GB2518967A

GB2518967A - Disinfectant composition

Info

Publication number: GB2518967A
Application number: GB1414619.5A
Authority: GB
Inventors: Navjeet Kaur Matharu
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-09-25
Filing date: 2014-08-18
Publication date: 2015-04-08
Also published as: GB201414619D0; GB201316982D0; GB2518607A

Abstract

A disinfectant composition comprises DMDM hydantoin, chlorhexidine digluconate and benzalkonium chloride. The composition may further comprise lauramine oxide, isopropyl alcohol, glycerol and/or hydroxyethyl cellulose as well as water. Also claimed is a method of disinfecting human or animal skin with the composition, and a method of preparing the disinfectant composition by mixing the ingredients in a mixer.

Description

Title: Disinfectant composition

Description of Invention

The present invention relates to a disinfectant composition. More particularly, the present invention relates to a disinfectant composition, for example an antiseptic composition, for cleaning human or animal skin. The present invention also relates to a method of forming a disinfectant composition for cleaning human or animal skin.

Disinfectants are regularly used to clean human or animal skin, for example before, during or after surgery. Human or animal skin provides an environment for, and provides a breeding ground for, potentially harmful pathogens. A potentially harmful pathogen is any organism which can cause disease. Non-limiting examples of potentially harmful pathogens include bacteria, fungi, viruses, moulds and yeasts.

Among other functions, human or animal skin acts as a barrier between the internal human or animal body and the atmosphere. When human or animal skin is perforated, for example by an accidental or non-accidental (for example surgical) cut, it is possible for pathogens on the surface of the skin to enter the bloodstream and potentially cause an ailment and/or a disease.

Furthermore, pathogens on the surface of the skin of a human or animal can multiply and enter the body of the host through a bodily orifice, for example the mouth, nose or ears.

Many pathogens exist on the surface of the skin of humans without causing infection. Surgery can permit such pathogens to enter the human blood stream and cause infection. An example of a pathogen which it is often desired to kill, in a surgical environment, is Candida albicans. Candida albicans is a fungus which is a causal agent of infections in humans, particularly in immunocompromised individuals. Another example of a pathogen which it is often desired to kill, in a surgical environment, is Staphylococcus aureus. Staphylococcus aureus is a bacteria. Both Candida albicans and Staphylococcus aureus are common causes of hospital acquired infections, for example after surgery.

It is common to clean human or animal skin with agents which act to mitigate and/or destroy potentially harmful pathogens. The cleaning of human or animal skin in this way is beneficial to human or animal health, so as to prevent the spread of disease and mitigate the chances of a subject or subjects contracting a disease by mitigating and/or destroying potentially harmful pathogens on the skin of a human or animal.

It is particularly beneficial to mitigate and/or destroy potentially harmful pathogens on the skin of a subject before, during and/or after surgery. During surgery it is common to pierce the skin of a subject with a scalpel or scissors, for example. Before piercing the skin of a subject, it is desirable to minimise the number of potentially harmful bacteria on the skin. Furthermore, before piercing the skin of a subject, it is desirable to minimise the number of potentially harmful bacteria on the skin of a surgeon, or other medical professional who may come into contact with the subject during surgery.

At the present time, there are often reports of persons contracting potentially harmful diseases in hospitals when they have gone to hospital for routine operations and/or procedures. There has been particularly visible media coverage, in the UK at least, of persons contracting, inter al/a, Clostridium difficile and Methicillin Resistant Staphylococcus Aureus (MRSA) whilst in hospital.

There are a number of products on the market which provide disinfectant actions when applied to skin. One example of a scrub used in a surgical environment is HiBiSCRUBTM, sold by Regent Medical Ltd in the UK. Another example of a scrub used in a surgical environment is OCTENSIANTM, sold by Schulke & Mayr UK Ltd in the UK.

In substantially disinfecting the skin of a human or animal, optionally before, during or after a surgical procedure, it is preferable for the disinfectant to be active on the surface of the skin for a period of time, for example, up to 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35,40,45,50 or55 minutes, 1,2,3,4,5,6,7,8,9 or hours, and all other times in between. It is particularly preferable for the anti-pathogen agent to be active for at least 6 hours in a surgical environment so that a surgical operative has sufficient time to complete surgical procedures without fear of contamination of an area undergoing surgery.

