PREPARATION OF SOLID WATER-SOLUBLE DIDECYLDIMETHYAMMONIUM BROMIDE.

Abstract

A solid formulation based on didecyl diethylammonium bromide (DDAB) mixed with urea in the ratio of 10-45% : 90-55% respectively is described. If the quantity of DDAB is around 31-32%, the crystalline material obtained has the characteristics of a defined chemical compound, while if the relationship with urea is different, solid mixtures are obtained.

Description

TITLE °RE 3ARATION OF 3R0MUR0 OF WATER-SOLUBLE SOLID DIDECYLDIMETHYLAMINUM. INV. DES. MORRIS E. STOLA? PRIORITY ISRAEL DOW. 3REV. H. 58536 OF 30 3TT33RE 1979 Rome, there ;i :o Register Λ «T'Piv « r roteerei ;o m.nis'e-3 osel'spustri* for ccmi-ercc ; le^l'ast.iìì.sa'c Provincial Office of Industry, Commerce and Crafts of Milan 'ΌΗΙΙ DH MINUTES OF PATENT DEPOSIT OF THE UNION OF THE INNOVATIONS OF THE Vt E la Ditta ' inno rt, 2C 1 li gicrnc CD. HSgfiEK by nazicnaMa 1 Israeli Via / / dei mese '-i—-<* 'ηττ j-ì - - with sece p-> '27-nO'T \ - sraele) óexocsQCs mezzo mancatane SOCIETÀ ' IT ÌLIiVA BREVETTI- Cu attilli i, De Benedetti, umodeo Sale eletti ci legge a · 1: iano - V 1 3 c arditeci $ to the agent he presented to me the following: essicre c un PATENT PER IWE.VZ10VE ESDI STRIALE L-omanoa :n co ; for a pL< have you for —. <O. -U-I.V titolo: } invention.' S ces Priority' cell 2: C; <pm C&6 of 30 October 1979 corrected here : - Description in copy writing pen. XBK£^HXKS2CZS-r^XXXXX3SaS3t«X - Letter with reserve - Document or ready 'and Italian translation - Act The inventor resigns. With reserve - Certificate of payment on postal no.CCeScCQA headed to the Office of Register of taxes and concessions Rome in L.4& · >00 issue C2ll'L'. Postal of Milan 26 on 2 / 2' / 1 980 no. 9290 - Mark the coiio for 2.SOC.- (Israel) is 43 Ο Α / 80 '· » .η. ΊL ,·ο :a ….<. t ι _ .r··.· rnaicne aderite ρ·?γ titó^a; PREPARATION OF WATER-SOLUBLE SOLID DIDSGILDYLTYLALOONIUM BROMIDE” three STOLAR MORRIS E. . ' ' '.'aa ; ì jifLttc * ·* 1 r*i ♦ ' - n - · τ ► * λ :. I Γ I : 1 v- < - Help. v ? ISRAEL f - . c : i 9 .· ic . · :i ' * a . 30 / 10 / 1979 * 58586 , j ' ; !' ' ΰηπ-; t ' TP· ae: 1 ' invention or two copies,&l£iie ri; ncri'.tcra; ] Alteration of the assignment with reservation: ) Inventor designation, with reservation L· a . r;f> / ma. cor n :e I'll f / rrr'. on r / r N oQG66bCv'i 46,500,- made on 2 / 9 / 80; λ ì'f; . <i·’ ~ f' ->*; ìì- ì Λ / > ; ilano. ^80 « · DESCRIPTION of the industrial invention entitled: PREPARATION OF DIDECYLDIMETHYAMMONIUM BROMIDE WATER-SOLUBLE SOLID on behalf of the Israeli company ABIC LTD. with headquarters in RAUAT-GAN (Israel) - registered The - with Ko. 24 43 0 A / 80 INVENTOR: STOLAR Morris E. SUMMARY A solid formulation based on didecyldiaethylammonium bromide (DDAB) mixed with urea in a ratio of 10-45% : 90-55%, respectively, is described. If the DDAB content is approximately 31-32%, the resulting crystalline material has the characteristics of a defined chemical compound, while if the ratio with urea is different, solid mixtures are obtained. oooooooooooooooooooooooooooooooooooooooooooooooo The present invention relates to the preparation of water-soluble solid didecyldimethylammonium bromide (hereinafter referred to as DDAB). DDAB is known to be an excellent disinfectant. However, known DDAB formulations have serious drawbacks in use. Pure DDAB is very difficult to prepare and comes in the form of a sticky paste that is unsuitable for practical use. DDAB is therefore usually used in ethanolic solution. This solution can be used by the end user, such as a farmer, as such or usually after dilution with a solvent, usually water, to achieve the desired concentration. The use of an ethanol solution has serious disadvantages, as it complicates handling, storage, and sales. Furthermore, ethanol is corrosive and flammable. It was therefore felt that it was necessary to find a way to obtain a composition or formulation containing DDAB that was solid, i.e., crystalline or powdery, and readily soluble in water. This formulation should present the advantages of DDAB without its disadvantages. It was surprisingly found that mixing DDAB or its ethanolic solution with urea yielded a solid crystalline formulation that could be easily handled, stored, and shipped, and which dissolved readily in water to produce a biologically active DDAB solution. The present invention therefore consists of a didecyldimethylammonium bromide-urea formulation comprising 10-45% didecyldimethylammonium bromide, the remainder being urea. In a preferred formulation the amount of DDAB present is 25-34% preferably 31-32%. It turns out that when the DDAB content is about 31-32%, the material is not a simple mixture, but a definite compound. Its crystals are hexagonal and different from urea, its melting point is 158-139°C (all melting points are given in °C) (urea 132°; DDAB 70-80°), and DDAB cannot be extracted with solvents such as ethyl acetate or chloroform, in which it is soluble. However, this does not exactly occur at higher DDAB concentrations, and in addition to a possible defined inclusion product, the remaining DDAB adheres to that product. When the DDAB concentration is below about 31%, the urea is partly free, and DDAB is included in only a portion of the available urea. The present invention is therefore not limited to the explanations given above, nor to a specific defined inclusion compound, but concerns formulations comprising from 10 to 45% DDAB, the part * « remaining being urea. The formulation according to the present invention can be obtained by mixing the conventional ethanolic formulation with urea, preferably in an inert solvent. The reaction is carried out from room temperature up to the boiling point of the solvent under reflux, if present. However, it is not necessary to use the ethanolic solution. Therefore, if free DDAB is prepared and mixed with urea in the desired percentages, the formulation according to the present invention is obtained. The term "inert solvent" in this invention means any solvent that does not react with the starting materials and the final formulation, and from which the final formulation can be obtained. Methanol is the preferred solvent, but other alcohols, polyalcohols, and water are also suitable. The ethanolic formulation is suitably prepared by the process described in Journal of Applied Chemistry (London) 1 Supplement No. 2, pages 86-94 (1951). However, the present invention is not limited to this process. The formulation according to the present invention can be stored and sold as such. It is then dissolved by the user as needed. For various indications, the final concentration of DDAB in water is preferably between 50 and 1000 ppm. The present invention will now be illustrated with reference to the following examples, without being limited thereby. EXAMPLE: 1 g of urea is added, with stirring and heating, to a mixture of 32 ml of methanol and 15.5 g of a 77.5% ethanolic solution of DDAB. The mixture is heated and the urea dissolved. The clear solution obtained is cooled to room temperature and the precipitated crystals are filtered off. The white crystalline material obtained is dried in vacuo (22.4 g). It contains approximately 32% DDAB; melting point 138-139°. To test the biological activity of this formulation, an aqueous solution is prepared and compared with aqueous solutions obtained from a normal ethanolic solution of DDAB. Tests conducted against bacterial strains of Escherichia coli and Staphylococcus aureus found that the dry powder was at least as active as the reference formulation. In fact, during these tests, its activity was found to be statistically significantly superior. EXAMPLE: 2 g of urea are added with stirring and heating to a mixture of 16 ml of methanol and 31.0 g of a 77.5% ethanolic solution of DDAB. The urea is dissolved under reflux, and the solution is cooled to room temperature. The separated crystals are filtered off and dried. The formulation (14.0 g) contains 44% DDAB; melting point 136-138°C. EXAMPLE 3 18 g of urea are mixed with 15.5 g of a 77.5% ethanolic solution of DDAB and 32 ml of methanol. The resulting mixture is heated under reflux. The solution was evaporated to dryness under vacuum. The final formulation (30,0g) comprises 40% DDAB; melting point 135-137°. EXAMPLE 4 7.8 g of a 77.5% ethanolic solution of DDAB are mixed with 32 ml of methanol, while 18 g of urea are added while stirring and heating under reflux. A clear solution is obtained, which is cooled to room temperature. The precipitated material is separated by filtration and dried. The formulation (20.5 g) contains 25.4% DDAB; melting point 156-137°. EXAMPLE 5 15.5 g of a 77.5% ethanolic solution of DDAB was evaporated under vacuum to a thick paste. 10 g of the resulting nearly pure DDAB was mixed with 20 g of powdered urea. The resulting sticky mass was allowed to stand for 5 days. A solid material (30 g) was thus obtained, which was ground into a fine powder. This powder contained 32.0% DDAB; melting point 134135°C.

