MICROPARTICLE COMPOSITION AND USE THEREOF

Abstract

The invention provides a personal care product or a home care product having self-assembled microparticles having an acid having two or more acid groups and an organic base in a solvent. The microparticles may form into a macrostructure and provide a support for carrying components of a personal care or home care composition. The particle is of micron scale. The microparticle may be obtained by contacting a bis-acid and organic base in a hydrophilic solvent, wherein the acid is insoluble or sparingly soluble in the hydrophilic solvent and the organic base is soluble in a hydrophilic solvent.

Claims

1. A personal care product comprising a personal care base composition and a particulate component comprising a self-assembled microparticle.

2. A personal care product according to claim 1 in which the personal care base composition is selected from a skin cream, cosmetic, fragrance, deodorant, hand or face wipe, hand wash, hand scrub, shampoo, conditioner, mouth wash and tooth paste.

3. A home care product comprising a home care base composition and a particulate component comprising a self-assembled microparticle.

4. A home care product according to claim 3 comprising a home care base composition selected from a surface treatment, a surface spray, a surface wipe, a detergent composition, a fabric softener, a fragrance and a dishwashing composition.

5. A personal care product or a home care product according to any one of the preceding claims in which the self-assembled microparticle comprises an acid having two or more acid groups and an organic base.

6. A personal care product or a home care product according to any one of the preceding claims in which the microparticle has a particle size of 0.5 to 10 microns, preferably 1 to 5 microns.

7. A personal care product or a home care product according to any one of the preceding claims in which the molar ratio of acid groups to basic groups in the acid and base is from 0.6 to 1.4:1.

8. A personal care product or a home care product according to any one of the preceding claims in which the microparticle comprises acid groups and basic groups in a molar ratio from 0.7 to 1.3:1.

9. A personal care product or a home care product according to any one of the preceding claims in which the microparticle comprises a self-assembled microparticle comprising an acid having two or more acid groups and an organic base obtainable by a process comprising contacting the acid and organic base in a hydrophilic solvent, wherein the acid is insoluble or sparingly soluble in the hydrophilic solvent and the organic base is soluble in a hydrophilic solvent.

10. A personal care product or a home care product according to claim 9 in which the solvent comprises an aqueous solution.

11. A personal care product or a home care product according to claim 9 in which the solvent comprises a water in oil emulsion within an aqueous phase.

12. A personal care product or a home care product according to any one of the preceding claims in which the microparticle comprises a bis-acid.

13. A personal care product or a home care product according to claim 12 in which the acid comprises a bis-aliphatic acid.

14. A personal care product or a home care product according to any one of the preceding claim 12 or 13 in which the acid comprises a bis-carboxylic fatty acid in which terminal carboxylic acids are linked by a region which is hydrophobic.

15. A personal care product or a home care product according to any one of the preceding claims in which the microparticle comprises an acid in which the acid groups are separated by a saturated, or unsaturated aliphatic chain; or substituted saturated, or unsaturated aliphatic chain.

16. A personal care product or a home care product according to claim 15 in which the acid comprises a compound of general formula HOOC(CH.sub.2).sub.nCOOH wherein n is sufficiently large that the bis acid is sparingly soluble or insoluble in water.

17. A personal care product or a home care product according to claim 16 in which wherein n is at least 5 and not more than 40.

18. A personal care product or a home care product according to any one of the preceding claims in which the microparticle comprises brassylic acid, sebacic acid and/or azelaic acid.

19. A personal care product or a home care product according to any one of the preceding claims comprising an organic base which comprises an aliphatic amine or an aromatic amine having a basic character or other nitrogen-containing base.

20. A personal care product or a home care product according to claim 19 in which the organic base comprises one or more of an alkylated amine and an alkylated polyamine.

21. A personal care product or a home care product according to claim 20 in which the organic base comprises one or more of N-methylmorpholine, N,N-dimethylaminoethanol, 4-dimethylaminopyridine, imidazole, 1-methylamidazole poly(diallyldimethylammonium chloride) (PDAC), didecyldimethylammonium chloride (DDAC), dodecyldipropylenetriamine (DDPT) and poly epsilon lysine.

22. A personal care product or a home care product according to any one of the preceding claims in which the microparticle comprises a multi-lamellar structure.

23. A personal care product or a home care product according to any one of the preceding claims in which the microparticle comprises a bis-acid and the bis-acid is reacted with an organic base to form a cross-linked species.

