WO2021209746A1

WO2021209746A1 - Aerosol disinfectant dispenser and method for disinfecting a fomite

Info

Publication number: WO2021209746A1
Application number: PCT/GB2021/050889
Authority: WO
Inventors: Michael Pritchard
Original assignee: Pritchard Spray Ip Limited
Priority date: 2020-04-15
Filing date: 2021-04-13
Publication date: 2021-10-21
Also published as: GB2597045A; GB202006730D0; GB202005499D0

Abstract

An aerosol fluid dispenser comprises a container for a liquid, a dispenser head fitted to the container and having a fluid outlet, a dip tube formed from a length of hollow membrane, the hollow membrane having an open end which is coupled to the dispenser head so as to be able to communicate with the fluid outlet, and having a closed end that sits within the container, a liquid disinfectant, and a propellant. The hollow membrane is adapted to pass liquid in preference to gas so that when the dispenser head is actuated liquid disinfectant travels from the liquid container through the wall of the dip tube to the fluid outlet under a pressure differential established across the wall of the membrane. A preferred disinfectant composition comprises a biocidal agent, a chelating agent and a surfactant, such a composition being suitable for disinfecting a fomite contaminated with a virus.

Description

AEROSOL DISINFECTANT DISPENSER AND METHOD FOR DISINFECTING A

FOMITE

Background to the Invention

Coronavirus SARS-CoV-2 (COVID-19) is the biggest threat to world health and global economy since the 1918 influenza pandemic or 'Spanish Flu'.

The course of an epidemic is defined by a series of key factors, some of which are poorly understood at present for COVID-19. The basic reproduction number (Ro), which defines the mean number of secondary cases generated by one primary case when the population is largely susceptible to infection, determines the overall number of people who are likely to be infected, or more precisely the area under the epidemic curve. For an epidemic to take hold, the value of Ro must be greater than unity in value. A simple calculation gives the fraction likely to be infected without mitigation. This fraction is roughly 1-1/Ro. With Ro values for COVID-19 in China around 2-5 in the early stages of the epidemic, calculations show that approximately 60% of the population would become infected. This is a very worst-case scenario for a number of reasons. We are uncertain about transmission in children, some communities are remote and unlikely to be exposed, voluntary social distancing by individuals and communities will have an impact, and mitigation efforts, such as the measures put in place in China, greatly reduce transmission. As an epidemic progresses, the effective reproduction number (R) declines until it falls below unity in value when the epidemic peaks and then decays, either due to the exhaustion of people susceptible to infection or the impact of control measures.

Governments will have at some point have to lift the lockdowns and allow people to start traveling while keeping social distancing measures in please. However, this will inevitably lead to an increase in transmission rates. There is a pressing need for a solution that mitigates the risk of secondary transmission until such times as an effective vaccine can be produced. There are already some rudimentary measures that exist such as lorries jet washing sanitising solutions onto roads and large electrically powered fogging devices to sanitise buildings. At a personal level, there are solutions such as alcohol hand sanitisers and sanitising wipes.

Hand operated trigger sprays that are used to sanitise fomites are not particularly effective as they leave large areas of surfaces uncovered. Human factors mean that the strength required to operate them on a continuous basis is unachievable in practice. Summary of the Invention

According to a first aspect of the present invention, an aerosol fluid dispenser comprises: a container for a liquid; a dispenser head fitted to the container and having a fluid outlet; a dip tube formed from a length of hollow membrane, the hollow membrane having an open end which is coupled to the dispenser head so as to be able to communicate with the fluid outlet, and having a closed end that sits within the container; a liquid disinfectant; and, a propellant, wherein the hollow membrane is adapted to pass liquid in preference to gas so that when the dispenser head is actuated liquid disinfectant travels from the liquid container through the wall of the dip tube to the fluid outlet under a pressure differential established across the wall of the membrane.

In a second aspect, the present invention is a disinfectant composition comprising a biocidal agent, a chelating agent and a surfactant.

It has surprisingly been found that the composition described above is particularly effective at removal of viral matter from fomites, particularly coronaviruses. Without wishing to be bound by theory, the combination of these three active agents may be particularly useful at breaking down enveloped viruses.

