BE1028847A9 - Arthropod Killing Composition and Applications - Google Patents

Abstract

The present invention relates to a composition for killing arthropods and their eggs, such as lice or ticks and nits. More particularly, the invention provides a composition for killing arthropods, said composition comprising at least 65% by weight of a mixture of saturated linear or branched hydrocarbons, said hydrocarbons being a mixture of saturated linear or branched C10 -C16 hydrocarbons and saturated linear or branched C17-C25 hydrocarbons wherein the ratio by weight of saturated linear or branched C10-C16 hydrocarbons to saturated linear or branched C17-C25 hydrocarbons is less than 15:85. The invention further relates to the use of such a composition for killing arthropods and to a method for killing arthropods comprising the use of the present composition.

Description

Field of the Invention This invention relates to a composition for killing arthropods and their eggs. More particularly, the invention provides a composition comprising essentially hydrocarbons for killing sucking and/or biting lice or ticks and nits. The invention further relates to a hair product comprising a composition according to the invention and a device comprising a composition according to the invention. Background of the Invention Parasitic arthropods such as lice or ticks are not only a nuisance, some lice and ticks are important vectors of disease. In dogs, for example, 7richodectes canis (louse species) can transmit the tapeworm Dipylidium canis. Human body louse (Pediculus humanus humanus) have been identified as the sole carriers of typhoid fever. Ticks (/xodidae spp.) are important vectors of a number of diseases, including, for example, Lyme disease.

Lice are mobile organisms that are highly adapted to their host species. Many of them feed only on certain parts of their host, for example pubic lice (Phtirus pubis) in the pubic area, head lice (Pediculus humanus capitis) on the scalp and body lice on the rest of the body. Head lice often infest human hair and are easily spread through contact, transmitting adult lice. Such infestations are especially common in young school-aged children, as they can spread easily in the associated institutional environment. A female louse can lay hundreds of eggs, starting from 12 days after hatching until she dies. The attachment of these eggs, called "nits," to the hair provides a reservoir of lice and maintains the infestation. Lice are divided into two Orders: Anoplura (sucking lice) and Mallophaga (biting lice), which show some anatomical/biochemical differences. Human lice belong to the First Order while the dog lice belong to the Mallophaga.

Killing head lice involves total removal or destruction of both the adult lice and the eggs on each host. Various attempts to achieve such destruction have been proposed in the prior art. For example, the many commercial hair lice removing compositions are known to kill the parasites by biochemical action. These compositions often contain potentially toxic insecticides which are usually

° BE2020/5868 belong to the group that includes permethrins, decamethrins, pyrethrins, piperonyl butoxide, malathion, DDT, gamexane, lindane, etc.

While effective against lice, such known insecticidal compositions have some drawbacks. Some of the above chemicals are very persistent in nature (eg DDT) and therefore their widespread use is not justified. Others may lead to serious (eg lindane) or less serious (eg malathion, pyrethrins) side effects. Malathion and the pyrethrins and permethrins are among the most commonly used insecticides for the treatment of head lice. However, due to their widespread and ongoing use, some parasites have become resistant to this treatment, which is one reason why the use of these insecticides is associated with treatment failure and low cure rates. In addition to an increasing lack of efficacy in adult lice, these insecticides are ineffective against nits, requiring at least two consecutive treatments, with a second treatment intended to kill hatched nits. Also, the efficacy of these insecticides varies between the two orders of louse. Attempts have been made in the prior art to provide compositions which overcome the above indicated problems related to the use of insecticides. For example, EP 1 215 965 B1 claims the use of a composition comprising a volatile and a non-volatile siloxane (silicone). This patent specifically refers to the use of a composition comprising a mixture of linear silicones such as dimethicone and cyclic silicones such as cyclomethicone. For example, cyclomethicones generally comprise a mixture of cyclotetrasiloxane or octamethylcyclotetrasiloxane (4 silicon atoms) and cyclopentasiloxane or decamethylcyclopentasiloxane (5 silicon atoms). However, cyclic silicones are known in the art to be toxic and their use in compositions for treating arthropods on skin or hair could therefore cause deleterious side effects. For example, there are reports that indicate the toxic character, for example on the skin, of cyclotetrasiloxanes or cyclopentasiloxane. Another major shortcoming of existing anti-lice compositions is their low cure rates, which usually do not exceed about 70%, typically about 50%. This means that more than 3 in 10 people are not lice free after two treatments. Such cure rates are not high enough, especially since it only takes one infected person to reinfect others. In addition, the effectiveness of the existing anti-lice compositions in killing nits is extremely low, requiring at least one repetition of the treatment. The fact that not all nits hatch at the same time further contributes to low cure rates. In fact, if the formulation does not kill all lice in the first treatment, some lice may lay eggs in the period between the two treatments. If these new eggs are not killed by an anti-lice compound on the second treatment, they will hatch after the second treatment, leading to treatment failure.

