AU2021200502B1

AU2021200502B1 - A Disinfectant

Info

Publication number: AU2021200502B1
Application number: AU2021200502A
Authority: AU
Inventors: Hartley Campbell Atkinson
Original assignee: AFT Pharmaceuticals Ltd
Current assignee: AFT Pharmaceuticals Ltd
Priority date: 2021-01-27
Filing date: 2021-01-27
Publication date: 2021-05-27
Anticipated expiration: 2041-01-27

Abstract

A problem with many known disinfectants is that they do not provide protection on the skin for very long. It is an object of the invention to address this problem. The invention involves the use of Organosilane and Benzalkonium in the manufacture of a disinfectant comprising 0.2% - 0.4 % wt Organosilane and 0.08% - 0.12% wt Benzalkonium. The disinfectant is for providing, and provides, effective sanitising protection on human skin for about 24 hours or more.

Description

TITLE

A Disinfectant

FIELD OF INVENTION

This invention relates to a long acting human skin disinfectant, for example for the hands.

BACKGROUND

It is known to apply a disinfectant liquid to the human skin to kill germs, for example bacteria and virus'. A problem with many known disinfectants is that they are only effective for a short period and have to be reapplied frequently otherwise the person using them is relatively unprotected from infection if, for example, they touch a surface on which germs are located.

OBJECT OF THE INVENTION

It is an object of preferred embodiments of the invention to go at least some way towards addressing the above problem. While this applies to preferred embodiments, it should not be seen as a limitation on claims expressed more broadly. The object of the invention in its broadest form is simply to provide the public with a useful choice.

DEFINITIONS

The term "comprises" or "has", if and when used in this document in relation to a combination of features, should not be seen as excluding the option of additional features in the combination that are not mentioned.

SUMMARY OF THE INVENTION

According to one aspect the invention comprises the use of Organosilane and Benzalkonium in the manufacture of a disinfectant comprising: a) 0.2% - 0.4 % wt Organosilane; and b) 0.08% - 0.12% wt Benzalkonium; wherein the disinfectant is for providing, and provides, effective sanitising protection* on human skin for about 24 hours or more.

* The term "effective sanitising protection" means that the disinfectant is kills 99% (preferably 99.99%) of germs on human skin.

Optionally the disinfectant comprises: a) 0.25% - 0.35 % wt Organosilane; and b) 0.09%-0.11%wtBenzalkonium.

Optionally the disinfectant comprises: a) about 0.3 % wt Organosilane; and b) about 0.1%wt Benzalkonium.

Optionally the Organosilane comprises 3-(trimethoxysilyl)propyl dimethyl octadecyl ammonium salt.

Optionally the Organosilane comprises 3-(trimethoxysilyl)propyl dimethyl octadecyl ammonium chloride.

Optionally the Benzalkonium is in salt form.

Optionally the salt form comprises Benzalkonium Chloride.

Optionally the sanitising protection is against one or more of Coronavirus (eg SARS-CoV-1 and/or SARS-CoV-2), E.hirae, P.aeruginosa, S.aureus, E coli, Norovirus, Candida, MRSA, Salmonella, Listeria, Flu Virus and MHV1 virus.

Optionally the sanitising protection is against one or more of Enterococcus hirae, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli.

Optionally the disinfectant comprises Phenoxyethanol which functions in the disinfectant as a preservative.

Optionally the Phenoxyethanol is present in the disinfectant at 0.7% - 1.3% wt.

Optionally the Phenoxyethanol is present in the disinfectant at 0.8% - 1.2% wt.

Optionally the Phenoxyethanol is present in the disinfectant at 0.9% - 1.1% wt.

Optionally the Phenoxyethanol is present in the disinfectant at about 1% wt.

Optionally the disinfectant comprises Ethylhexylglycerin which functions in the disinfectant as a preservative.

Optionally the Ethylhexylglycerin is present in the disinfectant at 0.07% - 0.13% wt.

Optionally the Ethylhexylglycerin is present in the disinfectant at 0.08% - 0.12% wt.

Optionally the Ethylhexylglycerin is present in the disinfectant at 0.09% - 0.11% wt.

Optionally the Ethylhexylglycerin is present in the disinfectant at about 0.1% wt.

Preferably the disinfectant is for application as a liquid to the skin liberally to provide the effective sanitising protection. For example an amount of 0.5 ml - 1 ml, and preferably about 0.75ml, was found to be sufficient for two hands of an adult male of average size.

