DE19748796A1 - Process for the production of liposomes - Google Patents

Abstract

The invention relates to a method for producing liposomes or dispersions of liposomes in an aqueous phase. The invention is characterized in that (I) (a) one lipid or one lipid mixture, (b) one optional oil phase, (c) one aqueous phase, (d) and one or more optional tensides are mixed together and homogenized at a temperature which is above the melting temperature of a lipid or lipid mixture and of the oil phase (in the case that one such oil phase is used). (II) The entirety of the homogenized components (a), (b), (c) and (d) forms a lamellar phase in a temperature interval [ theta ]. (III) The temperature of the homogenized mixture comprised of (a), (b), (c) and (d) is brought to a value within the temperature interval [ theta ] (production temperature theta 1) or to a value above the temperature interval [ theta ] (production temperature theta 2). (IV) Water is added to the homogenized mixture comprised of (a), (b), (c) and (d) and the formed liposomes or the formed liposome dispersion is brought to a temperature theta 3 which is below the temperature interval [ theta ].

Description

The present invention relates to a method for producing liposomes. Furthermore, the present invention relates to the cosmetic, medical or pharmaceutical pharmaceutical use of such structures.

Certain biomolecules that are structurally not at all uniform are in the biochemical terminology summarized under the term "lipids". in the Original meaning is to be understood by "lipids" fats (grch .: το λ℩ποζ = das Fat, oil), i.e. carboxylic acid esters of glycerol.

In a broader sense, this term means a group of insoluble in water Understood molecules that are characterized by at least one hydrophilic molecular range and at least one pronounced lipophilic Mark out the molecular range. The phosphoric acid esters of acylated glycerols so-called "phospholipids" and other compounds belong to this overall quite inhomogeneous group of chemical compounds.

Due to the structural conditions, lipids do not usually form real molecular solutions in vitro, for example in a mixture with water, but rather they either form colloids, they usually combine to form so-called micelles, in which the lipophilic molecular areas of the lipid molecules are located inside the micelle are located and the hydrophilic regions of the lipid molecules represent the outer region of the micelles, as described in FIG. 1, or else they form liquid-crystalline phases. The lipid molecules have a hydrophilic area (h) and a lipophilic area (I). The micelle (M) shown in FIG. 1 represents a sphere of lipid molecules, the interior of which is filled by the lipophilic residues of the molecules. Since the micelles are present in an aqueous environment (W), it is obvious that the outer shell of the micelle is formed by the hydrophilic groups of the lipid molecules.

The ability of the lipids to arrange themselves in the known lipid bilayers is of the greatest biological importance. Lipid membranes can, for example, be linear, curved (cubic phases, L ₃ phases) or self-contained (vesicles, L ₄ phases).

In an aqueous or generally polar environment, the individual lipid molecules attach to one another in such a way that two monomolecular layers of lipid molecules arranged in parallel come to lie on one another at their lipophilic regions. This is shown in Fig. 2. The lipid molecules have a hydrophilic area (h) and a lipophilic area (I). The lipid bilayer (L) shown in FIG. 2 represents a membrane made of lipid molecules, the interior of which is filled by the lipophilic residues of the lipid molecules. Since the lipid bilayer is present in an aqueous environment (W), it is obvious that the outer shell of the lipid bilayer is formed by the hydrophilic groups of the lipid molecules.

In FIG. 6, the near structure of a lamellar phase is shown in simplified form. The lipid bilayers shown represent membranes made of lipid molecules which have a hydrophilic region (h) and a lipophilic region (I). The inside of the membranes is filled out by the lipophilic residues of the lipid molecules. The lamellar structure is created by "stacking" the membranes, with the interlamellar spaces between the individual membranes being filled with water.

Although, as mentioned before, due to the structural conditions mostly merge into so-called micelles, it is under certain Conditions also technically possible, lipids to vesicles or liposomes to process.

Vesicles or liposomes are spherically closed microscopic objects which are delimited on the outside by a lipid bilayer and which contain a water phase inside. This is shown in Fig. 3. The lipid molecules have a hydrophilic area (h) and a lipophilic area (I). The lipid bilayer (L) of the vesicles shown in FIG. 3, as can be better seen in the enlarged detail, represents a hollow spherical membrane made of lipid molecules, the interior of which is filled by the lipophilic residues of the lipid molecules. Since the lipid bilayer is present in an aqueous environment (W), it is obvious that the outer shell of the lipid bilayer is formed by the hydrophilic groups of the lipid molecules. The center of the vesicles is filled with an aqueous phase. The diameter of liposomes usually ranges from a few (typically about 25) nanometers to about 1 µm.

In FIG. 4, a so-called multilamellar vesicles (M) is shown in cross-section and with enlargements. It consists of several - here two - lipid double membranes as the outer shell, the lipid double membranes consisting of lipid molecules with a hydrophilic region (h) and a lipophilic region (I). A thin layer of a polar, in particular aqueous phase (w) is generally arranged between the lipid double membranes. Inside the multilamellar vesicle is another polar, usually aqueous phase, which can also be loaded with active substances (here: Q)). It is also true for multilamellar vesicles that the lipid double membrane can also be loaded with active substances, which are then generally lipophilic in nature.

