill local cells is an effective means of treatment, but capillary occlusion due to such deposition must occur selectively only locally. First, it must not occur within blood vessels at other sites.

In addition, the composition of blood flowing in blood vessels is complex, so even if anticancer drugs are adsorbed to magnetic particles as described above, or conversely, magnetic particles are adsorbed to anticancer drug particles and administered, the blood will not be absorbed into blood vessels. When the drug is destroyed by the resulting dissolution, dialysis, etc., and the anticancer drug and the magnetic particles are separated, even if the magnetic particles circulate smoothly in the blood vessels and are guided and held by a locally installed magnetic field. However, although anticancer drugs remain localized, they easily spread to other areas and are not useful for eliminating or controlling side effects.

On the other hand, regarding the production method of colloidal solution of ferromagnetic particles, so-called magnetic fluid, Japanese Patent Publication No. 53-17118 and Japanese Patent Publication No. 54-4
No. 0069.

Magnetic fluids are broadly divided into those that use water as a solvent and those that use oil. Unlike ordinary suspensions, magnetic fluids have very good dispersibility, and the particle concentration can be reduced in the liquid by ordinary centrifugation or the application of a magnetic field. Since it can be regarded as a liquid with homogeneous magnetic properties without causing any difference, it appears that it can be used for intravascular administration as a carrier for anticancer drugs.

However, water-based magnetic fluids cannot be used as carriers for anticancer drugs because they dissolve and diffuse into blood, and oil-based magnetic fluids are not suitable because they contaminate the inner walls of blood vessels and block fine capillaries.

In view of the above-mentioned circumstances in chemotherapy for malignant tumors, the present invention aims to develop an anticancer drug composition that can be administered intravascularly, for example, and can also be used as a carrier to induce the anticancer drug locally. As a result of research aimed at this purpose, it was found that an emulsion of the above magnetic fluid containing an anticancer drug using water as a dispersion medium can be stably dispersed in the dispersion medium with a particle size (10μ or less) that can be administered intravascularly. Furthermore, it has been discovered that these emulsions can be locally introduced and used as carriers for anticancer drugs.

Although some of the purposes of the emulsion of this invention include oral administration or use in chemotherapy for the digestive system, the main purpose is to administer it intravascularly in chemotherapy for malignant tumors. This drug eliminates the drawbacks of other drugs.

The manufacturing process of the anticancer agent-containing emulsion of the present invention can be broadly divided into a process of manufacturing an anticancer agent-containing base liquid and a process of emulsifying the base liquid.

The manufacturing process of the base liquid of this invention involves first forming fine colloidal magnetic particles, then adsorbing a surfactant along with an anticancer agent onto the surface of the particles, and then using the magnetic particles to which the surfactant has been adsorbed as a base liquid. It consists of three steps of dispersion in the liquid, but these steps are not necessarily carried out independently or in conjunction with each other, but rather involve the formation of fine particles, the adsorption of surfactant, and the dispersion into the base liquid at the same time. It can also be implemented as

The colloidal magnetic fine particles herein refer to fine ferromagnetic particles with a particle size of 200A or less, and the material may include metals such as iron and nickel, or various oxides such as ferrite. Since fine metal powders have handling risks such as oxidation, explosion, and toxicity, it is preferable to use fine particles of ferrite in carrying out the present invention.

When ferrites become fine particles, they lose their ferromagnetic properties and exhibit superparamagnetism, but such properties of colloidal magnetic fine particles do not hinder the practice of the present invention.

As the surfactant to be adsorbed to the colloidal magnetic particles, unsaturated fatty acids such as oleic acid and linoleic acid are most preferable in terms of toxicity to the human body, adsorption to magnetic particles, and dispersibility, but other surfactants may also be used. No problem.

In principle, the amount of surfactant adsorbed to magnetic fine particles should be such that the active agent forms a monomolecular layer on the particle surface, but depending on the type of base liquid in which the fine particles are to be dispersed, adsorption may be a bimolecular layer. It is also effective.

In bimolecular layer adsorption, two layers may be made of the same surfactant, or the first and second layers may be made of different types of surfactants.

Oil or water can be used as the base liquid in which the magnetic fine particles are to be dispersed.

Although many anticancer drugs cannot be said to have high solubility in oil,
When a magnetic fluid emulsion is directly used as a carrier for an anticancer agent, oil should be used as the base liquid, since solubility with the anticancer agent is not an essential requirement when selecting oil as a base for reasons described later. I can do it.