DETAILED DESCRIPTION

Three aqueous foaming disinfectant formulations were prepared to have the make-up shown in the tables below.

Formulation A

INCI Name Function CAS No. % by Weight

Water Solvent/Diluent 7732-18-5 to 100

Glycerin Humectant 56-81-5 2.0

Phenoxyethanol Preservative 122-99-6 0.9

Benzalkonium Chloride Antimicrobial 68424-85-1 0.1

Ethylhexylglycerin Preservative 70445-33-9 0.1

3-(trimethoxysilyl)propyl Antimicrobial and 27668-52-6 0.1 dimethyl octadecyl Surfactant ammonium chloride

Formulation B

INCI Name Function CAS No. % by Weight

Water Solvent/Diluent 7732-18-5 to 100%

Glycerin Humectant 56-81-5 2.0%

Phenoxyethanol Preservative 122-99-6 0.9%

Benzalkonium Chloride Antimicrobial 68424-85-1 0.1%

Ethylhexylglycerin Preservative 70445-33-9 0.1%

3-(trimethoxysilyl)propyl Antimicrobial and 27668-52-6 0.3% dimethyl octadecyl Surfactant ammonium chloride

Formulation C

INCI Name Function CAS No. % by Weight

Water Solvent/Diluent 7732-18-5 to 100%

Glycerin Humectant 56-81-5 2.0%

Phenoxyethanol Preservative 122-99-6 0.9%

Benzalkonium Chloride Antimicrobial 68424-85-1 0.1%

Ethylhexylglycerin Preservative 70445-33-9 0.1%

3-(trimethoxysilyl)propyl Antimicrobial and 27668-52-6 0.5% dimethyl octadecyl Surfactant ammonium chloride

In each case the Formulation was prepared as follows

Step 1 Dissolve all the the 3-(trimethoxysilyl)propyl dimethyl octadecyl ammonium chloride in a sufficient portion of water so it makes up a pre-mix totaling about 6% weight of final product.

Step 2 Dissolve or suspend all the benzalkonium chloride in a sufficient portion of the water to provide a pre-mix solution or suspension totaling 0.2% weight of final product.

Step 3 In a separate mixing vessel, add water totaling 90.8% weight of the final product.

Step 4 Separately add each of the premixes (described in steps 1 and 2) to the water of step 3, and blend.

Step 5 Add all the phenoxyethanol and ethylhexylglycerin to the contents of the mixing vessel, and blend.

Step 6 Add all the glycerin to the components in the mixing vessel, and blend.

Step 7 Mix well (for >10 minutes) until all the ingredients are homogenized.

Tests for Disinfectant Performance

Each formulation was tested to see how effective it was in killing germs. This included a quantitative suspension test to evaluate bactericidal activity according to the well-known European test standard EN 13727. The formulations were also tested for virucidal activity by the surface carrier technique of ASTM 1053. Additionally, each formulation was subjected to tests to determine its effectiveness at 24 hours after being applied to human skin (hands). The tests were carried out as follows.

Step 1 (Culture Growth)

Two test organisms were selected and evaluated in the trial:

• Staphylococcus aureus NZRM 147 (ATCC 6538)

• Escherichia coli NZRM 2577 (ATCC 8739)

Culture suspensions were prepared for the organisms using overnight culture plates. The culture growth was harvested from each plate and inoculated to 10mL Tryptone Soy Broth (TSB) to achieve an approximate organism count of 109 cfumL.

Step 2 (Chemical Inactivation)

A combination of neutraliser and dilution was used to achieve an effective neutralising system. In particular, Tryptone soy broth with 0.5% Lecithin and 4% Tween 20 (TLT) was used as a neutralising solution. Hand Sanitizer Formulation at 'ready to use' (RTU) concentration was diluted at a ratio of 1:1000 (10pL in 10mL TLT, the same volume and dilution ratio as treated Vitro-skin 2cm 2 ). 10mL of the diluted formulation was then individually spiked to give a cell level sufficient to render a test organism concentration within the countable range. In the presence of TLT the antimicrobial property of the test products was neutralized in order to recover any viable micro-organisms. The recovery of the test organism in the presence of test product was not less than 70% of that recovered from the inoculum control.