There is a need for a new disinfectant which can be applied to the skin of a human or animal and which provides a relatively long anti-pathogen activity (at least 6 hours) and anti-pathogen activity against a range of pathogens, along with no harmful side affects on humans and animals.

According to the present invention, there is provided a disinfectant composition, comprising: DMDM hydantoin; chlorhexidine digluconate; and, benzalkonium chloride.

Preferably, comprising 2.00-8.00 % w/w chlorhexidine digluconate.

Further preferably, comprising 2.00-6.00 % w/w, or 2.50-5.00 % w/w, or 3.00- 4.50 % w/w chlorhexidine digluconate.

Advantageously, comprising 0.10-1.00 %wlw DMDM hydantoin; Preferably, comprising 0.10-0.50 % w/w, or 0.10-0.40 % w/w, or 0.10-0.30 % w/w DMDM hydantoin.

Further preferably, comprising 0.20-1.0 % w/w benzalkonium chloride.

Advantageously, comprising 0.30-0.80 % w/w, or 0.40-0.70 % w/w benzalkonium chloride.

Preferably, further comprising lauramine oxide or Ceteareth-20, wherein Ceteareth-20 is CH3{CH2)m(OCH2CH2)200H and rn is 15 or 17, or lauramine oxide and Ceteareth-20.

Further preferably, comprising 5.00-1 0.00 % w/w lauramine oxide or 0.1-10 % w/w Ceteareth-20, or 5.00-10.00 % w/w laurarnine oxide and 0.1-10 % w/w Ceteareth-20, any remaining balance being water.

Advantageously, further comprising isopropyl alcohol.

Preferably, comprising 5.00-20.00 % w/w isopropyl alcohol.

Further preferably, further comprising glycerol.

Advantageously, comprising 2.00-1 0.00 % w/w glycerol.

Preferably, further comprising hydroxyethyl cellulose.

Further preferably, comprising 0.20-1.0 % w/w hydroxyethyl cellulose.

Advantageously, corn prising or consisting of: deionised water; hydroxyethyl cellulose; glycerol; isopropyl alcohol; DMDM hydantoin; chiorhexidine digluconate; benzalkonium chloride; and, lauramine oxide or Geteareth-20, wherein Ceteareth-20 is GH3-(CH2)m- (OCH2CH2)20-OH and m is 15 or 17, or lauraniine oxide and Ceteareth-20.

Preferably, comprising or consisting of, in % w/w: 0.20-1.0 hydroxyethyl cellulose; 2.00-1 0.00 glycerol; 5.00-20.00 isopropyl alcohol; 0.10-1.00 DMDM hydantoin; 2.00-8.00 chlorhexidine digluconate; 0.20-1.00 benzalkonium chloride; and, 5.00-10.00 lauramine oxide or 0.10-10.00 Ceteareth-20, or 5.00-10.00 lauramine oxide and 0.10-1 0.00 Ceteareth-20; the balance being deionised water.

Further preferably, consisting of, in % w/w: 72.30 deionised water 0.50 hydroxyethyl cellulose; 5.00 glycerol; 10.0 isopropyl alcohol; 0.20 DMDM hydantoin; 4.00 chlorhexidine digluconate; 0.50 benzalkonium chloride; and, 7.50 lauramine oxide.

Alternatively, consisting of, in % wiw: 78.6 deionised water 0.50 hydroxyethyl cellulose; 5.00 glycerol; 10.0 isopropyl alcohol; 0.20 DMDM hydantoin; 4.00 chlorhexidine digluconate; 0.50 benzalkonium chloride; 0.90 lauramine oxide; and, 0.30 Ceteareth-20.

According to a further aspect of the present invention, there is provided an aqueous mixture comprising: water and a disinfectant composition according to any one of the above.

Preferably, wherein the water is tap water, potable water and/or deionised water.

Further preferably, wherein the aqueous mixture has a ratio of water to disinfectant composition of from 99% water to 1% disinfectant composition to 1% water to 99% disinfectant composition.

Advantageously, wherein the composition has a ratio of water to disinfectant composition of 99%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, 4%, 3%, 2%, 1.5%, 1%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1% or 0.05% water to disinfectant composition.

