ES2345806A1 - Nanoparticular systems elaborated on the basis of anionic polymers for administering bioactive molecules for cosmetic use (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

The present invention relates to a system for the administration of bioactive molecules for cosmetic use, comprising nanoparticles with an average size of less than 1 micrometer, which in turn comprise: (a) at least one anionic polymer; (b) a cationic crosslinking agent; and optionally (c) a cationic polymer; and at least one bioactive molecule for cosmetic use, preferably kinetin, characterized in that the nanoparticles are crosslinked by electrostatic-type interactions. Additionally, the invention relates to cosmetic and personal hygiene compositions comprising said nanoparticle system, as well as to procedures for its preparation and uses thereof. (Machine-translation by Google Translate, not legally binding)

Description

Nanoparticular systems made from anionic polymers for administering bioactive molecules for use cosmetic.

Field of the Invention

The present invention relates to the development of nanoparticular systems useful in the administration of bioactive molecules for cosmetic use, in particular kinetin. Plus specifically, the invention relates to nanoparticular systems comprising a polymer or a mixture of polymers provided with negative electrical charge and a molecule or mixture of molecules of low molecular weight positive charge able to act as ionic crosslinkers of the above undefined polymers chemical bonds with them. Additionally, the invention is refers to cosmetic compositions that comprise them, as well as to Procedures for its preparation.

Background of the invention

Nanotechnology in general and, more specifically, nanoparticular systems, have enormous potential clearly recognized in numerous fields (UNESCO, The ethics and politics of nanotechnology, Division of Ethics of Science and Technology, UNESCO Ed., Paris, 2006), having aroused great interest especially in the biomedical field (US Food and Drug Administration. Nanotechnology, A Report of the US Food and Drug Administration Nanotechnology Task Force, FDA Ed., Rockville, MD, July 2007), (WHO, Initiative for Vaccine Research of the Department of Immunization, Vaccines and Biologicals, WHO / IVB / 06.03 , WHO Ed., Geneva, Switzerland, April 2006 ). Despite the aforementioned, the nanoparticular systems developed to date have not responded to the expectations initially placed in them. Consequently, the general idea is that it is necessary to develop new systems capable of meeting the challenge of taking advantage of their recognized potential (M. Friede and MT Aguado, Advanced Drug Delivery Reviews , 57, 2005, 325-31) ; (TG Park, JH Jeong, SW Kim, Advanced Drug Delivery Reviews , 58, 2006, 467-486).

The causes of the limitations set forth above are diverse. Considering the specific case of chitosan-based nanoparticles, a polymer widely cited in the literature as indispensable for their formation by ionic cross-linking, recently there has been reference to the absence of added value of this type of systems compared to formulations more simple Specifically, the results presented by some works question the purported versatility and potential of chitosan nanoparticles, finding no significant differences in comparison with simple solutions of the bioactive molecule and said polymer (AM Dyer, M. Hinchcliffe, P. Watts, J. Castile, I. Jabbal-Gill, R. Nankervis, A. Smith, and L. Illum, Pharm. Res ., 19, 2002, 998-1008). On the other hand, the cytotoxicity associated with these chitosan nanoparticles has recently been pointed out, which has been directly related to the surface electric charge of these systems (B. Loretz and A. Bernkop-Schnürch, Nanotoxicology , 1, 2007, 139-148 ). This type of toxicity results are of particular concern to regulatory agencies such as the FDA, which believes it is important not to lose sight of aspects such as the significant positive burden associated with some nanoparticular systems (US Food and Drug Administration. Nanotechnology, A Report of the US Food and Drug Administration Nanotechnology Task Force, FDA Ed., Rockville, MD, July 2007). It is obvious, however, that the advantages or limitations of a nanoparticular system do not derive exclusively from a single characteristic such as its surface charge, but rather from a set of characteristics among which, in addition to the surface charge, one must also have taking into account the very nature of the components used in the elaboration of said nanoparticles. As an illustrative example we can remember that the mucoadhesive character and the ability to interact with the mucous surfaces of nanoparticles made from a polymer such as chitosan, have been exclusively related to the cationic nature of this polymer and the positive surface charge of the systems that They are based on their employment. However, surface loading cannot be considered the only factor responsible for such behavior or properties, given that they are not observed to the same extent when other cationic polymers are also used. In fact, in a previous study it has been possible to demonstrate how nanoparticular systems coated with cationic polymers such as polylysine and chitosan exhibit drastically different behaviors after in vivo administration, despite having similar net surface charge (Calvo P, Vila-Jato JL and Alonso MJ; Int J Pharm ., 153, 1997, 41-50). Therefore, it seems logical to think that the very nature of the components of this type of nanoparticular systems, together with their physical-chemical characteristics, are determinants of their behavior and, consequently, of their potential, as it has been recently indicated ( Moreau et al ., Journal of Drug Targeting , 10, 2002, 161-173).

