Highly concentrated mono-rhamnolipid solutions

Abstract

The invention relates to a composition comprising at least one mono-rhamnolipid in solution at very high concentrations at a specific acidic pH, a method to its production and its use.

Description

[0001] Highly concentrated mono-rhamnolipid solutions

[0002] Field of the invention

[0003] The invention relates to a composition comprising at least one mono-rhamnolipid in solution at very high concentrations at a specific acidic pH, a method to its production and its use.

[0004] Prior art

[0005] Rhamnolipids are surface active Glycolipids and metabolites of particular microorganisms. They have exceptional properties as surfactants as for example, strong foam formation and are of highest interest for a wide variety of technical applications.

[0006] Surfactants, that are mainly being used in cosmetic formulations (e.g. Shampoos, liquid soaps), household detergents as well as dishwashing detergents, have to be liquid at commonly used processing temperatures of the products' manufacturers, to maintain and enable their usage in the manufacturers’ respective pipeline systems and pumps. Therefore, the raw material’s viscosity should be rather low to maintain a simple and continuous delivery. At the same time, the highest possible surfactant concentration is desired to allow preparation of environmentally-friendly formulations having a low water content.

[0007] EP3023431 discloses compositions comprising 30% by weight to 70% by weight, of at least one rhamnolipid and 30% by weight to 70% by weight of water, where the percentages by weight refer to the total composition, wherein the pH of the composition at 25° C is from 5.5 to 7.0.

[0008] EP4155371 discloses the use of a composition comprising at least 92 wt-%, mono-rhamnolipids, wherein the weight percentages refer to all rhamnolipids comprised in the composition, for the preparation of a non-cosmetic cleaning formulation.

[0009] WO2015091294 discloses bacteriostatic compositions comprising a rhamnolipid, the rhamnolipid comprising at least 50 wt % mono-rhamnolipid.

[0010] EP0597358 discloses a method for the quantitative purification of glycolipids, characterized in that the purification of the glycolipids is achieved by acidification of the glycolipid-containing solution to pH 5.0, subsequent heating of the batch to 60°C - 130°C, subsequent cooling of the batch to 50°C and centrifugation of the batch for sedimentation of the glycolipid-containing phase.

[0011] Using this process solid suspensions or pastes are obtained having a high rhamnolipid solid content between 30 and 40 % by weight and a very high viscosity. EP2735605A1 discloses a process for the isolation of rhamnolipids, said process comprising:

[0012] A) providing an aqueous medium containing at least one rhamnolipid and having a pH of less than 6, B) bringing the aqueous medium into contact with at least one organic solvent to provide a multiphase system and separating off the aqueous phase, C) increasing the pH to a value of 6 or more to provide a multiphase organic system, and D) separating off a rhamnolipid-enriched organic phase.

[0013] One disadvantage of this product form is the undesired and relatively high drop in viscosity upon dilution. Another disadvantage is the reduced microbiological stability at a neutral pH value.

[0014] So far, no method is at hand that allows for very high concentrations of rhamnolipids to be useful for examples as a stock solution for the preparation of end consumer formulations.

[0015] It is an object of the invention to provide rhamnolipid solutions with exceptional high concentrations of rhamnolipids.

[0016] Description of the invention

[0017] It was found, surprisingly, that a particularly highly concentrated solution of mono-rhamnolipids can be obtained by the process according to the instant invention.

[0018] The present invention therefore provides a composition comprising at least one mono-rhamnolipid in solution wherein the total content of said mono-rhamnolipid in solution is from 71 .0 wt.-% to 98.0 wt.-%, characterized in that the pH of the composition at 25 °C is in the range of 2.5 to 4.2.

[0019] The invention further provides a process of producing a composition comprising at least one mono- rhamnolipid in solution.

[0020] An advantage of the present invention is that with a high active matter lower amounts are needed in the final formulation.

[0021] Another advantage of the invention is, that the ionic strength of the rhamnolipid-based composition can be kept low. Therefore, the formulator can have a high flexibility in the adjustment of the pH value and salt content in the final formulation.

[0022] Another advantage of the invention is, that the composition has an increased microbiological stability.

[0023] Another advantage of the invention is, that the composition can be readily diluted, as the rhamnolipid as active matter already is in its dissolved state. Another advantage of the invention is, that the composition can be thoroughly mixed with other surfactants.

