Controlled release active agent carrier

Abstract

The present invention relates to carriers for the controlled release of active agents, comprising surface reacted natural or synthetic calcium carbonate, one or more active agents, wherein said one or more active agent is associated with said surface-reacted calcium carbonate, and wherein said surface-reacted natural or synthetic calcium carbonate is a reaction product of natural or synthetic calcium carbonate with carbon dioxide and one or more acids, wherein the carbon dioxide is formed in situ by the acid treatment and/or is supplied from an external source. It further relates to the preparation of loaded carriers, as well as their use in different applications.

Claims

1. A cosmetic formulation comprising an admixture of: (a) a surface reacted natural calcium carbonate in powder or granule form that is a reaction product of natural calcium carbonate with carbon dioxide and one or more acids in an aqueous environment, wherein the carbon dioxide is formed in situ by the acid treatment and/or is supplied from an external source, and wherein the natural calcium carbonate is marble, calcite, chalk, limestone, or any mixture thereof, (b) one or more active agents adsorbed onto and/or absorbed into the surface-reacted calcium carbonate, and (c) one or more cosmetically acceptable carriers, wherein the cosmetic formulation is in the form of a powder, a cream, an emulsion, a gel, a paste, a soap, a gum, or a tablet.

2. The cosmetic formulation according to claim 1, wherein the one or more acids is selected from the group consisting of hydrochloric acid, sulphuric acid, sulphurous acid, hydrosulphate, phosphoric acid, or oxalic acid, and any mixture thereof.

3. The cosmetic formulation according to claim 1, wherein the one or more acids is phosphoric acid.

4. The cosmetic formulation according to claim 1, wherein the surface-reacted calcium carbonate has a specific surface area of from 5 m.sup.2/g to 200 m.sup.2/g, measured using nitrogen and the BET method according to ISO 9277.

5. The cosmetic formulation according to claim 1, wherein the surface-reacted calcium carbonate has a specific surface area of from 20 m.sup.2/g to 80 m.sup.2/g, measured using nitrogen and the BET method according to ISO 9277.

6. The cosmetic formulation according to claim 1, wherein the surface-reacted calcium carbonate has a specific surface area of from 30 m.sup.2/g to 60 m.sup.2/g, measured using nitrogen and the BET method according to ISO 9277.

7. The cosmetic formulation according to claim 1, wherein the surface-reacted calcium carbonate has a weight median grain diameter d.sub.50 of from 0.1 to 50 μm, measured according to the sedimentation method.

8. The cosmetic formulation according to claim 1, wherein the surface-reacted calcium carbonate has a weight median grain diameter d.sub.50 of from 0.5 to 25 μm, measured according to the sedimentation method.

9. The cosmetic formulation according to claim 1, wherein the surface-reacted calcium carbonate has a weight median grain diameter d.sub.50 of from 0.8 to 20 μm, measured according to the sedimentation method.

10. The cosmetic formulation according to claim 1, wherein the surface-reacted calcium carbonate has an intra-particle porosity determined as a pore volume per unit particle volume from 20 vol.-% to 99 vol.-%, calculated from a mercury porosimetry measurement.

11. The cosmetic formulation according to claim 1, wherein the surface-reacted calcium carbonate has an intra-particle porosity determined as a pore volume per unit particle volume from 30 vol.-% to 70 vol.-%, calculated from a mercury porosimetry measurement.

12. The cosmetic formulation according to claim 1, wherein the surface-reacted calcium carbonate has an intra-particle porosity determined as a pore volume per unit particle volume from 40 vol.-% to 60 vol.-%, calculated from a mercury porosimetry measurement.

13. The cosmetic formulation according to claim 1, wherein the one or more active agents is selected from the group consisting of a pharmaceutical active agent, a biological active agent, a scented agent, a flavoring agent, a biocide, a disinfecting agent, a surfactant, a defoamer, a softener, a mineral oil, a wetting agent, a wax, a hydrolytic agent and an anti-dusting oil.

14. The cosmetic formulation according to claim 1, wherein the one or more active agents is selected from the group consisting of triclosan, limonene, peppermint, silicon, paraffin, o-phenylphenol and Bronopol.