Considerations such as those described above have recently led to suggesting the interest of investigating the application of nanotechnologies to new materials and thus developing new nanoparticular systems (US Food and Drug Administration, FDA Consumer magazine, FDA Ed., November-December 2005 Issue, 2005). This interest becomes more evident in the case of nanosystems destined for systemic administration, where the toxicity problems and / or adverse or unwanted effects associated with the surface load or the characteristics of the materials used so far in its development, charge special importance. In fact, although a system with a positive net charge may be of great interest as a topical administration vehicle, that positive charge can also be a problem when administered systemically, since it will undoubtedly lead to hemagglutination and other related adverse effects. with its interaction with natural components of the organism (Kainthan et al ., Biomaterials 27, 2006, 5377-5390). Possibly for this reason, several experts in the field of gene therapy have even come to predict that the development of new vehicles is a field of work that will continue over the next 35 years (N. Blow, Nature , 450, 2007, 1117- 1120), making special mention of the limitations referred to in the development of systemic administration vehicles.

So far, several materials have been used to formulate nanoparticulate systems, many of which have been able to act as vehicles for administration of drugs or genetic material. However, although in many cases there is talk of nanoparticle systems, it is necessary to keep in mind that under such designation two clearly different types of systems can be included in terms of manufacturing technique, structure, ability to associate and release molecules, versatility and potential. These systems, clearly differentiated in the literature (JK Vasir and V. Labhasetwar, Expert Opinion on Drug Delivery , 3, 2006, 325-344) (Q. Gana, T. Wang, C. Cochrane, P. McCarron, Colloids and Surfaces B: Biointerfaces 44, 2005, 65-73), are the following:

- Nanoparticular complexes established between positively charged materials and a bioactive molecule with charge net negative, as a nucleic acid derivative. For example, the high density of amino groups present in the skeleton of the Chitosan allows the complexation of plasmids, DNA loading negative, leading to training spontaneously but not controlled of self-assembled complexes between both components. These complexes are obtained without being able to control properties so important as the size or surface charge of them, since that the formation of this type of particles is due to mere tropism which is established between two molecules of opposite charge. In fact, without the concurrence of the bioactive molecule of negative net charge no It would be possible to obtain such nanosystems. Therefore, it is not possible to develop white or unloaded nanoparticles of this type with said molecule.

- Nanoparticles made from polymers crosslinked Crosslinking is a controlled process that allows the obtaining nanoparticles of size and surface charge predetermined, homogeneous, adjustable and reproducible. The process Crosslinking can be chemical or ionic. The first of such processes is based on the formation of covalent bonds stabilizers due to the use of agents of the group of aldehydes, which are characterized by their toxicity and for not being accepted for use in humans. In addition, this type of agents they can also lead to crosslinking and inactivation of the own bioactive molecule that is intended to be associated with the system, about all if it is molecules with amino groups, as in the case of peptides and proteins All these aldehyde problems and chemical crosslinking agents are described in the literature.

On the contrary, the crosslinking technique ionic, also called ionic or ionotropic gelation, is characterized by its softness and being reversible. So traditional this technique has been developed between a macromolecule cationic and a polyanion, leading to the formation of systems which, unlike complexes, are characterized by being matrix structures in which the associated bioactive molecule is found totally or partially trapped inside the womb polymeric constituent thereof and generated in the process of ionotropic crosslinking. This polymer matrix is obtained as result of ionic inter-e junctions intra-molecular between the polyanion and the cationic macromolecule, which gels spontaneously in the form nanoparticular This training mechanism provides, as a value added with respect to complexes, a protection of the molecule bioactive against the external environment that cannot contribute equally measure those. Consequently, we are facing a fast technique, economical, easily reproducible and scalable and that requires a very simple technology, all aspects of undoubted interest for the industry

The ionic crosslinking technique has been described for the formation of chitosan nanoparticles, molecule cationic that is crosslinked with the polyanion tripolyphosphate. Do not However, the limitations indicated above for this type of systems that include in its chitosan composition have led to various authors to develop systems in which they combine with chitosan different ammonium macromolecules, such as acid hyaluronic, but they have always required the presence of Chitosan for its formation.

Other materials that have also been used in the state of the art for obtaining systems of Nanoparticles comprise dextrans, carrageenan and polyarginine.

Thus, documents WO2005021044 and US20077155658 describe systems smaller than 200 nm that they need in a first phase the use of carbohydrates capable of complexing the material genetic to associate and, subsequently, the addition of polyarginine

US 6,565,873 and US 7,053,034 describe nanoparticles for whose formation the use of fatty materials.

Documents US 2005/0266090 A1 and US 2005/0008572 A1 describe the formation of core-shell systems ("core-shell", "Core-coat" or "onion-like"), consisting of two distinct parts: a core polymeric and a polymeric crown of different composition surrounding said core. These structures are the result of applying a technique in which the constitutive polymers are added sequentially and in which it is necessary to use, among others, atomization steps of the solutions (Propok et al ., 2001; Prokop et al ., 2002).

On the other hand, the techniques used for the Nanoparticle formation and nanoparticulate systems are in generally complex and require certain compositions that impact on their properties and characteristics. He WO 2001/9620698 A1 describes nanoparticles obtained by an emulsification methodology that makes the use of organic solvents The use of such solvents involves a series of risks that are well known to industries for giving place of special concern on the part of the agencies Regulatory

The nanoparticles described in the US document 2005/0008572 A1 and containing a type of dextran (dextran polyaldehyde) need, for their formation, the establishment of a covalent bond with said component so that they form, finally leading to the formation of a chemical entity different.