[0024] Another advantage of the invention is, that the composition enables the formulation of concentrated end formulations (‘concentrates’).

[0025] Another advantage of the invention is, that the composition has a reduced foam tendency on account of their high concentrations and thus transport and conveying are simplified.

[0026] Another advantage of the invention is, that the composition enables easy incorporation of hydrophobic components such as oils, for example.

[0027] Another advantage of the invention is, that the compositions have a high storage stability.

[0028] Another advantage of the invention is, that when diluted with water no significant changes in viscosity can be observed.

[0029] Another advantage of the invention is, that the composition causes less contamination in pipelines during preparation and transport thereof, and therefore, enable simpler cleaning.

[0030] Another advantage of the invention is, that the composition causes a much lower energy consumption for its transportation and therefore, has a lower CO2 footprint.

[0031] Another advantage of the invention is, that it shows a lower water content and therefore hydrophobic raw materials, e.g., essential oils, can be solubilized and / or incorporated more easily. Another advantage of the invention is, that the composition can solubilize ceramide-based actives more efficiently if not at all.

[0032] Another advantage of the invention is, that the composition shows a lower foaming volume in a water-based solutions compared to di-Rhamnolipids.

[0033] Another advantage of the invention is, that the composition shows a higher colour stability compared to di-Rhamnolipids.

[0034] Another advantage of the invention is, that the composition shows reduced odour compared to di- Rhamnolipids.

[0035] Another advantage of the invention is, that incorporating the composition in a formulation reduces the need of an acid or reduced the amount needed to adjust the pH accordingly.

[0036] Another advantage of the invention is, that the composition can have very low viscosities, and thus can be handled easily, e.g., via pumps.

[0037] Another advantage of the invention is, that formulations with low foaming properties can be formulated from the composition of the instant invention, which can be utilized e.g., in dish washing applications, eye make-up remover and micellar water formulations.

[0038] The composition according to the instant invention comprises at least one mono-rhamnolipid in solution wherein the total content of said mono-rhamnolipid in solution is from 71.0 wt.-% to 98.0 wt.-%, preferably from 73.0 wt.-% to 95.0 wt.-%, more preferably from 75.0 wt.-% to 85.0 wt.-%, wherein the weight percentages refer to the total composition, characterized in that the pH of the composition at 25 °C is in the range of 2.5 to 4.2, preferably 3.0 to 3.9, more preferably 3.2 to 3.8, most preferably 3.2 to 3.4. Where average values are stated hereinbelow, then, unless stated otherwise, these are number- averaged average values.

[0039] Unless stated otherwise, percentages are data in percent by weight. The same is true for parts per million (ppm).

[0040] Wherever measurement values are stated hereinbelow, then, unless stated otherwise, these have been determined at a temperature of 25°C and a pressure of 1013 mbar.

[0041] When determining the content of rhamnolipids in the context of the present invention, the mass of the non-salt form is taken into account; thus, the weight of the corresponding cation is disregarded.

[0042] The term "rhamnolipids" in the context of the present invention preferably is understood to mean particularly compounds of the general formula (I) and salts thereof, R1RLand R2RL= mutually independently, identical or different, organic residues having 2 to 24, preferably 5 to 13 carbon atoms, in particular optionally branched, optionally substituted, particularly hydroxy-substituted, optionally unsaturated, in particular optionally mono-, bi- or triunsaturated alkyl residues, preferably those selected from the group consisting of pentenyl, heptenyl, nonenyl, undecenyl and tridecenyl and (CH2)O-CH3 where o = 1 to 23, preferably 4 to 12. If nRL = 1 , the glycosidic bond between the two rhamnose units is preferably in the a-configuration. The optically active carbon atoms of the fatty acids are preferably present as R-enantiomers (e.g. (R)-3-{(R)-3-[2-O-(a-L-rhamnopyranosyl)-a-L-rhamnopyranosyl]oxydecanoyl}oxydecanoate). The term "di-rhamnolipid" in the context of the present invention is understood to mean compounds of the general formula (I) or salts thereof, where nRL = 1.

[0043] The term "mono-rhamnolipid" in the context of the present invention is understood to mean compounds of the general formula (I) or salts thereof, where nRL = 0.

[0044] Distinct rhamnolipids are abbreviated according to the following nomenclature: "diRL-CXCY" are understood to mean di-rhamnolipids of the general formula (I) with mRL=1 , in which one of the residues R1RLand R2RL= (CH2)o-CHs where o = X-4 and the remaining residue R1or R2= (CH2)O-CH3 where o = Y-4.