15. The cosmetic formulation according to claim 1, which is a lipstick, a foundation, a deodorant, a sunscreen, a skin care formulation, a hair care product, a soap, a skin cream, a tooth paste, a bath additive, a foot powder, a facial powder, a sun screen, or a chewing gum.

16. A pharmaceutical formulation comprising an admixture of: (a) a surface reacted natural calcium carbonate in powder or granule form that is a reaction product of natural calcium carbonate with carbon dioxide and one or more acids in an aqueous environment, wherein the carbon dioxide is formed in situ by the acid treatment and/or is supplied from an external source, and wherein the natural calcium carbonate is marble, calcite, chalk, limestone, or any mixture thereof, (b) one or more active agents adsorbed onto and/or absorbed into the surface-reacted calcium carbonate, and (c) one or more pharmaceutically acceptable carriers, wherein the pharmaceutical formulation is in the form of a capsule, a tablet, a patch, or a cream.

17. An agricultural formulation comprising an admixture of: (a) a surface reacted natural calcium carbonate in powder or granule form that is a reaction product of natural calcium carbonate with carbon dioxide and one or more acids in an aqueous environment, wherein the carbon dioxide is formed in situ by the acid treatment and/or is supplied from an external source, and wherein the natural calcium carbonate is marble, calcite, chalk, limestone, or any mixture thereof, and (b) one or more active agents adsorbed onto and/or absorbed into the surface-reacted calcium carbonate, wherein the one or more active agents is selected from the group consisting of an agricultural agent, a biocide, a pesticide, or a herbicide.

Description

DESCRIPTION OF THE FIGURES

(1) FIG. 1 shows a SEM image of surface-reacted calcium carbonate useful in the present invention

(2) FIG. 2 shows an apparatus designed and suitable for making surface-reacted calcium carbonate tablets from wet suspensions.

(3) FIG. 3 shows a schematic cross-section of a die used for compacting powders.

(4) FIG. 4 shows a graph illustrating the release characteristics of a carrier according to the invention and a comparative sample.

(5) FIG. 5 shows a graph illustrating the sustained release effect of surface-treated calcium carbonate compared with conventional calcium carbonate

EXAMPLES

Example 1: Release Characteristics

(6) For comparing the release characteristics of the carrier according to the invention a tablet of surface reacted calcium carbonate was formed, as well as of a silica reference product featuring a similar high surface area as the surface-reacted calcium carbonate.

(7) Preparation of Surface-Reacted Calcium Carbonate

(8) The surface-reacted calcium carbonate was prepared in a 100 liter ESCO-reactor.

(9) 8000 g of dry natural calcium carbonate having a d50 of 0.7 μm (Sedigraph) (64 wt.-%<1 μm) was filled into the vessel. Then water was added until a solids content of 10 wt.-% was obtained. The resulting slurry was heated to 70° C., then 3733 g of phosphoric acid (=35 wt.-% dry/dry) was added during 90 minutes at a solids content of 75 wt.-%, under stirring with an anchor stirrer at 50 rpm and a disc stirrer at 2000 rpm. 30 minutes after the completion of the addition the temperature was decreased and the slurry upconcentrated in a filter press.

(10) The surface-reacted calcium carbonate used in the following example had a number mean particle size d.sub.50 (Sedigraph) of 3 μm a rose-like surface structure as can be taken from FIG. 1 a pH of 7.5 to 9.5 a specific surface area as measured by BET: 60 m.sup.2/g
Preparation of Surface-Reacted Calcium Carbonate Tablets

(11) The tablet was made from a suspension of surface-reacted calcium carbonate having a solids content of 30 wt-%±5 wt.-%. The tablets were formed by applying a constant pressure to the suspension for several minutes, typically 1-10 min, such that water is released by filtration through a fine 0.025 μm filter membrane resulting in a compacted tablet of the surface-reacted calcium carbonate. The apparatus used is illustrated in FIG. 2. It is further described in: Ridgway, C. J., Gane, P. A. C. and Schoelkopf, J., “Modified Calcium Carbonate Coatings with Rapid Absorption and Extensive Liquid Uptake Capacity”, Colloids and Surfaces A, 236(1-3), 2004, p. 91-102.

(12) The tablets were removed from the apparatus and dried in an oven at 80° C. for 24 hours.

