JP7184633B2 - retinol encapsulating liposome - Google Patents

Description

TECHNICAL FIELD The present invention relates to a liposome encapsulating retinol, a composition containing the liposome, a method for producing the liposome, and the like.

Liposomes are artificial capsules composed of phospholipids and the like, which are major constituents of biological membranes. Phospholipids are amphiphilic structures and form lipid bilayers (in other words, bilayers). An oil-soluble substance can be incorporated into the bilayer membrane. Utilizing this property, some oil-soluble substances are encapsulated in liposomes for the purpose of enhancing their stability.

Phospholipids used to prepare liposomes may also be hydrogenated (ie, hydrogenated phospholipids). However, in order to prepare liposomes using hydrogenated phospholipids, it is required to go through a heating and stirring step at a temperature equal to or higher than the phase transition temperature of the phospholipids. On the other hand, when preparing liposomes using non-hydrogenated phospholipids, the liposomes can be prepared without any problem even if they are stirred without heating. Most of them are phospholipids having carbon-carbon double bonds (in other words, the constituent fatty acids are unsaturated fatty acids). Therefore, the phospholipids are easily oxidized, and the prepared liposome solution is also easily separated. That is, the formed liposomes have poor stability over time.

Based on the above circumstances, when liposomes are used to enhance the stability of encapsulating substances, hydrogenated phospholipids are usually used to prepare liposomes. However, as described above, when preparing liposomes using hydrogenated phospholipids, a heating operation is required. is lost.

Japanese Unexamined Patent Application Publication No. 2009-256268

The present inventors conducted repeated studies to provide a technique for stably and efficiently encapsulating retinol, an oil-soluble substance with low heat stability, in liposomes prepared using hydrogenated phospholipids.

The present inventors have found that by preparing retinol-encapsulating liposomes using highly pure hydrogenated phosphatidylcholine, retinol may not be destabilized even by heating during the preparation process. I came to let you.

The invention includes, for example, the subject matter described in the following sections.
Section 1.
A liposome encapsulating retinol,
containing hydrogenated phosphatidylcholine as a membrane component,
The hydrogenated phosphatidylcholine is hydrogenated phosphatidylcholine with a purity of 70% or more,
Liposomes.
Section 2.
Item 2. The liposome according to Item 1, wherein the phospholipid contained as a membrane component is only hydrogenated phosphatidylcholine with a purity of 70% or more.
Item 3.
A pharmaceutical composition, cosmetic composition, food composition, or oral composition containing the liposome according to Item 1 or 2.
Section 4.
A method for producing a liposome encapsulating retinol,
A method comprising the steps of preparing a liposome raw material solution containing retinol, water, and hydrogenated phosphatidylcholine with a purity of 70% or higher, and heating and stirring the raw material solution.
Item 5.
The step of heating and stirring the raw material liquid is
A step of heating and stirring the raw material liquid to 40 ° C. or higher,
Item 4. The method according to item 4.
Item 6.
A method of increasing the thermal stability of retinol comprising:
A method comprising at least mixing retinol, water, and hydrogenated phosphatidylcholine with a purity of 70% or higher.
Item 7.
A method for enhancing the thermal stability of retinol for encapsulation in liposomes prepared through the steps of heating and stirring, comprising:
A method comprising at least mixing retinol, water, and hydrogenated phosphatidylcholine with a purity of 70% or more to prepare a liposome raw material liquid.

Retinol can be stably encapsulated in liposomes containing hydrogenated phospholipids as membrane components, which require heating during preparation.

The retinol content measurement result of each liposome is shown as a relative value when the amount of retinol used in each liposome preparation is taken as 100%.

Each embodiment included in the present invention will be described in further detail below. The present invention
Specific liposomes encapsulating retinol, methods for producing the liposomes, compositions containing the liposomes, methods for enhancing the thermal stability of retinol, and the like are preferably included, but are not limited to these. It includes all disclosed herein and recognized by a person skilled in the art.

The retinol-encapsulating liposome included in the present invention contains hydrogenated phosphatidylcholine as a membrane component. Hereinafter, the liposome included in the present invention is sometimes referred to as "the liposome of the present invention". A composition containing the liposome of the present invention is sometimes referred to as "the liposome composition of the present invention".

The liposome of the present invention is a liposome encapsulating retinol, containing hydrogenated phosphatidylcholine as a membrane component, wherein the hydrogenated phosphatidylcholine is hydrogenated phosphatidylcholine with a purity of 70% or more.

The hydrogenated phosphatidylcholine preferably has a purity of 71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90, 91, 92, 93, 94, 95, 96, 97, 98, or 99% or more. Hydrogenated phosphatidylcholine can be purchased and used as a commercial product, and most of the commercial products are sold with a specified purity. For example, hydrogenated phosphatidylcholine with a purity of 55 to 65%, hydrogenated phosphatidylcholine with a purity of 70%, or hydrogenated phosphatidylcholine with a purity of 95% are commercially available. Hydrogenated phosphatidylcholine used in the present invention can be purchased from, for example, Lipoidkosmetik.

