JPS6333414B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for producing stable dispersions of a water-immiscible liquid phase in an aqueous phase.

As is well known, when a water-immiscible liquid phase is mixed into an aqueous phase by mechanical stirring, e.g. by a hyperdisperser, the addition of an emulsifier is often necessary to stabilize the dispersion. The molecules of the emulsifier adsorb to the surface of the droplets of the water-immiscible liquid phase, forming a kind of continuous film that prevents direct contact between adjacent droplets when, for example, they receive a shot. prevent. The droplets of the water-immiscible liquid phase can contain substances soluble in the organic medium. Thus, a dispersion is produced which contains water-soluble substances in microscopic reservoirs similar to those formed by said droplets, which are capable of acting in concert with lipophilic substances contained in said droplets. It is hoped that

It is also known to produce aqueous dispersions of lipid globules, as described in French patents 2221122 and 2315991. The lipid globules have a structure consisting of several substantially concentric lipid membranes separated from each other by a layer of aqueous phase, and contain a water-soluble active substance in an aqueous chamber inside the lipid layer. Can be used to close (enclose).

According to the invention, it has been found that droplets of water-immiscible liquids can be stabilized by coexisting lipid globules of the type described above in the same dispersion. It can be expected that the amphiphilic liquid constituting the globule would adsorb onto the surface of the oil droplet and act as an emulsifier, but such stabilization of the oil droplet is due to the concentric inner thin films of the globule. Such stabilization according to the present invention is quite surprising to those skilled in the art, since it is believed that the Contrary to the expectations of those skilled in the art, globules consisting of concentric thin films of amphiphilic lipids stabilize droplets of immiscible liquid in the overall dispersion and vice versa. droplets contribute to the stabilization of lipid globules. The dispersions thus obtained are extremely stable under normal storage conditions. The globules remain intact, which is surprising since the organic liquid has a solvent effect on the amphiphilic lipids that make up the globules.

The dispersion obtained by the method of the invention therefore has:
It consists of an aqueous continuous phase suspending droplets of immiscible liquid and also concentric globules of lipid membranes. It is believed that the droplet is kept in a suspended state by the globules adsorbed on its surface. The formation and stability of this type of dispersion naturally depend firstly on the nature of the immiscible liquid in which it is dispersed, secondly on the nature of the amphiphiles forming the walls of the globules and finally on It depends on the conditions under which the product is manufactured.

Therefore, the present invention provides a concentric circular shape (substantially concentric circular shape is sufficient) in which the aqueous phase E is confined inside a lipid which is an ionic or nonionic amphiphilic substance capable of forming a thin film layer in water. ), and mixing this dispersion with a water-immiscible liquid phase L containing at least one water-immiscible liquid component. a stable dispersion of a water-immiscible liquid phase L in an aqueous phase D, characterized in that the phase L is dispersed in the phase D in the form of droplets by mechanically stirring the whole. Relating to a method of manufacturing.

In a preferred embodiment, the liquid phase L is added to the globule dispersion in order to mix the globule dispersion and the liquid phase L. The water-immiscible liquid phase L preferably contains one or more compounds, preferably one compound, each with a molecular volume of more than 200 cm ³ /mol.

Any known method for producing a dispersion of lipid globules in aqueous phase D can be used. For example, by dissolving the lipid in a volatile solvent, evaporating the solvent to create a thin film of lipid on the walls of the flask, and introducing into this flask the aqueous phase E to be confined, a dispersion of globules of the desired size is prepared. It is also possible to use a method consisting of mechanically stirring this mixture until . Preferably, the method described in French Patent No. 2,315,991 is used, according to which a liquid phase E to be confined to the liquid lipid is introduced at a temperature slightly above the melting point of the lipid to form a flat thin film. Form a layer and the resulting thin film phase,
adding an aqueous dispersion phase D, which may be the same or different from the aqueous phase E, and stirring vigorously, for example mechanically;
converting the flat thin film phase into a dispersion, thus forming an aqueous phase E
A dispersion of lipid globules in an aqueous phase D is obtained, entrapping the lipid globules. Depending on the means of preparing the dispersion (hyperdispersion machine and/or ultrasound) and on the duration of agitation (from 15 minutes to several hours), the average diameter of the globules varies between about 0.025 and 5 microns.