The preparation of liposomes, for example, is well known to the person skilled in the art common. One method is ultrasound treatment, for example of a lipid water system, with the choice of suitable lipids being obtained Liposomes only need to be filtered off. But also vesicle extrusion correspondingly suitable lipids through a membrane filter with a pore size of typically around 100 nm leads to the formation of liposomes.

Normally, the basic components of the Li piddoppelmembran selected from the group of phospholipids, often lecithin. Occasionally, especially with the so-called niosomes, also become non-ionic Surfactants used as shell material.  

In general, a distinction is made between "empty" liposomes, which consist of a Envelope and an aqueous interior, and "loaded" liposomes, the Interior represents an aqueous phase, which with water-soluble active ingredients is provided, or the shell is provided with lipophilic active ingredients. Microorganisms can be encapsulated, as it were, liposomally, In contrast to "normal" liposomes, "transfersomes" are said to be intact in the Penetrate epidermis. In general, however, liposomes do not penetrate intact, but adsorb to or in the top layers of the stratum corneum. There is much evidence that liposomes endocytotically into the body cell be included. In addition to topical administration of liposo preparations containing menopause also intravenous administration.

Of the lipids, the phospholipids in particular are of the highest biological quality Interest as this is the basic substance of the cell membranes of all living cells or represent their cell organelles.

Well over a thousand lipids from cell membranes have so far been isolated and identified graces. The vast majority of phospholipids take up about 40 to over 90% of the total lipid content of the cell. There are five types of Dominating phospholipids: phosphatidylcholine, phosphatidylethanolamine, Phosphatidylserine, cardiolipin (diphosphatidylglycerol) and sphingomyelin. Glycolipids are important components of the plasma membrane, the myelin endoplasmic reticulum and certain organelles, such as the Chloroplast photosynthesis of driving organisms.

Of great importance among the phosphatidylcholines, for example, are the lecithins, which are characterized by their general structure

distinguish, wherein R ₁ and R _{2 are} typically unbranched aliphatic radicals having 15 or 17 carbon atoms and up to 4 cis double bonds. Lecithins are not only important in the living cell, they are also preferably used as a basic component for the outer layer of the most common commercially available liposomes.

The basic structure of the sphingolipids is sphingosine or phytosphingosin, which are characterized by the following structural formulas:

Modifications of sphingolipids are characterized, for example, by the general basic structure

in which R ₁ and R ₃ independently of one another represent saturated or unsaturated, branched or unbranched alkyl radicals of 1 to 28 carbon atoms, R _{2 is} selected from the group: hydrogen atom, saturated or unsaturated, branched or unbranched alkyl radicals of 1 to 28 carbon atoms, sugar radicals, phosphate groups esterified or unesterified with organic radicals, sulfate groups esterified or unesterified with organic radicals and Y represents either a hydrogen atom, a hydroxyl group or another hetero-functional radical.

The most common sphingolipids include the naturally occurring ceramides, Cerebrosides, gangliosides, sphingophospholipids, of these in particular Sphingomyeline, Sphingosulfatide and Glycosphingoside as well as by chemical Analogs available for synthesis, examples of which are given below the:

Ceramides

R ₁ and R ₃ represent alkyl radicals, R ₂ = H.

Sphingophospholipids

R ₁ and R ₃ represent alkyl radicals, R ₄ represents an organyl radical.

Sphingomyeline are organylphosphorylated sphingolipids of the type

If R _{2 is} selected from the group of sugar residues in the structural formula of the ceramides, a distinction is usually made between whether monoglycosylceramides or di, tri or generally oligoglycosylceramides are present. Monoglycosylceramides are commonly called cerebrosides:

Oligoglycosylceramides are mostly called gangliosides.

Common sphingolipids are ceramide I, II, III and IV, glucosylceramide, Lactosylceramide and the gangliosides GM 1, 2 and 3.

Classic manufacturing processes for low-viscosity liposome dispersions are the:

(1) Hydration process

A mixture of phospholipids is dispersed in water and then in evaporated in a glass flask. A lipid film forms on the wall, the is moistened with a buffer solution, whereby liposomes spontaneously form. It multilamellar vesicles usually develop.

(2) Sonication with ultrasound

A phospholipid mixture dispersed in water is ultrasonically crushed, forming liposomes.

(3) The "French press" process

A phospholipid mixture dispersed in water is in transferred to liposomes in an extruder.

(4) The solvent injection method

The lipids, especially phospholipids, are in an organic Solvents such as ether, methanol dissolved and injected into warm water, in which the substance to be enclosed is in solution. After removing the solvent unilamellar vesicles usually form in a vacuum.

(5) The detergent method

An aqueous mixed micelle solution consisting of phospholipids, a detergent and the encapsulating substance is produced and then removed Detergent by dialysis or column chromatography.

(6) The "Reverse Phase Evaporation"

In excess of the organic phase is in a buffer, the phospholipids and a water-in-oil emulsion for the substances to be enclosed and then evaporated the volatile organic phase in vacuo. At the end of Evaporation process creates a suspension of large unilamellar Vesicles.