(13) Preparation of Reference Tablets

(14) The silicates used as a reference were products available under the tradename GASIL® HP39 and P101 available from INEOS Silicas and had the following characteristics:

(15) TABLE-US-00001 GASIL ® HP39 GASIL ® P101 Pore volume  1.8 ml/g  1.1 ml/g Average particle size 10.3 μm 10.0 μm (Malvern) Oil absorption 280 g/100 g 200 g/100 g pH 7.0 7.0 SSA (BET)  260 m.sup.2/g  363 m.sup.2/g

(16) The silicate powders were formed into tablets in the four of blocks by a dry compaction method as follows:

(17) For the preparation of the pigment blocks a cylindrical hardened steel die attached to a base plate with a single acting upper piston was used which is suitable for a wide range of particle sizes, chemistries and morphologies. The die is divisible into two parts to aid removal of the compacted pigment sample and the walls of the die are protected with a strip of plastic film to prevent sticking of the powder to the wall and to reduce edge friction (FIG. 3).

(18) Further details of the method for producing such kind of tablet blocks can be taken e.g. from Pennanen M., “Methods for producing and testing tablets of dry pigments and coating colors”, Research report, Åbo Akademi, Turku and OMYA, Oftringen, 1996; Ridgway C. J., Ridgway K., Matthews G. P., “Modelling of the void space of tablets compacted over a range of pressures”, J. Pharm. Pharmacol. 49, (1997), p. 377; and: Gane, P. A. C., Schoelkopf, J., Spielmann, D. C., Matthews, G. P., Ridgway, C. J., “Fluid Transport into Porous Coating Structures: Some Novel Findings”, Tappi Journal, 83(5), 2000, p. 77-78.

(19) Association of Active Agent

(20) The surface-reacted calcium carbonate tablets, which were previously ground to a cubic shape, as well as the silicate blocks were placed in dishes. Limonene (pure or in alcohol/water) was added to the dishes such that the top surfaces of the tablets remained in contact with air (allowing any air in the tablets to escape as limonene is absorbed).

(21) Wetting continued for an additional 12 hours following the visual observation that the surfaces of the cubes and blocks are wetted by the limonene.

(22) The tablets were removed from the dish and allowed to stand in an open environment under standard temperature and pressure conditions until limonene could not be detected by smelling any more (for up to 350 hours). At this point, the tablets were placed in a closed jar and heated in order to analyze the weight of remaining limonene.

(23) In all cases, surface reacted calcium carbonate provided for a slower release of limonene than silica (FIG. 4; The percentages given refer to wt.-% limonene in ethyl alcohol; W449 refers to limonene loaded surface reacted calcium carbonate according to the invention, D 304 refers to limonene loaded HP 39 silicate; D 297 refers to limonene loaded P101 silicate as described above).

(24) The quantification was carried out by gas chromatography in a HS TurboMatrix 40 Trap Perkin Elmer using the following parameters:

(25) Temp. Mode: Oven 90° C., Needle 100° C., Transfer 110° C., Trap Low 40° C., Trap High 280° C.

(26) Timing: Thermo 20.0 min, Delay: 0.8 min, Pressurize 1.0 min, Dry Purge 5.0 min, Desorb. 0.1 min, Trap Hold 5.0 min

(27) Column: 101 kPa, Vial: 101 kPa, Desorb: 101 kPa GC Method AutoSystem XL Perkin Elmer

(28) Column: Optima 5 MS 1.0 μm, 50 m*0.32 mm, Macherey-Nagel Injector 130° C., Split on

(29) Temp.: 130° C. 1.0 min, 10° C./min to 220° C. 0.0 min

(30) Pressure: 70 kPa

(31) MS Turbo Mass Perkin Elmer

(32) Solvent Delay 4.5 min

(33) Full Scan 25 to 300 (EI+)

(34) Calibration: 0.0200 g Limonene/100 ml EtOH

(35) 0.0517 g Limonene/50 ml EtOH

(36) 0.1050 g Limonene/50 ml EtOH

(37) 0.2394 g Limonene/50 ml EtOH

(38) 0.7597 g Limonene/50 ml EtOH

(39) 0.5 μl injected in a HS vial (0.100 μg/0.517 μg/1.050 μg/2.394 μg/7.597 μg Limonene)

(40) Korrelation r.sup.2:0.9994

Example 2: Transport and Release of Oily Substances in an Aqueous Environment

(41) For illustrating the properties of the carrier according to the present invention with respect to the transport and release of oily substances in an aqueous environment, bath bombs and bath tablets were produced with surface-reacted calcium carbonate saturated with scents (natural oils) such as amaranth as well as peppermint oil. The bath bombs or bath tablets were dropped into water at a temperature of 37° C. in order to extract and evaluate the released oil.

