JP3611130B2 - Preparation method of fat emulsion - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an improved method for preparing a fat emulsion using lecithin as an emulsifier. Specifically, the present invention relates to a method of effectively using lecithin for emulsification, for example, as a method of preparing an intravenous lipo formulation.
[0002]
[Prior art]
Fat emulsions (lipo preparations) are generally fat emulsions containing phospholipids, and have been developed for the purpose of caloric supplementation in high calorie nutritional infusion therapy.
The fat emulsion is basically an O / W type oil containing 10 to 20% by weight of soybean oil, 1.2 to 1.8% by weight of egg yolk or soybean lecithin (emulsifier) and 2.5% by weight of glycerin (isotonic agent). It is an emulsion. In some cases, fatty acids (emulsification aids), cholesterols (stabilizers), polymer substances, medicinal ingredients, and the like are added to the basic formulation. The particle size of the emulsion is adjusted to 1.0 μm or less from the viewpoint of emulsion stability and prevention of intravascular thrombosis.
[0003]
The preparation method of the lipo preparation as described above is described in, for example, JP-A-58-2222014, JP-A-60-149524, JP-A-2-101209, JP-A-4-69340, etc. All fat-soluble components including a lecithin component and water components (sometimes not including an isotonic component) are mixed at the same time. For this reason, a part of lecithin does not collect at the interface, a lecithin single aggregate is formed and dispersed, and the phenomenon of not emulsifying the fat-soluble component and the water component occurs. Since some of the added lecithin does not function as an emulsifier, a product with a certain quality cannot be obtained even as a preparation.
[0004]
For example, lecithin used as an emulsion material for intravenous injection is purified and solid such as powder, nougat or block, and has a lamellar structure when directly suspended in water. Even if lecithin is present in the oil, if it is dispersed in a crystalline state, a part of the lecithin directly comes into contact with water by virtue of strong emulsification and takes a lamellar structure.
It is very difficult to transfer lecithin having a lamellar structure into oil again. Since these lecithins are not effectively used for emulsification, it is necessary to increase the amount of lecithin added in order to maintain the emulsion stability. At the same time, the lamellar structure is more easily aggregated in the blood than the emulsion, leading to an increase in particle diameter and generation of precipitation. In addition, the pharmacological activity of the preparation itself may be affected.
[0005]
In the examples of the above-mentioned Japanese Patent Application Laid-Open No. 58-222201, only the fat-soluble component of the raw material components is first heated and mixed at 40 to 75 ° C. This temperature range partially overlaps with the temperature range of the present invention. However, in this example, as can be seen from the fact that about 10 times volume of the water component at 20 to 40 ° C. was added thereafter, lecithin, which is the object of the present invention and does not cause turbidity, functions sufficiently as an emulsifier. It does not disclose such a mixing method.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to prepare a stable emulsion by suppressing generation of a lamellar structure of a raw lecithin in preparation of a lecithin-containing fat emulsion.
[0007]
[Means for Solving the Problems]
The present invention relates to a method for preparing a fat emulsion using lecithin as the main emulsifier , firstly heating the oil component including lecithin to a temperature at which the lecithin does not cause turbidity in the oil component, and then does not cause turbidity. The emulsion is emulsified in a temperature range within the range of 15 ° C. added to the temperature so that the lecithin is not turbid during the preparation.
In order to ensure that all lecithin is used for the uniform emulsification of fats and oils, the temperature (hereinafter referred to as “cloud point”) at which lecithin hydrates and turbidizes only the fat-soluble components (including lecithin) in advance is not exceeded. The mixture is heated and mixed at a temperature of 5 ° C., and further emulsified with a water component at a temperature equal to or higher than the cloud point, thereby suppressing generation of a lamellar structure (liquid crystal component) and obtaining a stable emulsion.
[0008]
The cloud point of lecithin varies depending on the type of fat and oil to be used, the type and amount of fat-soluble components (fatty acids, fatty acid esters, sterols and the like) to be added or originally contained, and moisture. It also depends on the component composition of lecithin itself. The cloud point can be measured simply by heating until all the fat-soluble components are dissolved transparently, then slowly cooling, and observing it as a temperature at which the transparent solution starts to become cloudy. At temperatures below the cloud point, tens of percent or more of lecithin is not used for emulsification and forms another structure, but when emulsified above the cloud point, more than 90% of lecithin is used for emulsification, especially in the liquid crystalline state. Things are extremely few. This increases the stability of emulsification.