Certain lipid mixtures can result in liposome dispersions without using the methods described above. This so-called "spontaneous formation of vesicles" is determined by selecting the lipids, pH changes (Proc. Natl. Acad. Sci. USA, Vol 79, p. 1683, 1982) dilutions from ethanol-containing fatty alcohol and fatty acid mixtures (Biochemistry, Vol 17, No. 18, p. 3758, 1978) or from ethanol-containing phospholipid solutions (J. Pharm. Parinacol. 43, p. 154, 1991). Mixtures of phosphatidylcholine and lysophosphatidylcholine (Chemistry and Physics of Lipids, 43, p. 283, 1987) and dilution of mixtures of long-chain phospholipids with a short-chain phospholipid (deheptanoyl-phosphatidylcholine) can also spontaneously lead to liposome dispersions. Further mixtures which spontaneously form vesicles are described in the literature, for example mixtures of cholesterol and soap (Biochemistry, Vol. 17, No. 18, p. 3758, 1978), soap fatty acid mixtures (Chem. Phys. Lipids, 16 , P. 142, 1976), mixtures of alkyltrimethylammonium hydroxides (J. Phys. Chem. 87, p. 5020, 1983), mixtures of alkyltrimethylammonium tosylates and anionic cosurfactants such as sodium dodecylbenzenesulfonate, C ₈ -C ₁₂ alkyl sulfates (J. Phys. Chem. 96, p. 6698, 1992).

Furthermore, EP 0 211 647 discloses liposome preparations which, by mixing a C ₈ -C ₂₄ carboxylic acid (or an amine) with a compound which contains two ionizable groups (dicarboxylic acid, diamine, α-amino-ω-carboxylic acid), material and water to be encapsulated. It is disclosed that a proliposome gel is produced for manufacture, which is then diluted with water. The concentrate consists of the liposome-forming ingredient and the compound that contains two ionizable groups. The gel consists of a hydrated complex, which is in the form of a liquid crystal. In the next step, the liposomal dispersion is obtained from the gel by dilution in a phosphate buffer solution. The process for producing this liposome dispersion therefore requires two steps. In the first step, with the exclusion of water from phospholipids and oleic acid, a paste is prepared, which is then mixed with a second compound, such as arginine, to be dissolved in water to form the gel, which then spontaneously forms liposomes with water.

In EP 707847 a method is presented that allows ketoprofen and Phospholipids or nonionic amphiphiles spontaneously produce liposomes. First the pH of the mixture is adjusted to 6-8 and by Ab lowering the pH below pH = 6, liposomes are obtained spontaneously.

With suitable cosurfactants, liquid crystalline can be made from phospholides Prepare preparations (lamellar phases, for example). The lamellar phase arises when suitable lipids are mixed with water. The Water absorption capacity for liquid crystals is limited because of the addition large amounts of water the distances of the water channels and thus also the The distances between the lipid bilayers become so large that the liquid crystal becomes unstable becomes.

In any case, all of these prior art processes are distinguished some significant disadvantages, be it that they are expensive or be they produce unpredictable results. The object of the present invention was so to remedy these disadvantages.

Surprisingly, the disadvantages of the prior art are eliminated by a process for the production of liposomes or dispersions of liposomes in an aqueous phase, characterized in that

• (I) a) a lipid or a lipid mixture,
  • b) optionally an oil phase and
  • c) an aqueous phase
  • d) if appropriate, one or more surfactants are combined and homogenized at a temperature which is above the melting temperature of the lipid or lipid mixture and the oil phase - if one is used - and where
• (II) the entirety of the homogenized components (a), (b), (c) and (d) in forms a lamellar phase at a temperature interval [Θ],
• (III) the temperature of the homogenized mixture of (a), (b), (c) and (d) to a value within the temperature interval [Θ] (production temperature Θ ₁ )
  or is brought to a value above the temperature interval [Θ] (manufacturing temperature Θ ₂ ),
• (IV) to the homogenized mixture of (a), (b), (c) and (d) water and the liposomes or liposome dispersion which is formed is brought to a temperature Θ ₃

is brought, which is below the temperature interval [Θ].

It can be quite advantageous if the production temperature Θ _{1 is} above [Θ], since a so-called L ₂ phase, which consists of inverted micelles, is often present above the L _α phase (= lamellar phase). If you cool down, you get the L _α phase again, and then finally liposomes. However, inversely hexagonal phases and / or inversely micellar phases and / or cubic phases can also be present above the L _α phase, and also emulsion-like states.

In particular, if oil components which are optional but are to be used extremely advantageously according to the invention are present, emulsion-like conditions, for example also real W / O emulsions, can occur at production temperatures Θ ₂ above the temperature interval [Θ], which, at Passing the temperature interval [Θ] over the state of the liquid crystalline lamellar phase by dilution and cooling with water deliver liposomes. In this case, the liposomes are also multilamellar.

In Fig. 5 is a simplified phase diagram for a three-component system of water, surfactant and oil phase is exemplified. The symbols H mean a hexagonal phase, C a cubic phase, L a lamellar phase and _i H an inverse hexagonal phase.

In Fig. 7 is shown in simplified, which at the phase transitions with variation of the parameters temperature (Θ) and concentration of an ingredient (eg. As the lipids) may extend according to the invention.

From the state K ₁ in the phase region L _α , in which lamellar phases are present, the state K ₂ in the region L _ω , in which liposomes form, can be achieved by lowering the temperature.