(42) 1. Bath bombs

(43) a) Material

(44) Surface-reacted calcium carbonate: prepared as described under Example 1 above Natural oil: Amaranth oil Additives: Citric acid Sodium bicarbonate Hamamaelis water witch hazel Colour Vitasin Patentblue (Clariant) Food coloring red Food coloring yellow Solvent: n-Heptane
b) Compositions

(45) TABLE-US-00002 Sample 1 Sample 2 Sample 3 Citric acid 100.123 g 100.102 g 100.250 g Sodium 200.037 g 200.245 g 200.030 g bicarbonate Colour 3 drops colour 5 drops colour  0.016 g red brown Witch hazel approx. 2.5 to 3 g approx. 2 to  2.212 g water 2.5 g Surface-reacted  30.056 g calcium carbonate Oil Amaranth Amaranth Amaranth  9.9599 g Surface-reacted  12.304 g 20.4053 g calcium (of 7.7 g (of 17.32 g carbonate surface-reacted surface-reacted saturated with calcium calcium oil carbonate carbonate saturated with saturated with 5.55 g oil) 5.36 g oil) Calculated   1.8 wt-%   2.9 wt-%   1.7 wt-% content of oil
c) Preparation of the Bath Bombs

(46) Citric acid and sodium bicarbonate were provided and well blended manually in a mortar. The colour solutions were added and well mixed. Subsequently, the given amounts of surface-reacted calcium carbonate and amaranth oil were added, either by adding the surface-reacted calcium carbonate saturated with the amaranth oil and manually well mixed (sample 1 and 3), or by adding the components separately (sample 2). Onto these batches witch hazel was sprayed (with a squirt bottle) while stirring manually. As soon as the batch sticks together upon squishing, potions of the bulk are put into a conventional aluminium form.

(47) Any one of the resulting bombs was dried over night at room temperature. Then, each bomb was put into a 2000 ml beaker filled with 1000 ml tap water at approx. 37° C.

(48) After the resulting suspension (amaranth) had cooled down to less than 30° C. (in approx. 30 to 40 min.), the whole contents were extracted with heptane in a separation funnel.

(49) The water phase (pH 6.6±0.2) was discarded; the oil/solvent phase was filled into a 50 ml brown glass bottle and analyzed by determining the weight after evaporation of the solvent. The appearance of the solvent phases is turbid, milky white for the amaranth sample.

(50) d) Results and Discussion

(51) TABLE-US-00003 Calculated Calculated Content Content Weight oil content oil content recovered recovered bath bomb in wt-% in mg in mg in wt-% Sample 1a 24.2545 g 1.8 wt-% 437 mg 344 mg 78.8 wt-% Sample 1b 12.5365 g 226 mg 180 mg 79.8 wt-% Sample 2a 27.4791 g 2.9 wt-% 797 mg 356 mg 44.7 wt-% Sample 2b 31.1058 g 902 mg 322 mg 35.7 wt-%

(52) It can be taken from the above table that it is more favourable to saturate the calcium carbonate with the oil instead of just mixing it, wherein the recovery rate in samples 1a and b are very high confirming the good performance of the present invention with respect to the release of oily substances in an aqueous environment.

(53) 2. Bath Tablets

(54) a) Material

(55) Surface-reacted calcium carbonate: prepared as described under Example 1 above Natural oils: Amaranth oil Additives: Citric acid Sodium bicarbonate Hamamaelis aqua witch hazel Solvent: n-Heptane
b) Preparation of the bath tablets
Sample 4:

(56) 55 wt-% of a citric acid/sodium bicarbonate mixture (in a weight ratio of 1:2) were manually blended with 10 wt-% amaranth oil in a mortar. 35 wt-% of surface-reacted calcium carbonate were added in order to obtain a powdery batch.