Dispersions of the water-immiscible liquid phase L are advantageously prepared in the ambient temperature range using ultradispersers, and the stability of the components of the composition (especially if they are volatile or oxidizing) is advantageous. ) and economically very advantageous in terms of safety. To obtain good stability of the dispersion, it is preferred that the average diameter of the droplets of the liquid phase L is between 0.1 and a few microns.

The lipids used in the production of globules are natural or synthetic ionic or nonionic amphiphiles containing one or more long chains of hydrocarbons or hydroxyl, ether, carboxyl, or phosphate groups per molecule. , 1 selected from amine group and ammonium group
Contains one or more hydrophilic groups.

Among the ionic amphiphiles preferably used are natural phospholipids (e.g. egg lecithin, soybean lecithin or sphingomyelin), synthetic phospholipids (e.g. dipalmitoyl-phosphatidylcholine or hydrogenated lecithin) and Cationic or quaternized compounds, such as didodecyl- or distearyl-dimethylammonium chloride or bromide. Amphoteric and anionic compounds can also be used.

Among the nonionic amphiphilic compounds preferably used are (a) those having the formulas R[ _-OCH2 -CHOH- _CH2 ] _-o OH and (In the formula, represents the statistical average value, 1 to 6
R is an integer of saturated or unsaturated linear or branched aliphatic chains with 12 to 30 carbon atoms, hydrocarbon residues of lanolin alcohols or 2-hydroxyalkyl groups of long-chain α-diols. (b) polyoxyethylated aliphatic alcohols and polyoxyethylated sterine; (c) oxyethylated or non-oxyethylated polyol esters; ) Natural or synthetic glycolipids such as cerebrosides, and (e) ethers or esters of polyols containing two long-chain alkyl groups (having at least 8 carbon atoms) as hydrophobic groups.

To change the permeability or surface charge of the globules,
A seed volume additive can be used together with the lipid compound forming the globule. Such additives which may optionally be added include long-chain alcohols and diols, sterins such as cholesterin, long-chain amines and their quaternary ammonium derivatives, dihydroxyalkylamines, polyoxyethylenated fatty amines, long-chain amino Alcohol esters and their salts and quaternary ammonium derivatives, phosphoric esters of alcohols, especially phosphoric esters of aliphatic alcohols such as dicetyl phosphate, alkyl sulfates such as sodium cetyl sulfate and certain polymers such as polypeptides and proteins. The additive described above may be a compound that is capable of forming globules by itself, but is then limited to compounds that are not capable of forming stable globules by themselves, such as dicetyl phosphate. Ru. Compounds that can form stable globules by themselves are excluded from additives (although they can be used as original globule membrane-constituting lipids).

A dispersion of lipid globules is prepared using 2 to 10% of lipid based on the total weight of the dispersion of globules to be mixed with liquid phase L. In a preferred embodiment, aqueous phases D and E are isotonic; in the simplest embodiment, aqueous phases D and E are
are the same.

To form the liquid phase L, it is advantageous to choose at least one compound from the group consisting of hydrocarbons, halogenated hydrocarbons, polysiloxanes, esters and ethers or polyethers of organic or mineral acids. Among the hydrocarbons, mention may be made of hexadecane and paraffin oil; among the halogenated hydrocarbons, mention may be made of perfluorotributylamine and perfluorodecahydronaphthalene.

In a preferred embodiment, the liquid phase L is introduced into the dispersion of globules in a proportion of 2 to 70% by weight, based on the weight of the dispersion of globules. Preferably, about 20 to 2000% of the liquid phase L, based on the amphiphilic substance contained in the globule dispersion, is introduced into the globule dispersion.