24. A personal care product or a home care product according to any one of the preceding claims comprising an organic base wherein the base is displaced with another reactive base which is then reacted to form a cross-linked species.

25. A personal care product or a home care product comprising i) a personal care base composition or a home care base composition and ii) a macroporous material in which the macroporous material comprises cross-linked self-assembled microporous particles.

26. Use of a self-assembled cross-linked microparticle as a carrier for one or more components of a personal care base composition or a home care base composition.

27. An antimicrobial personal care product or an antimicrobial home care product according to any one of claims 1 to 25 in which the self-assembled microparticle has anti-microbial properties.

Description

[0090] The invention is illustrated by the following non-limiting examples.

Example 1Preparation of Self-Assembled Microparticles

[0091] Brassylic acid (1.54 g, 6.31 mmol) and 4-dimethylaminopyridine (DMAP, 1.54 g, 12.62 mmol) were dissolved in water (10 cm.sup.3) and a sample placed on a microscope. Almost monodispersed spherical entities of 3 m diameter were observed (FIG. 1).

Example 2Preparation of Self-Assembled Microparticles

[0092] Brassylic acid (1.54 g, 6.31 mmol) and dimethylaminoethanol (DMAE, 1.12 g, 12.62 mmol) were dissolved in water (10 cm.sup.3) and a sample placed on a microscope. Almost monodispersed spherical entities of 3 m diameter were observed.

Example 3Preparation of Self-Assembled Microparticles

[0093] Brassylic acid (1.54 g, 6.31 mmol) and 4-methylmorpholine (NMM, 1.275 g, 12.62 mmol) were dissolved in water (10 cm.sup.3) and a sample placed on a microscope. Almost monodispersed spherical entities of 3 m diameter were observed.

Example 4Preparation of Self-Assembled Microparticles

[0094] The above dicarboxylic acid dissolution experiments were also carried out using a range of acids and a range of water soluble organic bases. Some of the combinations tested are listed below. The combinations had an acid group to basic group molar ratio of 0.9 to 1.1:1. All of these combinations formed the spherical entities as described in Example 1. [0095] Pimelic acid plus NMM [0096] Suberic acid plus NMM [0097] Azelaic acid plus NMM [0098] Sebacic acid plus NMM [0099] Sebacic acid plus DMAP [0100] Sebacic acid plus DMAE [0101] Sebacic acid plus imidazole [0102] Dodecanedioic acid plus NMM [0103] Dodecanedioic acid plus DMAP [0104] Dodecanedioic acid plus DMAE [0105] C36 dimer acid plus NMM

Example 5Preparation of Cross-Linked Self-Assembled Microparticles

[0106] Brassylic acid (1.54 g, 6.31 mmol) and 4-dimethylaminopyridine (DMAP, 1.54 g, 12.62 mmol) were dissolved in water (10 cm.sup.3) and a sample placed on a microscope. Almost monodispersed spherical entities of 3 m diameter were observed (FIG. 1).

[0107] Poly-epsilon-lysine (PeK) (2 g, 12.04 mmol of NH.sub.2) was dissolved in water (10 cm.sup.3) and added to the above solution of Brassylic acid/DMAP microspheres. The mixture was filtered through a 0.45 m membrane and a sample placed on a microscope. Microspheres of 3 m diameter were still present. This solution was diluted with water to 100 cm.sup.3. N-(3-Dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride (EDCI)(4.6 g, 2.4 mmol) and HONSu (1.38 g, 1.2 mmol) were dissolved in water (10 cm.sup.3) and added to the above solution. The cross-linking reaction was left overnight, the resultant particles washed by tangential flow filtration (TFF) and recovered by lyophilisation (yield 2.35 g). FIG. 2 shows a scanning electron micrograph of the resultant microspheres.

Example 6Preparation of Cross-Linked Self-Assembled Microparticles Containing Protoporphyrin IX, Heme B

[0108] Brassylic acid (0.734 g, 3.3 mmol) and 4-dimethylaminopyridine (DMAP, 0.734 g, 6.6 mmol) were dissolved in water (10 cm.sup.3) and a sample placed on a microscope. Almost monodispersed spherical entities of 3 m diameter were observed (FIG. 1).