Step 3

In a Biological Safety Cabinet, two 2cm 2 synthetic skin swatches were each pre-treated with pL of the test product at the RTU concentration. Each pair of skin swatches was rubbed together to distribute the test product, and dried under HEPA laminar air. The formulation remained on the swatches for sufficient time to demonstrate the residual efficacy of each test product. Duplicate tests were performed at each time point for all test products (including the reference product) and the water control.

Step 4 - (Water control - Baseline Control)

The synthetic skin swatches were also pre-treated with sterile water in the same manner as the test product, and tested at the same time points along-side the test product.

Step 5

At various time points, each treated skin swatch was inoculated with 10pL of culture suspension at an approximate concentration of 109 cfu/mL, and evenly distributed with a sterile 1pL loop. An exposure time of 5 minutes was allowed prior to transferring the skin swatch into neutralising broth (TLT).

Step 6

The inoculated neutralising broth was mixed and serially diluted to aid in determining the number of viable bacteria remaining.

Step 7

Step 5 and 6 were followed to test the water control in the same manner as the test product.

Step 8

The neutralised solutions for the test products and the water control were serially diluted using 0.1% Peptone, and each dilution was plated in duplicate using Standard Plate Count Agar.

Step 9

The plates were incubated at 350 C ±1C for 48 hours.

The tests gave the results detailed below.

Results Quantitative Suspension test for evaluating bactericidal activity Methodology: EN13727

Test Conditions (per EN13727)

Test Concentration Neat

Contact Time 1 Minute

Formulation A: T6 1:10 (all organisms)

Neutralizer/Dilution Formulation B: T6 1:10 (all organisms) Formulation C: T6 1:10 - E.coli, P.aeruginosa and E.hirae; T5 1:100 S.aureus

Test Conditions Clean (0.03% BSA)

Test Temperature Room Temperature

Surviving Organisms after Exposure to each Formulation - 1 Minute Contact Time

(per EN13727)

Formulation Organism Inoculum Control Surviving Test Organisms Count

CFU/mL CFU/mL Log reduction

(Log1o) (Log1o)

Formulation A S.aureus 6.20 x 10' <10 >6.79 ATCC 6538 (7.79) (<1.00) E.coli 2.00 x 10' <10 >6.30 NCTC 10538 (7.30) (<1.00) P.aeruginosa 4.10 x 10' <10 >6.61 ATCC 15442 (7.61) (<1.00) E.hirae 3.90 x 10' <10 >6.59 ATCC 10541 (7.59) (<1.00) Formulation B S.aureus 2.35x 10' <10 >6.37 ATCC 6538 (7.37) <(1.00) E.coli 3.10 x 10 <10 >6.49 NCTC 10538 (7.49) <(1.00) P.aeruginosa 4.20 x 10' <10 >6.62 ATCC 15442 (7.62) <(1.00) E.hirae 1.55 x 10' <10 >6.19 ATCC 10541 (7.19) <(1.00) Formulation C S.aureus 4.85 x 107 <100 >5.69 ATCC 6538 (7.69) (<2.00) E.coli 3.65 x 107 <10 >6.56 NCTC 10538 (7.56) (<1.00) P.aeruginosa 2.60 x 107 <10 >6.41 ATCC 15442 (7.41) (<1.00) E.hirae 2.25 x 107 <10 >6.35 ATCC 10541 (7.35) (<1.00)

CFU =Colony Forming Unit

Neutralisation Validation Results (per EN13727)

FormuationValidation Formulation Experimental Neutralizer Method Suspension, Organism Condition, Control, Validation, Pass/Fail CFU/ml CFU/ml (A) CFU/ml (B) CFU/ml (C) (Nv) Formulation A S.aureus 41 49 58 39 Pass ATCC 6538 E.coli 42 32 30 35 Pass NCTC 10538

P.aeruginosa 103 73 105 105 Pass ATCC 15442 E.hirae 23 22 23 31 Pass ATCC 10541 Formulation B S.aureus 24 16 44 13 Pass ATCC 6538 E.coli 31 16 82 98 Pass NCTC 10538 P.aeruginosa 42 27 74 56 Pass ATCC 15442 E.hirae 16 16 90 83 Pass ATCC 10541 Formulation C S.aureus 66 73 62 51 Pass ATCC 6538 E.coli 42 32 30 43 Pass NCTC 10538 P.aeruginosa 103 73 105 94 Pass ATCC 15442 E.hirae 23 22 23 17 Pass ATCC 10541

Nv is the number of cells per ml in the validation suspension.