The applications of the stable dispersions obtained by the method of the invention are very wide, since they combine the fields of various types of emulsions with those of dispersions of ionic or non-ionic lipid globules. . Lipid globules allow a layer of aqueous phase containing a water-soluble active substance to be trapped inside a concentric lipid membrane, and furthermore, the lipid layer of the globule itself can contain an active organic substance. Among water-soluble active substances, mention may be made of organic or inorganic compounds with biological, fungicidal, fungicidal, insecticidal, vitamin or photosensitive activity, pharmaceuticals, chemical reagents, catalysts, dyes. , a complexing agent and a gas (O ₂ or CO ₂ ). Among the fat-soluble active substances that may be mentioned are antibiotics and antioxidants.

In the dispersion according to the invention, the advantage is increased by the presence of droplets of liquid phase L, which have the same activity as the substance confined inside the globules or are different from the substance inside the globules. This is because the droplets can contain substances that have opposite solubility and therefore essentially different activities and are soluble in the organic medium.
The liquid phase L has the advantage of acting as a solvent or carrier, so that it can transport the active substance to the site of application. For example, perfluorinated compounds are carriers of oxygen and carbon dioxide, so they can be expected to be used as blood substitutes. In some cases, the liquid phase L can also serve as a lubricant, extender, detergent or polishing agent. When the molecular weight is relatively small, it is very advantageous in the surface treatment or surface coating process to make the liquid phase L so volatile that it disappears after being deposited. The liquid phase L can also contain polymers, oligomers, prepolymers or monomers, and also fillers or additives such as dyes, opacifiers or gelling agents.

The aqueous continuous phase of the dispersion according to the invention can contain dissolved substances that are the same or different from those contained in the aqueous or lipid layer of the globules and in the lipid phase L.

The globules serve as the first type of microscopic reservoir, slowly releasing trapped water- and fat-soluble substances. Furthermore, the number of droplets of liquid phase L is 2
They act as microscopic reservoirs of the second type, in which dissolved compounds can be exchanged with organic substances, such as those of biological components. The action of the globules and the action of the liquid phase L are combined and complement each other,
Or a synergistic effect can occur. For example, the release of the active substance contained in the globules can be promoted by the combined action of temperature and solvent effects of the liquid phase L. This serves to carry out polymerization or crosslinking operations of the monomers.

In order that the invention may be better understood, some specific examples are set forth below, which are illustrative of the invention and in no way limit the scope of the invention.

Example 1 First step: Preparation of a dispersion of small spheres General formula (wherein R is a hexadecyl group and has a statistical average value of 3) 4.275 g of product, cholesterin 4.275
g and 0.45 g of dicetyl phosphate are weighed into a stainless steel pot.

This mixture is heated to a temperature of approximately 110°C until a clear liquid lipid phase is obtained, and then this is heated to 90°C.
Cool to temperature. 0.5M aqueous solution of glucose
Add 22.5g. The mixture is stirred gently with a spatula until a distinctly homogeneous phase is obtained.

This is cooled to a temperature of 70° C. and 68.5 g of the same 0.5M aqueous solution of glucose are added. the whole
ILA super dispersion machine (CX1020 type) rotating at 25000 rpm
Stir for 10 minutes. This is then cooled to 40°C.

Second stage: introduction of water-immiscible liquid phase L 12.5 g of perfluorodecahydronaphthalene is added to 100 g of the dispersion of globules obtained in the first stage. This mixture is stirred for 5 minutes using the same superdisperser used at the end of the first stage of this example.

A stable dispersion is thus obtained comprising globules with an average size of less than 1 micron and perfluorodecahydronaphthalene droplets with an average size of less than 1 micron. This dispersion can be used as a blood substitute.

To study the properties of this dispersion, the amount of glucose entrapped by the globules, used as perfluorodecahydronaphthalene stabilizer, is determined. For this purpose, the swelling S of the lipids that make up the globules is determined. If the weight of the confined glucose aqueous solution is expressed by WS and the weight of the lipid is expressed by WL, the swelling S is calculated by the formula S=WS/WS+WL.