From the state K ₃ in the phase region L ₂ , in which (here as an example) inverted micelles are present, the state K ₄ in the region L _ω in which liposomes form can be achieved by lowering the temperature.

From the state K ₅ in the phase region L _α , in which lamellar phases are present, the state K ₆ in the region L _ω , in which liposomes form, can be achieved by increasing the concentration P of a component (here water as an example).

From the state K ₇ in the phase region L ₂ , in which (here as an example) inverted micelles are present, by increasing the concentration P of a component (here as an example water) the state K ₈ in the region L _ω can be reached in which liposomes are located form.

You can also increase the temperature or change the concentration from K2 to K1, K4 to K3, K4 to K5 in the area of the lamellar phase or in  go the area above the lamellar phase and then cool again and receive liposomes according to the invention.

According to the invention, phospholipids, particularly those as described at the beginning of the background of the invention, used as lipids (a). The basic structures based on lipid double membranes can partial on all courses lipids natural, synthetic or partly synthetic Can be chosen. The phospholipids such as are particularly advantageous such as phosphatidylcholines, phosphatidylethanolamines, phosphatidylserines, cardio lipins (diphosphatidylglycerols) and sphingomyeline, also glycolipids or Glycerolipids.

Of particular importance are the lecithins, sphingolipids such as Sphingosine or phytosphingosine, ceramides, cerebrosides, gangliosides, Sphingophospholipids, of which in particular the sphingomyeline, Sphingosulfatide and Glycosphingoside as well as by chemical synthesis available analogs.

Examples of lipids which can be used according to the invention are, for example, dimethyldi octadecylammonium chloride, dimethyldioctadecylammonium bromide, 1-palmitoleyl 2-oleyl-sn-glycero-3-phosphatidylcholine, dimyristoleylphosphatidylcholine, 1-palmitoleyl-2-oleyl-3-phosphatidylglycerol.

Process step (IV) can be carried out with water at a temperature that are within, above or below [Θ], particularly advantageous with Water with a maximum temperature of 35 ° C.

Depending on the choice of components, especially the lipids and, ge if desired, the lamellar phases can contribute to the surfactants present Room temperature occur or only at a higher temperature or above larger temperature ranges. The production of the liposomes can therefore in Dependence on the chosen surfactant system both at room temperature and at a higher temperature (e.g. 85 ° C) and when diluted with water lead liposomes according to the invention.  

Surfactants are amphiphilic substances, the organic, non-polar substances in water to be able to solve. Due to their specific molecular structure, they also help at least one hydrophilic and one hydrophobic part of the molecule, for one Lowering the surface tension of the water, wetting the skin, facilitating dirt removal and removal, easy rinsing and - as desired - for foam regulation.

The hydrophilic parts of a surfactant molecule are mostly polar functional groups, for example -COO⁻, -OSO ₃ ^2- , -SO ₃ ⁻, while the hydrophobic parts generally represent non-polar hydrocarbon radicals. Surfactants are generally classified according to the type and charge of the hydrophilic part of the molecule. There are four groups:

• - anionic surfactants,
• - cationic surfactants,
• - amphoteric surfactants and
• - nonionic surfactants.

Anionic surfactants generally have carboxylate, sulfate or sulfonate groups as functional groups. In an aqueous solution they form negatively charged organic ions in an acidic or neutral environment. Cationic surfactants are characterized almost exclusively by the presence of a quaternary ammonium group. In aqueous solution they form positively charged organic ions in an acidic or neutral environment. Amphoteric surfactants contain both anionic and cationic groups and therefore behave in aqueous solution, depending on the pH value, like ionic or cationic surfactants. They have a positive charge in a strongly acidic environment and a negative charge in an alkaline environment. In the neutral pH range, however, they are zwitterionic, as the following example should illustrate:

RNH ₂ ⁺CH ₂ CH ₂ COOH X⁻ (at pH = 2) X⁻ = any anion, e.g. B. Cl⁻
RNH ₂ ⁺CH ₂ CH ₂ COO⁻ (at pH = 7)
RNHCH ₂ CH ₂ COO⁻ B + (at pH = 12) B⁺ = any cation, e.g. B. Na⁺.

Polyether chains are typical of non-ionic surfactants. Non-ionic surfactants do not form ions in an aqueous medium.

A. Anionic surfactants

Anionic surfactants to be used advantageously are acylamino acids (and their salts), such as

• 1. acylglutamates, for example sodium acylglutamate, Di-TEA-palmitoylaspartate and sodium caprylic / capric glutamate,
• 2. Acyl peptides, for example palmitoyl-hydrolyzed milk protein, sodium Cocoyl-hydrolyzed soy protein and sodium / potassium cocoyl hydrolyzed collagen,
• 3. Sarcosinates, for example myristoyl sarcosin, TEA-lauroyl sarcosinate, Na trium lauroyl sarcosinate and sodium cocoyl sarcosinate,
• 4. taurates, for example sodium lauroyl taurate and sodium methyl cocoyl taurate,
• 5. Acyl lactylates, lauroyl lactylate, caproyl lactylate
• 6. Alaninate

Carboxylic acids and derivatives, such as

• 1. Carboxylic acids, for example lauric acid, aluminum stearate, magnesium al kanolate and zinc undecylenate,
• 2. Ester carboxylic acids, for example calcium stearoyl lactylate, Laureth-6 citrate and sodium PEG-4 lauramide carboxylate,
• 3. ether carboxylic acids, for example sodium laureth-13 carboxylate and Sodium PEG-6 cocainide carboxylate,