In view of the above, it is apparent that there is a need in the art to improve the presently known compositions, especially those used against lice, and in particular those using insecticides as well as those using cyclic silicones. Yet another problem with existing anti-lice compositions is that their formulations are irritating or sensitizing. Existing formulations may cause skin irritation or rashes. In particular, many of the compositions used in existing formulations can cause contact dermatitis. Therefore, there is a further need in the art to provide a non-irritating composition and method for killing arthropods and their eggs. Yet another more common problem with existing anti-lice compositions is that their formulations are not always readily applicable. Existing formulations are not always easy to apply, and often require extensive shampooing or wetting of hair and scalp. In view of this, it is apparent that there is also a need in the art for an improved composition which is easier to apply, preferably to dry hair, and which more effectively contacts arthropods to kill. It is a further need in the art to provide a safe and effective method of killing arthropod parasites such as ticks and lice. There is still a further need in the art to provide a safe and effective method of killing arthropod eggs. It is therefore an object of the present invention to provide an improved composition which solves at least some of the above problems or drawbacks. In particular, it is an object of the present invention to provide a composition and method for killing arthropods, including, for example, sucking and biting lice and/or ticks, and their eggs, which is non-toxic and non-irritating.

In addition, it is an object of the invention to provide a composition and method for killing arthropods and their eggs which is easy to apply and which exhibits a rapid and definitive effect on the parasites. Summary of the Invention The present invention is directed to a composition for killing arthropods and is based on the Applicant's finding that compositions comprising the hydrocarbon mixture of the invention are highly effective in killing arthropods and their eggs, in particular lice and nits.

In a first aspect, therefore, the present invention relates to a composition for killing arthropods, said composition comprising at least 65% by weight of a mixture of saturated linear or branched hydrocarbons, said hydrocarbons being a mixture of saturated linear or branched C10 -C16 hydrocarbons and saturated linear or branched C17-C25 hydrocarbons where the ratio by weight of saturated linear or branched C10-C16 hydrocarbons to saturated linear or branched C17-C25 hydrocarbons is less than 15:85.

This mixture is non-irritating, highly effective at killing arthropods and their eggs, and enough spreadable and rinseable to be applied effectively to a scalp or hair. In a preferred embodiment, said composition further comprises between 0.01 and 10 wt% dimethicone having a viscosity of at least 20,000 centistokes at 25°C. In particular, the applicant has shown that a composition comprising a combination of high molecular weight hydrocarbons and siloxanes is effective in killing arthropods and their eggs. Furthermore, the Applicant has shown that a well-chosen molecular weight distribution yields a composition that is non-irritating and effective in killing arthropods and their eggs. The present invention includes a composition supplied as a composition. Preferably, the present composition can be applied directly to dry hair without shampooing or rinsing with lotion. In another preferred embodiment, the present invention provides a composition which is a non-aqueous composition. The present composition may further comprise a substituted siloxane polymer such as: anionic silicones:

> BE2020/5868 silicone sulfates, silicone phosphate esters, silicone carboxylates and silicone sulfosuccinates, cationic silicones: silicone alkyl quats (e.g. stearalkonium dimethicone, cetrimonium dimethicone...), silicone amido-quats and silicone amidazoline quats, amphoteric silicones: silicone amphoteric and silicone betaine, and non-ionic silicones: fluorosilicones, silicone copolyols (or PEGylated silicones), silicone alkanolamides, silicone esters (e.g. dimethicone copolyolavacodoate, dimethicone copolyolamandeloate, dimethicone copolyol olivate…), silicone taurines, silicone isethionates, alkyl silicones and silicone glycosides. The Applicant has surprisingly shown that hydrocarbons and preferably linear and branched hydrocarbons have a killing effect on arthropods and their eggs. In addition, the linear siloxane used in the present composition was shown to impart synergistic effects to the composition. Addition of the siloxane to the composition improves the effect of the hydrocarbon: the killing effect of a composition comprising a linear hydrocarbon and a siloxane is better than the killing effect of a composition without siloxane. Furthermore, it was shown that the siloxane also acts as an agent capable of stabilizing the composition, i.e. capable of maintaining the composition in a suitable application form without disintegration of the composition.