US 6,383,478 B1 refers to nanoparticles for whose preparation the required one is necessary incorporation of at least two polyanions, in addition to one or more Small cations In short, these are systems with a significant degree of complexity in terms of its composition.

US 7,045,356 describes multilayer nanoparticles for whose formation it is necessary to establish conditions such that allow the formation of links intermolecular between polymers.

US 6,916,490 deals with systems microparticular coacervates that require training chemical crosslinking between polymers.

US 6,919,091 and 7,098,032 describe nanoparticle systems less than 100 nanometers to whose formation it is necessary to develop three stages: (1st) complexation of the genetic material to be associated; (2nd) complexation with a second polymer; (3rd) final ionic crosslinking to ensure the system integrity

US 6,475,995 and 7,344,887 describe nanostructures produced by electrodeposition or by coacervation being the suggested gelatin policationes or chitosan

In view of the documents of the state of the technique and the inconveniences of current systems nanoparticles in terms of composition, toxicity and procedure of obtaining, there is, therefore, the need to develop nanoparticulate systems based on materials and reagents biocompatibles of low toxicity that provide high control in the physicochemical properties of nanoparticles and that can be obtained by procedures Simple and effective.

Brief Description of the Invention

The authors of the present invention have found that an easily obtainable nanoparticulate system by means of an ionic gelation procedure, where nanoparticles comprise an anionic polymer crosslinked in presence of a cationic crosslinking agent, allows an effective association of bioactive molecules for cosmetic use, in particular Kinetina and its consequent release in the right medium, release that can be controlled by selecting nanoparticle components. These nanoparticles present the additional characteristic of not presenting toxicity and being stable in biological media also preventing the degradation of molecules They have incorporated.

Thus, in a first aspect the invention is directed to a system for the administration of bioactive molecules for use cosmetic comprising nanoparticles with a lower average size at 1 micrometer, which include:

to)

to the less an anionic polymer;

b)

a cationic crosslinking agent; and optionally

C)

a cationic polymer;

and at least one bioactive molecule for use cosmetic, preferably kinetin,

characterized in that the nanoparticles are found crosslinked through type interactions electrostatic.

In another aspect, the invention refers to a cosmetic composition comprising a system as has been previously defined.

In another aspect, the invention is directed to a procedure for the preparation of a system as defined formerly comprising:

to)

prepare an aqueous solution of at less an anionic polymer;

b)

prepare an aqueous solution of a cationic crosslinking agent and, optionally adding to it a cationic polymer;

C)

mix under stirring the solutions obtained in a) and b) with spontaneous formation of the nanoparticles.

The invention also refers to the use of a system as defined above to improve the stability in a cosmetic product.

Brief description of the figures

Figure 1. System TEM images nanoparticles made from chondroitin sulfate associating kinetina.

Figure 2. System TEM images nanoparticles made from hyaluronic acid associating Kinetina

Figure 3. Kinetin release study a from nanoparticles: Modulation of release profiles by modification of the composition of the nanoparticles. Nanoparticles made using: hyaluronic acid (A), sulfate chondroitin (B) or chondroitin sulfate / gelatin mixtures previously cationized (C).

Figure 4. Lyophilization study: Medium size of nanoparticular systems made from sulfate Chondroitin associating kinetin (2.5% load) before and after lyophilization in the presence of different percentages of trehalose as a cryoprotective agent.

Figure 5. Stability study: Evolution of average size during storage at different temperatures of nanoparticulate systems made from sulfate Chondroitin associating kinetin (2.5% load), lyophilized in presence of different percentages of trealose as agent cryoprotectant

Detailed description of the invention

The present invention is directed to the elaboration of nanoparticular systems for the administration of molecules bioactive for cosmetic use, comprising nanoparticles with a average size less than 1 micrometer, where said nanoparticles they comprise at least one anionic polymer; a crosslinking agent cationic; and optionally a cationic polymer; and characterized because the nanoparticles are crosslinked by electrostatic type interactions.

In the present invention, for the term "nanoparticles" refers to stable structures and homogeneous, reproducible and modulable features perfectly differentials of self-assembled systems, which are formed as consequence of a controlled cross-linking process ionotropic of the constituent anionic polymer thereof by cationic crosslinking agents. Electrostatic interaction which results between the different components of the nanoparticles in the cross-linking process it generates physical entities characteristics, which are independent and observable, whose size average is less than 1 \ mum, that is, an average size of between 1 and 999 nm.

By the term "average size" is understand the average diameter of the nanoparticle population, which it comprises the polymeric crosslinked structure, which moves together in an aqueous medium. The average size of these systems can be measured using standard procedures known to the expert in the technique.

The nanoparticles of the system of the invention they have an average particle size less than 1 \ mum, it is that is, they have an average size between 1 and 999 nm, preferably between 50 and 600 nm, even more preferably of between 100 and 400 nm. The average particle size is mainly influenced by the composition and conditions of particle formation

On the other hand, nanoparticles can present an electric charge (measured by the potential Z), whose magnitude can take positive or negative values depending on the proportion of the different components in the system. In a particular embodiment of the invention, the nanoparticles present negative charge that can vary between -1 mV and -30 mV.