We know the weight WL of the lipid to be used, but to make this decision we need to determine the weight WS. 5 g of the final product are placed in a collodion dialysis bag and dialyzed against 200 g of a 1.5% aqueous sodium chloride solution (isoosmotic) with stirring. After the dialysis equilibration time (24 hours) the amount of glucose not confined within the vesicles is determined in the external salt medium. The amount of glucose locked up, WS, is then deduced and calculated to be S=86%.

For comparison, the swelling of the globules before using the oil stabilizer is determined by dialysis of 5 g of the dispersion obtained at the end of the first stage of this example against 200 g of an isotonic solution of sodium chloride. It can be seen that the swelling S is 87%.

Example 2 Step 1: Preparation of a dispersion of globules 6.75 g of soybean lecithin, marketed under the name "Epikuron 200" by Lucas Mayer, 1.8 g of cholesterin and 0.45 g of dicetyl phosphate are dissolved in chloroform in a glass flask. Dissolve in 20ml.

This solution is freeze-dried in a Virtis apparatus model 1020. 91 g of 1M glucose aqueous solution are added to the anhydrous lipid mixture obtained after lyophilization. The mixture is left to swell for 2 hours at 40° C. under a nitrogen atmosphere. This was processed using the super dispersion machine in Example 1 for 10
Stir for a minute and then cool to room temperature. In this way, a dispersion of globules is obtained.

Second stage: introduction of water-immiscible liquid phase L 12.5 g of perfluorodecahydronaphthalene are added to 100 g of the dispersion of globules obtained in the first stage. This mixture is stirred for 5 minutes at room temperature using the superdisperser used in the first stage. A dispersion is thus obtained containing spherules with a diameter of less than 1 micron and perfluorodecahydronaphthalene droplets with an average diameter of less than 1 micron. This dispersion can be used as a blood substitute.

Determining the swelling of the globules used for stabilization of perfluorodecahydronaphthalene. Swelling S is
It can be seen that it is 74%. The percentage of trapped glucose that leaks out over 5 days is 36%. However, it is not possible to directly determine the swelling of the globules before dispersing the oil. In fact, it was found that a 5 g sample of the dispersion obtained at the end of the first stage dialyzed very rapidly when dialyzed against 200 g of a 3% aqueous sodium chloride solution (isoosmotic). That is,
The globules lose their integrity and regenerate a viscous phase that clogs the dialysis bag. It is therefore clear that in this example the perfluorodecahydro droplets stabilize the globules obtained in the first stage. The swelling of the globules before dispersing the oil was determined by another method using lower concentrations of lipids and glucose and after filtration on a gel column, the swelling S was 74%.
It turns out that it is. The percentage of trapped glucose that leaks out over 5 days is 45%. It has therefore been found that the stability of the confinement is improved by the presence of droplets of water-immiscible liquid L.

The method used for the two-step preparation of the dispersion according to the invention described below is identical to the method described in Examples 1 and 2 above. The examples described below therefore only list the products used and the corresponding amounts in each of the two stages of each example. The examples also describe swelling of the globules before and after dispersion of oil, if appropriate.

Example 3 First step: Preparation of a dispersion of small spheres The following products are used:

general formula (wherein R is a hexadecyl group and has a statistical average value of 3) 4.275 g β-sitosterin 4.275 g dicetyl phosphate 0.45 g glucose 8.19 g water 82.81 g Obtain a dispersion of spheres.

2nd step: Introduction of water-immiscible liquid phase L 12.5 g of silicone oil commercially available from Dow Corning under the name "DOW344" is added to 100 g of the dispersion of globules obtained in the first step. .

The swelling index of the globules before dispersion of silicone oil is 87%, and the swelling of the globules after dispersion of silicone oil is 85%. The average diameter of the globules in the resulting dispersion is 1 micron, and the average diameter of the silicone oil droplets in the resulting dispersion is 2 microns.

The resulting dispersion can be used as an antifoam agent.

Example 4 First step: Preparation of a dispersion of small spheres The following products are used:

general formula (wherein R is a hexadecyl group and is a statistical average value of 3) 3.8 g Cholesterin 3.8 g Dicetyl phosphate 0.4 g Cholesterin oleate 0.8 g Water 91.2 g to obtain a dispersion of globules.

