METHOD FOR PRODUCING MICROPARTICLES WHICH ARE CHARGED WITH AN ACTIVE MATERIAL

Abstract

The present invention relates to processes for producing microparticles having, in their interior, at least one cavity which is connected via pores to the surface of the microparticles and which have been laden with at least one organic active of low molecular weight. The invention especially relates to a process for loading microparticles with at least one organic active of low molecular weight, wherein the active has been embedded in a matrix and/or the pores of the microparticles have been closed by means of a substance applied to the surface of the microparticles. The invention additionally relates to a process for sealing microparticles laden with at least one organic active of low molecular weight. The invention also relates to compositions of microparticles laden with at least one active of low molecular weight and to the use thereof.

Claims

1.-49. (canceled)

50. A process for producing microparticles laden with at least one organic active of low molecular weight, wherein the microparticles have been formed from an organic, polymeric wall material and in the unladen state, in their interior, have at least one cavity connected via pores to the surface of the microparticles, wherein (a) the unladen microparticles are impregnated with a liquid (1a) consisting essentially of i) the active, in molten, emulsified, suspended or dissolved form in the liquid, ii) at least one nonpolymerizable substance A which is solid at room temperature and is in molten, emulsified, suspended or dissolved form in the liquid, and iii) optionally one or more solvents; or (b) the unladen microparticles are impregnated with a liquid (1b) consisting essentially of i) the active, in molten, emulsified, suspended or dissolved form in the liquid, ii) at least one polymerizable substance B in emulsified or dissolved form in the liquid, iii) optionally a nonpolymerizable substance A which is solid at room temperature and is in molten, emulsified, suspended or dissolved form in the liquid, and iv) optionally one or more solvents; and then polymerization of substance B is brought about; or (c) the unladen microparticles are impregnated with a liquid (1c) consisting essentially of i) the active, in molten, emulsified, suspended or dissolved form in the liquid, ii) at least one substance C which is in dissolved or molten form in the liquid and can be solidified by addition of polyvalent ions, iii) optionally a nonpolymerizable substance A which is solid at room temperature and is in molten, emulsified, suspended or dissolved form in the liquid, and iv) optionally one or more solvents; and then a solution of polyvalent ions is added in order to bring about solidification of substance C.

51. A process for producing microparticles laden with at least one organic active of low molecular weight, wherein the microparticles have been formed from an organic, polymeric wall material and in the unladen state, in their interior, have at least one cavity connected via pores to the surface of the microparticles, wherein d1) the unladen microparticles are impregnated with a liquid (1d) comprising the active, and then d2) substance that seals the pores of the laden microparticles is applied to the surface of the laden microparticles.

52. A process for producing microparticles laden with at least one organic active of low molecular weight, wherein the microparticles have been formed from an organic, polymeric wall material and in the unladen state, in their interior, have at least one cavity connected via pores to the surface of the microparticles, wherein the unladen microparticles are impregnated with a liquid comprising the active by applying the liquid in finely divided form to the unladen microparticles.

53. The process according to claim 50, wherein the nonpolymerizable substance A is selected from the group consisting of organic polymers that melt at a temperature in the range from 30 to 150° C., organic polymers that are solubilizable in any solvent present, and waxes, and mixtures thereof.

54. The process according to claim 50, wherein the liquid (1a) used is a melt or solution consisting essentially of at least one active and at least one organic polymer and/or at least one wax, wherein the wax or organic polymer is in molten form or in the form of a solution in the active in the liquid.

55. The process according to claim 53, wherein the nonpolymerizable substance A is selected from the group consisting of vegetable or animal waxes, polyalkylene glycols, water-solubilizable polymers, and mixtures thereof.

56. The process according to claim 54, wherein the liquid (1a) used is a mixture of an aqueous solution or emulsion of the water-solubilizable polymer and the active.

57. The process according to claim 50, wherein the mass ratio of the at least one active to the nonpolymerizable substance A in the liquid (1a) is in the range from 99:1 to 10:90 and the mass ratio of the at least one active to the polymerizable substance B in the liquid (1b) is in the range from 99:1 to 10:90.

58. The process according to claim 50, wherein the polymerizable substance B is selected from the group consisting of ethylenically unsaturated monomers, silanes having hydroxyl or alkoxy groups, and oxidatively polymerizable aromatic compounds.