Embodiments of the disinfectant compositions described herein, including embodiments of the components of the compositions, apply to both the first and second aspects of the invention defined above.

The present invention includes a liquid disinfectant. The present invention is also a liquid disinfectant as described above. A liquid disinfectant is a composition that can kill bacteria and/or viruses. In general, disinfectants have three mechanisms of action or ways that they affect or kill an organism: cross-linking, coagulating, clumping; structure and function disruption; and oxidizing. Examples of disinfectants are alcohols, chlorine, peroxygen compounds, phenols and quarternary ammonium compounds. Some surfactants may also function as a disinfectant (by disrupting the structure of a virus, for example).

Dispensers and compositions of the invention may include a biocidal agent. Preferably, the biocidal agent is N-(3-aminopropyl)-N-dodecylpropane-l, 3-diamine as the active liquid disinfectant. Other suitable disinfectants include benzalkonium chloride, H202, sodium hypochlorite, pine oil, peracetic acid (PAA), and triclosan (TCS). In a preferred embodiment, the liquid disinfectant comprises a surfactant. Surfactants may be advantageous in disinfectant compositions because they achieve uniform wetting of surfaces and can lift virus particles from surfaces. The surfactants themselves may also have active disinfectant properties.

Certain viruses, such as coronaviruses are "enveloped viruses". This means they have a protective outer lipid bilayer (with a hydrophilic head and a hydrophobic tail). The hydrophilic heads are effective at sticking to surfaces such as a person's hand. The molecules, when expelled via a cough or a sneeze, remain in this tight bilayer to protect the viral matter.

A surfactant for use in the present invention may also act as an active disinfectant. In addition to acting in the usual surfactant manner, i.e. by removal the viral particles from a surface by forming a bilayer around the virus, the surfactant may disrupt the protective bilayer and kill the virus.

In a preferred embodiment, the surfactant is a non-ionic surfactant. Preferably, the surfactant is an alcohol ethoxylate, more preferably a C9-C20 alcohol ethoxylate, more preferably a C9-C11 alcohol ethoxylate. An example of such a surfactant is ALKOSYNT^® 9100 series, CAS: 68439-46-3, from Oxiteno.

Without wishing to be bound by theory, shorter C9-C11 alkyl chains may allow alcohol ethoxylates to typically wet a soiled surface at an increased rate as compared to longer alkyl chain (+C14) surfactants of identical molar ethoxylation. This increased rate of wetting is a direct consequence of the size of the surfactant's hydrophobic chain, as smaller alkyl chains tend to diffuse faster in solution than their larger counterparts. The diffusion of these types of alcohol ethoxylates quickly brings the surfactants to the interface of water and a given substrate (air, cotton, dirt, etc.). This rapid diffusion results in an alcohol ethoxylate that is excellent at wetting the surface of the virus.

Preferably, the alcohol ethoxylate for use in the invention has a high hydrophilic/lipophilic balance (HLB). Higher HLB C9-C11 alcohol ethoxylates (e.g. ALKOSYNT® 9160 HLB 12.5 and ALKOSYNT®9180 HLB 13.9) exhibit excellent wetting properties making them ideal for use as cleaning agents.

The wetting characteristics of the surfactant also means that any other active disinfectant agents present in the disinfectant for use in the invention, e.g. the N-(3- aminopropyl)-N-dodecylpropane-l, 3-diamine, is carried to the virus surface where it can penetrate and kill the virus.

In some embodiments, the disinfectant composition for use in the invention comprises a chelating agent. Chelating agents are known to boost the efficacy of biocidal formulations by extracting metal ions from the cell membranes of microorganisims and so making them more vulnerable for biocidal attack. An example is EDTA. Another example is glutamic acid, N,N-diacetic acid, tetrasodium salt.

In a preferred embodiment, compositions and disinfectants for use in the present invention comprise:

Water

A surfactant, which is preferably one or more alcohol ethoxylates A chelating agent A biocidal agent

More preferably, compositions and disinfectants for use in the present invention comprise:

Water

An alcohol ethoxylate up to 1% by weight A chelating agent up to 1% by weight A biocidal agent (one or more) up to 5% by weight

Preferably, the propellant is a gas propellant, more preferably air or carbon dioxide. Using compressed propellant gasses, such as air or carbon dioxide, that go into solution within the chosen liquid disinfectant allows for increased particle breakup over and above that achieved through the mechanical breakup caused by the actuator insert.