Phosphoric acid esters and salts, such as DEA-oleth-10-phosphate and dilaureth-4-phosphate,
Sulfonic acids and salts such as

• 1. acyl isethionates, e.g. B. sodium / ammonium cocoyl isethionate,
• 2. alkylarylsulfonates,
• 3. alkyl sulfonates, for example sodium coconut monoglyceride sulfate, sodium C _12-14 olefin sulfonate, sodium lauryl sulfoacetate and magnesium PEG-3 cocamide sulfate,
• 4. Sulfosuccinates, for example dioctyl sodium sulfosuccinate, disodium laureth sulfosuccinate, disodium lauryl sulfosuccinate and disodium undecylenamido MEA sulfosuccinate

such as
Sulfuric acid esters, such as

• 1. alkyl ether sulfate, for example sodium, ammonium, magnesium, MIPA, TlPA laureth sulfate, sodium myreth sulfate and sodium C _12-13 pareth sulfate,
• 2. Alkyl sulfates, for example sodium, ammonium and TEA lauryl sulfate.

B. Cationic surfactants

Cationic surfactants to be used advantageously

• 1. alkylamines,
• 2. alkylimidazoles,
• 3. Ethoxylated amines and
• 4. Quaternary surfactants.
• 5. Esterquats.

Quaternary surfactants contain at least one N atom with 4 alkyl or aryl groups is covalently linked. Regardless of the pH value, this leads to a positive charge. Alkyl betaine, alkyl amidopropyl betaine and alkyl are advantageous amidopropylhydroxysulfain. The cationic used in the invention Surfactants can furthermore preferably be selected from the group of the quaternary ones Ammonium compounds, especially benzyltrialkylammonium chlorides or bromides, such as, for example, benzyldimethylstearylammonium chloride, and also alkyl trialkylammonium salts, for example cetyltrimethylammonium chloride or bromide, alkyldimethylhydroxyethylammonium chlorides or bromides, Dialkyldimethylammonium chlorides or bromides, alkylamidethyltrimethylammoni umether sulfates, alkyl pyridinium salts, for example lauryl or cetyl pyrimidini umchloride, imidazoline derivatives and compounds with a cationic character such as Amine oxides, for example alkyldimethylamine oxides or alkyamino ethyldimethylamine oxides. Cetyltrimethyl are particularly advantageous to use ammonium salts.

C. Amphoteric surfactants

Amphoteric surfactants to be used advantageously

• 1. acyl-idialkylethylenediamine, for example sodium acylamphoacetate, Disodium acyl amphodipropionate, disodium alkyl amphodiacetate, Sodium acylamphohydroxypropylsulfonate, disodium acylamphodiacetate and Sodium acylamphopropionate,
• 2. N-alkylamino acids, for example aminopropylalkylglutamide, alkylamino propionic acid, sodium alkylimidodipropionate and Lauroamphocarboxyglycinate.

D. Non-ionic surfactants

Non-ionic surfactants to be used advantageously

• 1. alcohols,
• 2. alkanolamides, such as Cocamide MEN DEA / MIPA,
• 3. amine oxides, such as cocoamidopropylamine oxide,
• 4. esters obtained by esterification of carboxylic acids with ethylene oxide, glycerol, Sorbitan or other alcohols arise
• 5. ethers, for example ethoxylated / propoxylated alcohols, ethoxylated / pro poxylated esters, ethoxylated / propoxylated glycerol esters, ethoxylated / propoxylated cholesterols, ethoxylated / propoxylated triglyceride esters, ethoxylated propoxylated lanolin, ethoxylated / propoxylated polysiloxanes, propoxylated POE ethers and alkyl polyglycosides such as lauryl glucoside, Decylglycoside and cocoglycoside.
• 6. sucrose esters, ether
• 7. Polyglycerol esters, diglycerol esters, monoglycerol esters
• 8. Methyl glucose esters, esters of hydroxy acids.

It is also advantageous to use a combination of anionic and / or amphoteric surfactants with one or more non-ionic surfactants.

It is particularly surprising that the liposome size can be controlled via the relative ratio of surfactants (e.g. anionic surfactant) to Phospholipid, i.e. H. the more (e.g. anionic) surfactant it contains, the smaller it is the liposome as a whole, lower proportions of (e.g. anionic) surfactants automatically with the same total content of phospholipid and (e.g. anionic)  Surfactants to larger lipids. There is a linear relationship between Surfactant concentration and liposome radius, so that it is easy to calculate how the liposomes should be big.

Furthermore, the vesicles can also be further diluted without them disintegrate (e.g. in micelles).

The oil phase can advantageously be selected from the following group of substances:

• - mineral oils, mineral waxes
• - Oils, such as triglycerides of capric or caprylic acid, but preferably Castor oil;
• - fats, waxes and other natural and synthetic fat bodies, preferably esters of fatty acids with alcohols of low C number, e.g. B. with With isopropanol, propylene glycol or glycerin, or esters of fatty alcohols Low C number alkanoic acids or with fatty acids;
• - alkyl benzoates;
• - silicone oils such as dimethylpolysiloxanes, diethylpolysiloxanes, Diphenylpolysiloxanes and mixed forms thereof.