59. The process according to claim 50, wherein the liquid (1b) used is an emulsion or solution consisting essentially of at least one active and at least one polymerizable substance B, wherein the polymerizable substance B is in molten form or in the form of a solution in the active in the liquid.

60. The process according to claim 50, wherein the treating of the microparticles with the liquid (1a), (1b), (1c) or (1d) is accomplished by using the microparticles in the form of a powder.

61. The process according to claim 50, wherein the impregnating of the microparticles with the liquid (1a), (1b), (1c) or (1d) is accomplished by spray application or dropwise application of the respective liquid onto the microparticles or suspension of the microparticles in the respective liquid.

62. The process according to claim 51, wherein a solid coating is produced on the surface of the microparticles.

63. The process according to claim 62, wherein the microparticles are treated with a liquid (2d) comprising i) at least one film-forming substance D in molten, emulsified, dispersed or dissolved form in the liquid, and ii) optionally one or more solvents, in such a way as to form a solid coating on the surface of the microparticles.

64. The process according to claim 63, wherein the film-forming substance D is selected from the group consisting of organic polymers that melt at a temperature in the range from 30 to 150° C., organic polymers that are solubilizable and/or dispersible in any solvent present in the liquid (2d), vegetable or animal waxes, polyalkylene glycols, homo- and copolymers of vinyl acetate, water-solubilizable and/or water dispersible polymers, and mixtures thereof.

65. The process according to claim 64, wherein the liquid (2d) used is 1) a melt or solution consisting essentially of at least one organic polymer and/or at least one wax, wherein the wax or organic polymer is in molten form or in the form of a solution, dispersion or emulsion in the solvent in the liquid or 2) a solution, dispersion or emulsion of the water-solubilizable and/or water-dispersible polymer.

66. The process according to claim 65, wherein the film-forming substance D is selected from a polymerizable substance selected from the group consisting of ethylenically unsaturated monomers, silanes having hydroxyl or alkoxy groups, and oxidatively polymerizable aromatic compounds, and the film formation comprises polymerization of substance D.

67. The process according to claim 65, wherein the liquid (2d) is used in such an amount that the mass ratio of the microparticles obtained in step (d1) to substance D present in the liquid (2d) is in the range from 95:5 to 20:80.

68. The process according to claim 65, wherein a coating is produced on the surface of the microparticles by powdering the microparticles with a finely divided solid and then bringing about film formation on the surface of the microparticles or a coating is produced on the surface of the microparticles by depositing a volatile substance from the gas phase on the surface of the microparticles and converting it to a solid from the surface by chemical reaction.

69. The process according to claim 51, wherein step (d2) is conducted in such a way that the thickness of the coating obtained averages in the range from 0.01 to 1.5 times the average radius of the microparticles.

70. The process according to claim 50, wherein the impregnating of the microparticles with the liquid (1a), (1b), (1c) or (1d) is accomplished using a composition of microparticles in which the microparticles, prior to the filling, have an average particle diameter of 10 to 600 μm, wherein at least 80% of those microparticles that have a particle diameter that differs from the average particle diameter of the microparticles in the composition by not more than 20% each have an average of at least 10 pores having a diameter in the range from 1/5000 to ⅕ of the average particle diameter, and, in addition, the diameter of each of these pores is at least 20 nm.

71. The process according to claim 50, wherein the polymeric wall material comprises at least one aliphatic-aromatic polyester which is an ester of an aliphatic dihydroxy compound esterified with a composition of aromatic dicarboxylic acid and aliphatic dicarboxylic acid.

72. The process according to claim 50, wherein the wall material, besides the aliphatic-aromatic polyester, additionally comprises at least one further polymer that is different from aliphatic-aromatic polyesters and is selected from the group consisting of polymerized hydroxycarboxylic acids, aliphatic-aliphatic polyesters, polylactones, poly(p-dioxanones), polyanhydrides, polyesteramides, polylactic acid, aliphatic poly-C.sub.5-C.sub.12-lactones, aliphatic-aliphatic polyesters, and polyhydroxy fatty acids.

73. The process according to claim 50, wherein the active is liquid at 22° C. and 1013 mbar or has a melting point below 100° C.

74. The process according to claim 50, wherein the active is selected from the group consisting of aroma chemicals, organic crop protecting agents, organic pharmaceutical agents, cosmetic actives, and actives for construction chemical applications.

Description

FIGURES

[0689] FIG. 1 shows a scanning electron micrograph of the microparticles from example 1.