An important advantage of providing the present composition in the form of a liquid non-aqueous composition is sufficient rinseability. High molecular weight dimethicone is an oily, viscous substance. A composition comprising high molecular weight dimethicone and high molecular weight hydrocarbons will have problems in spreading the composition on the scalp and/or hair, as well as rinsing the non-aqueous composition from a scalp or hair. The present invention provides a liquid composition which is non-irritating, effective against arthropods and also sufficiently spreadable and rinseable to be used effectively.

In another embodiment, the composition of the present invention is foamable. An important advantage of this foam is, among other things, an easy application of the composition: the foam can be easily and homogeneously massaged on dry hair and the scalp, while this is not possible for an oily liquid substance. The latter will seep through the fingers after being poured into a hand and during application the substance can run from the scalp to the eyes and neck, leading to stains on clothing and possible eye irritation. In addition, applying a foam ensures a good spread over the surface

© BE2020/5868 hair and scalp, as the foam has to be rubbed over the surface until it breaks, this also allows better monitoring of the application so that no spot is missed. The present application has further surprisingly shown that the present composition can be advantageously formulated as a stable foaming composition, wherein the linear or branched hydrocarbon is used as the active ingredient and the siloxane is used as a foaming agent. It is surprising that the combination of hydrocarbon molecules and large siloxane molecules can form a stable foam. An important advantage of providing the present composition in the form of a foam includes ease of application of the composition: the foam can be easily and homogeneously massaged onto dry hair and the scalp. Applying a foam ensures good distribution over the hair and scalp as the foam has to be rubbed over the surface until it breaks, this also allows better monitoring of the application so that no spot is missed.

In addition, as noted above, prior art compositions have low cure rates and require repeated applications of the compositions. The present invention provides a solution to this problem by providing a composition which, in contrast to prior art compositions, is highly effective against arthropods and also against their eggs.

Thus, the applicant has shown that synergistic effects are obtained when hydrocarbons as defined herein are combined with a linear siloxane as defined herein in a composition according to the invention. In particular, such combined use provides a higher killing effect on both adult arthropods and their eggs. In addition, a composition as defined herein has the ability to form stable foam. These aspects provide the present composition with significant advantages over prior art compositions.

In particular, the invention relates to the use of a composition for killing arthropods and their eggs comprising at least 65% by weight of a mixture of saturated linear or branched hydrocarbons, said hydrocarbons being a mixture of saturated linear or branched C10-C16 hydrocarbons and saturated linear or branched C17-C>5 hydrocarbons, where the ratio by weight of saturated

/ BE2020/5868 linear or branched C10-C18 hydrocarbons until saturated linear or branched C17-C>5 hydrocarbons is less than 10:90; and said composition comprises between 0.01 and 10% by weight of dimethicone having a viscosity of at least 20,000 centistokes at 25°C.

Another advantage of the present composition is that it is substantially non-irritating to the skin for a given application time. To be effective, there is essentially no need to use acetic acid, formic acid, or other acidic substances such as vinegar, which are often found in commercial and homemade anti-lice formulations or insecticides. In addition, the Applicant has determined that this specific ratio by weight of saturated linear or branched C10-C16 hydrocarbons to saturated linear or branched C17-C25 hydrocarbons is not irritating. The composition of the present invention was found to be non-irritating and sufficiently spreadable and washable to be used on scalp and hair; in contrast to mixtures of linear or branched C10-C25 hydrocarbons which do not meet this ratio. In a preferred embodiment, the invention relates to the use of a composition as defined herein comprising between 1 and 4 wt% dimethicone. In another preferred embodiment, the invention relates to the use of a composition as defined herein, wherein the dimethicone has a viscosity of at least 40,000 centistokes at 25°C, and preferably of about 60,000 centistokes at 25°C. In another preferred embodiment, the invention relates to the use of a composition as defined herein comprising about 65 to 98 wt%, and preferably about 68 to 97 wt% of said mixture of saturated linear or branched hydrocarbons. Yet another advantage of the present composition is its effectiveness despite the fact that it contains little or no potentially toxic ingredients known and used in commercial products of this type, such as pediculicides. The present composition is essentially non-toxic: to be effective, it does not require the use of known potentially toxic agents commonly found in commercial formulations. The applicant has also shown that the present composition has a rapid killing effect on arthropods. The arthropod can be killed by direct contact with or immersion in the current composition. A composition according to the present invention impairs the respiration of the arthropods and can be regarded as an asphyxiant composition;