The oil phase is advantageously selected from the group of the esters from saturated and / or unsaturated, branched and / or unbranched alkane carboxylic acids a chain length of 3 to 30 carbon atoms and saturated and / or unsaturated, branched and / or unbranched alcohols with a chain length of 3 to 30 C- Atoms, from the group of esters from aromatic carboxylic acids and saturated ten and / or unsaturated, branched and / or unbranched alcohols Chain length from 3 to 30 carbon atoms. Such ester oils can then advantageously ge are selected from the group isopropyl myristate, isopropyl palmitate, isopropyl stea rat, isopropyl oleate, n-butyl stearate, n-hexyl laurate, n-decyl oleate, isooctyl stearate, iso nonyl stearate, isononyl isononanoate, 2-ethylhexyl palmitate, 2-ethylhexyl laurate, 2-He xyldecyl stearate, 2-octyldodecyl palmitate, oleyl oleate, olerlerucate, erucyl oleate, Eru cylerucat as well as synthetic, semi-synthetic and natural mixtures of such Esters, e.g. B. Jojoba oil.  

Furthermore, the oil phase can advantageously be selected from the group of branched and unbranched hydrocarbons and waxes, the silicone oils, the dialkyl ether, the group of saturated or unsaturated, branched or unbranched alcohols, as well as the fatty acid triglycerides, especially the triglyce pure esters of saturated and / or unsaturated, branched and / or unbranched Al can carboxylic acids with a chain length of 8 to 24, in particular 12-18 carbon atoms. The fatty acid triglycerides can, for example, advantageously be selected from the Group of synthetic, semi-synthetic and natural oils, e.g. B. olive oil, Sunflower oil, soybean oil, peanut oil, rapeseed oil, almond oil, palm oil, coconut oil, palm kernel oil and the like.

Any mixtures of such oil and wax components are also possible to be used advantageously for the purposes of the present invention. It can also may be advantageous, waxes, for example cetyl palmitate, as the sole Use lipid component of the oil phase.

The oil phase is advantageously selected from the group consisting of 2-ethylhexyl isostearate, octyl dodecanol, isotridecyl isononanoate, isoeicosane, 2-ethylhexyl cocoate, C _12-15 alkyl benzoate, caprylic capric acid triglyceride, dicaprylyl ether.

Mixtures of C _12-15 alkyl benzoate and 2-ethylhexyl isostearate, mixtures of C _12-15 alkyl benzoate and isotridecyl isononanoate and mixtures of C _12-15 alkyl benzoate, 2-ethyl hexyl isostearate and isotridecyl isononanoate are particularly advantageous.

Of the hydrocarbons, paraffin oil, squalane and squalene are advantageous in To use the sense of the present invention.

The oil phase can also advantageously contain cyclic or linear sili have oils or consist entirely of such oils, although an additional one is preferred in addition to the silicone oil or the silicone oils Content of other oil phase components to use.  

Cyclomethicone (octainethylcyclotetrasiloxane) is advantageous as according to the invention silicone oil to be used. But other silicone oils are also beneficial to use for the purposes of the present invention, for example hexamethylcy clotrisiloxane, polydimethylsiloxane, poly (methylphenylsiloxane).

Mixtures of cyclomethicone and are also particularly advantageous Isotridecyl isononanoate, from cyclomethicone and 2-ethylhexyl isostearate.

The aqueous phase of the preparations according to the invention optionally advantageously contains

• - Alcohols, diols or polyols of low C number, and their ethers, preferred as ethanol, isopropanol, propylene glycol, glycerin, ethylene glycol, ethyl lenglycol monoethyl or monobutyl ether, propylene glycolnonomethyl, monoethyl or monobutyl ether, diethylene glycol monomethyl or monoethyl ether and analog products, furthermore alcohols with a low C number, e.g. As ethanol, isopropanol, 1,2-propanediol, glycerin and in particular a or more thickeners, which one or which is advantageously chosen can be from the group silicon dioxide, aluminum silicates, Polysac charide or its derivatives, e.g. B. hyaluronic acid, xanthan gum, hydroxy propylmethyl cellulose, particularly advantageous from the group of Polyacrylates, preferably a polyacrylate from the group of so-called Carbopoles, for example carbopoles of types 980, 981, 1382, 2984, 5984, individually or in combination.

According to the invention, active ingredients can be selected very advantageously from the Group of antioxidants. It is beneficial to have antioxidants as the only ones Active ingredient class to use, for example, when a cosmetic or dermato Logical application is in the foreground like combating the oxidative Stress on the skin. But it is also favorable to the invention Preparations containing one or more antioxidants provided if the preparations are to serve another purpose, e.g. B. as Deodorants or sunscreens.  