[0109] Poly-epsilon-lysine (PeK) (1 g, 6.02 mmol of NH.sub.2) was dissolved in water (10 cm.sup.3) and added to the above solution of Brassylic acid/DMAP microspheres. The mixture was filtered through a 0.45 m membrane and a sample placed on a microscope. Microspheres of 3 m diameter were still present. This solution was diluted with a saturated solution of Heme B (50 cm.sup.3). N-(3-Dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride (EDCI)(2.3 g, 1.2 mmol) and HONSu (0.7 g, 0.6 mmol) were dissolved in water (5 cm.sup.3) and added to the above solution. The cross-linking reaction was left overnight, the resultant particles washed by tangential flow filtration (TFF) and recovered by lyophilisation (yield 0.93 g).

Example 7Preparation of Cross-Linked Self-Assembled Microparticles

[0110] Sebacic acid (0.619 g, 6.12 mmol) and NMM (0.62 g, 6.12 mmol) were dissolved in water (10 cm.sup.3) and a sample placed on a microscope. Almost monodispersed spherical entities of 2.5 m diameter were observed.

[0111] Poly-epsilon-lysine (PeK) (1 g, 5.83 mmol of NH.sub.2) was dissolved in water (10 cm.sup.3) and added to the above solution of Sebacic acid/NMM microspheres. The mixture was filtered through a 0.45 m membrane and a sample placed on a microscope. Microspheres of 2.5 m diameter were still present. This solution was diluted with water to 50 cm.sup.3. EDCI (2.24 g, 11.7 mmol) and HONSu (2.0 g, 17.4 mmol) were dissolved in water (10 cm.sup.3) and added to the above solution. The cross-linking reaction was left overnight, the resultant particles washed by TFF and recovered by lyophilisation.

Example 8Preparation of Cross-Linked Self-Assembled Microparticles

[0112] Sebacic acid (5.06 g, 25 mmol) and imidazole (3.4 g, 50 mmol) were dissolved in water (50 cm.sup.3) and a sample placed on a microscope. Almost monodispersed spherical entities of 2.5 m diameter were observed.

[0113] Poly-epsilon-lysine (PeK) (8.576 g, 50 mmol of NH.sub.2) was dissolved in water (50 cm.sup.3) and added to the above solution of Sebacic acid/imidazole microspheres. The mixture was filtered through a 0.45 m membrane and a sample placed on a microscope. Microspheres of 2.5 m diameter were still present (FIG. 3). This solution was diluted with water to 500 cm.sup.3. EDCI (4.8 g, 25 mmol) was dissolved in water (20 cm.sup.3) and added to the above solution. The cross-linking reaction was left for 1 h then a further 25 mmol of EDCI added before leaving overnight. The resultant particles washed with water by decantation and recovered by lyophilisation (FIG. 4).

Example 9Preparation of Cross-Linked Self-Assembled Microparticles

[0114] Sebacic acid (5 g, 24.7 mmol) and (3-Aminopropyl)trimethoxysilane (8.42 g, 46.9 mmol) were dissolved in water (50 cm.sup.3) and a sample placed on a microscope. Almost monodispersed spherical entities of 2.5 m diameter were observed.

[0115] The mixture was left overnight then acidified with concentrated hydrochloric acid. The addition of hydrochloric acid led to the formation of silica within the particles creating a Sebacic acid/silica composite.

Example 10Preparation of Cross-Linked Self-Assembled Microparticles

[0116] Sebacic acid (5 g, 24.7 mmol) and N-[3-(Trimethoxysilyl)propyl]ethylenediamine (5.77 g, 51.9 mmol of amine) were dissolved in water (50 cm.sup.3) and a sample placed on a microscope. Almost monodispersed spherical entities of 2.5 m diameter were observed.

[0117] This solution was diluted with water to 500 cm.sup.3. EDCI (20 g, 104 mmol) was dissolved in water (100 cm.sup.3) and added to the above solution. The mixture was left overnight then acidified with concentrated hydrochloric acid. The addition of hydrochloric acid led to the formation of silica within the particles creating a Sebacic acid/silica composite.

Example 11Preparation of Cross-Linked Self-Assembled Microparticles

[0118] Sebacic acid (5 g, 24.7 mmol) and N1-(3-Trimethoxysilylpropyl)diethylenetriamine (4.37 g, 46.9 mmol of amine) were dissolved in water (50 cm.sup.3) and a sample placed on a microscope. Almost monodispersed spherical entities of 2.5 m diameter were observed.

[0119] This solution was diluted with water to 500 cm.sup.3. EDCI (20 g, 104 mmol) was dissolved in water (100 cm.sup.3) and added to the above solution. The mixture was left overnight then acidified with concentrated hydrochloric acid. The addition of hydrochloric acid led to the formation of silica within the particles creating a Sebacic acid/silica composite.