for example, for lice, the current composition can block the stigmas. These are small openings on the surface of parasites that lead to the trachea and allow oxygen and fluid exchange with the environment. Preferably, the arthropods which can be killed according to the present invention comprise insects or arachnids, and are preferably sucking or biting lice.

In another aspect, the present invention provides the use of a composition as defined herein for killing arthropods and a method for killing arthropods comprising applying to said arthropods a composition as defined herein.

The present invention further provides a hair product for killing arthropods and eggs of arthropods, said arthropod being an insect or arachnid, and preferably a sucking or biting louse, comprising a composition according to the present invention.

In yet another aspect, the invention provides a device comprising a composition or a hair product according to the invention and means for distributing said composition or hair product.

The present invention also provides a method of killing arthropods and eggs of arthropods, wherein the arthropod is an insect or arachnid, and preferably a sucking or biting louse, comprising applying to the arthropod and the arthropod egg a composition as defined herein or a hair product as defined herein.

In order to better demonstrate the features of the invention, some preferred embodiments and examples are described below with reference to the accompanying drawings. Description of the Drawings Figure 1 illustrates the killing effect of various compositions of the present invention on lice (7richodectes canis).

Figure 2 compares the efficacy of various compositions of the present invention with controls and compositions known in the art. In particular, FIG. 2 the killing effects of various compositions of the present invention on lice (7richodectes canis).

Figure 3 compares the efficacy of various compositions of the present invention with controls and compositions known in the art. Detailed Description of the Invention The present invention is directed to a composition for killing arthropods and their eggs and the use of such compositions. in methods of killing arthropods and their eggs. The compositions of the present invention are non-aqueous compositions comprising hydrocarbons and siloxanes. Each of these components is described in detail below.

The compositions of the present invention may comprise, consist of, or consist essentially of the essential elements and limitations of the invention described herein, as well as any of the additional or optional ingredients, components or limitations described herein.

All percentages, parts and ratios are based on the total weight of the instant compositions unless otherwise indicated. All of these weights related to the ingredients listed are based on the active level and therefore do not include carriers or by-products that may be incorporated into commercially available materials unless otherwise noted.

The articles 'a' and 'one' are used herein to refer to one or more than one, i.e. at least one of the grammatical objects of the article. By way of example, "a sample" means one sample or more than one sample.

In this application, the term "approximately" is used to indicate that a value includes the standard deviation of errors for the device or method used to determine the value.

Recitation of numeric ranges by endpoints includes all integers and, where applicable, fractions included within that range (e.g., 1 to 5 may include 1, 2, 3, 4 when referring to, for example, a number of samples, and may also include 1.5, 2, 2.75 and 3.80 when referring to concentrations, for example). Indicating endpoints also includes the endpoint values themselves (e.g., from 1.0 to 5.0 includes both 1.0 and 5.0).