[0045] "monoRL-CXCY" are understood to mean mono-rhamnolipids of the general formula (I) with mRL=1 , in which one of the residues R1RLand R2RL= (CH2)o-CHs where o = X-4 and the remaining residue R1RLor R2RL= (CH2)o-CH3 where o = Y-4.

[0046] The nomenclature used therefore does not distinguish between "CXCY" and "CYCX". For rhamnolipids where mRL=0, monoRL-CX or diRL-CX is used accordingly.

[0047] If one of the above mentioned indices X and / or Y is provided with ":Z", this signifies that the respective residue R1RLand / or R2RLis equal to an unbranched, unsubstituted hydrocarbon residue having X-3 or Y-3 carbon atoms having Z double bonds.

[0048] Methods for preparing the relevant rhamnolipids are disclosed, for example, in EP2786743 and EP2787065; if mixtures of di- and mono-rhamnolipids are obtained, they can be converted with rhamnosidase to the mono-rhamnolipids.

[0049] Rhamnolipids applicable in the context of the instant invention can also be produced by fermentation of Pseudomonas, especially Pseudomonas aeruginosa, which are preferably non genetically modified cells, a technology already disclosed in the eighties, as documented e.g. in EP0282942 and DE4127908. Rhamnolipids produced in Pseudomonas aeruginosa cells which have been improved for higher rhamnolipid titres by genetical modification can also be used in the context of the instant invention; such cells have for example been disclosed by Lei et al. in Biotechnol. Lett. 2020 Jun;42(6):997-1002.

[0050] Rhamnolipids produced by Pseudomonas aeruginosa are commercially available from Jeneil Biotech Inc., e.g. under the tradename Zonix, from Logos Technologies (technology acquired by Stepan), e.g. under the tradename NatSurFact, from Biotensidion GmbH, e.g. under the tradename Rhapynal, from AGAE technologies, e.g. under the name R90, R95, R95Md, R95Dd, from Locus Bio-Energy Solutions and from Shanghai Yusheng Industry Co. Ltd., e.g. under the tradename Bio- 201 Glycolipids.

[0051] Most of the products mentioned above are mixtures of di- and mono-rhamnolipids which need to be converted to the mono-rhamnolipids, for example with rhamnosidase.

[0052] The compositions according to the instant invention comprises at least one mono-rhamnolipid in solution. The term “mono-rhamnolipid in solution” in the context of the instant convention means, that the mono-rhamnolipids are comprised in the specified amount in the composition according to the instant invention in a liquid phase, so that the mono-rhamnolipids do not settle when centrifuging at 500g for 10 minutes.

[0053] Of course, however, additional rhamnolipids exceeding the specified concentration ranges might be comprised in settable form.

[0054] Preferably said mono-rhamnolipid in solution comprised in the composition according to the instant invention is in aqueous solution.

[0055] A preferred composition according to the instant invention is characterised in that the mono- rhamnolipid content in the composition is from 85.0 wt.-% to 100.0 wt.-%, preferably from 95 wt.-% to 100.0 wt.-%, more preferably from 98.0 wt.-% to 100.0 wt.-%, wherein the weight percentages refer to all rhamnolipids comprised in the total composition.

[0056] A preferred composition according to the instant invention is characterised in that the mono- rhamnolipids comprise

[0057] 12 wt.-% to 32 wt.-% monoRL-C8C10,

[0058] 51 wt.-% to 81 wt.-% monoRL-C10C10,

[0059] 1 wt.-% to 9 wt.-% monoRL-C10C12,

[0060] 1 wt.-% to 9 wt.-% monoRL-C10C12:1, wherein the weight percentages refer to all mono-rhamnolipids comprised in the composition.

[0061] A preferred composition according to the instant invention is characterised in that it has a viscosity of 0.3 to 5, preferably 0.5 to 3, particularly preferably 0.6 to 2 Pas, measured in a rheometer at a shear rate of 10 s-1

[0062] The viscosity is measured using a rheometer (MCR 302, Anton Paar Germany) in a parallel plate measuring system. The upper plate has a diameter of 40 mm, the gap distance is 0.5 mm, measuring temperature is 25° C. The measurement was conducted in the shear rate range of 0.1- 100 s-1.