Second stage: introduction of water-immiscible liquid phase L 40 g of perfluorodecahydronaphthalene is added to 100 g of the dispersion of globules obtained in the first stage. A dispersion is thus obtained in which the average diameter of the globules is less than 1 micron and the average diameter of the perfluorodecahydronaphthalene droplets is less than 1 micron.

The dispersion thus obtained can be used as a blood substitute.

Example 5 First step: Preparation of a dispersion of small spheres The following products are used:

9 g of soybean lecithin, commercially available from Lucas Mayer under the name "Epikuron 145" 91 g of distilled water A dispersion of globules was thus obtained.

Second stage: introduction of water-immiscible liquid phase L 12.5 g of hexadecane are added to 100 g of the dispersion of globules obtained in the first stage. This results in a dispersion containing globules with an average diameter of 0.5 microns and hexadecane droplets with an average diameter of 2 microns.

This dispersion can be used as a textile lubricant.

Example 6 First step: Preparation of a dispersion of small spheres The following products are used:

Synthetic diparmit leak -synthetic lecithin 8.5 g corystellin 1.0 g glicastine 1.0 g glucelhetto 0.5 g nacl 0.054 G KCCL 0.032 G MGCL _{0.032 G MGCL 2 0.007} G NAH ₂ PO ₄ 0.0096G NA _{2 PH7.44} Amount Distilled water Amount to bring the total amount to 110 g In this way, a dispersion of globules is obtained.

Second stage: introduction of water-immiscible liquid phase L 30 g of perfluorotributylamine are added to 100 g of the dispersion of globules obtained in the first stage.

A dispersion according to the invention is thus obtained comprising spherules with an average diameter of less than 1 micron and perfluorotributylamine droplets with an average diameter of less than 1 micron.

Dispersions of this type can be used as blood substitutes.

Example 7 First step: Preparation of a dispersion of small spheres The following products are used:

N-(tallow fat alkyl)-N-(dodecyl)-N-
Sodium salt of (N',N'-diethylaminoethyl)-aspartic acid (as described in French Patent No. 1397231) 4.95 g Cholesterin 3.6 g Dicetyl phosphate 0.45 g Glucose 8.19 g Water 82.81 g In this way, a dispersion of globules is obtained.

Second stage: introduction of water-immiscible liquid phase L 11 g of perfluorotributylamine are added to 100 g of the dispersion of globules obtained in the first stage.
Swelling of the globules before and after the second stage is determined to be 78%.

A dispersion according to the invention is thus obtained comprising spherules with an average diameter of less than 1 micron and perfluorotributylamine droplets with an average diameter of less than 1 micron. Dispersions of this type can be used as blood substitutes.

Example 8 First step: Preparation of a dispersion of small spheres The following products are used:

Dioctadecyl-dimethylammonium chloride
3g Distilled water 97g Thus a dispersion of globules is obtained.

Second stage: introduction of water-immiscible liquid phase L 12.5 g of hexadecane are added to 100 g of the dispersion obtained in the first stage. Thus the average diameter is 1
A dispersion of the invention is obtained containing micron spherules and hexadecane droplets with an average diameter of about 2 microns.

This dispersion can be used as a textile lubricant.

Example 9 First step: Preparation of a dispersion of small spheres The following products are used:

Oxyethylated phytosterin with a statistical average variance of 5 (commercially available from Henkel under the name GENEROL 115E5)
6.75g Cholesterin 2.25g Distilled water 91.0g A dispersion of globules is thus obtained.

Second stage: introduction of water-immiscible liquid phase L 25 g of paraffin oil is added to 100 g of the dispersion obtained in the first stage. Thus the average diameter is 0.5
A dispersion according to the invention is obtained containing micron globules and paraffin oil with an average diameter of 1 micron.

This dispersion can be used as an intestinal lubricant.

Of course, the specific examples described above are in no way limiting to the invention, and various desirable changes and modifications are possible without departing from the scope of the invention.