[0009]
On the other hand, it is desirable to dissolve and emulsify the fat-soluble component at a temperature as low as possible in order to avoid oxidative degradation of the oil, emulsification aid and lecithin used. In addition, when an emulsion is used as a carrier of a drug that is relatively unstable to heat, it is desirable to prepare at the lowest possible temperature in order to prevent loss of the drug due to heat. According to the method of the present invention, since the emulsion can be stabilized by emulsification at a temperature higher than the cloud point, it is not necessary to perform the treatment at an unnecessarily high temperature. The object can be sufficiently achieved in a temperature range of within ° C.
[0010]
In the emulsion prepared in the present invention, there is little generation of a lamellar structure such as a liposome (lecithin liquid crystal membrane package), and lecithin accumulates at the interface of the emulsion and is effectively used.
Conventional liposomes tend to exhibit pharmacologically specific kinetics as a dosage form, and changes in the liposome content may lead to changes in the pharmacological properties of the entire emulsion due to the influence of the liposomes. It is not uncommon for liposomes to have particles of a size that can be visually observed because they are generally less stable in blood and tend to aggregate.
Thus, the high content of liposomes and the varying content were important problems for the stability of pharmacological effects. However, the emulsion prepared according to the present invention has very few such problems.
The cloud point when blending 10 g of refined olive oil with 1.2 g of egg yolk lecithin is 54 ° C., and the cloud point when blending 10 g of refined soybean oil with 1.8 g of egg yolk phosphatidylcholine and 0.24 g of oleic acid is 53 ° C. It is.
[0011]
In this invention, fats and oils are highly purified refined fats and oils, what kind of thing may be used if it can be used for the emulsion formulation for intravenous injection, and refined olive oil and refined soybean oil are illustrated. For example, refined olive oil and refined soybean oil have an unsaponifiable matter of 0.5% or less, preferably 0.1% or less by purification such as steam purification.
[0012]
In the present invention, lecithin is purified lecithin such as egg yolk lecithin and soybean lecithin, and can be prepared by a fractionation method using a conventional organic solvent. That is, for example, crude egg yolk phospholipids are dissolved in cold n-hexane-acetone, gradually added with stirring, insolubles are collected by filtration, and this operation is repeated once more, and then the solvent is distilled off. By doing so, purified lecithin can be obtained. This mainly consists of phosphatidylcholine and phosphatidylethanolamine, and also contains phosphatidylinositol, phosphatidylserine, sphingomyelin and the like as other phospholipids. Moreover, the lecithin obtained here can be further fractionated by the difference in solubility in ethanol, or a specific component, mainly phosphatidylcholine concentrated or isolated by column chromatography can be used.
[0013]
The fat emulsion is mainly composed of 5 to 50% by weight of fat and oil, 1 to 50 parts of lecithin, preferably 5 to 30 parts, and an appropriate amount of water with respect to 100 parts of fat and oil. The content of lecithin in the fat emulsion can be appropriately increased or decreased depending on the form and use of the emulsion, but is generally contained in a very small amount, for example, 0.5 to 50 mg / ml in the emulsion.
[0014]
In the present invention, when emulsification is performed at an emulsification temperature equal to or higher than a temperature at which lecithin does not cause turbidity in the oil component, an alcohol can be further added. Examples of the alcohol include ethanol, methanol, and isopropanol. Preferably, the alcohol is ethanol or hydrous ethanol. After adding alcohol to lecithin in advance, it can be added to fats and oils. Alcohol is effective even at about 1% of fats and oils. Depending on the components of the fats and oils, even a trace amount may show a sufficient effect. In the case of an intravenous emulsion, if ethanol is used as an alcohol, it is easily biodegraded and has no adverse effects on the human body. Even if this amount of ethanol remains, the preparation and stability of the formulation may be improved, but never worsen.
[0015]
The method for producing the fat emulsion of the present invention requires that a predetermined amount of oil, lecithin, fat-soluble components (fatty acids, fatty acid esters, sterols) and the like are mixed in a predetermined temperature range and then prepared in a predetermined temperature range. Add a sufficient amount of water, coarsely emulsify with a normal homogenizer (eg, TK homomixer, polytron, etc.), then homogenizer suitable for fine emulsification (eg, pressure jet type homogenizer, ultrasonic homogenizer, etc.) Is used to make an oil-in-water emulsion. Depending on the production convenience, additives such as stabilizers and isotonic agents may be added after the formation of the fat emulsion.