According to a further aspect of the present invention, there is provided a method of disinfecting human or animal skin, comprising: providing a disinfectant composition or an aqueous mixture according to any one of the above; and, applying the composition or mixture to human or animal skin.

According to a further aspect of the present invention, there is provided a method of preparing a disinfectant according to any one of the above, comprising: providing the ingredients according to any one of the above; and, mixing the ingredients in a mixer.

Some of the components of the disinfectant compositions of the present invention, together with their sources, are set out below.

DMDM Hydantoin DMDM Hydantoin is an antimicrobial agent with the following chemical structure:

OH

N OH

DMDM acts to mitigate and/or destroy pathogens by releasing formaldehyde.

Chlorhexidine Digluconate Chlorhexidine Digluconate is an antimicrobial agent with the following chemical structure: ci ___lI___ jfcH2(cH2)4cH2/)-"' 1Ici 20.2 HOL Chiorhexidine is effective against both Gram-positive and Gram-negative bacteria.

Benzalkonium Chloride Benzalkonium chloride is an antimicrobial agent with the following chemical structure: n = 8, 10,12, 14,160118 Benzalkonium chloride is a quaternary ammonium compound. Benzalkonium chloride acts as to mitigate and/or kill bacteria, moulds and yeasts.

Without wishing to be bound by theory, it is believed that the combination of DMDM Hydantoin, Chlorhexidine Digluconate and Benzalkonium Chloride, provides a disinfectant composition with beneficial properties. In particular, it is believed that this combination provides a synergistic effect.

Composition A Composition A (sometimes referred to as composition NPP49O by the applicant), shown in Table 1, is a non-limiting example of a composition according to the present invention:

Table I

Composition A Component CAS number Amount (% w/w) Action(s) Deionised water 7732-18-5 72.30 Solvent Hydroxyethyl 9004-62-0 0.50 Gelling agent cellulose Glycerol 56-81-5 5.00 Humectant and (EC No. 200-289-5) moisturiser Isopropyl alcohol 67-63-0 10.0 Solvent DMDM Hydantoin 6440-58-0 0.20 Antimicrobial Chlorhexidine 18472-51-0 4.00 Antiseptic digluconate Benzalkonium 63449-41 -2 0.50 Biocide and chloride surfactant Lauramine oxide 308065-28-4 7.50 Amine oxide (Previously surfactant 68155-0909) Total 100 Composition A is a disinfectant composition according to a preferred embodiment of the present invention. The names of the components of the composition, along with the CAS (Chemical Abstract Service) number, are given. The CAS number has been given in each case because the CAS registry is a standard reference for persons looking to classify chemical compounds which are known in the scientific literature. In the case of glycerol, the EC number (European Chemical number, from the EC registry) is given instead of the CAS number. In Table 1, the amount of each component of the composition is provided in weight % (also referred to in this specification as wt % or % w/w).

Alternatively, the Lauramine oxide in Composition A may be replaced, either partially or fully, by a different surfactant, for example Ceteareth-20 (a surfactant), wherein Ceteareth-20 is CHr(CH2)m(OCH2CH2)2rOH and m is 15 or 17. When Lauramine oxide in Composition A is replaced, either partially or fully, by Ceteareth-20, the amount of Ceteareth-20 is preferably 0.3% wlw, the remaining balance being deionised water. When Lauramine oxide is replaced in Composition A partially by Ceteareth-20, the amount of Ceteareth-20 is preferably 0.3% w/w, the amount of Lauramine oxide is preferably 0.9% w/w, the remaining balance being deionised water: this composition is referred to as Composition Al.

Composition A has a clear and colourless appearance. Composition A is a viscous liquid and has a pH of between 6.0 and 7.5.

The action of composition A against certain pathogens has been tested and is discussed below.

Ranges for each of the ingredients in composition A are provided in Table 2, below. All disinfectant compositions falling within these boundaries are expected to have the same effects. The ranges are provided to show the ranges which have been tested for disinfectant activity. The ranges include each intermediate value, for example 5-20 includeS, 6, 7,8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 and 20, and each further intermediate value.