The zeta potential of particle systems of the invention can be measured using standard procedures known to those skilled in the art, and described, by example, in the experimental part of the present report descriptive

Anionic polymer

By the term "anionic polymer" is means any polymer, preferably of natural origin, with a negative net charge, including in that definition those ammonium polymers on which modifications have been made such as enzymatic or chemical fragmentation or derivatization. In a particular embodiment, the anionic polymer is selected from hyaluronic acid or salts thereof, chondroitin sulfate, as well as fragments thereof or derivatives thereof.

Hyaluronic acid

Hyaluronic acid or hyaluronan acid is a glycosaminoglycan widely distributed throughout tissues conjunctive, epithelial and neural. It is one of the main components of the extracellular matrix and generally contributes significantly to cell proliferation and migration.

Hyaluronan is a linear polymer that it comprises the repetition of a disaccharide structure formed by alternate addition of D-glucuronic acid and D-N-acetylglucosamine, bound alternating beta-1,4 links and beta-1,3 glycosides as shown in the following formula:

one

in which the integer n represents the degree of polymerization, that is, the number of disaccharide units in the chain Hyaluronan

In the context of the present invention, you can use hyaluronic acid with a wide range of weights molecular. High molecular weight hyaluronic acid is commercially available while the molecular weight lower can be obtained by acid fragmentation high molecular weight hyaluronic, using, for example, a hyaluronidase enzyme.

The term "hyaluronic acid, hyaluronic acid, hyaluronan "as used herein it includes either hyaluronic acid or a conjugate base of same (hyaluronate). This conjugate base may be an alkaline salt. of hyaluronic acid including inorganic salts such as, by example, sodium, potassium, calcium, ammonium, magnesium, aluminum salts and lithium, organic salts such as salts of basic amino acids at Neutral pH, preferably said salts are pharmaceutically acceptable. In a preferred embodiment of the invention, the salt Alkaline is the sodium salt of hyaluronic acid.

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Chondroitin Sulfate

Chondroitin Sulfate is a sulfated glucosaminoglycan (GAG) composed of a chain of alternating sugars It is normally bound to proteins such as part of a proteoglycan. It is represented by the following structure:

2

where n is an integer and represents the degree of polymerization, that is, the number of disaccharide units in the chondroitin sulfate chain and in which R 1, R 2 and R 3 are independently hydrogen or a group SO_ {3} H. Each monosaccharide can be left without sulphating, sulphate once, or sulphate twice. The sulfation is sulfotransferase mediated specific.

In the context of the present invention, the term "chondroitin sulfate" includes all its different isomers and derivatives, as well as combinations thereof.

In a particular embodiment, the sulfate of Chondroitin is selected from the following substances and combinations thereof:

-

chondroitin sulfate A which is sulfated predominantly in carbon 4 of sugar N-acetylgalactosamine (GalNAc) and that also known as 4-chondroitin sulfate (R1 = H, R 2 = SO 3 H and R 3 = H)

-

chondroitin B sulfate called also dermatan sulfate. This substance is composed of linear repeating units containing N-acetylgalactosamine and or acid L-iduronic or glucuronic acid, and each disaccharide may be sulfated once or sulfated two times.

-

chondroitin sulfate C which is sulfated predominantly in carbon 6 of GalNAc sugar and that It is also known as 6-chondroitin sulfate (R 1 = SO 3 H, R 2 = H and R 3 = H);

-

chondroitin sulfate D which is sulfated predominantly in carbon 2 of glucuronic acid and in carbon 6 of GalNAc sugar and is also known as sulfate of 2,6-chondroitin (R 1 = SO 3 H, R 2 = H and R 3 = SO 3 H);

-

chondroitin sulfate E which is sulfated predominantly in carbons 4 and 6 of GalNAc sugar and is also known as 4,6-chondroitin sulfate (R 1 = SO 3 H, R 2 = SO 3 H and R 3 = H);

The term "chondroitin sulfate" also includes organic and inorganic salts thereof. Generally, such salts are prepared, for example, by reacting the basic form of this compound with a stoichiometric amount of the appropriate acid in water or in an organic solvent or in a mixture of both. Generally, non-aqueous media such as ether, ethyl acetate, ethanol, isopropanol or acetonitrile are preferred. Examples of inorganic salts include, for example, sodium, potassium, calcium, ammonium, magnesium, aluminum and lithium salts, and organic salts include, for example, ethylenediamine, ethanolamine, N, N -dialkylene-ethanolamine, triethanolamine salts, glucamine and basic amino acids. Preferably the salts are pharmaceutically acceptable.

Chondroitin functions depend on a good part of the properties of the global proteoglycan of which it is a part. These functions can be broadly divided into regulatory and structural roles. However, this division does not it is absolute and some proteoglycans can play roles both structural as regulators.

With respect to its structural role, sulfate Chondroitin is a major component of the extracellular matrix, and it is important to maintain the structural integrity of the tissue. As a part of an aggrecan, chondroitin sulfate is a main component of cartilage. The sulfate groups extremely loaded and compact packaging of chondroitin sulfate they generate electrostatic repulsions that provide much of the compressive cartilage resistance.

Queratane Sulfate is a glucosaminoglycan sulfated similar to chondroitin sulfate in which the group Sulfate is found in glucuronic.