[0690] FIG. 2 shows a scanning electron micrograph of the microparticles from production example 1.

[0691] FIG. 3 shows a scanning electron micrograph of the microparticles from example 5.

EXAMPLES

[0692] Materials

[0693] Unless stated otherwise, the following materials and components were used: [0694] polybutylene sebacate terephthalate (PBSeT): Ecoflex™ FS Blend A1300 product from BASF SE [0695] polybutylene succinate adipinate (PBSA): BioPBS™ FD92 product from MCPP Germany GmbH [0696] polylactic acid (PLA) [0697] polycaprolactone (PCL) Capa6506 product from Perstorp [0698] polyethylene glycol (PEG9000): Pluriol E 9000 from BASF SE [0699] aroma chemical mixture: A water-immiscible fragrance mixture having a fruity, pearlike note and characterized by the following evaporation rate at 25° C. and 1 bar:

TABLE-US-00001 Aroma chemical mixture Time [hours] Δ M [%]* 0 0 3 8 5 10 94 46 145 51 170 54 190 57 480 69 *Decrease in mass of the aroma chemical mixture in % by weight normalized to the starting value [0700] beeswax: melting point 63° C., density of 0.96 to 0.964 g/mL at 15° C. (Fisher Scientific) [0701] triglyceride mixture: Myritol® 318 from BASF SE [0702] polyvinyl alcohol: degree of hydrolysis 88 mol %, viscosity 25 mPa*s (4% strength aqueous solution at 20° C.), proportion of carboxyl groups 3 mol %

Methods

Determining the Average Particle Diameter in Aqueous Suspension/Emulsion by Light Scattering

[0703] The particle diameter of the w/o/w emulsion or the particle suspension is determined with a Malvern Mastersizer 2000 from Malvern Instruments, England, Hydro 2000S sample dispersion unit, by a standard test method documented in the literature. The value D[4,3] is the volume-weighted average.

Determining the Average Particle Diameter of the Solid

[0704] The microparticles are determined as powder with a Malvern Mastersizer 2000 from Malvern Instruments, England, including Scirocco 2000 powder feed unit, by a standard test method documented in the literature. The value D[4,3] is the volume-weighted average.

Production Example 1: Production of Spherical Finable Microparticles

[0705] Spherical finable microparticles were produced analogously to example 8 of WO 2018/065481. The matrix-forming polymer used was a polymer blend of 70% by weight of polybutylene sebacate terephthalate (PBSeT; Ecoflex™ FS Blend A1300 product from BASF SE) and 30% by weight of polylactic acid (PLA). The procedure was as follows:

Pore former solution: 0.54 kg of ammonium carbonate was dissolved in 53.5 kg of water (pore former).
Solution of the aliphatic-aromatic polyester: 15.1 kg of PBSeT and 6.5 kg of PLA were stirred into 270.0 kg of dichloromethane and dissolved at 25° C. while stirring.

[0706] The w/o emulsion was produced by emulsifying the pore former solution in the solution of the aliphatic-aromatic polyester at 170 rpm with a twin-level cross-beam stirrer for 15 minutes.

[0707] The w/o emulsion thus created was transferred into 423 kg of a 0.8% strength by weight, aqueous polyvinyl alcohol solution and likewise emulsified with shear and energy input (one minute at 120 rpm with an impeller stirrer).

[0708] Stirring of the w/o/w emulsion thus created was then continued with an impeller stirrer at 120 rpm, while reducing the pressure to 800 mbar and gradually increasing the jacket temperature to 40° C. and keeping it at this temperature for 4 hours. Thereafter, the microparticle suspension was cooled to room temperature, filtered and dried at 37° C.

[0709] The average particle diameter D[4,3], determined from the aqueous suspension, was 220 μm. Bulk density was determined to DIN EN ISO 60:1999 and was 0.15 g/cm.sup.3. The pore size was 8.5 μm and was determined by means of mercury porosimetry. Visual evaluation was likewise effected and showed an average pore size at the surface of 7 μm.

Production Example 2: Production of Spherical Finable Microparticles

[0710] Spherical tillable microparticles were produced analogously to example 8 of WO 2018/065481. The matrix-forming polymer used was a polymer blend of 70% by weight of PBSeT and 30% by weight of PBSA. The procedure was as follows:

Pore former solution: 0.54 kg of ammonium carbonate was dissolved in 53.5 kg of water (pore former).
Solution of the aliphatic-aromatic polyester: 15.1 kg of PBSeT and 6.5 kg of PBSA were stirred into 270.0 kg of dichloromethane and dissolved at 25° C. while stirring.