[0063] The compositions according to the instant invention preferably comprise at least one cosmetic active ingredient, preferably selected from ceramides and sphingoid bases.

[0064] The sphingoid base is preferably selected from the group sphingosine, sphinganine, 6- hydroxysphingosine and phytosphingosine. A preferred composition according to the instant invention is characterised in that said cosmetic active ingredient is selected from the group comprising, preferably consisting of, ceramide NP, ceramide AP, ceramide EOP, ceramide NDS, ceramide ADS, ceramide EODS, ceramide NS, ceramide AS, ceramide EOS, ceramide NH, ceramide AH and ceramide EOH, preferably selected from the group comprising, preferably consisting of, ceramide NP, ceramide AP, ceramide NS, ceramide EOP and ceramide EOS.

[0065] A preferred composition according to the instant invention is characterised in that said cosmetic active ingredient, especially at least on ceramide, is comprised in an amount of from 0.5 wt.-% to 10.0 wt.-%, preferably from 0.8 wt.-% to 7.0 wt.-%, more preferably from 1.2 wt.-% to 4.0 wt.-%, wherein the weight percentages refer to the total composition.

[0066] The compositions according to the instant invention preferably comprise at least one preservative.

[0067] The compositions according to the instant invention preferably is characterized in that said preservative is selected from the group comprising, preferably consisting of, p-anisic acid, benzoic acid, levulinic acid, sorbic acid, lactic acid, mandelic acid, salicylic acid, dehydroacetic acid, caprylhydroxamic acid, cinnamic acid, geranic acid, pelargonic acid, and the salts of the aforementioned acids, methylparaben, ethylparaben, phenylpropanol, benzyl alcohol, phenethyl alcohol, phenoxyethanol, propanediol, pentylene glycol, 1,2-hexanediol, caprylyl glycol, undecyl alcohol, methylpropanediol, ethylhexylglycerin, n-octylglycerin, n-heptylglycerin, n-hexylglycerin, methylheptylglycerin, undecylenamidopropyltrimonium methosulfate, isothiazolinones, preferably selected from chloromethylisothiazolinone (CIT), methylisothiazolinone (MIT), benzisothiazolinone (BIT) , butylbenzisothiazolinone (BBIT), triethyl citrate, citral, hydroxymethylglycinate, glyceryl caprylate, iodopropynyl butylcarbamat (IPBC), and Sodium Caproyl / Lauroyl Lactylate.

[0068] The present invention furthermore provides a process of producing a composition comprising at least one mono-rhamnolipid in solution comprising the steps of

[0069] A) providing a source-composition comprising at least one mono-rhamnolipid, preferably with a content of said mono-rhamnolipid from 0.5 wt.-% to 15.0 wt.-%, preferably from 5 wt.-% to 14.0 wt.-%, more preferably from 8.0 wt.-% to 12.0 wt.-%, wherein the weight percentages refer to the total source-composition, B) lowering the pH of said source-composition into the range of 1.8 to 3.5, preferably 2.2 to 3.4, more preferably 2.5 to 3.2, most preferably 2.6 to 3.1, while obtaining a multi-phase system,

[0070] C) removing the water rich phase from said multi-phase system, and increasing the pH of the remaining fraction, preferably into a range of 2.5 to 4.2, preferably 3.0 to 3.9, more preferably 3.2 to 3.8, most preferably 3.2 to 3.4.

[0071] Preferably the compositions according to the instant invention are produced by the method according to the instant invention.

[0072] A preferred process according to the instant invention is characterised in that the mono-rhamnolipid content in said source-composition is from 85.0 wt.-% to 100.0 wt.-%, preferably from 95 wt.-% to 100.0 wt.-%, more preferably from 98.0 wt.-% to 100.0 wt.-%, wherein the weight percentages refer to all rhamnolipids comprised in the total source-composition.

[0073] Mono-rhamnolipids can be produced by fermentation processes of micro-organisms known in the art. A preferred process according to the instant invention is characterised in that the sourcecomposition provided in step A) is a cell free fermentation broth.

[0074] The term “cell free” in the context of the instant invention means, that the cells of the mono- rhamnolipid producing organism have been removed, e.g. by centrifugation.

[0075] A preferred process according to the instant invention is characterised in that the pH in process step B) is lowered using an acid, in particular an inorganic acid, which is particularly preferably selected from HCI, H2SO4, nitric acid, phosphoric acid, carbonic acid, and is in particular HCI or H2SO4.