[0016]
Several emulsification machines have long been known for the preparation of emulsions, but their atomization capabilities are different. Since the fat emulsion is a formulation directly administered intravenously, it is prepared as an emulsion having an average particle size of oil droplets of 0.2 to 0.3 μm in consideration of the size in the blood vessel. Therefore, a high-pressure homogenizer is essential for preparing a fat emulsion. In order to maximize the capability of the high-pressure homogenizer, it is effective to perform atomization of about several μm as a pretreatment. The particles are very fine, the average particle size is 1.0 μm or less, and the storage stability is very good.
[0017]
The fatty acid having 6 to 22 carbon atoms as the emulsification aid can be used as long as it can be added to pharmaceuticals. The fatty acid may be either linear or branched, but linear stearic acid, oleic acid, linoleic acid, palmitic acid, linolenic acid, myristic acid, etc. are preferably used. As these salts, physiologically acceptable salts such as alkali metal salts (sodium salt, potassium salt, etc.) can be used. Cholesterol or phosphatidic acid as a stabilizer can be used as long as it can be used for medicine.
[0018]
As the albumin, vinyl polymer, and nonionic surfactant used as the polymer substance for the emulsion stabilizer, the following are preferable. That is, albumin derived from humans is used because of antigenicity. Examples of the vinyl polymer include polyvinyl pyrrolidone. Further, as the nonionic surfactant, polyalkylene glycol (for example, polyethylene glycol having an average molecular weight of 1000 to 10,000, preferably 4000 to 6000), polyoxyalkylene copolymer (for example, average molecular weight of 1000 to 20000, preferably 6000 to 10,000 polyoxyethylene-polyoxypropylene copolymer), hydrogenated castor oil polyoxyalkylene derivatives (for example, hydrogenated castor oil polyoxyethylene- (40) -ether, same- (20) -ether, same- ( 100) -ether), castor oil polyoxyalkylene derivatives (for example, castor oil polyoxyethylene- (20) -ether, i- (40) -ether, i- (100) -ether, etc.) can be used.
[0019]
The drugs include prostaglandin analogs such as prostaglandin E1, highly unsaturated fatty acid cascade hormones such as leukotriene, fat-soluble hormones such as steroid hormones such as gestagen, and fat-soluble hormones such as adriamycin. Anti-cancer drugs, non-steroidal fat-soluble analgesics such as ibuprofen, other fat-soluble components and derivatives with pharmacological action, and fat-solubilized derivatives of drugs that are not fat-soluble Drugs. Emulsions of these drugs are used after being dissolved in fats and oils, emulsifiers and other fat-soluble components.
[0020]
【Example】
The details of the present invention will be described in Examples. The present invention is not limited to these examples.
In the following examples, the average particle size was measured with Zetasizer 3 (Malvern, UK).
[0021]
Example 1
100 g of purified olive oil (made by Showa Sangyo Co., Ltd.) and 12 g of purified egg yolk lecithin (manufactured by Kewpie Co., Ltd.) are mixed at 60 ° C., and then glycerin isotonic solution heated to 60 ° C. is added to make 1000 ml. After the rough emulsification, the emulsion was obtained by 10 passes at a total pressure of 600 kg / cm ² using a high-pressure emulsifier (Manton Gaurin type) while maintaining the temperature at 60 ° C. The average particle size of this fat emulsion was 189 nm in distilled water, and ultracentrifugation precipitated solids at 100,000 G were less than 1% of the total solids. The average particle size increase rate after 24 hours at 37 ° C. in the serum of this emulsion was 2%.
[0022]
Example 2
10 g of purified soybean oil (produced by Showa Sangyo Co., Ltd.) 1.8 g of egg yolk phosphatidylcholine (isolated of phosphatidylcholine by high performance liquid chromatography using egg yolk lecithin produced by Kewpie Co., Ltd.) After mixing 0.24 g of oleic acid at 55 ° C. and adding to glycerin isotonic solution heated to 55 ° C. to make 100 ml, coarsely emulsified with a stirring type homomixer, using a high-pressure emulsifier (trade name: Nanomizer) An emulsion was obtained by 10 passes at a total pressure of 450 kg / cm ² . The average particle size of this fat emulsion was 199 nm in distilled water, and ultracentrifugation precipitated solids at 100,000 G were 1% or less of the total solids. The average particle size increase rate after 24 hours at 37 ° C. in the serum of this emulsion was 3%.