[0711] The w/o emulsion was produced by emulsifying the pore former solution in the solution of the aliphatic-aromatic polyester at 170 rpm with a twin-level cross-beam stirrer for 15 minutes.

[0712] The w/o emulsion thus created was transferred into 423 kg of a 2.4% strength by weight, aqueous polyvinyl alcohol solution and likewise emulsified with shear and energy input (one minute at 120 rpm with a round anchor stirrer).

[0713] Stirring of the w/o/w emulsion thus created was then continued with an impeller stirrer at 120 rpm. In the process, the pressure was reduced to 800 mbar and the jacket temperature gradually increased to 40° C. and it was kept at this temperature for 4 hours. Thereafter, the microparticle suspension was cooled to room temperature, filtered and dried at 37° C.

[0714] The average particle diameter D[4,3], determined from the aqueous suspension, was 130 μm.

Production Example 3

[0715] Spherical finable microparticles were produced analogously to example 8 of WO 2018/065481. The matrix-forming polymer used was a polymer blend of 70% by weight of PBSeT and 30% by weight of PCL. The procedure was as follows:

Pore former solution: 0.54 kg of ammonium carbonate was dissolved in 53.5 kg of water (pore former).
Solution of the aliphatic-aromatic polyester: 15.1 kg of PBSeT and 6.5 kg of PCL were stirred into 270.0 kg of dichloromethane and dissolved at 25° C. while stirring.

[0716] The w/o emulsion was produced by emulsifying the pore former solution in the solution of the aliphatic-aromatic polyester at 170 rpm with a twin-level cross-beam stirrer for 15 minutes.

[0717] The w/o emulsion thus created was transferred into 423 kg of a 0.8% strength by weight aqueous polyvinyl alcohol solution and likewise emulsified with shear and energy input (one minute at 120 rpm with a round anchor stirrer).

[0718] Stirring of the w/o/w emulsion thus created was then continued with an impeller stirrer at 120 rpm. In the process, the pressure was reduced to 800 mbar and the jacket temperature was gradually increased to 40° C. and it was kept at this temperature for 4 hours. Thereafter, the microparticle suspension was cooled to room temperature, filtered and dried at 37° C.

[0719] The average particle diameter D[4,3], determined from the aqueous suspension, was 110 μm.

Example 1

[0720] A homogeneous mixture of beeswax and an aroma chemical mixture was produced by melting 5.0 g of beeswax in a water bath at 85° C. and adding 5.0 g of the aroma chemical mixture.

[0721] 0.29 g of the melt produced was dripped onto 0.29 g of the tillable spherical microparticles from example 1 while stirring. Then the formulation was cooled to room temperature.

Comparative Example 1

[0722] As a reference sample, microparticles from production example 1 were filled with the aroma chemical mixture in analogy to the method of example 1, but without substance A. The quantitative ratios of microparticles to aroma chemicals were chosen so as to obtain the same mass ratio between aroma chemical mixture and spherically tillable microparticles as in example 1. For this purpose, while stirring, 0.15 g of the aroma chemical mixture from example 1 was dripped onto 0.29 g of the tillable spherical microparticles from production example 1 while stirring.

Study of Storage Stability

[0723] The microparticle compositions from example 1 and comparative example 1 were stored together at 25° C. and a relative air humidity of 50% in a climate-controlled cabinet. The decrease in mass of the aroma chemical mixture was determined via the decrease in weight of the sample. The results are summarized in Table 1.

TABLE-US-00002 TABLE 1 Example 1 Comparative example 1 Time [hours] Δ M [%]* Δ M [%]* 0 0 0 30 11 25 46 12 33 74 26 41 145 30 40 170 34 54 480 42 69 650 43 73 1180 57 82 *Decrease in mass of the sample in % by weight normalized to weight of the aroma chemical mixture

Example 2

[0724] A homogeneous mixture of polyethylene glycol (PEG9000) and the aroma chemical mixture was produced by melting 5.0 g of PEG9000 in a water bath at 85° C. and adding 5.0 g of the aroma chemical mixture. 0.29 g of the melt thus produced was dripped onto 0.29 g of the tillable spherical microparticles from example 1 while stirring. Then the composition thus obtained was cooled to room temperature.