Denoting hydrocarbons by ranges designating hydrocarbons having a specified number of carbon atoms as endpoints includes all hydrocarbons having an integer number of carbon atoms specified in the range, e.g., 'from about C10 to about C12 carbon atoms' or 'C10 — Cı2 hydrocarbons' are equivalent terms and are intended to include hydrocarbons having C 10 , C 1 , C 11 carbon atoms. Indicating endpoints also includes the endpoint values themselves (e.g., 'from about C10 to about C12° or 'C10 — C° includes both C10 and C12). Indicating hydrocarbons with a specified number together with a +, e.g. 'C25+' indicates the fraction of hydrocarbons with 25 and more carbon atoms. The fraction of hydrocarbons with 25 carbon atoms is included herein. Indicating hydrocarbons with a specified number, along with a -, e.g. 'C12.' indicates the fraction of hydrocarbons with 12 and fewer carbon atoms. Where a percentage is mentioned with respect to an amount, this refers to a weight ratio (wt%). The term "low molecular weight" hydrocarbons as used herein refers to linear or branched hydrocarbons having 10 to 22 carbon atoms. The term high molecular weight "siloxanes" as used herein refers to linear or branched siloxanes having 900 to 5,000 silicon atoms. In other words, a molecular weight of 50,000 to 300,000 or a viscosity of 10,000 cS to

1,000,000 cs.

HYDROCARBONS In a preferred embodiment, the present arthropod killing compositions comprise greater than 65 wt% of a mixture of saturated, preferably linear or branched hydrocarbons, and preferably greater than 55; 60; 65; 70; 75; 80; 85; 90; 95 or 96 wt% of one or more saturated linear or branched hydrocarbons. For example, the concentration of hydrocarbons in the present composition may range from 65 to 99 wt%, preferably from 85 to 98 wt% and even more preferably from 90 to 97 wt% or from 95 to 96 wt%, and for example 90, 91 92, 93, 94, 95, 96, 97, 98 or 99% by weight of one or more saturated linear or branched hydrocarbons. The hydrocarbons for use in the present composition are preferably saturated, straight (linear) chained or branched hydrocarbons. In a preferred embodiment, the hydrocarbons used in the present composition are saturated linear or branched hydrocarbons having about 10 to about 25 carbon atoms, more preferably

"I BE2020/5868 about 10 to about 22 carbon atoms, more preferably about 12 to about 22 carbon atoms, more preferably about 13 to about 22 carbon atoms, more preferably about 14 to about 22 carbon atoms, more preferably about 15 to about 22 carbon atoms, more preferably about 15 to about 22 carbon atoms, more preferably about 15 to about 22 carbon atoms, most preferably from about 15 to about 22 carbon atoms Specific examples of suitable hydrocarbons include, but are not limited to decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eicosane, heneicosane, isodecane, isoundecane, isododecane, isotridecane, isotetradecane, isopentadecane, isohooeptadecone, isohooeptadecane, mixture thereof, isohooeptadecane. are branched aliphatic hydrocarbons.The name or 'C°' followed by the numbers represents the number of carbon atoms in the hydrocarbon, including the main hydrocarbon chain and the branched alkyl chain.

In yet another embodiment, the composition comprises a mixture of saturated linear or branched C18 -C19 and C18 -C>2 hydrocarbons. In yet another embodiment, the invention may relate to a composition comprising a mixture of saturated linear or branched C13-C15, C16-C19, and C18-C22 hydrocarbons.

Preferably, the ratio between saturated linear or branched C10-C18 hydrocarbons and saturated linear or branched C17-C25 hydrocarbons in a C10-C16/C17-C25 mixture is between 5:95 and 15:85, and for example 10:90.

In another preferred embodiment, the ratio between saturated linear or branched C10-C15 hydrocarbons and saturated linear or branched C16-C19 hydrocarbons in a C10-C15 /Cie C19 mixture is between 1:100 and 1:10, and for example 1:20.

In yet another embodiment, the ratio is between saturated linear or branched C15.C19 hydrocarbons and saturated linear or branched C20-C25 hydrocarbons in a C15-C19/Coo. C25 mixture between 2:1 and 1:2, and for example 1:1.

In yet another preferred embodiment, the ratio of saturated linear or branched C10-C15 and Cis-C18 and C20-C18 hydrocarbons in a C10-Ci5s / Cis-Ci9 / C20-Cos hydrocarbon mixture may be 1:10:10 or 1:20:20 or 1:10:20 or 1:20:10 or 1:10:10, most preferably about 1:20:20. The inventors have discovered that the distribution of the saturated linear or branched hydrocarbons in relation to the chain length is particularly important.

Mixtures with many short chains, especially those below C1s, lead to significant irritation and skin sensitization.

However, mixtures with no or insufficiently short chains yield a composition which is very difficult to wash out.

Consequently, these compositions are not suitable for use on hair.