Table 2

Composition A ranges Component CAS number Amount (% w/w) Ranges (°A w/w) Deionised water 7732-1 8-5 72.30 49.00-85.50 Hydroxyethyl 9004-62-0 0.50 0.20-1.0 cellulose Glycerol 56-81-5 5.00 2.00-1 0.00 (EC No. 200-289-5) Isopropyl alcohol 67-63-0 10.0 5.00-20.00 DMDM Hydantoin 6440-58-0 0.20 0.10-1.0 Chlorhexidine 18472-51-0 4.00 2.00-8.00 digluconate Benzalkonium 63449-41 -2 0.50 0.20-1.0 chloride Lauramine oxide 308065-28-4 7.50 5.00-1 0.00 (Previously 68155-0909) Total 100 Composition A, according to the present invention, is in compliance with Regulation (EC) 1223/2009 (on cosmetic products), the Biocidal Products Directive 9818/EC,the UK Biocidal Products (Amendment) Regulations 2007 and the (EU) Biocides Regulation 528/2012 (EU BPR). In other words, the ingredients comply with the relevant European law on the safety of cosmetic products.

Alternatively, the Lauramine oxide in Composition A may be replaced, either partially or fully, by a different surfactant, for example Ceteareth-20, wherein Ceteareth-20 is CH3-(CH2)-(OCH2CH2)20-OH and m is 15 or 17. When Lauramine oxide is replaced by Ceteareth-20, either partially or fully, the amount of Ceteareth-20 is preferably in the range 0.10-1 0.00 % w/w, any remaining balance being deionised water.

Manufacturing protocol for composition A The following is a protocol for forming a cleaning liquid according to composition A, shown in Table 1. The amounts of each component used at each step are shown above, i.e. they are not specified in the method below.

In one exemplary embodiment, all of the components of composition A are mixed in any order, in the amounts specified in Table 1, to result in a composition according to the present invention.

In another exemplary embodiment, the compositions of the present invention are prepared as follows: Select a clean manufacturing vessel, for example a stainless steel mixing vessel with a propeller shaft.

ii. Introduce the deionised water into the pre-cleaned mixing vessel.

iii. Introduce the hydroxyethyl cellulose into the mixing vessel, stir and permit hydration.

iv. Introduce the DMDM hydantoin into the mixing vessel and continue stirring.

v. Introduce the glycerol into the mixing vessel and continue stirring.

vi. Introduce the isopropyl alcohol into the mixing vessel and continue stirring.

vii. Introduce the chlorhexidine digluconate into the mixing vessel and continue stirring until the solution turns clear.

viii. Introduce the benzalkonium chloride into the mixing vessel and continue stirring.

ix. Gradually (over ten minutes) reduce the speed of mixing to mitigate the build up of any foam.

x. Introduce the lauramine oxide or Ceteareth-20 into the mixing vessel and continue stirring for 10 to 30 minutes.

After step x., the composition can be portioned into plastic container vessels and stored, ready for use. A preferred and non-limiting plastic container vessel is a clean 1000L CHEP ULTRA PalleconTM container securely lined with FlexsolTM Liner Natural LLDPE polymer. This liner meets European and FDA requirements for food contact materials.

Alternatively, when Ceteareth-20 is included, as in composition Al, the compositions of the present invention may be prepared as follows: Select a clean manufacturing vessel, for example a stainless steel mixing vessel with a propeller shaft.

ii. Introduce the deionised water into the pre-cleaned mixing vessel.

iv. Introduce the DMDM hydantoin into the mixing vessel and continue stirring.

v. Introduce the isopropyl alcohol into the mixing vessel and continue stirring.

vi. In an auxiliary clean vessel dissolve cetereath-20 in 3% warm deionised water at 60°C. Allow the auxiliary vessel to cool to ambient temperature and add the dissolved mixture to the mixing vessel mixture obtained by step v.

vii. Introduce the glycerol into the mixing vessel and continue stirring.

ix. Introduce the chlorhexidine digluconate into the mixing vessel and continue stirring until the solution turns clear.

x. Gradually (over ten minutes) reduce the speed of mixing to mitigate the build up of any foam.

xi. Introduce the lauramine oxide to the mixing vessel and continue stirring for 10 to 30 minutes.

After step xi., the composition can be portioned into plastic container vessels and stored, ready for use. A preferred and non-limiting plastic container vessel is a clean 1000L CHEP ULTRA PalleconTM container securely lined with FlexsolTM Liner Natural LLDPE polymer. This liner meets European and FDA requirements for food contact materials.