(57) Sample 5:

(58) 35 wt-% of surface-reacted calcium carbonate were manually mixed with 10 wt-% amaranth oil in a mortar. The mixture was then added to 55 wt-% of a citric acid/sodium bicarbonate mixture (in a weight ratio of 1:2) and manually mixed in order to obtain a powdery batch.

(59) Sample 6:

(60) 34.5 wt-% of surface-reacted calcium carbonate were manually mixed with 10 wt-% amaranth oil in a mortar. The mixture was then added to 54.5 wt-% of a citric acid/sodium bicarbonate mixture (in a weight ratio of 1:2) and manually mixed in order to obtain a powdery batch. While squishing manually, 2 wt-% of Hanmamelis water witch hazel was sprayed onto the batch in order to get a sticky powder.

(61) From each of these samples tablet structures were formed by using a cylindrical hardened steel die attached to a base plate with a single acting upper piston. The die is divisible into two parts to aid removal of the compacted powder sample and the walls of the die are protected with a strip of plastic film to prevent sticking of the powder to the wall and to reduce edge friction. Additionally, the powders were covered with a cellulose membrane at the bottom as well as on top before being compacted in a hydraulic press for 1 minute at a predetermined force of 75 kN (an effective pressure of 35 bar). The tablets were formed of 1.5 to 1.8 cm in height and a diameter of 4.8 cm. All tablets were well compacted.

(62) The height of the powder in the instrument was approximately 4.5 to 5 cm (the maximum height of the cylindrical steel is 8 cm).

(63) c) Results and Discussion

(64) Subsequently, 10 g of each tablet were dissolved in tap water at 37-38° C. The dissolution took about 6 minutes for samples 4 and 5 and more than 6 minutes for sample 6.

Example 3: Transport and Release of Oily Substances in an Oily Environment

(65) For illustrating the properties of the carrier according to the present invention with respect to the transport and release of oily substances in an oily environment, as it is often present in cosmetic formulations, a formulation of surface-reacted calcium carbonate was compared with a formulation of non surface-reacted calcium carbonate.

(66) a) Material

(67) Surface-reacted calcium carbonate: prepared as described under Example 1 above Commercially available non surface-reacted calcium carbonate (Omyacarb 2 of OMYA AG) Commercially available methylbutyl isovalerat Hexadecane GC-MS: Before GC-MS analysis, the samples were 21.25× diluted in hexadecane (80 μl sample and 1620 μl solvent) GC Method AutoSystem XL Perkin Elmer Column: Optima 5 MS 1.0 μm, 50 m*0.32 mm, Macherey-Nagel Injector 300° C., Split on Temp.: 220° C. 8.0 min Pressure: 70 kPa MS Turbo Mass Perkin Elmer Solvent Delay 3.74 min SIR Scan, Mass 43, 70, 85 3.75 to 8.0 min (EI+)
b) Preparation of the Formulations

(68) 2 g of each of the calcium carbonate samples was manually mixed with a spatula in a dish with 0.06 g of methylbutyl isovalerat.

(69) 100 ml hexadecane were placed into a dish on an electric stirring base. A magnet was placed in the dish and allowed to turn at a minimal rotation speed.

(70) The pigment/methylbutyl isovalerat mixture was placed in the dish with the hexadecane to one side away from the stirrer. After a certain time period, a sample of the fluid phase was removed for analysis.

(71) This process was repeated for increasing lengths of time, each time using a fresh calcium carbonate/methylbutyl isovalerat mixture.

(72) c) Results and Discussion

(73) The following table also showing the mixture weights as well as the time periods of the experiments, as well as FIG. 5 clearly illustrate the sustained release effect of surface-treated calcium carbonate compared with conventional calcium carbonate.

(74) TABLE-US-00004 Sample 7 (Comparative) Sample 8 (Invention) Non Methyl- Methyl- surface- butyl- surface- butyl- reacted iso- Hexa- reacted iso- Hexa- Time CaCO.sub.3 valerate decane CaCO.sub.3 valerate decane [min] [g] [g] [ml] Recovery [g] [g] [ml] Recovery 2 0.2003 0.0606 100.0  96 ppm 0.2002 0.0624 100.0  30 ppm (15.8 wt-%)  (4.8 wt-%) 5 0.2009 0.0649 100.0 178 ppm 0.2005 0.0628 100.0  59 ppm (27.4 wt-%)  .sup.  9.4 wt-%) 15 0.2008 0.0625 100.0 455 ppm 0.2001 0.0633 100.0 115 ppm (72.8 wt-%) 18.2 wt-%) 30 0.2007 0.0619 100.0 555 ppm 0.2004 0.0606 100.0 300 ppm (89.7 wt-%) 49.5 wt-%) 60 0.2005 0.0612 100.0 585 ppm 0.2006 0.0616 100.0 417 ppm (95.6 wt-%) 67.7 wt-%) 120 0.2002 0.0600 100.0 577 ppm 0.2000 0.0640 100.0 476 ppm (96.2 wt-%) 74.4 wt-%)