Claims

1. CLAIMS 1. Formulation consisting of didecyldimethylammonium bromide and urea, comprising 10-45% didecyldimethylammonium bromide, the remainder being urea.

2. Formulation according to claim 1, wherein the amount of didecydimethylammonium bromide present is 25-34%.

3. Formulation according to claim 1 or 2 wherein the amount of didecyldimethylammonium bromide present is 31-32%.

4. Formulation according to any of claims 1 to 3, characterised by being in powder form.

5. Formulation consisting of didecyldimethylammonium bromide and urea, substantially as described with reference to the Examples.

6. Process for preparing a didecyldimethylammonium bromide-urea formulation according to any of claims 1 to 5, characterised in that the didecyldimethylammonium bromide is mixed with urea and the formulation is then optionally isolated by filtration or evaporation.

7. Process according to claim 6, wherein didecylmethylammonium bromide is used as the ethanolic solution.

8. Process according to claim 6 or 7 characterised in that it is carried out in a solvent.

9. Process according to claim 8, wherein the solvent is ethanol.

10. Process for the preparation of a didecyldimethylammonium bromide-urea formulation, substantially as described with reference to the Examples.

11. Aqueous solution containing substantially DDAB prepared by dissolving in water a formulation according to any of claims 1 to 5. BI-4506 LA / vr