In use, the compositions of the present invention may be mixed with water.

Preferable mixing ratios with water for composition A are, in percentage terms (where 1% means 99 parts water to 1 part exemplary composition) 100%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, 4%, 3%, 2%, 1.5%, 1%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1% and 0.05%.

In use, the disinfectant compositions of the present invention may be applied to the skin of a user, optionally prior to surgery. The compositions may be applied to the skin of a user by application on a sponge, a flannel, a wipe or a towel.

A preferred application regime, in a hospital environment, for compositions of the present invention is as follows: i. Wet the body of a subject, for example in a shower.

ii. Turn off water supply.

iii. Wash hair with composition A. iv. Place some of composition A on a hand or wet sponge and wash the body of the subject, paying particular attention to the mouth, nose, armpits, navel, groin and genitals of the subject.

v. Optionally, leave the foamed composition on the surface of the skin for 1-2 minutes.

vi. Turn on the water supply.

vii. Rinse off composition A. vih. Repeat steps ii. to vU. so the subject is washed twice.

ix. Dry subject with a clean towel.

Trials Tests were carried out on the effectiveness of composition A of the present invention, namely that detailed in Table 1.

a. Minimum inhibitory concentration test comparisons Panspermia Microbiology Laboratories Ltd (Panspermia"), Burnham-on-Crouch, Essex, UK, carried out minimum inhibitory concentration tests on composition A (from Table 1) and a number of other comparison compositions.

These tests were carried out under a non-disclosure agreement.

Panspermia's minimum inhibitory concentration test method: * Make up a working solution of the anti-microbial composition to be tested in a nutrient broth. The solution is 50% w/w of the neat anti-microbial agent and 50% w/w nutrient broth.

* Sterilise and label 12 test tubes containing 5m1 of nutrient broth (not including the anti-microbial agent).

* Aseptically add 5m1 of the working solution to the first tube using a sterile pipette.

* Vibrationally mix the tube to homogenise the broth.

* Serially dilute the sample by taking 5m1 from the first tube into a second tube, vibrationally mixing, and then taking 5m1 of the resulting mixture into a third tube, and so on, until all tubes containing 5m1 of liquid, each tube being half the concentration of the previous tube.

* Inoculate each tube with 1 drop from a pipette of an overnight culture of the test organism. Vibrationally mix each tube after addition of inoculums.

* Incubate the tubes at 30°C for 12 hours.

* After incubation, vibrationally mix the tubes to ensure even mixing.

* Take a sub-culture (using a sterile plastic loop) from each tube and place each sub-culture onto separate agar plates suitable for the microorganism (for example: bacteria = tryptone soy agar; yeasts = Sabouraud dextrose agar).

* Incubate each agar plate for the same amount of time (12 hours) and assign each plate with a reading of growth: ClCC = no growth; "+" = sparse growth; 4+" or "+++" = growth; "++++" = profuse growth.

Table 3 shows the results of Panspermia's trials. In summary, the minimum inhibitory concentrations of different compositions were tested against Staphylococcus aureus ATCC 6538 and Candida albicaris ATCC 10231. (The ATCC numbers refer to the numbers applied to these microorganisms by the American Type Culture Collection).

Referring to Table 3, the compositions tested by Panspermia were: Tester 1: Same as composition A (from Table 1), without any DMDM Hydantoin.

Tester 2: Same as composition A (from Table 1), without any Chlorhexidine digluconate.

Tester 3: Same as composition A (from Table 1), without any Benzalkonium chloride.

Tester 4: HiBiSCRUBTM, as sold Regent Medical Ltd in the UK.

Tester 5: Composition A (from Table 1).

Tester 6: Placebo (isopropyl alcohol 10% w/w in deionised water).

The concentrations of each of testers 1-6 in deionised water were changed, as shown along Table 3 (from 25% to 0.01%). A mark for a particular tester at a particular concentration shows the tester is effective in killing the microorganism at that concentration. A "+" mark shows sparse growth of the microorganism. A ++" or "++-" mark shows some growth. A ++++" mark shows profuse growth.

All of tester compositions 1-5 showed a greater effect than the placebo against Staphylococcus aureus.