Example 4: Further Formulations Comprising the Carrier of the Invention

(75) 1. Tooth Pastes

(76) a) Preparation of Surface-Reacted Calcium Carbonate

(77) The surface-reacted calcium carbonate was prepared in a 5 m.sup.3 reactor.

(78) 414 kg of dry natural calcium carbonate (undispersed marble) having a d.sub.50 of 3 μm (Sedigraph) was filled into the vessel. Then water was added until a solids content of 15 wt.-% was obtained. The resulting slurry was heated to 70° C., then phosphoric acid (in the form of a 30% by mass solution) was added in an amount corresponding to 30 wt.-% dry/dry during 11 minutes, under stirring at 200 rpm. 5 minutes after the completion of the addition the temperature was decreased and the slurry filtered on a drum filter and then dried using a flash dryer.

(79) The surface-reacted calcium carbonate used in the following example had a number mean particle size d.sub.50 (Sedigraph) of 4.5 μm a rose-like surface structure a pH of 7.5 to 9.5 a specific surface area as measured by BET: 40 m.sup.2/g
b) Material

(80) TABLE-US-00005 Sample 9 Sample 10 Sorbitol 70% 35.00 wt-%  35.00 wt-%  Water 29.60 wt-%  38.60 wt-%  Sodium monofluorophosphate 1.10 wt-% 1.10 wt-% (Phoskadent NA 211 of BK- Gulini) Potassium acesulfam (SUNETT 0.10 wt-% 0.10 wt-% of Nutrinova) Calcium carbonate powder 15.00 wt-%  15.00 wt-%  (Foodgrade limestone with d.sub.50 = 3 μm of Omya AG) Titanium dioxide powder (specific 1.00 wt-% 1.00 wt-% surface area of about 3.9 m.sup.2/g) surface-reacted calcium carbonate 5.00 wt-% 5.00 wt-% Spearmint aroma 0.80 wt-% 0.80 wt-% Cellulose gum 1.40 wt-% 1.40 wt-% Sodium lauryl sulfate 1.00 wt-% 0.00 wt-% Cocamidopropyl betaine 0.00 wt-% 2.00 wt-% Water 10.00 wt-%  0.00 wt-%
c) Preparation of a Tooth Paste Formulation

(81) Sorbitol, sodium monofluorophosphate, potassium acesulfam and water were thoroughly mixed together. To this mixture, a non surface reacted calcium carbonate powder/titanium dioxide powder blend was added and wetted therewith. Then, a mixture of surface-reacted calcium carbonate as described above and spearmint aroma, which was dropwise added to the surface reacted calcium carbonate while manually stirring, and, subsequently, cellulose gum were added while stirring in order to obtain a homogenous paste. The paste is further stirred slowly and cooled down to room temperature. Then, sodium lauryl sulphate in water/cocamidopropyl betaine is slowly added while stirring, under vacuum if required.

(82) 2. Skin Care Formulation

(83) This example describes the loading of an oil in water emulsion into surface-reacted calcium carbonate acting as a carrier in a skin care formulation.

(84) If the oil itself is loaded into the surface-reacted calcium carbonate, it would be displaced by water as soon as the loaded surface-reacted calcium carbonate is introduced into an aqueous formulation. Subsequently the oil would be visible as floating macroscopic droplets.

(85) a) Preparation of Surface-Reacted Calcium Carbonate

(86) The surface-reacted calcium carbonate was prepared in a 10 m.sup.3 reactor.