A, B and C are the numbers of surviving cells in the experimental conditions control (A), neutralizer control (B) and method validation (C), at the end of the contact time

A, B &C should preferably be 250% the value of Nv.

By way of summary, (TMD 110, EN13727), Formulations A and B showed greater than 6 log reduction against S.aureus, E.coli, P.aeruginosa and E.hirae at 1 minute contact time. Formulation C showed greater than 6 log reduction against E.coli, P.aeruginosa and E.hirae and greater than 5 log reduction against S.aureus at 1 Minute contact time. All three formulas resulted in a >99.99% reduction in microorganisms after 1 minute contact.

Results of Virucidal Test by Carrier Method Methodology: ASTM E1053

Test Conditions (ASTM E1053)

Virus Strain Murine hepatitis virus (MHV1) ATCCNR-261 Cell Substrate A9 cells ATCC/CCL- 1.4 Test Concentration Neat Contact Time 1 minute

Test Temperature Room temperature Test Condition Clean Neutraliser 3 cc Sephadex Gel in PBS (Phosphate Buffer Saline)

Formulation A: MHVI test/control results (1 minute contact) Number of Virus Virus Dilution Inoculated Cytotoxicity Neutralisation Test Sample Wells Control 10-1 4 4+/4 C C C 10- 4 4/4 0+/4 40/4 3+/4 10-1 4 4+/4 0+/4 40/4 3*/4 10-4 4 4*/4 N/A N/A 1*/4 10-* 4 4T/4 N/A N/A 0/4 10-1 4 3+/4 N/A N/A 0*/4 10-' 4 2+/4 N/A N/A N/A 10-1 4 0*/4 N/A N/A N/A Log1 o - 6.77 1.5 1.5 3.33 Log 1 oReduction of Virus after Treatment 3.44

Formulation B: MHVI Test/Control Results (1 minute contact)

Number of Virus Virus Dilution Inoculated Cytotoxicity Neutralisation Test Sample Wells Control 10-1 4 4+/4 C C C 10- 4 4/4 0*/4 40/4 4+/4 10-1 4 4*/4 0*/4 4*/4 3+/4 10-4 4 4"/4 N/A N/A 0T/4 10-0 4 4*/4 N/A N/A 0*/4 10-1 4 3*/4 N/A N/A 00/4 10-' 4 2*/4 N/A N/A N/A 10-1 4 0*/4 N/A N/A N/A Log1 o - 6.77 1.5 1.5 3.33 Log 1 oReduction of Virus after Treatment 3.44

Formulation C: MHVI Test/Control Results (1 minute contact)

Number of Virus Virus Dilution Inoculated Cytotoxicity Neutralisation Test Sample Wells Control 10- | 4*/4 C C C 10-2 4 4*/4 0*/4 4*/4 40/4 10-3 4 4+/4 | 0/4 4"/4 4+/4 1- | 4 4+/4 N/A N/A 1'/4 i0- 4 4*/4 N/A N/A 0*/4 10-11 4 3*/4 N/A N/A 0*/4 10-' 4 2"/4 N/A N/A N/A 10-11 4 0*/4 N/A N/A N/A Log1 o - 6.77 1.5 1.5 3.67 Log 1 oReduction of Virus after Treatment 3.10

Note: Presence of virus is presented in a X+ of 4 format i.e. X*/4:

X' - number of wells (X) with presence of virus(+) 4 - total number of inoculated wells. Example: In the event of a 3+/4 result, this indicates that 3 of the total 4 wells show a positive virus response. Absence of virus in each response is recorded as "0" Cytotoxic response is recorded as "C" Calculated virus titre = 106.77TCID50/0.1ml (6.77 log10) Cell control - 4 wells with healthy cell monolayer * The Reed & Muench LD50 Method was used for determining the virus titre endpoint.

To summarise the results (TMCV 006, ASTM El053), regarding cytotoxicity and neutralisation, the Formulations A and B showed virucidal efficacy against MHV1 by achieving 3.44 log reduction in virus concentration after 1 minute's exposure period at room temperature. The formulations C also showed virucidal efficacy against MHV1 by achieving 3.10 log reduction in virus concentration after 1 minute's exposure period at room temperature. This indicates that each formulation results in >99.9% reduction in viral count after 1 minute contact time, with Formulas A and B exhibiting slightly better results than Formula C.