Composition A (Tester 5) showed by far the greatest kill effect against Gandida albicans at low concentrations out of all of the testers. Without wishing to be bound by theory, this indicates that the combination of DMDM Hydantoin, Chlorhexidine Digluconate and Benzalkonium Chloride provides a synergistic effect.

b. Hospital tests The effectiveness of composition A was tested in a hospital environment at the Hospital Infection Research Laboratory, Queen Elizabeth Hospital, Birmingham, UK. The tests were carried out under a non-disclosure agreement.

Test products: i. HiBiSCRUBTM (Tester 7) H. Composition A (from Table 1) (Tester 8) Concentrations: Both products were tested at in-use compositions, i.e. not diluted.

Test organisms: Staphylococcus aureus NCTC 10788 Methicilin-resistant Staphylococcus aureus NCTC 12493 Candida albicans ATCC 10231 NCTC refers to the reference number given to the microorganism provided by the National Collection of Type Cultures.

Test temperature: 20°C Test method: As set out in EN 13727: (2003) Chemical disinfectants and antiseptics -Quantitative suspension test for the evaluation of bactericidal activity of chemical disinfectants for instruments in the medical area. EN 13727 is a European standard test, as set out by the European Standardisation Organisation. A copy of EN 13727 is available from BSI, 389 Chiswick High Road, London, W4 4AL. EN 13727 was modified to test different microorganisms from those tested in the published European standard. Also, the maximum time tested was 5 minutes.

The test method involved mixing 1 ml of the test organisms with 1 ml of interfering substance (0.3% w/v Bovine albumin), and then adding 8 ml of the test product. After the required contact time, 0.1 ml was removed to 9.9 ml of recovery broth (8.9 ml neutraliser and 1 mlwater)for5minutesafterwhich is was placed onto Tryptone Soya Agar to detect surviving test bacteria, and Sabouraud Dextrose Agar to detect surviving test organism.

The neutralisers used were: * TweenTM 80 (30g/l), lecithin (3g11), saponin (30g/l), histidine (lgIl), sodium thiosulphate (5g11), sodium chloride (8.5g/l) and tryptone (lg/l) -for Candida albicans.

* TweenTM 80 (30g/l), lecithin (3g11), sodium lauryl sulphate (4g11), sodium chloride (8.5g/l) and tryptone (1 gIl) -for Staphylococcus aureus.

Referring to Tables 4 and 5, the compositions tested at the Hospital Infection Research Laboratory were: Tester 7: HiBiSCRUBTM, as sold Regent Medical Ltd in the UK.

Tester 8: Composition A (from Table 1).

Validation of test method: Vc = Viable count Nv0 = cfu/ml of test organism suspension The methodology is valid if, A and B are equal to or greater than 0.5 x Nvo, and C is equal to or greater than 0.5 x B.

Table4

-C Ltua,neutilinho conft{ th grns.rn ExpenineitI NeatS7er Cl ar -rest oi:rgnisin ss,eris1on tøxicity eontrW ean.-.---. .--A) __ 1Tester7TS3 Vc: 337,346 \ 406418 Vc: 220,278 Vc:205, 190 Ve: 137, 158 3/aphykcoccus <mms(NCTC Nyc,: 683 A: 824 E: $38 C:395 C: 315 MRSA (NCTC \c: 50G,428 ye: 5Z3 Vc 339322 Vc: 290.145 Vc, 271.254 Nv0: 934 A: 1075 8: 661 C: 535 C: 525 cwtaidaaThIcdn Ve: 14,8 Vo 171 15 Ve: g Vc: 5,5 Ve: 9,11 (ATCC 10231.) 1 Nv0:22 A: 92 8.16 I C 10 C: 20 Table 4 shows that the results of this trial are validated.

Table 5 shows the microbicidal activity of Tester 7 and Tester 8, using the modified EN 13727 test set out above. The tests were carried out in duplicate.