It is critical when applying a sanitising solution that a dense spray pattern is applied to the whole of infected fomites, irrespective of the orientation of that fomite. Providing a continuous high-density spray delivered in any orientation allows the user to cover virtually all of a surface with high speed and with minimal effort, meaning that can be completely wetted, sanitised and decontaminated effectively.

The present invention provides a lightweight, handheld decontamination and secondary transmission suppression system. The system is easy to store, easy to operate, with a low training burden, and typically provides over 4 minutes (dependent upon bottle size) of continuous high-density spray. Working in 360° of orientation (including upside down), it delivers complete wettability to all surfaces and breaks the contamination chain.

The present invention is designed for use by essential personnel to rapidly decontaminate fomites such as vehicles, rooms, fixtures/fittings, clothing and personnel, thereby to mitigate the secondary transmission risk.

Our 'Personal Protection Decontamination System' (PPDE) will help slow and starve the virus of hosts and places to hide until we have a vaccine.

Brief Description of the Drawings

An example of the present invention will now be described in detail with reference to the accompanying drawings, in which:

Figure 1 shows an aerosol spray canister filled with a liquid disinfectant and a propellant; and,

Figure 2 is a cross section through a dip tube of the aerosol spray canister of Figure 1.

Detailed Description

Figure 1 shows an example of a fluid dispenser 20 in accordance with the present invention. In this example the container is a conventional aerosol spray canister 21 having a conventional aerosol push-button spray head 22, but with a dip tube 23 formed from a hollow fibre membrane having an open end which is coupled to a fluid port 24 in the aerosol dispenser head so as to be able to communicate with the outlet 25, and having a closed end that sits within the body of the spray canister.

The spray canister 21 is self-pressurised, containing a suitable propellant in addition to a fluid to be dispensed. The propellant creates a pressure differential so that, as indicated in Figure 2, when the push-button is manually actuated any liquid within the canister in contact with any portion of the surface of the dip tube 23 travels through the wall of the dip tube and thereafter along its internal bore to the outlet 25. This spray canister operates in substantially any orientation and is effective to dispense substantially the entire contents of the canister.

Hollow fibre membranes suitable for use as dip tubes 23 with the present invention are available commercially, for example X-flow (TM) capillary membranes from Norit (www.norit.com) may be used. The hollow fibre membrane for the dip tube preferably comprises materials selected from the group consisting of polytetrafluoroethylene, polyamide, polyimide, polysulfone, polyethersulfone, polyvinylidene fluoride, polypropylene, polyvinyl chloride, polyvinyl pyrrolidone, polycarbonate, polyacrylonitrile, cellulose, cellulose acetate, mixtures, blends and co-polymers thereof.

Preferred hollow fibre membrane materials for the dip tube are selected from the group consisting of polysulfone, polyethersulfone, polyvinylidene fluoride, polyvinyl pyrrolidone, polyacrylonitrile, cellulose, cellulose acetate, mixtures, blends and co polymers thereof.

A particularly preferred hollow fibre membrane material comprises a blend of polyethersulfone and polyvinylpyrrolidone. Polyethersulfone (PES) polyvinylpyrrolidone (PVP) blends are highly oxidant tolerant (>250,000 ppm hours for chlorine, tolerant to permanganate and ozone), are tolerant to wide pH range, and are highly hydrophilic.

Preferred dip tubes have a pore size in the range of 0.05 microns to 0.80 microns. The precise pore size, wall thickness, length, shape and configuration of the dip tube, internal bore, colour, and transparency can be selected according to the fluid to be dispensed and/or the propellant to be used, the resultant nature of the fluid once it is expelled i.e., the fineness of the mist to be created, the degree of atomisation, the mix of propellant to product, and the nature of the container body in terms of size and shape.

Pore size selection should also be chosen based upon the bubble point of the liquid, the start and finishing pressure required, the surface area of membrane of the dip tube in contact with the liquid across the life of the pack.

Flow rate can be controlled by altering the internal bore of the dip tube and by changing the length of the dip tube exposed to the liquid.