The oil used as the base liquid is usually preferably a vegetable oil such as cottonseed oil, safflower oil or soybean oil, but sometimes animal oil or synthetic oil such as fluorocarbon oil can also be used.

Water also serves as a good base liquid for the magnetic fluid in the present invention, and is therefore particularly important when the anticancer agent is water-soluble or when excessive separation or deposition of the magnetic fluid in local areas is undesirable.

The amount of magnetic fine particles dispersed in the base liquid is important in setting the magnetization of the magnetic fluid and the holding force for locally retaining the magnetic fluid as a carrier of the anticancer agent.

The inventors of the present application determined the relationship between the concentration of dispersoid in a magnetic fluid and the magnetization of the magnetic fluid using magnetite having an average particle size of 150 A as magnetic particles, and as a result, the relationship shown in FIG. 1 was obtained.

In other words, in the range where the concentration of dispersoids in the magnetic fluid is up to 50% (by weight) of large pores, there is a proportional relationship between the magnetization of the magnetic fluid and the concentration of dispersoids, but the magnetic fluid is still retained locally as a carrier for the anticancer agent. In order for this to occur, the following relational expression must hold between the coercive force F and the magnetization M of the magnetic fluid.

F=M−H/4π where H: Magnitude of the magnetic field formed in the blood flow path M: Magnetization of the magnetic fluid in the magnetic field H Therefore, the dispersoid concentration in the magnetic fluid of this invention is expressed as
% (weight) as a limit, magnetization can be set according to the required holding force and the magnetic field formed in the blood flow path.

If the concentration of the dispersoid exceeds 50, the dispersibility becomes unstable and there is a risk of aggregation, so it is better to avoid this.

On the other hand, anticancer agents include alkylating agents, antimetabolites, antibiotics, hormones, alkaloids, etc., and those used in this invention are mainly alkylating agents and antimetabolites.

Typical alkylating agents include nitrogen mustard, N-oxide, chloroamptyl, triethylene melamine, sifurommannitol, CCNU (1
-3-cyclohexyl-1-nitrosourea),
Representative anti-metabolite drugs include 6-MP (6-mercaptopurine), 6-TG (6-thioguanine), and FT.
-207 (N1-5-fluorouradel), cytosine arabinoside (1-β-D-arabinofuranosilicytosine), and 5FU (fluorouracil), and these anticancer agents are included in the base liquid. and use it.

As a method for adsorbing an anticancer agent to magnetic powder, first, an anticancer agent dissolved in a solvent is mixed with magnetic powder, and the mixture is placed in a rotary evaporator to evaporate the solvent.

If the solubility of the anticancer drug is low and you want to adsorb a large amount, repeat this operation to obtain the desired concentration of the anticancer drug.

The anticancer agent-adsorbing magnetic powder obtained as described above is generally oil-based.

However, it cannot be completely dispersed in vegetable oil.

Therefore, in order to completely disperse this powder in vegetable oil, H
, L, B, low surfactants (for example, sorbitan monolaurate, sorbitan tritol oil, fatty acid esters, etc., alkylphenol ethylene oxide adducts, castor oil, ethylene oxide adducts of higher alcohols, lecithin, glycerin, Activators such as polyglycerin fatty acid ester, propylene glycol fatty acid ester, polyethylene glycol fatty acid ester, polyoxyethylene castor oil, hydrogenated castor oil derivatives, lanolin, beeswax derivatives, pyridoxine fatty acid ester, etc.) are added by 0.5 to 10.0 parts. By doing so, it is possible to obtain an oil-based magnetic fluid that is uniformly dispersed in vegetable oil.

Furthermore, when creating a W10 emulsion, a safe W10 emulsion can be created by gradually adding water to the above dispersion system and stirring at high speed with a homomixer or the like.

Approximately what range is the ratio of vegetable oil and water (10 to 90 parts, 9
0 to 10 parts).

On the other hand, when creating a 0/W emulsion, add water to
H, L, B.

High surfactant (H, L, B, 13 or more), e.g.
Polyoxyethylene castor oil, hydrogenated castor oil derivatives, polyoxyethylene sorbitan fatty acid ester, glycerin propylene glycol fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene alkylphenol ether, polyoxyethylene nonylphenol formaldehyde (
0.5-10%) and gradually added to the aforementioned vegetable oil magnetic fluid with high speed stirring to obtain a 0/W emulsion.