The Applicant discovered that mixtures comprising saturated linear or branched hydrocarbons with a well-defined chain length distribution as described herein were foamable, highly effective and non-irritating.

In a particularly preferred embodiment, the invention relates to a composition wherein said hydrocarbons are a mixture of saturated linear and branched hydrocarbons.

Preferably, the ratio between saturated linear hydrocarbons and saturated branched hydrocarbons is between 1:4 and 2:1, more preferably between 1:4 and 1:1, most preferably between 1:4 and 1:2. These ratios were found to improve the stability of the foam.

In another preferred embodiment, the invention relates to a composition comprising no more than 10 wt% saturated linear or branched C10 - C15 hydrocarbons, more preferably the composition comprises no more than 9 wt% saturated linear or branched C10 - C15 hydrocarbons, with more preferably the composition comprises no more than 8 wt% saturated linear or branched C10 - C15 hydrocarbons, more preferably the composition comprises no more than 7 wt% saturated linear or branched C10 - C18 hydrocarbons, more preferably the composition comprises no more than 6 wt% saturated linear or branched C10 - C15 hydrocarbons, more preferably the composition comprises no more than 5 wt% saturated linear or branched C10 - C15 hydrocarbons, more preferably the composition comprises no more than 4 wt% saturated linear or branched C10 - C18 hydrocarbons, more preferably the composition comprises no more than 3 wt% saturated linear or translational categorized C10 - C18 hydrocarbons, more preferably the composition comprises no more than 2 wt% saturated linear or branched C10 - C15 hydrocarbons, most preferably the composition comprises no more than 1 wt% saturated linear or branched C10 - C18 hydrocarbons.

In another preferred embodiment, the invention relates to a composition which is substantially free of

C1 to C10 saturated linear or branched hydrocarbons. Preferably the composition comprises less than 1,000 wt% C1 - C10 hydrocarbons, more preferably the composition comprises less than 0.1% wt% C1 - C10 hydrocarbons, more preferably the composition comprises less than 0.010 wt% C1 - C10 hydrocarbons, with the most preferably, the composition comprises less than 0.001 wt% C1 - C10 hydrocarbons.

In another and more preferred embodiment, the invention relates to a composition wherein said hydrocarbons are a mixture of saturated linear or branched hydrocarbons selected from the group consisting of C10, C1, Co, C13, C14, C18, C18, C17, C18, C19, Coo, Ca1, C22, C23, C24 and C2s hydrocarbons, and preferably - from 0.0 to 15.0 wt% C10, Ci, C2 , C13, C14, and/or C15 hydrocarbons, preferably from 0, 0 to 10.0 wt% Co, Ci, Cz, C13, C14, and/or C15 hydrocarbons and more preferably less than 9.0 wt% C10, Ci, Cn, C13, C14, and/or C15 hydrocarbons, and more preferably less than 8.0 wt% C10, C1, Cn, C13, C14, and/or C15 hydrocarbons, and more preferably less than 7.0 wt% C10, C1, Cn, C13, C14, and/or C15 hydrocarbons, and more preferably less than 6.0 wt®% Co, Ci, Cn, C13, C14, and/or C15 hydrocarbons, and more preferably less than 5.0 wt®% C10, Ci, Cn, C13 , C14, and/or C15 hydrocarbons, and more preferably mi less than 4.0 wt% C10, Ci, Cn, C13, C14, and/or C15 hydrocarbons, and more preferably less than 3.0 wt% Co, Ci, Cn, C13, C14, and/or C15 hydrocarbons , and more preferably less than 2.5 wt% C10, Ci, Cn, C13, C14, and/or C15 hydrocarbons, and most preferably less than 2 wt% C10, C1, Cy, C14, C14, and/ or C15 hydrocarbons, and - from 0 to 20 wt% C18 hydrocarbons, preferably from 1 to 15 wt% C16 hydrocarbons and more preferably from 1 to 10 wt% C18 hydrocarbons, more preferably from 2 to 8 wt% C16 hydrocarbons, more preferably from 3 to 7 wt% C16 hydrocarbons, more preferably about 5 wt% C16 hydrocarbons, - from 0 to 30 wt% C17 hydrocarbons, preferably from 1 to 20 wt% C17 hydrocarbons and more preferably from 5 to 15 wt% C17 hydrocarbons, most preferably about 10 wt% C17 hydrocarbons, from 0 to 30 wt% C18 hydrocarbons, preferably 1 to 20 wt% C18 hydrocarbons and more preferably hr from 5 to 15 wt% C18 hydrocarbons, most preferably about 12 wt% C18 hydrocarbons,