[0076] A preferred process according to the instant invention is characterised in that in process step C) the pH is increased by means of an inorganic base, in particular alkaline earth metal base or alkali base, preferably aqueous, or ammonia, with NaOH and KOH being particularly preferred.

[0077] The inorganic base preferably is in the form of a solution in water at a concentration of 0.01 M to 15 M, preferably 0.1 M to 5 M.

[0078] The present invention furthermore provides a composition comprising at least one mono- rhamnolipid in solution obtainable by a process according to the instant invention. This composition according to the instant invention is preferably obtained by a process of the instant invention which consists of the process steps A) to D).

[0079] The present invention furthermore provides a process for the production of a cosmetic or pharmaceutical formulation comprising mono-rhamnolipid and ceramide comprising the steps of

[0080] I) providing a composition according to the instant invention, wherein said composition comprises at least one ceramide and preferably at least one sphingoid base,

[0081] II) formulating said composition with at least one further additional component selected from the group of emollients, emulsifiers, co-emulsifiers, thickeners, viscosity regulators, stabilizers, hydrotropes, solids, fillers, pearlescent additives, opacifiers, insect repellents, self-tanning agents, surfactants, preservatives, conditioning agents, perfumes, colorants, cosmetic active substances, care additives, refatting agents, electrolytes, UV filters and solvents.

[0082] A preferred process according to the instant invention is characterised in that said ceramide is selected from the group comprising, preferably consisting of, ceramide NP, ceramide AP, ceramide EOP, ceramide NDS, ceramide ADS, ceramide EODS, ceramide NS, ceramide AS, ceramide EOS, ceramide NH, ceramide AH and ceramide EOH, preferably selected from the group comprising, preferably consisting of, ceramide NP, ceramide AP, ceramide NS, ceramide EOP and ceramide EOS.

[0083] The sphingoid base preferably co-comprised in said provided composition is selected from the group sphingosine, sphinganine, 6-hydroxysphingosine and phytosphingosine.

[0084] Substances that can be used as exemplary representatives of the individual groups for said further additional component in process step II) of the process of the instant invention are known to those skilled in the art and can for example be taken from German application DE102008001788.4. This patent application is hereby incorporated as reference and is thus considered to form part of the disclosure.

[0085] As regards said further additional components and also the amounts used of said further additional components, reference is expressly made to the relevant handbooks known to those skilled in the art, for example K. Schrader, “Grundlagen und Rezepturen der Kosmetika" [Fundamentals and formulations of cosmetics], 2nd edition, pages 329 to 341, Hiithig Buch Verlag, Heidelberg.

[0086] The amounts of the respective additives depend on the intended use.

[0087] Typical starting formulations for the relevant applications are known prior art and are contained for example in the brochures of the manufacturers of the relevant base materials and active substances. These existing formulations can generally be adopted unchanged. However, any desired modifications necessary for adjustment and optimization can be made in a straightforward manner through simple tests.

[0088] Preferred said further additional component in process step II) comprises water and preferably cholesterol.

[0089] In a preferred process according to the instant invention in process step I) a composition according to the instant invention comprising ceramide NP and phytosphingosine and preferably additionally ceramide AP and ceramide EOP, is provided and said further additional component in process step II) comprises water and preferably cholesterol.

[0090] The present invention furthermore provides the use of a composition according to the instant invention for the production of an end-customer product, preferably a formulation, especially a cleaning or care formulation, more preferably a household care or cosmetic formulation.

[0091] The cleaning formulation preferably is a laundry formulation, a dish washing formulation, a car cleaning formulation, a hard floor cleaning formulation, a glass cleaner, a bathroom cleaner, a kitchen cleaner, an over cleaner, an all purpose cleaner, a wet wipe, a metal cleaner, a membrane cleaner for food and beverage applications, a CIP (cleaning in place) cleaner, a big kitchen cleaner, a traffic film remover, a carpet cleaner, an alkaline cleaner, a prespotter, a mild cleaner or a neutral cleaner.

[0092] Brief description of the figures:

[0093] Figure 1 : Foam volume over time different test solutions

[0094] The examples adduced hereinafter describe the present invention by way of example, without any intention that the invention, the scope of application of which is apparent from the entirety of the description and the claims, be restricted to the embodiments specified in the examples.