However, the emulsion produced by this method has the disadvantage that the particle size is rather large, so in order to produce an emulsion on the micron scale, it is desirable to produce an 0/W emulsion using phase inversion.

This method first involves dissolving the above-mentioned low H, L, and B surfactant in 100 parts of vegetable oil (0.5 to 10%), and then adsorbing a separately prepared anticancer agent into the magnetic powder. body (5
~50 parts) and stir at high speed.

Add 0.5 of the above-mentioned high H, L, B surfactant into this.
Slowly add 100-300 parts of ~10% dissolved water.

(It is desirable to use vegetable oil and water heated to 70 to 80°C.) Then, a W10 emulsion is obtained.

Furthermore, NaOH is added to this W10 emulsion. When 2 to 10 parts of an alkali such as KOH, alkanolamine, or morpholine NH4OH is added to raise the pH to 10 or more, the viscosity decreases rapidly and reversal of emulsification occurs.

That is, a 0/W emulsion is obtained. This product is a very fine emulsion that can be diluted to any desired ratio by adding it to water.

If you need a low-concentration emulsion, diluting it will be sufficient to achieve your purpose.

Furthermore, pH the product with HCt, H2SO4 or other organic acids.
I will return it to neutrality.

On the other hand, if a somewhat unstable emulsion is required, pH 5
If adjusted to ~6, a complex emulsion of O/W and Wlo will be obtained and the dispersibility in water will be poor.

As described above, the production of O/W emulsion using phase inversion is a manufacturing method that can be used in a very wide range of applications because the concentration adjustment and the dispersibility in water can be arbitrarily changed.

The oil droplets emulsified in this way are sufficiently finely divided and have a particle size of IOμ or less, so they do not obstruct blood flow even when administered into blood vessels.

Therefore, oil droplets made of oil-based magnetic fluid or oil droplets containing water-based magnetic fluid do not flow within the blood vessels, and there is no risk of deposition or occlusion.

Furthermore, since oil droplets are not easily compatible with blood, anticancer agents containing oil droplets are less likely to be eluted or transferred into the blood and circulate within the body.

If a magnetic field is provided locally, it will be guided and held.

Therefore, the emulsion according to the present invention can be used as a carrier for anticancer drugs.

If anticancer drugs and magnetic particles are bonded tightly enough to overcome the complex effects within blood vessels, they can be effectively held locally by a magnetic field; They do not separate from the magnetic particles, preventing absorption, adsorption, decomposition, etc., and as a result, they are unable to exert sufficient medicinal efficacy.

However, since the anticancer drug carrier according to the present invention is composed of oil droplets containing the anticancer drug dispersed as an emulsion in an aqueous dispersion medium, when a magnetic field is set, these emulsions can be easily dispersed locally by the action of the magnetic field. Once destroyed, the emulsion of magnetic fluid containing the anti-cancer drug or the anti-cancer drug and magnetic particles come into contact with the local area and exert a medicinal effect.

In this case, the O/W type emulsion is destroyed by the magnetic field, and the emulsion of the magnetic fluid containing the anticancer agent comes into direct contact with the local area.

In the case of the W10/W type emulsion, the aqueous magnetic fluid is first captured as oil droplets, and then the oil droplets are broken and the magnetic fluid containing the anti-cancer agent, or the anti-cancer agent, or the magnetic particles come into local contact.

In either case, the anticancer agent and magnetic particles are finally separated, and the anticancer agent exerts its medicinal effect when it comes into contact with the local area.

The magnetic particles are also retained by the magnetic field, occluding local capillaries and causing local blunting.

This increases the therapeutic effect. Of course, the emulsion of this invention is extremely stable outside of magnetic fields, so
Capillary occlusion by magnetic particles occurs selectively only in the local area where the magnetic field is formed, and does not interfere with blood flow in other areas.

In addition, selective concentration or adsorption of drugs to local areas can also be enhanced by adding to the magnetic fluid a substance that has excellent affinity for local areas along with anticancer drugs.

For example, albumin is selectively absorbed by the liver of human organs, and glucose is selectively absorbed by malignant tumors, so in the manufacturing process of the present invention, these substances are incorporated into the magnetic fluid by the same means as described above to form an emulsion. It is also effective to do so.

By applying a donut-shaped or ring-shaped annular permanent magnet such as barium ferrite to the local area, it becomes easy to guide the anticancer agent-containing magnetic emulsion of the present invention intensively into the magnetic field of the annular magnet.