[0725] The microparticle composition from example 2 was stored together with the microparticle composition from comparative example 1 at 25° C. and a relative air humidity of 50% in a climate-controlled cabinet. The decrease in mass of the aroma chemical mixture was determined via the decrease in weight of the sample. The results are summarized in Table 2.

TABLE-US-00003 TABLE 2 Example 2 Comparative example 1 Time [hours] Δ M [%]* Δ M [%]* 0 0 0 25 10 23 70 21 40 140 32 51 190 38 56 240 40 58 500 52 69 670 53 73 *Decrease in mass of the sample in % by weight normalized to weight of the aroma chemical mixture

Example 3

[0726] 5.0 g of the microparticles from production example 1 were mixed with 20.0 g of the aroma chemical mixture on a roll mixer for five hours. Subsequently, the suspension was filtered, and the filtercake was rinsed three times with 10% by weight aqueous propanediol solution and then dried at room temperature overnight. 0.97 g of the filled microparticles thus obtained, comprising the aroma chemical mixture in an amount of 60%, based on the total weight of the particles, was removed and stirred with a melt of 2.23 g of beeswax, so as to form a wax film on the microparticles. The mixture was cooled and stored.

Example 4

[0727] 5.0 g of the microparticles from production example 1 were mixed with 20.0 g of the aroma chemical mixture on a roll mixer for five hours. Subsequently, the suspension was filtered, and the filtercake was rinsed three times with 10% by weight aqueous propanediol solution and then dried at room temperature overnight. 0.14 g of the filled microparticles thus obtained, comprising the aroma chemical mixture in an amount of 60%, based on the total weight of the particles, was removed and stirred in a melt of 1.34 g of carnauba wax (melting range from 82 to 86° C.), so as to form a wax film on the microparticles. The mixture was cooled and stored.

Comparative Example 2

[0728] 5.0 g of the microparticles from production example 1 were mixed with 20.0 g of the aroma chemical mixture on a roll mixer for five hours. Subsequently, the suspension was filtered, and the filtercake was rinsed three times with 10% by weight aqueous propanediol solution and then dried at room temperature overnight. The filled microparticles thus obtained, comprising the aroma chemical mixture in an amount of 60%, based on the total weight of the particles, were removed and used to examine storage stability.

[0729] The microparticle compositions from examples 3 and 4 were stored together with the microparticle composition from comparative example 2 at 25° C. and a relative air humidity of 50% in a climate-controlled cabinet. The decrease in mass of the aroma chemical mixture was determined via the decrease in weight of the sample. The reference examined was the decrease in mass of the pure, unencapsulated aroma chemical. The results are summarized in Table 3.

TABLE-US-00004 TABLE 3 Example 3 Example 4 Comparative example 2 Time [hours] Δ M [%]* Δ M [%]* Δ M [%]* 0 0 0 0 3 3 n.d. 4 5 8 8 20 94 36 29 38 145 39 39 56 170 41 43 59 190 42 49 71 260 47 56 79 *Decrease in mass of the sample in % by weight normalized to weight of the aroma chemical mixture

Examples 5a-5f

[0730] a) 500 g of the microparticles from production example 1 were initially charged in a ploughshare mixer and sprayed with 1000 g of a triglyceride mixture at 20° C. by means of a single-substance nozzle having a nozzle diameter of 0.5 mm (spray pressure 2 bar) within 2 mins (flow rate 500 ml/min). 400 g of the filled microparticles thus obtained were again initially charged in a ploughshare mixer and sprayed by means of a single-substance nozzle (spray pressure 4 bar, flow rate 100 ml/min) at 70° C. with 100 g of a beeswax melt (heated to 75° C.) within 10 min, so as to form a wax film on the microparticles. The microparticles thus obtained were cooled and discharged from the mixer. [0731] b) Example 5a can be conducted in the same way with a mixture of the aroma mixture with the triglyceride mixture. [0732] c) Example 5a can be conducted in the same way with the pure aroma mixture. [0733] d) Example 5a can be conducted in the same way with a 10% by weight solution of L-menthol in propane-1,2-diol. [0734] e) Example 5a can be conducted in the same way with a 10% by weight solution of rose oxide in propane-1,2-diol. [0735] f) Example 5a can be conducted in the same way with a 10% by weight solution of Dihydrorosan in propane-1,2-diol.