- 0 to 30 wt% C19 hydrocarbons, preferably 1 to 20 wt% C19 hydrocarbons and more preferably 5 to 20 wt% C19 hydrocarbons and/or more preferably 10 to 20 wt% C19 hydrocarbons, most preferably about 16 wt % C19 hydrocarbons, - from 0 to 70 wt% C20 -hydrocarbons, preferably from 20 to 65 wt% C0+ hydrocarbons and more preferably from 30 to 60 wt% C20+ hydrocarbons, and more preferably from 40 to 60 wt% C20+ hydrocarbons , most preferably about 55 wt% C20 + hydrocarbons.

SILOXANES In another preferred embodiment, the present arthropod killing composition comprises one or more (poly)siloxanes, preferably linear or branched polysiloxanes. It is noted that in the present invention, for the avoidance of doubt, the term "siloxane" or "polysiloxanes" are used synonymously and are used herein to include silicones.

In a preferred embodiment, the linear siloxanes used in the present compositions comprise non-volatile siloxanes. For the purposes of this application, the term "non-volatile" means that the siloxane exhibits very low or no significant vapor pressure at ambient conditions, e.g. 0.60 mm Hg at 20°. The non-volatile siloxane preferably has a boiling point at ambient pressure above about 170°C, preferably above about 200°C, and more preferably above about 250°C. It will be appreciated that viscosity can be expressed as absolute viscosity, which is measured in poises (gsec"! cm") or centipoises, or as kinematic viscosity. Kinematic viscosity is the ratio of viscosity to density and is measured in stokes or centistokes. For convenience, viscosity will be expressed herein in centistokes unless otherwise noted. In a preferred embodiment, the non-volatile linear siloxanes for use herein preferably have a viscosity of at least 10,000, preferably at least 20,000 centistokes at 25°C, and more preferably at least 30,000, 40,000, 50,000, 60,000 centistokes. In a preferred embodiment, the non-volatile linear siloxanes for use herein preferably have a viscosity of no more than 1,000,000 centistokes bi j 25°C, more preferably maximum

600,000 cS, more preferably up to 500,000 cS, more preferably up to 400,000 cS, more preferably up to 300,000 cS, more preferably up to 200,000 cS, more preferably up to 100,000 cS, most preferably about 60,000 centistokes at 25°C.

Viscosity can be measured using a glass capillary viscometer. The technique for measuring kinematic viscosity is well known in the art and therefore will not be described here. Dimethicone with these chain lengths and viscosity was found to be the most effective against lice and their nits. Further increasing the viscosity led to problems in the correct application and spreading of the composition, decreasing its effectiveness in practice.

In another preferred embodiment, the present composition comprises between 0.01 and 50 wt% and preferably between 0.01 and 20 wt%, more preferably between 0.1 and 10 wt% and most preferably between 1 and 4 wt% and for example 1, 1.5, 2, 2.5, 3, 3.5 or 4 wt% of the siloxanes.

Suitable siloxanes preferably include polyalkylsiloxanes, polyarylsiloxanes, polyalkylarylsiloxanes or mixtures thereof. Thus, the siloxanes herein may include polyalkyl or polyaryl siloxanes having the following structure as shown in FORMULA I:

RR IR AO PO BTA R R R N

FORMULA I wherein - R substituents are independently selected from the group comprising alkyl or aryl, - n is an integer from about 1 to 15,000, and preferably from 10 to about 10,000, and most preferably from 1000 to 5000, - ' A' represents groups that block the ends of the siloxane chains, and are preferably selected from the group comprising hydroxy, methyl, methoxy, ethoxy, propoxy and aryloxy.

The term 'alkyl' by itself or as part of another substituent refers to a straight or branched chain saturated hydrocarbon group linked by single carbon-carbon bonds of 1 to 20 carbon atoms, e.g. 1 to 10 carbon atoms, e.g. 1 to 8 carbon atoms, preferably 1 up to 6 carbon atoms, more preferably 1, 2, 3 or 4 carbon atoms. Examples of alkyl groups are methyl, ethyl, propyl, isopropyl, butyl,

isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, pentylisoamyl and its isomers arven, hexyl and its isomers, heptyl and its isomers and octyl and its isomer.