Results The 24-hour Residual Anti-Microbiological Study of the Hand Disinfectant Product Methodology: The above Custom In-vitro Study Protocol

Test Conditions

Test Organism • Staphylococcus aureus NZRM 147 (ATCC 6538) • Escherichia coli NZRM 2577 (ATCC 8739)

Test Concentration Neat or Ready To Use

Conditioning Time Points 5 minutes, 30 minutes, 1hr, 2hr, 4hr, 6hr and 24hr

Contact Time 5 Minutes at each conditioning time point

Tryptone soy broth with 0.5% Lecithin and 4% Tween 20 (TLT)/I:1000 Neutralizer/Dilution Dilution (10p in 10mL TLT, same volume and dilution ratio as the treated 2cm 2 synthetic skin substrate)

Test Conditions In Biological Safety Cabinet, two 2cm2 synthetic skin swatches were each pre-treated with 1OpL of the test product at the RTU concentration

Test Temperature Ambient Temperature (defined as 20± 5C)

• ASTM E3058 - 16: Standard Test Method for Determining the Residual Kill Activity of Hand Antiseptic Formulations. • PAS2424:2014 - Quantitative surface test for the evaluation of residual antimicrobial (bactericidal and/or yeasticidal) efficacy of References liquid chemical disinfectants on hard non-porous surfaces - Test method. • TGA instructions for disinfectant testing Version 2.1, March 2020. • British Pharmacopoeia 2020 Appendix XVI C. Efficacy of AntimicrobialPreservation.

Neutraliser Validation 10pL in 10mL TLT (1 in 1,000 dilution) Formulation/Sample Organism Average Recovery Result E.coli 70.6 103.5 Pass Formulation A S.aureus 67.8 105.3 Pass E.coli 69.4 101.8 Pass Formulation B S.aureus 61.6 95.7 Pass E.coli 68.6 100.6 Pass Formulation C S.aureus 67.4 104.7 Pass Reference E.coli 71.6 105.0 Pass Formulation S.aureus 66.8 103.7 Pass E.coli 68.2 N/A N/A Inoculum Control _________ S.aureus 64.4 N/A N/A

Residual Efficacy against Staphylococcus Aureus NZRM 147 (ATCC 6538) Conditioning Sample Result Average Log10 LogReduction Time Point (CFU/Swatch) result Formula A 21500000 19600000 7.29 0.12 Formula A duplicate 17700000 Formula B 15 15 1.18 6.24 Formula B duplicate <10 Formula C 16500000 minutes 16525000 7.22 0.20 Formula C duplicate 16550000 Formula Ref 28000000 27250000 7.44 -0.02 Formula Ref duplicate 26500000 Water control - Baseline 26000000 26000000 7.41 N/A Baseline duplicate 26000000 Formula A 24000000 23000000 7.36 -0.11 Formula A duplicate 22000000 Formula B 180 590 2.77 4.48 minutes Formula B duplicate 1000 Formula C 20000000 23250000 7.37 -0.12 Formula C duplicate 26500000 Formula Ref 28000000 26750000 7.43 -0.18

Formula Ref duplicate 25500000 Water control - Baseline 18500000 17750000 7.25 N/A Baseline duplicate 17000000 Formula A 21500000 21250000 7.33 0.17 Formula A duplicate 21000000 Formula B <10 380 2.58 4.92 Formula B duplicate 380 Formula C 32500000 1 hour 28250000 7.45 0.05 Formula C duplicate 24000000 Formula Ref 28000000 31250000 7.49 0.01 Formula Ref duplicate 34500000 Water control - Baseline 29500000 31750000 7.50 N/A Baseline duplicate 34000000 Formula A 31000000 28250000 7.45 -0.04 Formula A duplicate 25500000 Formula B 4200 4750 3.68 3.73 Formula B duplicate 5300 Formula C 29000000 2 hour 28500000 7.45 -0.05 Formula C duplicate 28000000 Formula Ref 25500000 27500000 7.44 -0.03 Formula Ref duplicate 29500000 Water control - Baseline 20500000 25500000 7.41 N/A Baseline duplicate 30500000 Formula A 27000000 29500000 7.47 -0.03 Formula A duplicate 32000000 Formula B 1700 4000 3.60 3.83 Formula B duplicate 6300 Formula C 35500000 4 hour 34000000 7.53 -0.10 Formula C duplicate 32500000 Formula Ref 26000000 28250000 7.45 -0.02 Formula Ref duplicate 30500000 Water control - Baseline 30000000 27250000 7.44 N/A Baseline duplicate 24500000 Formula A 22000000 31250000 7.49 0.03 Formula A duplicate 40500000 Formula B <10 <10 <1 >6.52 Formula B duplicate <10 Formula C 27500000 6 hour 28750000 7.46 0.06 Formula C duplicate 30000000 Formula Ref 24500000 30500000 7.48 0.04 Formula Ref duplicate 36500000 Water control - Baseline 39000000 ___________duplicate _1_27500000_33250000 7.52 N/A Baseline duplicate 27500000