[0095] Example 1: Preparation of highly concentrated mono-rhamnolipids

[0096] Mono-rhamnolipids were produced by a fermentation of a Pseudomonas putida strain pBBR1 MCS2-Plac-rhlAB, which was created just like the Pseudomonas putida strain pBBR1MCS2-Plac-rhlABC-T-Ptac-rhlC-T described in EP2786743, yet the Bsu36l restriction site was inserted directly behind the stop codon of the rhIB gene, thereby omitting rhIC. The preculture in a shake flask was carried out as described in EP2598646. For the main culture, a mineral medium (M9) was likewise employed. The fermentation was conducted in a 2 litre fermenter in a carbon-limited manner via a glucose feed input. The glucose feed input takes place by reference to the dissolved oxygen signal. The dissolved oxygen was regulated at 20% saturation via the stirrer speed. The pH is regulated to 7 via a pH electrode and addition of 2M sulphuric acid or a 20% by weight ammonia solution. To prevent excessive foaming of the fermentation broth, the defoamer Dow Corning 1500 was added as required. The fermentation was conducted over 4 days to a dry biomass of 16 g / L. The mono-rhamnolipid concentration was determined by HPLC and was 8.5 g / L.

[0097] After separating off the cells by means of centrifugation at 10,000 g, the fermentation broth was adjusted to a pH of 3.1 by adding concentrated H2SO4.

[0098] A multiphase composition was obtained, which was separated by centrifugation at 10,000 g and the upper aqueous phase was discarded.

[0099] The remnant was treated further.

[0100] The compositions listed in tablel were obtained by elevating the pH using KOH (aq) and diluting with water to the given mono-rhamnolipid concentration; percentage by weight referring to the total composition.

[0101] The viscosity was measured using a rheometer (MGR 302, Anton Paar Germany) in a parallel plate measuring system. The upper plate had a diameter of 40 mm, the gap distance was 0.5 mm, measuring temperature was 25° C. The measurement was conducted in the shear rate range of 0.1-100 s-1.

[0102] Table 1: Viscosity (Pas, shear rate 10 1 / s) of mono-rhamnolipid compositions as a function for rhamnolipid concentration (% by weight) and pH

[0103] Table 1 shows the viscosities of mono-rhamnolipid solutions in dependence of pH and concentration. At a concentration of 50 % and below pH4 all samples show phase separation leading to even multiple phases. In case of a phase separation (multiple phase) the measurement of viscosities is not possible.

[0104] At pH 4.0 or higher the samples are homogenous, and the viscosity decreases with an increasing pH.

[0105] At concentrations of 60% and 70% the phase separation is dominant.

[0106] At a concentration of 75.5% the mixtures show no phase separation at any listed pH. Surprisingly a low viscosity is observed at pH3.3. At this pH a highly concentrated, low viscosity rhamnolipid solution is provided.

[0107] A viscosity minimum was detected at a pH of 3.3, that was the lowest of all compositions, even when mRL concentration is significantly reduced.

[0108] Example 2: Solubilization of Ceramide 3B, aka NP

[0109] The dissolution capacity of the mono-rhamnolipid was investigated by mixing these with ceramides. A maximum amount of ceramides solubilized in mono-rhamnolipids was determined by adding ceramides to a mixture according to the present invention and heating to a temperature of 70°C. The evaluation of the maximum amount is determined by the mixture resulting in a clear formulation. The sample was assessed visually and additionally by microscopic analysis using polarized light. When no illumination of the sample is observed the solution is free from crystals and according to the definition clear.

[0110] In addition, the turbidity values were determined by turbidity measurements (HACH 2100AN IS Turbidimeter) in 11 mm glass cuvettes. All samples which revealed a turbidity value of <30 NTU were assessed as non-turbid. After cooling to 20° C., a "clear mixture” must not become turbid again over a period of 2 days.

[0111] In Table 2, the amounts used for the combinations are shown.

[0112] Table 2: Examples of combinations of mono-rhamnolipids, di-rhamnolipids, sophorolipids and ceramides

[0113] * according to the invention Examples 2D and 2E did not give clear solutions at pH3.3.

[0114] Example 3: Preparation of a cosmetic formulation comprising ceramide and mono-rhamnolipid.

[0115] Composition 2C from example 2 was used to prepare a micellar gel and a shampoo formulation based on stock solutions.