Crosslinking agent

The nanoparticles of the invention are characterized by having been formed through a mechanism of ionic interaction that causes the joint precipitation of components of said nanoparticles in the form of nanoclusters as consequence of the addition of a charge crosslinking agent positive. In addition to being a simple procedure, the use of organic solvents or toxic auxiliary substances. The Presence of the cationic crosslinking agent allows the cross-linking of the anionic polymer, and where appropriate the crosslinking thereof with the optional cationic polymer, through an ionic gelation process causing formation Spontaneous nanoparticles. This way you get nanoparticles with a size, potential and characteristics structural structures that make them suitable as systems of administration of bioactive molecules.

In a particular embodiment, the crosslinking agent is an amine of the formula H 2 N - [(CH 2) x -NH- (CH 2) y]] z -NH_ {2}, where x , y and z independently take a value between 1 and 66. Preferably, x , y and z , independently, have a value between 1 and 10.

More preferably, the amine is selected from natural amines such as spermine, spermidine and salts thereof. These amines are natural components of cells and body fluids and play a fundamental role in the processes of cell proliferation and differentiation and of synthesis of biological macromolecules. Although cells are able to synthesize the amines they need for cell growth processes, cell internalization mechanisms that allow them to obtain these amines from the bloodstream have been described. These mechanisms are influenced by proteoglycans such as chondroitin sulfate and hyaluronic acid (Belting M. Et al . Biochem J 1999, 338, 317-323). Therefore, it seems logical to assume a synergistic effect between the constituents of the nanoparticles object of the present invention and the crosslinked agent used in its preparation.

In a particular embodiment, the relationship in Cross-linking agent / anionic polymer weight is between 0.1 / 1 and 0.5 / 1, preferably between 0.2 / 1 and 0.4 / 1, which provides formulations with low polydispersity.

Cationic polymer

In a particular embodiment of the invention, the nanoparticles that constitute the system can optionally comprise a positively charged polymer in order to modulate the characteristics of nanoparticular systems that are more important present in their interaction with biological media, such as the particle size, surface electric charge and composition and provide them with greater versatility.

In the context of the present invention, "cationic polymer" means any polymer, preferably of natural origin, with a positive net charge. In a particular embodiment, the cationic polymer is a protein modified as cationized gelatin.

By "cationized jelly", the modified gelatin molecule so that groups are introduced amino that give a greater cationic character to the one who can possess unmodified.

The nanoparticles of the present invention they provide systems with a high association capacity of bioactive molecules for cosmetic use. Consequently, in a additional aspect the invention relates to a system such as that It has been defined above that it further comprises a molecule bioactive The release of bioactive molecules can be controlled by selecting the components of the nanoparticles, which is a clear benefit over conventional galenic formulations, in which it is not possible exercise control over the release of an associated molecule.

The term "bioactive molecule for use cosmetic "refers to any substance that is used as cosmetic, as well as that compound that is intended to regenerate tissues or tissue engineering. The nanoparticles object of the present invention are suitable for associating bioactive molecules for cosmetic use regardless of the characteristics of solubility thereof. The association capacity will depend on the incorporated molecule, but in general terms it will be high both for hydrophilic molecules, and for those of marked character hydrophobe. In a particular embodiment, the bioactive molecule is select between peptides, proteins, lipid compounds or lipophilic, saccharide compounds, nucleic acid compounds or nucleotides such as oligonucleotides, polynucleotides or combinations of the cited molecules. In one more embodiment In particular, the bioactive molecule is kinetin.

Kinetin is a type of cytokinin, a group of plant hormones that promote division and differentiation mobile.

3

Its structure derives from an adenine with a side chain attached to the amino group in position 6, responds to the N 6 -furfuryladenine.

Kinetin has antioxidant properties and anti-aging and for these reasons it is used in treatments anti-aging

The proportion of bioactive molecule incorporated in nanoparticles it can reach up to 95% by weight with with respect to the total weight of the nanoparticle components. Without However, the appropriate proportion will depend in each case on the bioactive molecule to be incorporated, the indication for which It is used and administration efficiency. In one embodiment In particular, the proportion of bioactive molecule is between 1 and 10% by weight.

All bioactive molecules for use cosmetic that can be incorporated into the nanoparticle system of the invention mentioned above, can be added to the solutions of the constituent polymers of the nanoparticles prior to their formation or they can be added to the nanoparticles once formed.

In a further aspect, the present invention it is directed to a cosmetic composition comprising the system of nanoparticles previously described. This nanoparticular system is especially advantageous to constitute a cosmetic composition due to its good properties for administration over or to through the skin, and its lasting stability.

The cosmetic compositions according to the invention include any liquid composition (suspension or dispersion of nanoparticles) or any composition that comprises the system of the invention and which is in the form of gel, cream, ointment or balm for topical administration.

Said cosmetic composition can be applied to various surface parts of the human or animal body such as the skin, hair and hair system, nails, lips and genitals external, and to teeth or mucous membranes of the human or animal body.

In a particular embodiment of the invention, the composition comprising the system of the invention has a purpose of personal or aesthetic hygiene, to neutralize or eliminate ectoparasites, to perfume, modify the appearance of the surface body and / or correct body odors and / or protect or maintain it in good state.