Example 12Preparation of a Self-Assembled Macroporous Cross-Linked Sheet

[0120] Sebacic acid (0.619 g, 6.12 mmol) and NMM (0.62 g, 6.12 mmol) were dissolved in water (10 cm.sup.3) and a sample placed on a microscope. Almost monodispersed spherical entities of 2.5 m diameter were observed.

[0121] Poly-epsilon-lysine (PeK) (1 g, 5.83 mmol of NH.sub.2) was dissolved in water (10 cm.sup.3) and added to the above solution of Sebacic acid/NMM microspheres. The mixture was filtered through a 0.45 m membrane and a sample placed on a microscope. Microspheres of 2.5 m diameter were still present. EDCI (2.24 g, 11.7 mmol) and HONSu (2.0 g, 17.4 mmol) were dissolved in water (10 cm.sup.3) and added to the above solution. The cross-linking reaction was left overnight, the resultant sheets washed with water and dried by lyophilisation. The SEM shown in FIG. 5 clearly demonstrates the fused microsphere structure of the macroporous polymer formed.

Example 13Preparation of a Self-Assembled Macroporous Cross-Linked Sheet

[0122] (12-Phosphonododecyl)phosphonic acid (330 mg, 1 mmol) and NMM (404 mg, 4 mmol were dissolved in water. A sample placed on a microscope confirmed the presence of virtually monodispersed microspheres. PeK (343 mg, 2 mmol NH.sub.2) was dissolved in water (10 cm.sup.3) and added to the bis-phosphonic acid solution prepared above. Microspheres were still present at this stage. EDCI (1.15 g, 6 mmol) dissolved in water (10 cm.sup.3) was added and the mixture immediately poured into a tray. Again microspheres were still present at this stage. A sheet formed after 2 h which was washed thoroughly with water. The final sheet had a rubbery texture.

Example 14

[0123] The self-assembled microparticles and macroporous cross-linked sheets of Examples 1 to 13 were all suitable for use in personal care products and in home care products according to the invention. The microparticles may be used to replace microplastics in known home care and personal care compositions. The products according to the invention have the benefit of containing microscale particles which do not contain non-biodegradable microplastics but have functionality provided by the presence of microparticles whilst being biodegradable.

Example 15Biocide Formulations

[0124] Biocides for personal care, cosmetics, home care and general disinfection are currently limited by the time they stay in contact with the surface to be treated due to abrasion. For example, surface sprays of the type used for disinfection in hospitals have a limited active lifetime and consequently reduced activity against hospital infections such as MRSA, p.auregenosa and c.difficile. In addition, some surface sprays contain organic solvents such as isopropanol or non-biodegradable components such as silicone oils to reduce abrasive removal of the biocides.

[0125] Cationic and amphoteric biocides such as quaternary ammonium compounds act against pathogens by solubilising the cell membrane, resulting in cell lysis and death. There are many biocides used commercially for disinfection which include chlorhexidine, benzalkonium chloride, climbazole, didecyldimethylammonium chloride, dodecyldipropylenetriamine, which are cationic compounds. Additionally some biocides are polymeric cationic compounds such as Poly(diallyldimethylammonium chloride). These compounds can be readily formulated into spherical microparticles using the technology described herein, which will allow for reduced abrasive removal on surfaces, skin and hair; potentially allowing for controlled release of the biocide. Additionally, biocides containing multiple cationic compounds in the same microparticle are possible and may provide formulations that can be tailored and targeted to specific applications where the source of infection is well defined.

[0126] The samples produced were as follows:

Poly(diallyldimethylammonium chloride) (PDAC) SpheriSomes

[0127] PDAC (1.615 g, 10 mmol) was dissolved in water (50 cm.sup.3) and NaOH (0.4 g, 10 mmol) added. Brassylic acid (1.22 g, 5 mmol) was added to this solution and allowed to dissolve overnight. This appeared to be a clear solution but was confirmed to be a suspension of 3 m microparticles and a novel formulation of PDAC when observed under the microscope and the results are shown in FIG. 8 shows PDAC-Brassylic acid microparticle formulation.

Didecyldimethylammonium chloride (DDAC)

[0128] DDAC (9.04 cm.sup.3 of 40% w/v solution, 10 mmol) was diluted with water to 50 cm.sup.3 and NaOH (0.4 g, 10 mmol) added. Brassylic acid (1.22 g, 5 mmol) was added to this solution and allowed to dissolve overnight. This appeared to be a hazy solution but was confirmed to be a suspension of 3 m microparticles and a novel formulation of DDAC when observed under the microscope.