Furthermore, if powdered ferrite is placed locally and a magnetic field is applied, the magnetic field can be concentrated in the area where the ferrite is placed, making it easier to introduce the anticancer agent-containing magnetic emulsion as described above.

Furthermore, substances such as dextran are known as a means of imparting sustained efficacy to locally held anticancer drugs;
It is also effective to incorporate these substances into a magnetic fluid to form an emulsion.

Examples of this invention will be shown below.

Example 1 100% each of 1 molar aqueous solutions of ferrous sulfate and ferric sulfate were collected and mixed, and a 6N NaOH aqueous solution was added to this with stirring.
It was added until H was 11.5.

This was heated to 60° C. with vigorous stirring and kept warm for 10 minutes to obtain a magnetite colloid suspension.

On the other hand, 9.6 - of a 3N aqueous NaOH solution was added to linoleic acid 81, and while stirring, 5C7 of water was added and heated to 60°C.

The resulting sodium linoleate was added to the magnetite suspension prepared previously and kept at 90° C. for 30 minutes while stirring.

After cooling, a HC7 solution of IN was added to adjust the pH to 5.5 to coagulate the suspended matter.

After repeating filtration and washing of the aggregated suspended matter, the separated cakes were placed in a dryer and dried at 110°C for 3 hours.

On the other hand, thoroughly polished in a mortar, the particle size was 1 μm in the field of view of an optical microscope.
5-fluorouracil lO1 determined as follows was added to 10 m of purified soybean oil, and the above dry cake 51 was further added and thoroughly mixed in an emulsifier to obtain a black magnetic fluid.

The magnetization of the obtained oil-based magnetic fluid containing the anticancer agent was 525 gauss in a magnetic field of 3.3 KOe.

Next, a 40 mole ethylene oxide adduct of hydrogenated castor oil (trade name NI KKOLHCO-) was added to 200-mol of physiological saline.
40 (manufactured by Nikko Chemicals) 0.2f was dissolved and added to the above magnetic fluid while stirring.

This mixture was passed through a homogenizer to obtain a brown emulsion.

This emulsion is stable, with no separation of oil and water even after standing for 10 days, and a particle size of I/iIOμ confirmed by an optical microscope.
It was below.

Also, add the above emulsion to the flow path of a glass tube with a diameter of 20φ,
Next, when a magnetic field of 5000 e (calculated value) was placed outside the center of the glass tube, it was confirmed that the oil droplets in the emulsion were captured by the magnetic field of the flow channel (Figure 2C).

Example 2 A mixture of 3001 magnetite and 201 oleic acid was pulverized and mixed continuously in a ball mill for 5 days, and then
- Add 400 heads of refined safflower oil to which 60 moles of hydrogenated castor oil mixed with fluorouracil 11 and ethylene oxide adduct (HCO-60) were added, and while cooling,
Grinding was continued for 0 days.

After leaving this solution for one day, safflower oil was further added to the filtrate, which was suction-filtered to remove the precipitate.
It was set to 0m1.

The magnetic fluid containing the anticancer drug thus obtained is centrifuged (
Even when the solution was heated at 200 rpm for 20 minutes, the components did not precipitate and separate, resulting in a uniform solution.

The concentration of iron compounds in the solution, determined as Fe2O3, is 4
20? /l, the content of 5-fluorouracil estimated from fluorine analysis is 1.89L? /l.

Next, sorbitan monooneate 20 mole ethylene oxide adduct (NIKKOLTO-10
) 4f was dissolved, and the above-mentioned magnetic fluid 100- was added to this solution while stirring, and further emulsified with a homogenizer to obtain a uniform and stable emulsion.

Example 3 The dry cake 101 obtained during the magnetic fluid manufacturing process in Example 1 was treated with glycerin monostearate (NIKKO).
L MGS-A) 1.2f added to physiological saline,
The mixture was stirred and dispersed to obtain an aqueous magnetic fluid.

20~ of dibromomannitol was added to this aqueous magnetic fluid, and stirring was continued to obtain an aqueous magnetic fluid containing an anticancer agent.

Example 4 Ferrofluid dried cake 101 was mixed with 6-mercaptopurine 1
% ethanol solution, and then the ethanol was removed using an evaporating dish.