(87) 1700 kg of dry natural calcium carbonate having a d.sub.50 of 1.6 μm (Sedigraph) was filled into the vessel. Then, water was added until a solids content of 27 wt.-% was obtained. The resulting slurry was heated to 55° C., then phosphoric acid (in the form of a 35% by mass solution) was added in an amount corresponding to 13 wt.-% dry/dry during 20 minutes, under stirring at 100 rpm. 10 minutes after the completion of the addition the temperature was decreased and the slurry filtered on Sweco filter and then dried using a jet dryer.

(88) The surface-reacted calcium carbonate used in the following example had a number mean particle size d.sub.50 (Sedigraph) of 2.2 μm a rose-like surface structure a pH of 7.5 to 9.5 a specific surface area as measured by BET: >25 m.sup.2/g
b) Preparation of a Skin Care Formulation

(89) First, an emulsion was prepared. This operation was carried out by using a rotor-stator dissolver from Kinematika, Polytron PT 300 at 10000 min.sup.−1. For the preparation of the emulsion, 94.031 g of demineralised water was charged with 1.028 g of PEG-40 hydrogenated castor oil and homogenised until the emulsifier is well dissolved. Subsequently, 5.001 g of amaranth oil was added dropwise and dispersed well until a homogeneous milky emulsion was formed.

(90) In a next step, the surface-reacted calcium carbonate was loaded with the resulting emulsion. For this step 15.004 g of surface-reacted calcium carbonate was weighed into a ceramic mortar (Ø180 mm) and 20.209 g of the emulsion was added dropwise under mixing with pestle into the surface-reacted calcium carbonate until a white glossy creme was formed.

(91) Then, the loaded surface-reacted calcium carbonate was blended with a gel formulation having the following composition:

(92) TABLE-US-00006 Gel formulation composition 1,2-Propanediol 2.00 wt-% 1,3-Butylene glycol 3.00 wt-% Ammonium acryloyldimethyltaurate/vinylpyrrolidone 1.00 wt-% copolymer Water 66.82 wt-%  Lauryl PEG/PPG-18/18 Methicone (Dow Corning 5200 0.50 wt-% Formulation aid) PEG-12 Dimethicone (Dow Corning 5329 Emulsifier) 4.00 wt-% Butyrospermum Parkii (Shea butter) and dimethicone (and) 8.00 wt-% Ceteth-20 (and) Steareth-21 (Dow Corning 7-3121 Shea Blend Emulsion) Dimethicone/Vinyl Dimethicone Crosspolymer (and) 5.00 wt-% C12-14 pareth-12 (Dow Corning 9509 Silicone Elastomer Suspension) Water (and) Alcohol (and) Lecithin (and) Caffeine (and) 5.00 wt-% Carnitine (and) Centella asiatica (and) Potassium Phosphate (and) Sodium Hydroxide (and) Theobromine (Dow Corning DS-2007 Modeling Liposome) Divinyldimethicone/Dimethicone Copolymer (and) C12-13 2.00 wt-% Pareth-23 (and) C12-13 Pareth-3 (Dow Corning HMW 2220 non-ionic emulsion) Phenoxyethanol (and) Methylparaben (and) Ethylparaben 1.00 wt-% (and) Butylparaben (and) Propylparaben (and) Isobutylparaben (Phenochem; SLI Chemicals GmbH) 25% menthyl lactate solution in ethanol 1.60 wt-% Sodium hydroxide (10% solution) 0.08 wt-%

(93) The gel formulation was prepared by mixing 1,2-propanediol, butylene glycol and water, subsequent interspersing under stirring ammonium acryloyldimethyltaurate/VP Copolymer and allowing swelling resulting in a gel. Then, Lauryl PEG/PPG-18/18 Methicone, PEG-12 Dimethicone, Shea Blend Emulsion, Silicone Elastomer Suspension, Liposome, non-ionic emulsion and Phenochem were mixed under stirring and added to the gel. To this emulsion gel the mixture of 25% menthyl lactate solution in ethanol and 10% sodium hydroxide solution was added, and the resulting gel was quickly and intensively homogenized and stirred for another 15 minutes.

(94) For obtaining the skin care formulation, 20 g of the loaded surface-reacted calcium carbonate was blended manually with 100 g of the gel formulation until a homogenous white glossy creme was formed.

(95) The resulting creme had a pH of 6.94 a Brookfield viscosity of 23480 mPa.Math.s (Brookfield DV-II (RT; RV 5, 30 s/10 rpm))