The antioxidants are particularly advantageously selected from the group consisting of
Amino acids (e.g. histidine, tyrosine, tryptophan) and their derivatives, imidazoles (e.g. urocanic acid) and their derivatives, peptides such as D, L-carnosine, D-carnosine, L-carnosine and their derivatives (e.g. Anserin), carotenoids, carotenes (e.g. α-carotene, β-carotene, lycopene) and their derivatives, lipoic acid and their derivatives (e.g. dihydroliponic acid), aurothioglucose, propylthiouracil and other thiols (e.g. thioredoxin , Glutathione, cysteine, cystine, cystamine and their glycosyl, N-acetyl, methyl, ethyl, propyl, amyl, butyl and lauryl, palmitoyl, oleyl, γ-linoleyl, cholesteryl and Glyceryl esters) as well as their salts, dilaurylthiodipropionate, distearylthiodipropionate, thiodipropionic acid and their derivatives (esters, ethers, peptides, lipids, nucleotides, nucleosides and salts) as well as sulfoximine compounds (e.g. buthioninsulfoximines, homocysteine sulfoximine, buthioninsulfoximine, pentahioninsulfoximine, pentahioninsulfoximine, pentahioninsulfoximine, pentahioninsulfoximine, pentahioninsulfoximine, pentahionine sulfoximine, pentahionine sulfoxin, penta- in very low tolerable doses (e.g. pmol to µmol / kg), far away r (metal) chelators (e.g. B. α-hydroxy fatty acids, α-hydroxy xypalmitic acid, phytic acid, lactoferrin), α-hydroxy acids (e.g. citric acid, lactic acid, malic acid), humic acid, bile acid, bile extracts, bilirubin, biliverdin, EDTA, EGTA and their derivatives, unsaturated fatty acids and their derivatives (e.g. γ-linolenic acid, linoleic acid, oleic acid), folic acid and their derivatives, ubiquinone and ubiquinol their derivatives, vitamin C and derivatives (e.g. Ascor bylpalmitate, Mg-Ascorbylphosphate, Ascorbylacetate), Tocopherols and Deriva te (e.g. vitamin E acetate), vitamin A and derivatives (vitamin A palmitate) as well as coniferyl benzoate of benzoin, rutinic acid and its derivatives, ferulic acid and its derivatives, butylated hydroxytoluene, butylated hydroxyanisole, nordihydroguajakh resinic acid, nordihydroguajaretic acid and trihydroxybutyric acid and trihydroxybutyric acid their derivatives, zinc and their derivatives (e.g. ZnO, ZnSO ₄ ) selenium and their derivatives (e.g. seleninethionine), stilbenes and their derivatives (e.g. stil benoxid, T rans-stilbene oxide) and the derivatives suitable according to the invention (salts, esters, ethers, sugars, nucleotides, nucleosides, peptides and lipids) of these active substances.

Oil-soluble anti oxidants are used.  

The amount of antioxidants (one or more compounds) in the preparation tion is preferably 0.001 to 30 wt .-%, particularly preferably 0.05-20 % By weight, in particular 1-10% by weight, based on the total weight of the zu preparation.

If vitamin E and / or its derivatives represent the antioxidant (s), is advantageous whose respective concentrations range from 0.001-10 % By weight, based on the total weight of the formulation.

If vitamin A, or vitamin A derivatives, or carotenes or their derivatives, the or the antioxidants are advantageous, their respective concentrations from the range of 0.001-10% by weight, based on the total weight of the Wording to choose.

However, one or more substances selected from the group consisting of acetylsalicylic acid, atropine, azulene, hydrocortisone and its derivatives, eg. B. Hy drocortison-17-valerate, vitamins, e.g. B. ascorbic acid and its derivatives, vitamins of the B and D series, very cheap vitamin B ₁ , vitamin B _12, vitamin D ₁ , but also salicylic acid, sodium salicylate, enzymes, DNA, bisabolol, unsaturated fatty acids, especially the essential ones Fatty acids (often also called vitamin F), especially γ-linolenic acid, oleic acid, eicosapentaenoic acid, docosahexaenoic acid and its derivatives, chloramphenicol, caffeine, prostaglandins, thymol, camphor, extracts or other products of plant and animal origin, e.g. B. evening primrose oil, borage oil or currant seed oil, fish oils, cod liver oil but also ceramides and ceramide-like compounds and so on.

Although also the use of hydrophilic active substances according to the invention is a further advantage of the preparations according to the invention that especially oil-soluble or lipophilic active ingredients with particularly high effectiveness be made biologically available.

Processes according to the invention can advantageously be carried out in the absence of an oil component, for example as follows:

• a) The lipid (s) (again advantageous: phospholipids) will or will Room temperature (if desired with the ingredients to be encapsulated) in a solvent, especially a polar solvent (e.g. a Polyol such as glycerin, erythritol, dipropylene glycol, propylene glycol, sorbitol or else also dissolved ethanol). A surfactant (dissolved in water) is added until the Liquid crystal occurs and the mixture is mixed with water and others water-soluble additives diluted to form liposomes according to the invention.
• b) The lipid (s) (again advantageous: phospholipids) is or will be in the Heat (25-85 ° C) (if desired with the ingredients to be encapsulated) in a solvent, especially a polar solvent (e.g. a Polyol such as glycerin, erythritol, dipropylene glycol, propylene glycol, sorbitol or else also dissolved ethanol). A surfactant (dissolved in water) is added until the Liquid crystal occurs and the mixture is mixed with water and others water-soluble additives diluted to form liposomes according to the invention.
• c) The lipid (s) (again advantageous: phospholipids) is or will be in the Heat (25-85 ° C) with a surfactant and, if desired, to be encapsulated Ingredients in a solvent, especially a polar solvent (e.g. a polyol such as glycerin, erythritol, dipropylene glycol, propylene glycol, sorbitol or else ethanol) dissolved. Water is added until the liquid crystal occurs and the mixture is mixed with water and other water-soluble additives diluted to form liposomes according to the invention.