The external diameter of the dip tube may be selected according to the internal or external diameter of the fluid port within the dispenser head or any other connecting body. The hollow fibre membrane used to form the dip tube can be closed at one end by heat sealing/welding, crimping, gluing, chemical sealing, and ultrasonic or high frequency welding.

Suitable containers include those made of plastics, glass, metals, ceramics, paper or composites.

Although in the above examples only one dip tube is provided, in some preferred embodiments more than one dip tube may be provided. The dip tubes may have the same material properties and performance. Alternatively, the dip tubes may be manufactured to perform differently, for example by varying the pore size, wall thickness, rigidity, shape, materials, coupling position and length. The dip tube may be directly coupled to the dispenser head (as shown in the examples) or may instead be coupled indirectly to the dispenser head via another length of tubing.

Many commercially available disinfectants have as their base active chlorine-based chemistry, peroxide chemistry or alcohol chemistry. They also use flammable liquified gasses. All of these when aerosolised can cause dangers including explosive risks, flammability risks and human factor risks such as skin damage and hung damage. Accordingly, in preferred embodiments of the present invention, we use water-based, non-flammable disinfectants with the low risk to human health. Disinfectants that are effective against bacteria and viruses that are preferred include N-(3-aminopropyl)-N- dodecylpropane-1,3- diamine available from Nouryon. Other suitable active disinfectants include benzalkonium chloride, H202, sodium hypochlorite, pine oil, peracetic acid (PAA), and triclosan (TCS).

Preferred pressures for the filled dispenser are between 8 bar (0.8MPa) and 12 bar (1.2 Mpa), and more preferably around 10 bar (1 Mpa). Preferred product fill rates are between 60% and 88% of the total volume capacity of the fluid dispenser.

Preferred dispensing gasses are air, carbon dioxide and nitrogen. Air and carbon dioxide have the advantage that some of the gas will be absorbed into the liquid disinfectant and be dispensed with it in use, thereby assisting in the breakup of particles, creating a more effective aerosol and increasing the wettability of fomites. Commercial examples

The following are some examples of commercial embodiments.

Size of container: 600ml brim full Volume of liquid: 65%-70% of the brim full

Pressure of gas: 10 bar (1 MPa) preferred at 70% fill; 8.5 bar (0.85 MPa) at 65% fill Propellent: compressed air or compressed C02 Dip tube length: 230mm Dip tube porosity: 0.2microns to 0.55microns Dip tube bore internal diameter: 3.0mm Dip tube external diameter: 4.45mm

Preferred disinfectant blends for use in the present invention include:

Blend 5

Blend 5 is also an example of a disinfectant composition according to the invention.

Practical applications:

Ambulances are complex multifaceted environments to decontaminate. Indeed, there are some 20 common touch points on the outside of the vehicle alone. Internally they have hundreds of common touch points and some 50 doored storage compartments with hundreds of surfaces in multiple planes. The gurney itself is a particularly complex construction with multiple touch points, surfaces and ingress points where contamination can hide. The present invention is designed to reach these areas with ease, completely wetting surfaces and ingress points no matter the angle of approach or the complexity of their location.

Secondary transmission and breaking the contamination chain is of particular concern as it relates to COVID-19. The point at which PPE is removed is a specific hot spot (zone) for both becoming contaminated and secondary transmission events. The present invention's ability to produce a continuous high-density fine spray in any orientation, is ideal in the current environment. It can simply be used to spray the PPE before it has been removed, during the removal process and during the bagging and sealing process.

In addition to the above, mitigating the risk to all service personnel is of vital importance to those individuals who put themselves directly on the front line of this fight. It is also of vital importance to the NHS and the nation. We are relying on service personnel to provide essential support services to the NHS and other Government bodies. Every person taken out of action by this virus is a weakening of the logistics support chain. The effect of providing key personnel with personal protective decontamination equipment systems should not be underestimated in this fight against coronavirus both from a personal and personal space decontamination perspective, but also in breaking the contamination chain.

Nothing currently exists for the protection of individuals and their 2 metres of personal space. With the prospect of a deliverable vaccination 18 months to 2 years off, protecting the individual and mitigating the risks of secondary transmissions is vital.