[0116] Stock solutions of mono-rhamnolipids and ceramides and further lipids were prepared like described in example 2. Additional components were added like the ceramides:

[0117] Table 3: Stock solutions of mono-rhamnolipids and ceramides and further lipids

[0118] * according to the invention

[0119] A micellar gel was prepared by using the stock solutions:

[0120] Xanthan Gum was diluted in water. Phase A is mixed using an Ultra-Turrax® for 10min (8000 rpm). All ingredients of phase B including the stock solutions were added in the given order while stirring with a spatula. The pH was adjusted with Citric Acid to 6.

[0121] Table 4: Micellar gel

[0122] A Shampoo was prepared by using the stock solutions:

[0123] The cationic guar was dissolved in water. The ingredients including the stock solutions were added in the given order and the pH was adjusted to 5.5

[0124] Example 4: Evaluation of foaming properties using the SITA Foam Tester

[0125] Foamability of surfactants and surfactant-based cleansing products is an important consumer- perceived attribute. This parameter can be determined using the “SITA foam tester R-2000” measuring device from SITA Messtechnik GmbH. In this device, foam is generated by introducing air into a defined volume of a surfactant solution through a special rotor. The total volume of liquid and resulting foam is measured over time by means of a computer-controlled sensing technique.

[0126] Compositions were prepared, that comprised a total mono-rhamnolipid concentration of 0.5 wt.-% at a total hardness of 10° dH (German hardness) with a pH of 6 and a pH of 7 respectively.

[0127] Two different mono-rhamnolipid concentrates of table 1 above were taken for the preparation of the compositions: 75%@pH 3.3 and 50%@pH7.0

[0128] * according to the invention

[0129] For evaluating the foaming performance, 300 mL of each test solution were tested for their foamability at 30°C using a constant stirring speed of 1500 rpm for 10 sec. A total of 8 such measurement intervals was carried out for each test solution. All samples were tested in duplicate. Figure 1 illustrates the foam volume over time for each test solution:

[0130] Measurement parameters: temperature: 30 °C ± 0,5 °C; sample volume / measurement: 300 mL; concentration of test sample: 0.5 wt% in water (10 °dH (German hardness)), pH adjusted with NaOH, stirring speed: 1500 rpm; stirring time: 10 sec; number of intervals: 8; number of repetitions: 2.

[0131] As seen in Figure 1 the compositions containing mono-rhamnolipids from the 75%@pH 3.3 concentrate in general show a much lower foam volume, compared to mono-rhamnolipids from the 40%@pH7.0 concentrate. The highest foam volume can be observed for the mono-rhamnolipids from the 40%@pH7.0 concentrate at a pH = 7 and in high contrast no foam volume at all can be observed for the mono-rhamnolipids from the 75%@pH 3.3 concentrate at the same pH value. At pH values of 6, lower foam volume can be observed for the mono-rhamnolipids from the 75%@pH 3.3 concentrate as well. This result is desired as a low foam volume is preferred in many applications, e.g. eye make-up remover and micellar water formulations.

Claims

Claims1 . A composition comprising at least one mono-rhamnolipid in solution wherein the total content of said mono-rhamnolipid in solution is from 71.0 wt.-% to 98.0 wt.-%, preferably from 73.0 wt.-% to 95.0 wt.-%, more preferably from 75.0 wt.-% to 85.0 wt-%, wherein the weight percentages refer to the total composition, characterized in that the pH of the composition at 25 °C is in the range of 2.5 to 4.2, preferably 3.0 to 3.9, more preferably 3.2 to 3.8, most preferably 3.2 to 3.4.

2. A composition according to claim 1 characterised in that the mono-rhamnolipid content in the composition is from 85.0 wt.-% to 100.0 wt.-%, preferably from 95 wt.-% to 100.0 wt.-%, more preferably from 98.0 wt.-% to 100.0 wt.-%, wherein the weight percentages refer to all rhamnolipids comprised in the total composition.

3. A composition according to claim 1 or 2 characterised in that the mono-rhamnolipids comprise12 wt.-% to 32 wt.-% monoRL-C8C10,51 wt.-% to 81 wt.-% monoRL-C10C10,1 wt.-% to 9 wt.-% monoRL-C10C12,1 wt.-% to 9 wt.-% monoRL-C10C12:1, wherein the weight percentages refer to all mono-rhamnolipids comprised in the composition.