Formula A 29500000 30500000 7.48 0.02 Formula A duplicate 31500000 Formula B 700 375 2.57 4.93 Formula B duplicate 50 Formula C 34500000 24 hour 35750000 7.55 -0.04 Formula C duplicate 37000000 Formula Ref 35000000 34000000 7.53 -0.02 Formula Ref duplicate 33000000 Water control - Baseline 29000000 32250000 7.51 N/A Baseline duplicate 35500000

Residual Efficacy against Escherichia Coli NZRM 2577 (ATCC 8739)

Conditioning Sample Result Average Log10 LogReduction Time Point (CFU/Swatch) result Formula A 36500000 39750000 7.60 -0.03 Formula A duplicate 43000000 Formula B <10 <10 <1 >6.57 Formula B duplicate <10 Formula C 35500000 minutes 33500000 7.53 0.04 Formula C duplicate 31500000 Formula Ref 42000000 38000000 7.58 -0.01 Formula Ref duplicate 34000000 Water control - Baseline 37000000 36750000 7.57 N/A Baseline duplicate 36500000 Formula A 36500000 31750000 7.50 0.03 Formula A duplicate 27000000 Formula B <10 10 1.00 6.53 Formula B duplicate 10 Formula C 34500000 minutes 33750000 7.53 0.00 Formula C duplicate 33000000 Formula Ref 40000000 34000000 7.53 0.00 Formula Ref duplicate 28000000 Water control - Baseline 32500000 33750000 7.53 N/A Baseline duplicate 35000000 Formula A 34500000 27500000 7.44 0.04 Formula A duplicate 20500000 Formula B <10 <10 <1 >6.57 1 hour Formula B duplicate <10 Formula C 30500000 34750000 7.54 -0.06 Formula C duplicate 39000000 Formula Ref 24000000 18500000 7.27 0.22

Formula Ref duplicate 13000000 Water control - Baseline 34500000 30500000 7.48 N/A Baseline duplicate 26500000 Formula A 31000000 29000000 7.46 0.05 Formula A duplicate 27000000 Formula B 75 142.5 2.15 5.35 Formula B duplicate 210 Formula C 31500000 2 hour 32000000 7.51 0.00 Formula C duplicate 32500000 Formula Ref 39500000 33250000 7.52 -0.01 Formula Ref duplicate 27000000 Water control - Baseline 36500000 32250000 7.51 N/A Baseline duplicate 28000000 Formula A 45000000 36750000 7.57 0.07 Formula A duplicate 28500000 Formula B <10 234500 5.37 2.27 Formula B duplicate 234500 Formula C 30000000 4 hour 40000000 7.60 0.04 Formula C duplicate 50000000 Formula Ref 32500000 33750000 7.53 0.11 Formula Ref duplicate 35000000 Water control - Baseline 40500000 43500000 7.64 N/A Baseline duplicate 46500000 Formula A 34000000 35500000 7.55 0.04 Formula A duplicate 37000000 Formula B <10 <10 <1 >6.57 Formula B duplicate <10 Formula C 38500000 6 hour 38750000 7.59 0.00 Formula C duplicate 39000000 Formula Ref 23500000 24000000 7.38 0.21 Formula Ref duplicate 24500000 Water control - Baseline 41000000 38750000 7.59 N/A Baseline duplicate 36500000 Formula A 41000000 42750000 7.63 -0.10 Formula A duplicate 44500000 Formula B 102500 119250 5.08 2.46 Formula B duplicate 136000 Formula C 45500000 24 hour 44750000 7.65 -0.12 Formula C duplicate 44000000 Formula Ref 44000000 40500000 7.61 -0.07 Formula Ref duplicate 37000000 Water control - Baseline 36000000 ___________duplicate _1_35500000_34250000 7.53 N/A Baseline duplicate 35500000