Examples 6a-6f

[0736] a) 500 g of the microparticles from production example 2 were initially charged in a plowshare mixer. To this was added dropwise 1000 g of a triglyceride mixture by means of a funnel at 20° C. within 5 min. 400 g of the filled microparticles thus obtained were in turn initially charged in a plowshare mixer and sprayed by means of a one-phase nozzle (spray pressure 4 bar, flow rate 100 ml/min) with 100 g of a beeswax melt (at a temperature of 75° C.) at 70° C. within 10 min, such that a wax film forms on the microparticles. The microparticles thus obtained were cooled down and discharged from the mixer. [0737] b) Example 6a can be conducted in the same way with a mixture of the aroma mixture with the triglyceride mixture. [0738] c) Example 6a can be conducted in the same way with the pure aroma mixture. [0739] d) Example 6a can be conducted in the same way with a 10% by weight solution of L-menthol in propane-1,2-diol. [0740] e) Example 6a can be conducted in the same way with a 10% by weight solution of rose oxide in propane-1,2-diol. [0741] f) Example 6a can be conducted in the same way with a 10% by weight solution of Dihydrorosan in propane-1,2-diol.

Examples 7a-f

[0742] a) 500 g of the microparticles from production example 3 were sprayed with 1000 g of a triglyceride mixture by the method of example 5a. 400 g of the filled microparticles thus obtained were in turn initially charged in a plowshare mixer and sprayed with 100 g of a beeswax melt (at a temperature of 75° C.) by means of a one-phase nozzle (spray pressure 4 bar, flow rate 100 ml/min) at 70° C. within 10 min, so as to form a wax film on the microparticles. The microparticles thus obtained were cooled down and discharged from the mixer. [0743] b) Example 7a can be conducted in the same way with a mixture of the aroma mixture with the triglyceride mixture. [0744] c) Example 7a can be conducted in the same way with the pure aroma mixture. [0745] d) Example 7a can be conducted in the same way with a 10% by weight solution of L-menthol in propane-1,2-diol. [0746] e) Example 7a can be conducted in the same way with a 10% by weight solution of rose oxide in propane-1,2-diol. [0747] f) Example 7a can be conducted in the same way with a 10% by weight solution of Dihydrorosan in propane-1,2-diol.

Example 8

[0748] 500 g of the microparticles from production example 1 were sprayed by the method of example 5a with 1000 g of a mint aroma mixture consisting of 2.3% by weight of L-isopulegol, 3.1% by weight of L-methyl acetate, 36.4% by weight of L-menthone and 58.2% by weight of L-menthol. 400 g of the filled microparticles thus obtained were in turn initially charged in a plowshare mixer and sprayed with 100 g of a beeswax melt (at a temperature of 75° C.) by means of a one-phase nozzle (spray pressure 4 bar, flow rate 100 ml/min) at 70° C. within 10 min, so as to form a wax film on the microparticles. The microparticles thus obtained were cooled down and discharged from the mixer.

Example 9

[0749] In this example, a mixture of aroma chemicals having comparable evaporation characteristics to the aroma chemical mixture used in the other examples but a different fruity, apple-like note was used.

[0750] 200.0 g of the aroma chemical mixture were then applied dropwise while stirring to 100.0 g of the microparticles from production example 1. 0.30 g of the filled microparticles thus obtained was initially charged in an aluminum dish and sprayed with 0.8 g of a mixture of a tetra(ethylene glycol) diacrylate and the photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone in a mass ratio of 98:2. Subsequently, the microparticles thus treated were irradiated with a LED-UV source, Bluepoint LED eco from Dr. Hönle AG, at a power of 80% of the maximum power, which led to immediate curing of the tetra(ethylene glycol) diacrylate.

[0751] The microparticle composition thus obtained was stored in a climate-controlled cabinet together with the unencapsulated aroma chemical mixture at 25° C. and a relative air humidity of 50%. The decrease in mass of the aroma chemical mixture was determined via the decrease in weight of the sample. The results are compiled in table 4.

TABLE-US-00005 TABLE 4 Example 9 Aroma chemical Time [hours] Δ M [%]* Δ M [%]* 0 0 0 7 0 24 13 3 33 36 13 45 *decrease in mass of the sample in % by weight, normalized to weight of the aroma chemical mixture