Hydrogenated phosphatidylcholine with low purity (less than 100%) includes phospholipids or hydrogenated phospholipids different from hydrogenated phosphatidylcholine. In other words, as used herein, hydrogenated phosphatidylcholine with a purity of less than 100% means a mixture of hydrogenated phosphatidylcholine and other phospholipids and/or hydrogenated phospholipids. Other phospholipids and/or hydrogenated phospholipids contained in hydrogenated phosphatidylcholine with a purity of less than 100% used in the present invention are not particularly limited, but lecithin and/or hydrogenated lecithin (e.g., soybean lecithin, water Hydrogenated soybean lecithin, corn lecithin, hydrogenated corn lecithin, cottonseed oil lecithin, hydrogenated cottonseed oil lecithin, egg yolk lecithin, hydrogenated egg yolk lecithin, egg white lecithin, hydrogenated egg white lecithin, etc.), especially soybean lecithin and/or water Soybean lecithin is preferred. As hydrogenated phosphatidylcholine with a purity of less than 100% used in the present invention, hydrogenated lecithin obtained by hydrogenating lecithin after increasing the purity of phosphatidylcholine can be preferably used. (that is, increase the purity) and further hydrogenated can be used more preferably.

In addition, in the liposome of the present invention, the phospholipid contained in the membrane is more preferably only hydrogenated phosphatidylcholine with a purity of 70% or more.

The liposomes of the present invention can be prepared, for example, by heating and stirring a liposome raw material solution obtained by mixing at least retinol, water, and phosphatidylcholine with a purity of 70% or more. A polyhydric alcohol is preferably blended in the raw material liquid. Polyhydric alcohols include, for example, glycerin, 1,3-butylene glycol, propylene glycol, and dipropylene glycol, with propylene glycol being particularly preferred. In addition, the raw material liquid may contain other components known to be used in the field of liposomes. For example, sterols, preservatives, and the like may be added. Preferred examples of sterols include cholesterol. Moreover, as a preservative, for example, paraoxybenzoic acid methyl ester (methylparaben) is preferably exemplified.

The content of each component in the liposome raw material solution is not particularly limited as long as it does not impair the effects of the present invention. For example, with respect to 4 parts by mass of hydrogenated phosphatidylcholine with a purity of 70% or more, retinol is preferably about 0.01 to 1 part by mass, more preferably about 0.05 to 0.5 part by mass, and still more preferably 0.08. About 0.2 parts by mass, and the polyhydric alcohol is preferably about 5 to 20 parts by mass, more preferably about 8 to 17 parts by mass, still more preferably about 10 to 15 parts by mass. Further, when sterol is included, it may be included, for example, in an amount of about 0.5 to 2 parts by mass with respect to 4 parts by mass of hydrogenated phosphatidylcholine with a purity of 70% or higher. Further, for example, water is preferably contained in an amount of about 80 parts by mass or more with respect to 4 parts by mass of hydrogenated phosphatidylcholine with a purity of 70% or more. Moreover, water is preferably contained in an amount of about 80% by mass or more of the entire liposome raw material solution.

Liposomes are prepared by heating and stirring the liposome raw material solution. In the operation, it is preferable to stir while heating. Heating is preferably carried out so that the liposome raw material solution reaches 40° C. or higher. , 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, or 75°C or higher. . As an example of a more specific heating and stirring operation, there is an operation of putting the liposome raw material solution in a beaker, placing the beaker in a high-temperature tank, and stirring the raw material solution in the beaker using, for example, a homomixer. mentioned. In this case, the temperature of the stirring vessel can be appropriately set so that the liposome raw material solution is at the above temperature or higher, and is preferably about 50, 55, 60, 65, 70, 75, or 80° C. or higher, for example.

The invention also includes a method of increasing the thermal stability of retinol. The method includes at least mixing retinol, water, and hydrogenated phosphatidylcholine with a purity of 70% or higher. This step corresponds to the step of preparing the liposome raw material solution described above. Therefore, the components mixed in this step are preferably the materials of the liposome raw material solution described above. In addition, the contents of the liposome raw material liquid and the liposome production method described above can be preferably applied to the method as they are.

The present invention also includes liposomal compositions containing the liposomes of the present invention. Preferably, the liposomal composition is an aqueous composition. In addition, the composition can be used, for example, as a pharmaceutical composition (in particular, an external pharmaceutical composition), a cosmetic composition, a food composition, an oral composition, and the like. These compositions can be prepared, for example, by conventional methods.

As described above, liposomes are prepared by heating and stirring the liposome raw material liquid, and a liposome suspension is obtained from the liposome raw material liquid. The liposome suspension thus obtained can be used as it is as a liposome composition containing the liposomes of the present invention. In addition, the liposome suspension can also be used as a liposome composition by appropriately blending known components for topical pharmaceutical compositions, oral compositions, and cosmetic compositions.