In a particular aspect of the invention, the cosmetic or personal hygiene composition can also incorporate active molecules of lipophilic and hydrophilic nature that, although not have no therapeutic effect, have properties as an agent Cosmetic or personal hygiene. Among the active molecules that agents can be incorporated into the nanoparticles emollients, preservatives, fragrance substances, anti-acne agents, antifungal agents, antioxidants, deodorants, antiperspirants, anti-dandruff agents, depigmenting agents, agents antiseborrheic, dyes, tanning lotions, light absorbers UV, enzymes, among others.

In another aspect, the present invention is refers to a procedure for the preparation of a system of nanoparticles as previously defined comprising:

to)

prepare an aqueous solution of al less an ammonium polymer;

b)

prepare a solution of an agent cationic crosslinker and, optionally add to said solution a cationic polymer;

C)

mix the solutions under stirring obtained in a) and b) with spontaneous formation of the nanoparticles.

The incorporation of the anionic polymer (s) it is carried out by aqueous solution thereof at a concentration between 0.1 and 6 mg / mL, more preferably between 0.1 and 5 mg / mL.

According to another particular embodiment, the cationic crosslinking agent dissolves in water at a concentration between 0.0625 and 1.5 mg / mL, preferably between 0.25 and 1.5 mg / mL

The formation of the nanoparticles subject to The present invention is a consequence of a controlled process of ionotropic cross-linking of the components that are charged opposite. Fruit of said controlled process, called crosslinking ionic or ionotropic, nanoparticles of size and charge are obtained surface predetermined, homogeneous, adjustable and reproducible, regardless of whether or not any bioactive molecule is associated and of the electric charge that is present.

The bioactive molecule for cosmetic use, and / or a stabilizing compound, is dissolved in one of the solutions a) or b), depending on the load it has, that is, if it has a load negative dissolves in solution a) and, if on the contrary, It has a positive charge, it dissolves in solution b). In a particular aspect, when the bioactive molecule is kinetin, it preferably dissolve in solution b), given that at pH Kinetin acid has a positive charge.

The procedure for preparing mentioned nanoparticles may include an additional stage of lyophilization, in order to preserve them during storage so that they retain their initial characteristics and reduce the Product volumes to be handled. On the other hand, the degree of cross-linking of nanoparticles can increase with this process, since an approximation between the chains can take place polymeric, which could facilitate increasing the degree of polymeric crosslinking, as well as enhancing the effect of crosslinking agent. For lyophilization of nanoparticles it may only be necessary to add small amounts of sugars such as glucose, sucrose or trehalose at a concentration ranging from 1 to 5% or other molecules that act as cryoprotectants and / or lioprotectors. The nanoparticles of the invention have the additional advantage that particle size before and after lyophilization is not modified so significant. That is, nanoparticles have the advantage that they can be lyophilized and resuspended without any alteration in the characteristics of them.

Next, for a better understanding of The features and advantages of the present invention will be made reference to a series of examples that are explanatory complete the above description, without assuming in any way that This is limited to them.

Examples

As a common procedure to the examples detailed below, the nanoparticles have been characterized from the point of view of size, the zeta potential (or charge superficial) and encapsulation efficiency.

During the exhibition of some of the The following examples refer to results obtained by the following techniques:

The particle size has been determined using the photonic correlation spectroscopy (PCS) technique and making use of a Zeta Sizer (Zeta Sizer, Nano) series, Nano-ZS, Malvern Instruments, UK) getting the average population size and the polydispersion index of the same. For this, the samples were conveniently diluted in water mili-Q.

The potential Zeta particle has been determined using the laser dispersion anemometry (LDA) technique and using, for this, a Zeta Sizer (Zeta Sizer, Nano series, Nano-ZS, Malvern Instruments, UK). For this the samples were conveniently diluted in a solution millimolar of KCl.

The efficacy of association of kinetin with nanoparticles has been determined by a technique spectrophotometric To do this, he separated into the different Kinetin formulations associated with the nanoparticles of the Free kinetin, using ultrafiltration membranes (AmiconUltra 5000 MW, Milipore, US) in a centrifuge (Microfuge 22R centrifuge, Beckman Coulter, US) (7500 xg, 30 minutes). Free kinetin is quantified at a λ = 265 nm against the corresponding line of calibration and by difference the efficacy of association.

For the study of the release of Kinetin associated with the nanoparticles were incubated at 37 ° C in different media (HEPES buffer pH 7.4, acetate buffer pH 5.5, HCl 0.01N pH 2). Kinetin released at different times was determined according to the methodology described above.

The following polymers, as used In the following examples, they were purchased from different houses Commercial: Hyaluronic acid, or hyaluronic acid (Bioibérica, Spain), Chondroitin Sulfate (Calbiochem, USA).

The spermine was acquired from Sigma Aldrich (Spain).

Kinetin was acquired from Sigma Aldrich (Spain).

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Example 1 Preparation of sulfate-based nanoparticles chondroitin and their association with a bioactive molecule

Sulfate nanoparticles of Chondroitin using spermine as a crosslinking agent according to previously described procedure. The association of a hydrophilic molecule for cosmetic use in its composition, selecting for this purpose a cytokinin, the kinetin. Is about a positively charged molecule in the formation conditions of the nanoparticles, so it was incorporated together with the agent crosslinker, also positively charged, to avoid the appearance of interactions prior to particle formation.

