Description

In many areas of life, it is necessary to prepare a homogeneous mixture from inorganic and organic salts which, under certain conditions, precipitate each other due to chemical reactions or other transformations, and thus it is impossible to prepare an aqueous solution having suitable ion composition in homogeneous form. This is the case, for example, with many therapeutic solutions that also contain metal ions, where the non-compatible ions often precipitate each other and a homogeneous solution cannot be prepared from them with the usual stabilizers (ionic or non-ionic additives, detergents, etc.). The precipitation changes the composition of the solution and thus reduces its therapeutic or other usability.

Examples of such solutions are the solutions used in therapy for replacing iron or other microions or the infusions, which contains several inorganic and organic components in addition to the organic materials. Another area of application is the case of hydroponic cultures, which are increasingly used in sustainable crop production, where 20-50, often non compatible salts, organic or inorganic plant nutrients are to be dissolved in such a way that that they neither precipitate in the so called hydroponic solution nourishing the plants nor in the devices belonging to hydroponic equipment, such as the pipelines.

The compatibility problems can be reduced to some extent by converting the components in the solution into nanoparticles in the usual and known manner. This can be performed by physically grinding the particles and then sieving the particles having unsuitable particle size, etc. as a physical removal. According to the common experience, the nanoparticle formation alone is not sufficient to adequately solve the non-compatibility problems (that is, to increase the solubility of one or more key components causing precipitation by at least 100-fold). It also does not lead to the solution of compatibility problems if the nanoparticles are precipitated from colloids and transfer into the mixture without preparation or optionally by filtering or by other preparation method.

In our experiments we have surprisingly found that by nanoising and then properly stabilizing the inorganic and organic components in the solution, the adequate compatibility of the solutes can be provided. The invention can be implemented in batch equipments, such as flasks or reactors, but it is preferred that one, more, or all of the non-incompatible salts or other compounds are nanoised in a flow reactor.

Examples of flow reactors include the microfluidic flow reactor described, for example, in publication: I. Homyak, B. Borcsek and F. Darvas, Microfluid Nanofluid DOI 10.1007/s 10404-008-0257-9.

The size of the nanoised salts according to the invention is less than 1000 nm, preferably less than 500 nm or preferably less than 300 or preferably 200 nm.

The salts of the invention include inorganic or organic salts in the ionic state. The inorganic salts may contain, for example, the following ions: Ca ²⁺ , Mg ²⁺ , K ⁺ , NO3 , SO4 ² , H2PO4 ; the examples of ions forming organic salts include ammonium ions, e.g. NH ⁺ .

For the preparation of nanoised salts of the invention the following stabilizers mentioned as representative examples can be used: cellulose or derivatives thereof, polysaccharides, such as mannitol or sorbitol, polyvinylpyrrolidone, sodium lauryl sulfate, gelatin, cetostearyl alcohol, polyethylene glycols, acetic acid, polyvinylpyrrolidone-vinyl acetate copolymers, sodium dodecyl benzene sulfonate, sodium dodecyl benzoyl sulfonate, tocopheryl polyethylene glycol succinate, urea, citric acid, sodium acetate, poly(oxyethylene stearate), polyvinyl alcohol (PVA), poly(methacrylate) based polymers and copolymers, 4-(l, 1,3,3- tetramethylbutyl)-phenol polymer with ethylene oxide and formaldehyde groups (e.g. tyloxapol, superione and triton), poloxamers (e.g. Pluronic, which are block copolymers of propylene oxide and ethylene oxide), poloxamines (e.g. Tetronic, which is a tetrafunctional block copolymer), polyethylene glycol-polycaprolactam-polyvinyl acetate graft copolymers (Soluplus), D-alpha-tocopheryl polyethylene glycol succinate, poly(2-ethyl-2-oxazoline), poly(methyl vinyl ether), random copolymers of vinyl pyrrolidone and vinyl acetate, such as Plasdone S630.

Examples of useful ionic stabilizers include, but are not limited to polymers, biopolymers, polysaccharides, celluloses, alginates, phospholipids, and other nonpolymeric compounds, such as zwitterionic stabilizers, poly-n-methylpyridinium, anthryul pyridinium chloride, cationic phospholipids, chitosan, polylysine, polyvinylimidazole, polybrene, polymethyl methacrylate, trimethyl ammonium bromide (PMMTMABr), hexyldesyl trimethyl ammonium bromide (HDMAB), and polyvinylpyrrolidone-2-dimethyl aminoethyl methacrylate dimethyl sulfate. For support of the process of the present invention, an experiment was performed by selecting two non-compatible salts, such as calcium chloride and silver nitrate, and these were mixed into a nutrient solution used in hydroponic cultures. The experiment is shown in Figure 1. Mixing the silver nitrate with the solution containing the non-nanoised ions an abundant white precipitate formed immediately, however, if this experiment was executed with the nanoised components, we have surprisingly found that no precipitate formed, moreover, the solution remained homogeneous after 24 and 72 hours.

1. Composition and particle size of the produced nanoparticles formed from inorganic nutrient salts, measured immediately and 24 hours after redispersion.