4. A composition according to at least one of the preceding claims characterised in that it has a viscosity of 0.3 to 5, preferably 0.5 to 3, particularly preferably 0.6 to 2 Pas, measured in a rheometer at a shear rate of 10 s-1.

5. A composition according to at least one of the preceding claims characterised in that it comprises at least one cosmetic active ingredient, preferably selected from ceramides and sphingoid bases.

6. A composition according to claim 5 characterised in that said cosmetic active ingredient is selected from the group comprising ceramide NP, ceramide AP, ceramide EOP, ceramide NDS, ceramide ADS, ceramide EODS, ceramide NS, ceramide AS, ceramide EOS, ceramide NH, ceramide AH and ceramide EOH, preferably selected from the group comprising ceramide NP, ceramide AP, ceramide NS, ceramide EOP and ceramide EOS.

7. A composition according to claim 5 or 6 characterised in that said cosmetic active ingredient is comprised in an amount of from is from 0.5 wt.-% to 10.0 wt.-%, wherein the weight percentages refer to the total composition.

8. A composition according to at least one of the preceding claims characterised in that it comprises at least one preservative.

9. A composition according to claim 8 characterised in that the preservative is selected from the group comprisingp-anisic acid, benzoic acid, levulinic acid, sorbic acid, lactic acid, mandelic acid, salicylic acid, dehydroacetic acid, caprylhydroxamic acid, cinnamic acid, geranic acid, pelargonic acid, and the salts of the aforementioned acids, methylparaben, ethylparaben, phenylpropanol, benzyl alcohol, phenethyl alcohol, phenoxyethanol, propanediol, pentylene glycol, 1,2-hexanediol, caprylyl glycol, undecyl alcohol, methylpropanediol, ethylhexylglycerin, n-octylglycerin, n-heptylglycerin, n-hexylglycerin, methylheptylglycerin, undecylenamidopropyltrimonium methosulfate, isothiazolinones, triethyl citrate, citral, hydroxymethylglycinate, glyceryl caprylate, iodopropynyl butylcarbamat and Sodium Caproyl / Lauroyl Lactylate.

10. A process of producing a composition comprising at least one mono-rhamnolipid in solution comprising the steps ofA) providing a source-composition comprising at least one mono-rhamnolipid, preferably with a content of said mono-rhamnolipid from 0.5 wt.-% to 15.0 wt.-%, preferably from 5 wt.-% to 14.0 wt.-%, more preferably from 8.0 wt.-% to 12.0 wt.-%, wherein the weight percentages refer to the total source-composition,B) lowering the pH of said source-composition into the range of 1.8 to 3.5, preferably 2.2 to 3.4, more preferably 2.5 to 3.2, most preferably 2.6 to 3.1 , while obtaining a multiphase system,C) removing the water rich phase from said multi-phase system, andD) increasing the pH of the remaining fraction, preferably into a range of 2.5 to 4.2, preferably 3.0 to 3.9, more preferably 3.2 to 3.8, most preferably 3.2 to 3.4.

11. A process according to claim 10 characterised in that the source-composition provided in step A) is a cell free fermentation broth.

12. A process according to claim 10 or 11 characterised in that the pH in process step B) is lowered using an acid, in particular an inorganic acid, which is particularly preferably selected from HCI, H2SO4, nitric acid, phosphoric acid, carbonic acid, and is in particular HCI or H2SO4.

13. A composition comprising at least one mono-rhamnolipid in solution obtainable by a process according to at least one of the claims 10 to 12.

14. A process for the production of a cosmetic or pharmaceutical formulation comprising mono- rhamnolipid and ceramide comprising the steps ofI) providing a composition according to any of the claims 1 to 9 and 13, wherein said composition comprises at least one ceramide and preferably at least one sphingoid base,II) formulating said composition with at least one further additional component selected from the group of emollients, emulsifiers, co-emulsifiers, thickeners, viscosity regulators, stabilizers, hydrotropes, solids, fillers, pearlescent additives, opacifiers, insect repellents, selftanning agents, preservatives, conditioning agents, perfumes, colorants, cosmetic active substances, care additives, refatting agents, electrolytes, UV filters and solvents.

15. Use of a composition according to at least one of the claims 1 to 9 or 13 for the production of an end-customer product, preferably a formulation, especially a cleaning or care formulation, more preferably a household care or cosmetic formulation.

Images