Dodecyldipropylenetriamine (DDPT)

[0129] DDPT (9.97 cm.sup.3 of 30% w/v solution, 10 mmol) was diluted with water to 50 cm.sup.3 and Brassylic acid (3.66 g, 15 mmol) was added to this solution and allowed to dissolve overnight. This appeared to be a clear solution but was confirmed to be a suspension of 3 m microparticles and a novel formulation of DDPT when observed under the microscope.

Example 16Antimicrobial Macroporous Sheets

[0130] The hydrophilic nature of the porous polymer formed by collision of the biscarboxy fatty acid microparticles is advantageous in for absorbent sheets. When the biscarboxy fatty acids are combined with poly--lysine and cross-linked to form such a porous matrix the natural antimicrobial activity of the components of the wound dressing can be retained and enhanced when necessary. In cationic form, where there is an excess of poly--lysine over the fatty acids the materials have been shown to retain the characteristics of the food preservative providing novel antimicrobial sheets. The porous nature of the material will allow for improved moisture retention combined with a cationic nature capable of destroying microbial biofilms.

[0131] The anti-biofilm capability of a cationic sheet was assessed using a mixed microbial species CDC reactor model. The product of Example 13 was employed in these experiments.

[0132] Two mixed species biofilms were prepared as shown below and tested against PBS and a control anionic dressing.

Multi Species Biofilm 1

[0133] Staphylococcus aureus NCTC 8325 [0134] Pseudomonas aeruginosa NCIMB 10434 [0135] Acinetobacter baumannii ATCC 19606 [0136] Staphylococcus epidermidis

Multi Species Biofilm 2

[0137] Staphylococcus aureus NCTC 8325 [0138] MRSA [0139] VRE faecalis NCTC 12201 [0140] Candida albicans ATCC MYA-2876 SC5313 [0141] Escherichia coli NCTC 12923 Page 3 of 6 DOT 202 (03)

Preparation of Mixed Inoculum 1

[0142] Twenty-four hour cultures of Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus epidermidis were harvested from appropriate agar plate using a sterile swab and suspended in 20 cm.sup.3 of Tryptone Soya Broth (TSB). The mixed species suspension was diluted in TSB to give an overall concentration of 1075106 cfuml1 and used as the inoculum for the CDC reactor. The CDC reactor was incubated for 72 hours at 37 C. with shaking at 50 rpm in order to encourage biofilm growth.

Preparation of Mixed Inoculum 2

[0143] Twenty-four hour cultures of Staphylococcus aureus, Methicillin-resistant staphylococcus aureus, Vancomycin-resistant Enterococcus, Candida albicans and Escherichia coli were harvested from appropriate agar plate using a sterile swab and suspended in 20 cm.sup.3 of TSB. The mixed species suspension was diluted in TSB to give an overall concentration of 1075106 cfuml1 and used as the inoculum for the CDC reactor. The CDC reactor was incubated for 72 hours at 37 C. with shaking at 50 rpm in order to encourage biofilm growth.

Biofilm Treatment

[0144] After incubation the test coupons were removed from the CDC reactor and washed 3 times in sterile phosphate buffered saline (PBS) in order to remove planktonic cells. The washed coupons were then treated by sandwiching the coupon between two discs of the wound dressing material. The dressings were activated prior to testing by the addition of 400 mm.sup.3 PBS+1% TSB to each disc. Control coupons were submerged in 1 cm.sup.3 of PBS +1% TSB. All samples were tested in triplicate. Following the 24 hour treatment period, the coupons were placed in 1 cm.sup.3 PBS and sonicated for 15 minutes in order to recover any viable microorganisms attached to the coupons. Recovered microorganisms were quantified using serial dilutions and spread plates.

Mixed Inoculum 1

[0145] Following treatment with the control dressing (A), bacterial recovery was similar to PBS only treatment controls as shown in FIG. 9. No viable organisms were recovered from coupons treated with cationic dressing (B). This represents a greater than 5 log reduction compared to PBS treated controls. The surviving organism post treatment were predominantly Pseudomonas aeruginosa (FIG. 10).

Mixed Inoculum 2

[0146] Treatment with control dressing (A) resulted in a 1.27 log reduction in the number of viable bacteria recovered compared to the PBS treated controls. No viable organisms were recovered from coupons treated with cationic dressing (B). This represents a greater than 7 log reduction compared to the PBS treated controls (FIG. 11). Surviving organisms were mixed species (FIG. 12).