Table 5

Memn kg%, reduction --Contact Logo 7 1 Tster8 lestcrganism rnthal -----couin Test 1 1 e 2 Mean Test 1 lest 2 Mean 4t 429 4.17 >585 585 >sssT Staph ploco&us miE >5 85 525 >585 >5 85 >585 >585 aurern.-785 2mm >585 >585 >5.85 -85 >585 >5.85 (NCTC 10788) - >5.85 >585 >5.85 >185 >5:85 >5.85 491 >599 >545599 599 >599 MRSA L 1mm 599 >599 499 >599 >599 >599 ______ _799 _____ ____ 12491) 2mm >599 >599 >599 >99 t599 >599 Suvn >599 599 >599 59Q >599 >599 ----10 sec 012 017 015 >441) 440 >440 CandWa Ha:4 022 070 046 -4 4(k >44J >440 d&caus 640 k--___ -____ 2mm 050 055 05 >440 440 >440 (ATCCJOZAI) 1 ---_____ -____ miii OW 0.70 0.60 >4.40 ->4.41) >4.40 Table 5 shows that Tester 7 possesses antibacterial activity, achieving >5 login reduction against Staphylococcus aureus and MRSA within one minute.

However, Tester 7 displayed negligible activity against Candida albicans during the five minute test period.

Tester 8 (Composition A, as set out in Table 1, above) showed effective antimicrobial activity against every tested microorganism within 30 seconds.

c. Comparison with HiBiSCRU BTM Composition A of the present invention contains less % w/w chlorhexidine digluconate, and less overall % w/w active components, than HiBiSCRUBTM, but has a stronger effect against certain pathogens. Minimising the % w/w of active ingredients is desirable because, although the necessary amounts of active ingredients to mitigate and/or kill pathogens is essential, it is also desirable to keep the amounts of active chemicals to a minimum. This saves resources and reduces the chance of adverse reactions in users. Qualitative results from use of Composition A on different individuals shows reduced skin irritation, compared with the use of HiBiSCRUBTM.

The amounts of chlorhexidine digluconate, DMDM hydantoin and benzalkonium chloride present in composition A, according to the present invention, are well within the limits set by EC regulations for human use.

d. Contact time tests Panspermia, under a non-disclosure agreement, tested the contact time of Composition A (as set out in Table 1) at different times to calculate percentage kills after differing amounts of time.

Method: To 20m1 of a sample was added 1 ml of an overnight culture of the test organism (either Staphylococcus aureus ATCC 6358 or Candida albicans ATCC 10231). At each contact time (1 minute or 6 hours), 1 ml of each sample was removed, neutralised and the microorganism present was enumerated.

Log reductions of greater than 6.54 for Staphylococcus aureus, and greater than 4.92 for Candida albicans, were seen at both 1 minute and 6 hours. This data shows that composition A of the present invention swiftly kills these microorganisms and there is no subsequent regrowth 6 hours after the initial contact. This 6 hour time is particularly beneficial in a surgical and/or hospital environment.

Panspermia, under a non-disclosure agreement, also tested the contact time of Composition Al at different times to calculate percentage kills after differing amounts of time.

Log reductions of greater than 6.57 for Staphylococcus aureus, and greater than 4.39 for Candida albicans, were seen at both 1 minute and 6 hours. This data shows that composition Al of the present invention swiftly kills these microorganisms and there is no subsequent regrowth 6 hours after the initial contact. This 6 hour time is particularly beneficial in a surgical and/or hospital environment.

e. Stability Composition A, when packed in a sealed plastic container and kept at 20°C, was found to be stable for at least 2 years. There was no measurable loss of activity after 2 years.

Samples of composition A, when packed in a sealed plastic container, were placed in ovens at 6°C, 20°C, 30°C and 40°C, and left for 6 months. The disinfectant effects of each sample remained the same after leaving each sample at the allotted temperature for 6 months.

As can be seen from the above results, disinfectant compositions according to the present invention have beneficial properties.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