Next, the cake with the anti-cancer agent adsorbed is placed in cottonseed oil 101 (sorbitan sesquioleate with low H, L, and B).
0.2 f was added and stirred to prepare a cottonseed oil magnetic fluid.

Example 5 Tucor HCO-60) 5? in hydrogenated castor oil in 100 d of water? was dissolved and gradually stirred into the cottonseed oil magnetic fluid prepared in Example 4 to form a W10 emulsion.

Add caustic soda to this solution until the pH becomes 10-11,
Upon vigorous stirring, a stable emulsion was formed.

This was adjusted to pH around 7 with HCl, and when this very stable emulsion was viewed under a microscope, it was found to be a W10/W emulsion.

Further, among these, the particle size of the oil droplets was 10 μm or less.

Example 6 46.3 μ/ml magnetite in ethyl oleate
Oil-soluble C as an anticancer agent in a solution dispersed at a concentration of
A mixture of CNU at a ratio of 307 q/d was used as the dispersoid, while casein was used at 1% (701%) as the amphoteric activator.
The dispersion medium was an aqueous solution containing an aqueous solution adjusted to pH 8, the above dispersoid 20 mA, and the dispersion medium 8077271! were mixed and emulsified using an emulsifying stirrer at 37° C. and 1000 rpm for 5 minutes to obtain an O/W emulsion.

Next, the rat was anesthetized and fixed so that its lungs were positioned between the gaps of the electromagnets, and the above 0/W emulsion 0.2r111 was administered into the tail vein.

A magnetic field of 012,000 G and 6,000 G was formed in the gap of the electromagnet, and after each magnetic field treatment was performed for 10 minutes, the lungs were removed, the lung homogenate was extracted with chloroform, and CCNU was quantified using a colorimetric method. When the amount of CCNU retained in the lungs was investigated, it was found that those subjected to magnetic field treatment retained a large amount of CCNU in the lungs, as shown in the following table.

Example 7 100 rnl of a solution prepared by adding 3 parts of atriazine as an aqueous anticancer agent to an aqueous magnetic liquid, 60 parts of oleic acid, 5 parts of stearic acid, 25% lecithin, and a surfactant (SPAN
80) 200 g of a 10% mixed solution was mixed and emulsified using an emulsifier to obtain Wlo emulsion solution A.

Furthermore, an aqueous solution B5007 in which 3% of sodium dodecyl sulfate salt and 2.5% of glycerin are dispersed and dissolved in water! and above A) 30077271! Mixed and emulsified LW107 Emulsion solution (C1 was obtained).

On the other hand, after inoculating 5 x 105 pieces of liver cancer AH-81 on the back of a rat, 24 hours later, the above C) was administered at a rate of 2.5rnl/Kg, and the back inoculation site was treated with a magnetic field of 8 KG for 30 minutes. Two weeks later, the rats were sacrificed and the weight of the sores was measured.

The results are shown in the table below. (2) The above results are values obtained using 5 rats each under the same conditions.

As is clear from the above results, when the above (C) was applied and treated with a magnetic field, a therapeutic effect was observed due to concentrated retention of the anticancer drug.

[Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between the dispersoid concentration in the magnetic fluid and the magnetization of the magnetic fluid. Figure 2 is a diagram showing the relationship between the dispersoid concentration in the magnetic fluid and the magnetization of the magnetic fluid. Figure 2 shows the emulsion of Example 1 added to a glass tube with a diameter of 20φ, and a magnetic field of 5000 e applied from the outside. FIG. 2A is a diagram showing the state of physiological saline, FIG. 2A is a diagram showing the state when emulsion is added to physiological saline, and FIG. Figure 3 shows the state when a magnet is brought close to the glass tube, Figure 3a is a micrograph of the dispersion liquid shown in Figure 2 of the above, magnified 1000 times, Figure 3 is the same as that of Figure 2C of the same. It is a micrograph diagram showing an agglomerated area magnified 1000 times.

Claims (1)

[Claims] 1. An anticancer agent characterized by containing an anticancer agent in an oily base liquid of colloidal magnetic fine particles, and further dispersing the base liquid in water to form an 0/W type emulsion. An emulsion containing cancer drugs. 2. An aqueous base liquid of colloidal magnetic particles is impregnated with an anticancer agent and then wrapped in oil, or the resulting oil droplets are dispersed in water, and W10
Emulsion 43 containing an anticancer drug, characterized in that it is formed by forming a /W-type emulsion. An emulsion containing anticancer agents.