[0023]
Comparative Example 1
After adding 12 g of egg yolk lecithin and isotonic solution of glycerin to 100 g of purified olive oil to make 1000 ml, coarsely emulsified with a stirring type homomixer at 60 ° C. and then using a high-pressure emulsifier (Mantongaurine type) at a total pressure of 600 kg / cm ² . The emulsion was obtained by passing. The average particle size of this fat emulsion was 194 nm in distilled water, and ultracentrifugation precipitated solids at 100,000 G were 4.2% of the total solids. The average particle size increase rate after 24 hours at 37 ° C. in the serum of this emulsion was 25%.
[0024]
Comparative Example 2
12 g of egg yolk lecithin was mixed at 60 ° C. with 100 g of purified olive oil, and then cooled to 20 ° C. Add glycerin isotonic solution adjusted to 20 ° C to 1000ml, coarsely emulsify with a stirring type homomixer, and then 10 passes at a total pressure of 600kg / cm ² using a high-pressure emulsifier (Manton Gaurin type) while maintaining at 20 ° C. To obtain an emulsion. The average particle size of this fat emulsion was 212 nm in distilled water, and the ultracentrifugation precipitated solid at 100,000 G was 3.4% of the total solids. The average particle size increase rate after 24 hours at 37 ° C. in the serum of this emulsion was 19%.
[0025]
Comparative Example 3
To 10 g of purified soybean oil, 1.8 g of egg yolk phosphatidylcholine, 0.24 g of oleic acid, and glycerin isotonic solution are added to make 100 ml, and the mixture is roughly emulsified with a stirring type homomixer at 55 ° C., and then a high-pressure emulsifier (trade name: Nanopass was used for 10 passes at a total pressure of 450 kg / cm ² to obtain an emulsion. The average particle size of this fat emulsion was 187 nm in distilled water, and the ultracentrifugation precipitated solid at 100,000 G was 3.6% of the total solid. The average particle size increase rate after 24 hours at 37 ° C. in the serum of this emulsion was 31%.
[0026]
Comparative Example 4
After 10 g of purified soybean oil and 1.8 g of egg yolk phosphatidylcholine and 0.24 g of oleic acid are mixed at 60 ° C., the mixture is cooled to 30 ° C. and clouded. Add glycerin isotonic solution heated to 30 ° C to make 100 ml, coarsely emulsify with a stirring type homomixer, and then emulsify by 10 passes at a total pressure of 450 kg / cm ² using a high pressure emulsifier (trade name: Nanomizer). I got a thing. The average particle size of this fat emulsion was 200 nm in distilled water, and the ultracentrifugation precipitated solid at 100,000 G was 3.1% of the total solids. The average particle size increase rate after 24 hours at 37 ° C. in the serum of this emulsion was 23%.
[0027]
【The invention's effect】
It is possible to prepare a stable lecithin-containing fat emulsion while suppressing the occurrence of the lamellar structure of the raw lecithin. A lecithin-containing fat emulsion, which is a product of uniform quality that is not affected by the presence state of the raw material lecithin (liquid crystal, solid, etc.) and has no difference between lots, can be prepared.

Claims (3)

In a method for preparing a fat emulsion containing at least lecithin, fats and oils and using lecithin as the main emulsifier, the oil component including lecithin is first heated and the cloud point at which lecithin does not cause turbidity in the oil component. After making the above temperature , emulsify in the temperature range from the temperature above the cloud point to the temperature of 15 ° C added to that temperature, and mix and emulsify the water component and other additive components from the mixing and dissolution of the oil component. A method for preparing a fat emulsion, wherein the temperature range is controlled during all preparation steps until an emulsion preparation is obtained . The method for preparing a fat emulsion according to claim 1, wherein the emulsification is carried out in a temperature range of 69 ° C or less from the cloud point . The method for preparing a fat emulsion according to claim 1 or 2, wherein the fat emulsion is an intravenous lipo preparation.