Claims 1. A disinfectant composition, comprising: DMDM hydantoin; chlorhexidine digluconate; and, benzalkonium chloride.
2. The disinfectant composition according to claim 1, comprising 2.00-8.00 % w/w chlorhexidine digluconate.
3. The disinfectant composition according to claim 1 or claim 2, comprising 2.00-6.00 % wiw, or 2.50-5.00 % w/w, or 3.00-4.50 % w/w chlorhexidine digluconate.
4. The disinfectant composition according to any one of claims 1-3, comprising 0.10-1.00 %w/w DMDM hydantoin.
5. The disinfectant composition according to any one of claims 1-4, comprising 0.10-0.50 % w/w, or 0.10-0.40 % w/w, or 0.10-0.30 % wlw DMDM hydantoin.
6. The disinfectant composition according to any one of claims 1-5, comprising 0.20-1.0 % w/w benzalkonium chloride.
7. The disinfectant composition according to any one of claims 1-6, comprising 0.50-1.0 % wlw, or 0.30-0.80 % wlw, or 0.40-0.70 % w/w benzalkonium chloride.
8. The disinfectant composition according to any one of claims 1-7, further comprising lauramine oxide or Ceteareth-20, wherein Ceteareth-20 is CH3- (CH2)m(OCH2CH2)2rOH and m is 15 or 17, or lauramine oxide and Ceteareth-20.
9. The disinfectant composition according to claim 8, comprising 5.00- 10.00 % w/w lauramine oxide or 0.1-10% wlw, or 0.2-0.5% w/w Ceteareth-20, or, 5.00-10.00 % w/w lauramine oxide and 0.1-10% w/w, or 0.2-0.5% w/w, Ceteareth-20, any remaining balance being water.
10. The disinfectant composition according to any one of claims 1-9, further comprising isopropyl alcohol.
11. The disinfectant composition according to claim 10, comprising 5.00- 20.00 % wlw isopropyl alcohol.
12. The disinfectant composition according to any one of claims 1-11, further comprising glycerol.
13. The disinfectant composition according to claim 12, comprising 2.00- 10.00 % w/w glycerol.
14. The disinfectant composition according to any one of claims 1-13, further comprising hydroxyethyl cellulose.
15. The disinfectant composition according to claim 14, comprising 0.20-1.0 % wiw hydroxyethyl cellulose.
16. The disinfectant composition according to any one of claims 1-15, comprising or consisting of: deionised water; hydroxyethyl cellulose; glycerol; isopropyl alcohol; DMDM hydantoin; chlorhexidine digluconate; benzalkonium chloride; and, lauramine oxide or Ceteareth-20, wherein Ceteareth-20 is CH3(CH2)m (OCH2GH2)20-OH and m is 15 or 17, or lauramine oxide and Ceteareth-20.
17. The disinfectant composition according to any one of claims 1-16, comprising or consisting of, in % w/w: 0.20-1.0 hydroxyethyl cellulose; 2.00-1 0.00 glycerol; 5.00-20.00 isopropyl alcohol; 0.10-1.00 DMDM hydantoin; 2.00-8.00 chlorhexidine digluconate; 0.20-1.00 benzalkonium chloride; and, 5.00-10.00 lauramine oxide or 0.10-10.00 Ceteareth-20, or 5.00-10.00 lauramine oxide and 0.10-1 0.00 Ceteareth-20; the balance being deionised water.
18. The disinfectant composition according to any one of claims 1-17, consisting of, in % w/w: 72.30 deionised water 0.50 hydroxyethyl cellulose; 5.00 glycerol; 10.0 isopropyl alcohol; 0.20 DMDM hydantoin; 4.00 chlorhexidine digluconate; 0.50 benzalkonium chloride; and, 7.50 lauramine oxide; or 0.30 Ceteareth-20; or 0.9 lauramine oxide and 0.30 Ceteareth-20, the remaining balance being deionised water.
19. An aqueous mixture comprising: water and a disinfectant composition according to any one of claims 1-18.
20. The aqueous mixture of claim 19, wherein the water is tap water, potable water and/or deionised water.
21. The aqueous mixture of one of claims 19 or 20, wherein the aqueous mixture has a ratio of water to disinfectant composition of from 99% water to 1% disinfectant composition to 1% water to 99% disinfectant composition.
22. The aqueous mixture of claim 21, wherein the composition has a ratio of water to disinfectant composition of 99%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, 4%, 3%, 2%, 1.5%, 1%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1% or 0.05% water to disinfectant composition.
23. A method of disinfecting human or animal skin, comprising: providing a disinfectant composition or an aqueous mixture according to any one of claims 1 to 22; and, applying the composition or mixture to human or animal skin.
24. A method of preparing a disinfectant according to any one of claims 1- 18, comprising: providing the ingredients according to any one of claims ito 18; and, mixing the ingredients in a mixer.
25. A disinfectant composition as hereinbefore described, with reference to Table 1 and/or Table 2.
26. Any novel feature or combination of features disclosed herein.