Summary of Residual Efficacy Results (Formulation A) 24 hours Result Average Log 10 Log (cfu/swatch) result reduction (cfu/swatch) Staphylococcus Formula Repeat1 29500000 30500000 7.48 0.02 aureus NZRM Repeat2 31500000 147(ATCC Water Repeat1 29000000 32250000 7.51 6538) Control Repeat 2 35500000

24 hours Result Average Log 10 Log (cfu/swatch) result reduction (cfu/swatch) Escherichia Formula Repeat1 41000000 42750000 7.63 coli NZRM Repeat2 44500000 -0.10 2577 (ATCC Water Repeat1 36000000 34250000 7.53 8739) Control Repeat 2 32500000

Summary of Residual Efficacy Results (Formulation B) 24 hours Result Average Log 10 Log (cfu/swatch) result reduction (cfu/swatch) Staphylococcus Formula Repeat 1 700 375 2.57 4.93 aureus NZRM Repeat 2 50 147(ATCC Water Repeat 1 29000000 32250000 7.51 6538) Control Repeat 2 35500000

24 hours Result Average Log 10 Log (cfu/swatch) result reduction (cfu/swatch) Escherichia Formula Repeat1 102500 119250 5.08 2.46 coli NZRM Repeat2 136000 2577 (ATCC Water Repeat1 36000000 34250000 7.53 8739) Control Repeat 2 32500000

Summary of Residual Efficacy Results (Formulation C) 24 hours Result Average Log 10 Log (cfu/swatch) result reduction (cfu/swatch) Staphylococcus Formula Repeat1 34500000 35750000 7.55 -0.04 aureus NZRM Repeat2 37000000 147 (ATCC Water Repeat1 29000000 32250000 7.51 6538) Control Repeat 2 35500000 1_1_1

24 hours Result Average Log 10 Log (cfu/swatch) result reduction (cfu/swatch) Escherichia Formula Repeat1 45500000 44750000 7.65 -0.12 coli NZRM Repeat2 44000000 2577 (ATCC Water Repeat1 36000000 34250000 7.53 8739) Control Repeat 2 32500000

By way of summary, Formulation B (at RTU volume) demonstrated residual efficacy with log reduction of between 2.27 and >6.57 throughout the 24 hour's period (at 5 mins, 30 mins, 1hr, 2hr, 4hr, 6hr and 24hr) against Staphylococcus aureus NZRM 147 and Escherichia coli NZRM 2577. In comparison, Formulations A and C did not exhibit effective residual efficacy against either bacterial strain (maximum log reduction for either organism did not exceed 0.2 at any time point).

Formulation B demonstrated residual biocidal activity against both Staphylococcus aureus and Escherichia coli after 24 hours (4.93 and 2.46 log reduction, respectively). This translates to a >99.99% and >99% reduction in the count of Staphylococcus aureus and Escherichia coli, even if exposure to either organism occurs 24 hours after application of Formula B. Conversely, Formulation A exhibited a low log reduction against Staphylococcus aureus (0.02) after 24 hours, in addition to exhibiting a negative log reduction against Escherichia coli (-0.10), indicating growth of organism. Similarly, Formula C resulted in negative log reductions against both Staphylococcus aureus (-0.04) and Escherichia coli( 0.12) after 24 hours, indicating organism growth.

This is significant as it indicates that Formula B exhibits residual efficacy against microorganisms on synthetic skin, even after significant time has passed following application of the formula. This is believed to be related to a synergistic interaction provided by the Benzylkonium and Organosilane ingredients in Formulation B.

Other Forms of Benzakonium

While preferred formulations according to the invention utilise Benzakonium chloride, in other embodiments this may be substituted by other forms of Benzakonium, for example Benzalkonium free base or one or more alternative Benzalkonium salts (e.g. Benzalkonium Bromide, Benzalkonium Saccharinate and Acesulfame Benzalkonium)-In each case the weight amounts would be adjusted to provide more or less equivalent function.

Other Organosilanes

Similarly, while preferred forms of the invention utilise 3-(trimethoxysilyl)propyl dimethyl octadecyl ammonium chloride, in other embodiments this may be substituted by other organosilanes, for example one or more of 3-(trihydroxysilyl) propyl dimethyl octadecyl ammonium chloride (CAS 199111-50-7) and n,n-dimethyl-n-[3-(trimethoxysilyl)propyl]-1 tetradecanaminium chloride (CAS 41591-87-1)- In each case the weight amounts would be adjusted to provide more or less equivalent function.