The liposomes and liposome compositions of the present invention may contain components other than those described above as long as the effects of the present invention are not impaired. Examples include oily components, lipids, water-soluble substances, physiologically active substances, and the like. In particular, ingredients known to be used in topical pharmaceuticals or cosmetics can be preferably used. Although not particularly limited, for example, disinfectants (especially phenolic disinfectants such as isopropylmethylphenol); organic acids such as lactic acid and citric acid; alkaline compounds such as potassium hydroxide and sodium hydroxide; phosphatidylglycerol and phosphatidylethanol lipids such as amines; natural polymers such as chitosan, fucoidan and hyaluronic acid; synthetic polymers such as polyethylene glycol and carboxyvinyl polymer; carbohydrates such as trehalose, lactulose and maltitol;

In this specification, the term "comprising" includes "consisting essentially of" and "consisting of." In addition, the present invention encompasses all arbitrary combinations of the constituent elements described herein.

Also, the various characteristics (property, structure, function, etc.) described for each of the embodiments of the invention described above may be combined in any way to identify subject matter encompassed by the invention. That is, the invention encompasses all subject matter consisting of any and all possible combinations of the features described herein.

The present invention will be described in more detail below, but the present invention is not limited to the following examples.

A liposome raw material solution was prepared according to the composition shown in Table 1 and heated and stirred to prepare liposomes of Examples 1 and 2 and Comparative Example 1. The value of each component in Table 1 indicates % by mass. In Table 1, PG indicates propylene glycol and PC indicates phosphatidylcholine. In addition, 90H is commercially available hydrogenated phosphatidylcholine Phosphoripon 90H (Lipoidkosmetik), 80H is commercially available hydrogenated phosphatidylcholine Phosphoripon 80H (Lipoidkosmetik), and S-10M is commercially available hydrogenated phosphatidylcholine Recinol S- 10M (Nikko Chemicals Co., Ltd.) are shown, respectively. 90H is hydrogenated phosphatidylcholine with a purity of 95% or higher, 80H is hydrogenated phosphatidylcholine with a purity of 70% or higher, and S-10M is hydrogenated phosphatidylcholine with a purity of 55-65%.

More specifically, according to the composition shown in Table 1, propylene glycol, hydrogenated phosphatidylcholine, retinol, cholesterol, and methylparaben were added to a beaker placed in a constant temperature bath at 80°C and dissolved (heated at 80°C). Water heated to 80° C. was added, and the mixture was stirred at 5000 rpm for 1 hour while being heated in a constant temperature bath of 80° C. to prepare liposome suspensions of Examples and Comparative Examples. The stirring treatment was performed using a homomixer (Homomixer MARK II: PRIMIX).

The amount of retinol contained in each liposome obtained was measured. Retinol was quantified by high performance liquid chromatography (WATERS Alliance HPLC system). (Column: SunShell C18 2.1 × 100 mm (2.6 μm), column temperature: 40 ° C., mobile phase: 0.1% acetic acid methanol solution: 0.1% acetic acid aqueous solution = 90: 10, flow rate: 0.3 mL / min, injection volume 10 μL, detector: 325 nm). A retinol standard solution was prepared by first weighing 0.01 g of retinol and adding it to 100 mL of methanol (100 ppm). After that, this was diluted to 10 ppm, 5 ppm, and 1 ppm, and these three points were used as a calibration curve. As for the liposomes, 10 μL of the liposome solution after heating was sampled, and 990 μL of IPA (isopropyl alcohol) was added and dissolved to obtain a measurement sample.

The results of measuring the retinol content of each liposome are shown in FIG. 1 as relative values when the amount of retinol used in preparing each liposome is taken as 100%. When hydrogenated phosphatidylcholine with a purity of 70% or more was used, the residual amount of retinol exceeded 75%. was found to increase.

Claims (7)

A liposome encapsulating retinol,
containing hydrogenated phosphatidylcholine as a membrane component,
Containing 0.05 to 0.3 parts by mass of retinol with respect to 4 parts by mass of the hydrogenated phosphatidylcholine,
The liposome, wherein the hydrogenated phosphatidylcholine is hydrogenated phosphatidylcholine with a purity of 70% or more. 2. The liposome according to claim 1, wherein the phospholipid contained as a membrane component is only hydrogenated phosphatidylcholine with a purity of 70% or more. A pharmaceutical composition, cosmetic composition, food composition, or oral composition containing the liposome according to claim 1 or 2. A method for producing a liposome encapsulating retinol ,
A step of preparing a liposome raw material solution containing 0.05 to 0.3 parts by mass of retinol and water with respect to 4 parts by mass of hydrogenated phosphatidylcholine having a purity of 70% or more, and a step of heating and stirring the raw material solution. including, method. The step of heating and stirring the raw material liquid is
A step of heating and stirring the raw material liquid to 40 ° C. or higher,
5. The method of claim 4. A method of increasing the thermal stability of retinol comprising:
A method comprising at least mixing 0.05 to 0.3 parts by mass of retinol with 4 parts by mass of hydrogenated phosphatidylcholine with a purity of 70% or more, and water. A method for enhancing the thermal stability of retinol for encapsulation in liposomes prepared through the steps of heating and stirring, comprising:
A method comprising at least the step of mixing 0.05 to 0.3 parts by mass of retinol with 4 parts by mass of hydrogenated phosphatidylcholine with a purity of 70% or more, and water to prepare a liposome raw material solution.

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