For this, aqueous solutions of Condrotine sulfate in acetate buffer (15 mM, pH 5.5) at 1.5 mg / mL concentration. The crosslinking agent was used spermine dissolved in mili-Q water at a concentration of 0. 375 mg / mL. Kinetin was incorporated into a proportion of 2.5 and 5% by weight with respect to the components above, for which it was previously dissolved in 0.1N HCl and incorporated into the solution of the crosslinking agent. Dissolution resulting was mixed with chondroitin sulfate solution, under magnetic stirring, which was maintained for half an hour, allowing the complete evolution of the system towards a form stable nanoparticular. Table 1 shows the average diameter, load surface electric (zeta potential) and association efficiency from kinetin to the systems obtained.

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TABLE 1 Physicochemical characteristics of Chondroitin sulfate (ChS) nanoparticles using spermine (PMS) as a crosslinking agent and associating kinetin (n = 3)

4

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Example 2 Morphological characterization of elaborated nanoparticles based chondroitin sulfate associating a bioactive molecule

Nanoparticles were prepared from sulfate of chondroitin using spermine as a crosslinking agent according to procedure previously described, containing kinetin (load of 2.5%) The systems were morphologically characterized by Transmission microscopy (TEM) (CM12, Philips, Eindhoven, The Netherlands), using 1% phosphotungstic acid as an agent of contrast. Figure 1 shows the corresponding images. In these images can be verified that nanoparticular systems They have a regular spherical shape.

Example 3 Preparation of sulfate-based nanoparticles Chondroitin associating a bioactive molecule and modulating its surface charge by incorporating a polymer cationic

Sulfate nanoparticles of Chondroitin using spermine as an ionic crosslinking agent, according to the procedure previously described. He proceeded to the incorporation of a polymeric carrier of opposite load to the chondroitin sulfate, the previously cationized gelatin with spermine, in order to modulate the characteristics of nanoparticles, specifically the surface electric charge. further the incorporation of kinetin was incorporated along with the crosslinking agent, also positive charge, and gelatin cationized to avoid the appearance of interactions prior to particle formation

For this, an aqueous solution of Chondroitin sulfate in HEPES buffer (15 mM, pH 7.4) at concentration of 1.5 mg / mL and an aqueous solution of gelatin previously cationized in mili-Q water at a concentration of 2 mg / mL, and mixed in a mass ratio of 5: 3.5. As a crosslinking agent, spermine dissolved in water was used milli-Q at a concentration of 0.375 mg / mL. The Kinetin was incorporated in a proportion of 2.5% by weight with respect to to the previous components, for which it was previously dissolved in 0.1N HCl and incorporated into the solution of the crosslinking agent and cationized jelly. The resulting solution was mixed with the Chondroitin sulfate solution, under magnetic stirring, the which remained for half an hour, allowing complete system evolution towards a stable nanoparticular form.

In this way, nanoparticles were prepared with an average particle size of 248 ± 2 nm (index of polydispersion of 0.047), negative surface electric charge, of -5.8 ± 1.2 mV and an association efficiency of the molecule bioactive of 41 ± 4%.

Example 4 Preparation of acid-based nanoparticles hyaluronic and association to them of a bioactive molecule

Acid nanoparticles were prepared hyaluronic using spermine as a crosslinking agent according to previously described procedure. The association of Kinetin that was incorporated together with the cross-linking agent, loading also positive, to avoid the appearance of previous interactions to the formation of particles.

For this, aqueous solutions of hyaluronic acid in acetate buffer (15 mM, pH 5.5) at concentration of 4.5 mg / mL. The crosslinking agent was used spermine dissolved in mili-Q water at a concentration of 1,125 mg / mL. Kinetin was incorporated into a proportion of 5 and 10% by weight with respect to the components above, for which it was previously dissolved in 0.1N HCl and incorporated into the solution of the crosslinking agent. Dissolution resulting was mixed with the solution of hyaluronic acid, under magnetic stirring, which was maintained for half an hour, allowing the complete evolution of the system towards a form stable nanoparticular. Table 2 shows the average diameter, load surface electric (zeta potential) and association efficiency of the systems obtained.

TABLE 2 Physicochemical characteristics of hyaluronic acid (HA) nanoparticles using spermine (PMS) as a crosslinking agent and associating kinetin (n = 3)

5

Example 5 Morphological characterization of elaborated nanoparticles based of hyaluronic acid associating a bioactive molecule

Nanoparticles were prepared from acid hyaluronic using spermine as a crosslinking agent according to procedure previously described, containing kinetin (load of 5%). The systems were morphologically characterized by Transmission microscopy (TEM) (CM12, Philips, Eindhoven, The Netherlands), using 1% phosphotungstic acid as an agent of contrast. Figure 2 shows the corresponding images. In these images can be verified that nanoparticular systems They have a regular spherical shape.

Example 6 Release profiles of a bioactive molecule from nanoparticles and modification thereof by selecting the components of said nanoparticles

Nanoparticles were prepared using spermine as a crosslinking agent according to the procedure previously described, associating kinetin (5% load). The systems were subjected to an in vitro release study in different release media (HEPES buffer buffer pH 7.4, acetate buffer pH 5.5 or 0.01N HCl pH 2). Figure 3 shows the corresponding release profiles. As can be seen, said profiles can be modulated by an appropriate selection of the nanoparticle composition: made using: hyaluronic acid (A), chondroitin sulfate (B) or chondroitin sulfate / previously cationized mixtures (C).