Methods according to the invention can advantageously be carried out in the presence of an oil component, for example as follows:

• d) the lipid (s) (again advantageous: phospholipids) will or will Room temperature with a surfactant, one or more oil components and ge if desired with ingredients to be encapsulated in a solvent, especially a polar solvent (e.g. a polyol such as glycerin, Erythritol, dipropylene glycol, propylene glycol, sorbitol or ethanol). Water is added until the liquid crystal appears and the mixture is mixed with  Water and other water-soluble additives diluted to form liposomes according to the invention.
• e) The lipid (s) (again advantageous: phospholipids) is or will be in the Heat (25-85 ° C) with a surfactant, one or more oil components and ge if desired with ingredients to be encapsulated in a solvent, especially a polar solvent (e.g. a polyol such as glycerin, Erythritol, dipropylene glycol, propylene glycol, sorbitol or ethanol). Water is added until the liquid crystal appears and the mixture is mixed with Water and other water-soluble additives diluted to form liposomes according to the invention.

The following are advantageous embodiments of the present Invention listed without being limited to these examples is intended.  

Preparation example 1 for vesicle dispersion

15 mg sodium lauroyl lactylate and 95 mg phospholipon 90 are in 500 ml Dissolved ethanol at 80 ° C. Then you drip at this temperature, Nasser until a liquid crystalline phase occurs. Further dilute this phase with 13.5 g water provides a dispersion of liposomes with an average radius of approx. 145 nm.

Preparation example 2 for vesicle dispersion

16 mg sodium lauroyl lactylate and 104 mg phospholipone 90 are made in 1027 mg Glycerin dissolved at 80 ° C. Then water is dropped at this temperature to, further dilute with 11.1 g of water and obtain a dispersion of liposomes with an average radius of approx. 117 nm.

Preparation example 3 for vesicle dispersion

17 mg sodium lauroyl sarcosinate and 100 mg phospholipon 90 are in 500 ml Dissolved ethanol at 80 ° C. Then water is dropped at this temperature until a liquid crystalline phase occurs. Further dilute this phase with 11.2 g water provides a dispersion of liposomes with an average radius of approx. 148 nm.

Preparation example 4 for vesicle dispersion

18 mg sodium lauroyl lactylate and 100 mg phospholipone 90 become 1041 mg Propylene glycol dissolved at 80 ° C. Then you dilute with this Temperature with 12.0 g of water and receives a dispersion of liposomes average radius of approx. 161 nm.

Preparation example 5 for vesicle dispersion

16 mg cetyltrimethylammonium bromide and 105 mg phospholipon 90 are in Dissolved 996 mg of propylene glycol. Then add a total of 12 g of water and receives a liposomal dispersion (117 nm radius).  

Preparation example 6 for vesicle dispersion

18 g lauryl glycoside (Plantaren 1200) and 127 mg phospholipon 90 are in 1048 mg of propylene glycol dissolved. Then add a total of 12 g of water and receives a liposomal dispersion (283 nm radius).

Preparation example 7 for vesicle dispersion

20 mg glyceryl stearate citrate and 131 mg phospholipon 90 are made in 1027 mg Proylene glycol dissolved. Then a total of 12 g of water are added and obtained a liposomal dispersion (235 nm radius).

Preparation example 8 for vesicle dispersion with oil component

87 mg sodium lauroyl lactylate and 260 mg phospholipone 90 are in 126 mg Ethanol and 82 mg dicaprylyl ether dissolved. Then slowly water becomes at 80 ° C dripped. A gel forms which is diluted with water. It is formed multilamellar vesicles. In total, it is diluted with 8 g of water.

Preparation example 9 for vesicle dispersion with oil component

79 mg sodium lauroyl lactylate and 305 mg phospholipone 90 are made into 80 mg Dissolved ethanol and 85 mg dicaprylyl ether. Then slowly water becomes at 80 ° C dripped. A gel forms which is diluted with water. It is formed multilamellar vesicles. In total, it is diluted with 7 g of water.

Claims (1)

1. A process for the preparation of liposomes or of dispersions of liposomes in an aqueous phase, characterized in that

• I) a) a lipid or a lipid mixture,
  • b) optionally an oil phase and
  • c) an aqueous phase
  • d) if appropriate, one or more surfactants are combined and homogenized at a temperature which is above the melting temperature of the lipid or lipid mixture and the oil phase - if one is used - and where
• II) the entirety of the homogenized components (a), (b), (c) and (d) forms a lamellar phase in a temperature interval [Θ],
• III) the temperature of the homogenized mixture of (a), (b), (c) and (d) to a value within the temperature interval [Θ] (manufacturing temperature Θ ₁ ) or to a value above the temperature interval [Θ] (manufacturing temperature Θ ₂ ) is brought
• IV) water is added to the homogenized mixture of (a), (b), (c) and (d) and the liposomes or liposome dispersion which is formed is brought to a temperature Θ ₃ which is below the temperature interval [Θ] is located.