In addition to the above mentioned, mitigating the risk to all service personnel is of vital importance to those individuals who put themselves directly on the front line of this fight. It is also of vital importance to the NHS and the nation. We are relying on service personnel to provide essential support services to the NHS and other Government bodies. Every person taken out of action by this virus is a weakening of the logistics support chain. The effect of providing key personnel with personal protective decontamination equipment systems should not be underestimated in this fight against coronavirus both from a personal and personal space decontamination perspective, but also in breaking the contamination chain.

The present invention is designed to deliver a high-density fine mist in 360° of orientation (including upside down) and is good to the last drop of product. It is easy to operate with little to no training required. The effort required compared to operating a standard hand pumped trigger, or sanitising wipe is significantly lower.

Claims

1. An aerosol fluid dispenser comprising: a container for a liquid; a dispenser head fitted to the container and having a fluid outlet; a dip tube formed from a length of hollow membrane, the hollow membrane having an open end which is coupled to the dispenser head so as to be able to communicate with the fluid outlet, and having a closed end that sits within the container; a liquid disinfectant; and, a propellant, wherein the hollow membrane is adapted to pass liquid in preference to gas so that when the dispenser head is actuated liquid disinfectant travels from the liquid container through the wall of the dip tube to the fluid outlet under a pressure differential established across the wall of the membrane.

2. A fluid dispenser according to claim 1, filled with a liquid disinfectant having an active ingredient selected from N-(3-aminopropyl)-N-dodecylpropane-l, 3-diamine, benzalkonium chloride, H202, sodium hypochlorite, pine oil, peracetic acid (PAA), and triclosan (TCS).

3. A fluid dispenser according to claim 1 or 2, in which the propellant is a compressed gas propellant, preferably air or carbon dioxide, and which is preferably pressurised to between 0.8 Mpa and 1.2 Mpa, more preferably around IMpa.

4. A fluid dispenser according to any preceding claim, in which the propellant is partially dissolved within the liquid disinfectant.

5. A fluid dispenser according to any preceding claim, wherein the hollow membrane is arranged within the liquid container such that it is in communication with liquid regardless of the orientation of the container.

6. A fluid dispenser according to any preceding claim, comprising a plurality of hollow membranes coupled to the dispenser head.

7. A fluid dispenser according to any preceding claim, wherein the hollow membrane is flexible.

8. A fluid dispenser according to any preceding claim, wherein the hollow membrane extends substantially across an entire length of the liquid reservoir.

9. A fluid dispenser according to any preceding claim, wherein the hollow membrane is hydrophilic.

10. A fluid dispenser according to any preceding claim, in which the dip tube is arranged within the dispenser such that the dispenser is effective to discharge liquid disinfectant irrespective of the orientation of the container.

11. A fluid dispenser according to any preceding claim, wherein the liquid disinfectant comprises a surfactant.

12. A fluid dispenser according to claim 11, wherein the surfactant is an alcohol ethoxylate, preferably a C9-C11 alcohol ethoxylate.

13. Use of a fluid dispenser according to any preceding claim to disinfect fomites.

14. Use of a fluid dispenser according to claim 13, to treat fomites potentially contaminated with a virus, preferably a coronavirus, more preferably SARS-CoV-2.

15. A liquid disinfectant composition comprising a biocidal agent, a chelating agent and a surfactant.

16. A liquid disinfectant composition according to claim 15, wherein the biocidal agent and/or surfactant are as defined in any preceding claim.

17. A liquid disinfectant composition according to claim 15 or 16, which comprises, and preferably consists of, water; N-(3-aminopropyl)-N-dodecylpropane-l, 3-diamine; Alcohols, C13-15, branched and linear, ethoxylated; Alcohols, C9-11, ethoxylated; sodium carbonate; glutamic acid, N,N-diacetic acid, tetrasodium salt; and citric acid, and which is preferably in the amounts as disclosed herein as Blend 5.

18. A method of disinfecting a fomite comprising applying an aerosolised liquid disinfectant according to any of claims 15 to 17 to a fomite, wherein the fomite is potentially contaminated with a virus, preferably a coronavirus, more preferably SARS- CoV-2.