Preservatives, Humectants and Surfactants Further, formulations according to the invention may use alternative preservative, humectant and/or surfactant materials to those of Formulations A, B and C, adjusting the weight amounts as appropriate to provide more less equivalent function. Examples of these are as follows

Preservative Humectant Surfactants

• Chlorhexidine gluconate • Propylene glycol • Alternative organosilanes, e.g. 3 1, 2-Hexanediol • Glycerol (trihydroxysilyl) propyl dimethyl • Benzoic acid • Aloe vera octadecyl ammonium chloride (CAS • Benzethonium chloride 199111-50-7) and/or n,n-dimethyl-n • Ethylparaben [3-(trimethoxysilyl)propyl]-1 tetradecanaminium chloride (CAS 41591-87-1)

In terms of disclosure, this document hereby discloses each item, feature or step mentioned herein in combination with one or more of any of the other item, feature or step disclosed herein, in each case regardless of whether such combination is claimed.

While some preferred embodiments of the invention have been described by way of example it should be appreciated that modifications and improvements can occur without departing from the scope of the following claims.

Claims

1. The use of Organosilane and Benzalkonium in the manufacture of a disinfectant comprising: a) 0.25% - 0.35 % wt 3-(trimethoxysilyl)propyl dimethyl octadecyl ammonium salt; and b) 0.09% - 0.11% wt Benzalkonium; wherein the disinfectant is for providing, and provides, effective sanitising protection on human skin for about 24 hours or more.

2. The use according to claim 1, wherein the disinfectant comprises: a) 0.25% - 0.35 % wt 3-(trimethoxysilyl)propyl dimethyl octadecyl ammonium chloride ; and b) 0.09%- 0.11%wtBenzalkonium.

3. The use according to claim 1, wherein the disinfectant comprises:

a) about 0.3 % wt 3-(trimethoxysilyl)propyl dimethyl octadecyl ammonium chloride; and b) about 0.1%wt Benzalkonium.

4. The use according to any one of the preceding claims, wherein the Benzalkonium is in salt form.

5. The use according to claim 4, wherein the salt form comprises Benzalkonium Chloride.

6. The use according to any one of the preceding claims, wherein the sanitising protection is against Coronavirus.

7. The use according to any one of the preceding claims, wherein the sanitising protection is against SARS-CoV-1 and/or SARS-CoV-2 (eg CoVid-19 causing Coronavirus).

8. The use according to any one of the preceding claims, comprising Phenoxyethanol which functions in the disinfectant as a preservative.

9. The use according to claim 8, wherein the Phenoxyethanol is present in the disinfectant at 0.7% - 1.3% wt.

10. The use according to claim 8, wherein the Phenoxyethanol is present in the disinfectant at 0.8% - 1.2% wt.

11. The use according to claim 8, wherein the Phenoxyethanol is present in the disinfectant at 0.9% - 1.1% wt.

12. The use according to claim 8, wherein the Phenoxyethanol is present in the disinfectant at about 1% wt.

13. The use according to any one of the preceding claims, comprising Ethylhexylglycerin which functions in the disinfectant as a preservative.

14. The use according to claim 13, wherein the Ethylhexylglycerin is present in the disinfectant at 0.07% - 0.13% wt.

15. The use according to claim 13, wherein the Ethylhexylglycerin is present in the disinfectant at 0.08% - 0.12% wt.

16. The use according to claim 13, wherein the Ethylhexylglycerin is present in the disinfectant at 0.09% - 0.11% wt.

17. The use according to claim 13, wherein the Ethylhexylglycerin is present in the disinfectant at about 0.1% wt.

18. The use according to any one of the preceding claims, wherein the sanitising protection is against one or more of E.hirae, P.aeruginosa, S.aureus, E coli, Norovirus, Candida, MRSA, Salmonella, Listeria, Flu Virus and MHV1 virus.

19. The use according to any one of the preceding claims, wherein the sanitising protection is against one or more of Enterococcus hirae, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli.

20. The use according to any one of the preceding claims wherein the disinfectant is for providing, and provides, effective sanitising protection on human hands for about 24 or more hours.

21. A disinfectant prepared according to the use of any one of the preceding claims.

22. A disinfectant substantially as below-

Component Approximate %by Weight

Glycerin 2.0%

Phenoxyethanol 0.9%

Benzalkonium Chloride 0.1%

Ethylhexylglycerin 0.1%

3-(trimethoxysilyl)propyl dimethyl 0.3% octadecyl ammonium chloride

Water to 100%