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Example 7 Lyophilization of nanoparticles made from sulfate Chondroitin associating a bioactive molecule

Nanoparticles were prepared from sulfate of chondroitin using spermine as a crosslinking agent according to procedure previously described, associating kinetin (load of 2.5%) The suspension of the nanoparticles was lyophilized at concentration of 1 mg / mL in the presence of trehalose as agent Cryoprotectant at different concentrations (10, 5 and 2.5% w / v). For the formulations were subjected to a freezing process at -80 ° C and subsequent lyophilization (Virtis Genesis freeze dryer, 25ES, Virtis, NY, USA). After lyophilization, the systems nanoparticles were resuspended without difficulty by adding 1 mL of mQ water, resulting in a suspension of the nanoparticles at a concentration of 1 mg / mL and then determined the average size of the nanoparticles. Figure 4 shows the average size of nanoparticular systems before and after lyophilization As you can see, the average size of the nanoparticular systems is maintained during the process of lyophilization

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Example 8 Stability of elaborated lyophilized nanoparticular systems based on chondroitin sulfate associating a bioactive molecule during storage at different temperatures

Nanoparticles were prepared from sulfate of chondroitin using spermine as a crosslinking agent according to procedure previously described, associating kinetin (load of 2.5%) The suspension of the nanoparticles was lyophilized according to the procedure previously described at a concentration of 1 mg / mL and in the presence of 5% w / v trehalose. Subsequently lyophilized They were stored at different temperatures. At different times of storage nanoparticular systems were resuspended without difficulty by adding 1 mL of mQ water, resulting in a suspension of the nanoparticles at a concentration of 1 mg / mL and then the average size of the nanoparticles. Figure 5 shows the evolution of the average size on average size of nanoparticular systems. How can checked, this is maintained during storage at different temperature conditions

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Example 9 Jelly Cationization

Jelly cationized with spermine has been synthesized according to the method described by Seki et al . (Journal of Pharmaceutical Sciences 2006, 95 (6), 1393-1401). To this end, a solution of 1% w / v gelatin (100 mg of gelatin in 10 ml of 0.1 M phosphate buffer, pH 5.3) was prepared, to which 1620 mg (4.65 mmol) of spermine and 267.5 mg (1.39 were added mmol) of N- (3-dimethylaminopropyl) -N'-ethyl-carbodiimide hydrochloride (EDC). The pH (pH = 4.5) was then adjusted to a pH value = 5 with NaOH, and the whole was allowed to react for 18 h in a thermostated bath, at 37 ± 1 ° C. Subsequently, the whole was dialyzed and lyophilized, thus obtaining the cationized gelatin with ethylenediamine that was reserved for later use.

Claims (14)

1. A system for the administration of bioactive molecules for cosmetic use comprising nanoparticles with an average size of less than 1 micrometer, comprising:

(to)

to the less an anionic polymer;

(b)

a cationic crosslinking agent; and optionally

(C)

a cationic polymer;

and at least one bioactive molecule for use cosmetic, preferably kinetin, characterized in that the nanoparticles are crosslinked by electrostatic interactions.

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2. System according to claim 1, wherein the anionic polymer is selected from hyaluronic acid or salts of the same and chondroitin sulfate. 3. System according to any of the preceding claims, wherein the cationic crosslinking agent is an amine selected from spermine and spermidine, or salts of the same. 4. System according to any of the preceding claims, wherein the cationic polymer is select from modified proteins, preferably gelatin cationized 5. System according to any of the preceding claims, where the nanoparticles meet in lyophilized form. 6. A cosmetic or hygiene composition personnel comprising a system as defined in any of claims 1 to 5. 7. Composition according to claim 6, for administration on skin, hair and hair system, nails, lips, external genital organs, teeth or mucous membranes. 8. Composition according to any of the claims 6 to 7, further comprising emollient agents, preservatives, fragrance substances, anti-acne agents, agents antifungals, antioxidants, deodorants, antiperspirants, anti-dandruff agents, depigmenting agents, antiseborrhoeic agents, dyes, tanning lotions, UV light absorbers, or enzymes. 9. A procedure for the preparation of a system as defined in any one of claims 1 to 5 which includes:

to)

prepare an aqueous solution of al less an anionic polymer;

b)

prepare an aqueous solution of a cationic crosslinking agent and, optionally adding to it a cationic polymer;

C)

mix the solutions under stirring obtained in a) and b) with spontaneous formation of the nanoparticles.

10. Method according to claim 9, which It also includes the addition of a bioactive molecule for use cosmetic, and / or a stabilizing compound, in solution a) if it is of an anionic nature or in solution b) if it is of a nature cationic 11. Method according to claim 10, wherein the bioactive molecule is kinetin that is incorporated into the solution b). 12. Procedure according to any of the claims 9 to 11, comprising an additional step after of step c) in which the nanoparticles undergo a process Freeze drying. 13. Method according to claim 12, which it comprises an additional stage in which the lyophilized nanoparticles. 14. Cosmetic or personal hygiene composition as defined in claims 6 to 8, for use in hygiene or aesthetics, to neutralize or eliminate ectoparasites, to perfume, modify the appearance of the body surface and / or correct body odors and / or protect or keep it in good state.