Claims (1)

[Scope of Claims] 1. A globular aqueous phase consisting of a concentric lipid thin film enclosing an aqueous phase E inside a lipid which is an ionic or nonionic amphiphilic substance capable of forming a thin film phase in water. A dispersion in D is prepared, this dispersion is mixed with a water-immiscible liquid phase L containing at least one water-immiscible liquid component, and the whole is mechanically stirred to form a small A method for producing a stable dispersion of a water-immiscible liquid phase L in an aqueous phase D, characterized in that the phase L is dispersed in the phase D in the form of drops. 2. The method according to item 1, wherein the globules made of concentric lipid thin films have an average diameter of 0.025 to 5 microns. 3. The method according to item 1, in which the liquid phase L is dispersed in the form of droplets with an average diameter of 0.1 to several microns. 4. The method according to item 1, wherein phase L is added to the globule dispersion in order to mix the globule dispersion and liquid phase L. 5 Liquid phase L has a molecular volume of 200 cm ³ /mol or more 1
The method according to item 1 above, which comprises one or more compounds. 6. The method according to item 5, wherein the liquid phase L consists of one type of compound. 7 To obtain a dispersion of globules in aqueous phase D, a flat thin film phase is created by introducing aqueous phase E into the liquid lipid, then aqueous phase D is added, and the desired globules are dispersed. The method according to item 1 above, wherein the whole is vigorously stirred to obtain a dispersion. 8. The method according to item 4 above, in which the whole is stirred vigorously at ambient temperature after adding the liquid phase L. 9 As the lipid constituting the thin film of the globules, each molecule contains one or more long chains of hydrocarbons, and one type selected from hydroxyl groups, ether groups, carboxyl groups, phosphoric acid groups, amine groups, and ammonium groups. 2. The method according to item 1 above, which uses at least one natural or synthetic ionic or nonionic amphiphile containing at least one hydrophilic group. 10 Natural phospholipids such as egg lecithin, soybean lecithin and sphingomyelin as ionic amphiphiles, synthetic phospholipids such as dipalmitoyl-phosphazylcholine or hydrogenated lecithin, cationic or quaternized compounds such as didodecyl-
or the method according to item 9 above, wherein at least one product selected from the group consisting of distearyl-dimethylammonium chloride or bromide, amphoteric compounds, and anionic compounds is used. 11 As nonionic amphiphilic substances, (a) have the formulas R[-OCH ₂ -CHOH-CH ₂ ]- _o OH and (In the formula, represents the statistical average value, 1 to 6
R is an integer of saturated or unsaturated linear or branched aliphatic chains with 12 to 30 carbon atoms, hydrocarbon residues of lanolin alcohols or 2-hydroxyalkyl groups of long-chain α-diols. (b) polyoxyethylated aliphatic alcohol or polyoxyethylated sterine; (c) oxyethylated or non-oxyethylated polyol ester; ) natural or synthetic glycolipids such as cerebrosides; and (e) ethers or esters of polyols containing two alkyl groups having at least 8 carbon atoms as hydrophobic groups. Method described. 12. The method according to item 1 above, wherein at least one additive is added to the amphiphilic substance forming the globules in order to change the permeability or surface charge of the globules to be formed. 13. The method according to item 1 above, wherein the amphiphile is used in an amount of 2 to 10% by weight based on the total weight of the globule dispersion to be obtained. 14 Paragraph 1 in which the aqueous phases D and E are isotonic.
The method described in. 15. The method according to item 14, wherein the aqueous phases D and E are the same. 16 To form the liquid phase L, at least one component selected from the group consisting of hydrocarbons, halogenated hydrocarbons and especially perfluorinated hydrocarbons, polysiloxanes, esters and ethers or polyethers of mineral or organic acids is added. Use the previous item 1
The method described in. 17 2 to 70% by weight based on the weight of the small sphere dispersion
The method according to item 1 above, wherein the liquid phase L is mixed with the dispersion of small spheres at a ratio of . 18. The method according to item 17, wherein the liquid phase L is introduced into the globule dispersion in a proportion of 20 to 2000% by weight based on the weight of the amphiphilic substance contained in the globule dispersion.