The term "aryl" as used herein by itself or as part of another group refers to, but is not limited to, 5 to 24 carbon atoms homocyclic (i.e., hydrocarbon) monocyclic, bicyclic or tricyclic aromatic rings or ring systems having 1 to 4 rings fused or covalently linked, usually with 5 to 8 atoms; at least one of which is aromatic.

The aromatic ring may optionally comprise one to three additional rings (either cycloalkyl, heterocyclyl or heteroaryl) fused thereto.

The alkyl or aryl groups substituted on the siloxane chain (R) or on the ends of the siloxane chains (A) may be of any structure so long as the resulting siloxane remains liquid at room temperature, is not irritating, toxic or otherwise harmful in use, is compatible with the other components of the composition and chemically stable 1s under normal conditions of use and storage.

The two R groups on the silicon atom and the two A groups may represent the same group or different groups.

Preferably, the two R groups and the two A groups represent the same group.

Particularly suitable R groups include methyl, ethyl, propyl, phenyl, methylphenyl and phenylmethyl.

The preferred siloxanes are polydimethylsiloxane, polydiethylsiloxane and polymethylphenylsiloxane.

Polydimethylsiloxane, also known as dimethicone, is particularly preferred.

The polyalkylsiloxanes that can be used include, for example, polydimethylsiloxanes.

Polyalkylarylsiloxanes may also be used and include, for example, polymethylphenylsiloxanes.

These siloxanes are commercially available, for example from Dow Corning.

In a particularly preferred embodiment, the invention provides a composition comprising between 0.01 and 50 wt% and preferably between 0.01 and 20 wt%, more preferably between 0.1 and 10 wt% and most preferably between 1 and 4 wt%, and for example 1, 1.5, 2, 2.5, 3, 3.5 or 4 wt% dimethicone, preferably dimethicone having a viscosity of at least 20,000 centistokes at 25°C, and more preferably of at least 40,000, or even about 60,000 centistokes at 25°C.

The term "approximately" means a standard deviation of 15% from the viscosity value.

SUBSTITUTED SILICONE COPOL YMER In another embodiment, the invention relates to an arthropod killing composition further comprising a substituted siloxane polymer. The term "substituted siloxane polymer" as used herein refers to a siloxane polymer of formula I above, wherein one or more R groups have further functional groups attached to the carbon atom. These functional groups may include, but are not limited to: one or more alkenyl, alkynyl, carboxyl, hydroxy, acrylate, ester, ether, alkoxy, halogen, cyano, mercapto, amino and carbohydrate groups. The substituents in R may be neutral or contain cationic centers such as quaternary ammonium or anionic centers such as sulfonic acid or thiosulfate groups. In a preferred embodiment, the invention provides a composition comprising between 0.1 and 4% by weight, and for example 0.5; 0.75; 1; 1.25; 1.5; or 1.75% by weight of the substituted siloxane polymer. In a preferred embodiment, the substituted siloxane polymer is a quaternary silicone copolymer. Quaternary silicone polymers include silicone polymers, which have a pendant [English: 'pendant' | contain a quaternary nitrogen group. Preferably, quaternary silicone copolymers are used in a composition according to the present invention represented by FORMULA II: on 2 O-CH 3 -CH-CH 3 -N-CH 3 (CH), Ro j d 1 ++ A 7 Si - so Si - Si- A R4 R4 R4 R4 29 nm

FORMULA II wherein R 1 has the same meaning as R 1 given for formula I, and wherein R 1 is preferably methyl, wherein A and n have the same meaning as given for formula I, and wherein A is preferably methyl,

wherein m is selected such that the sum of m and n is between 2 and 15000 wherein R0 is alkyl as defined above, and preferably methyl. Quaternary silicone copolymers are commercially available from Siltech Inc, under the tradename SILQUAT. In another preferred embodiment, the substituted siloxane polymer is a perfluorosilicone copolymer. Perfluorosilicone copolymer refers to fluorine-containing silicone compounds in which all hydrogen atoms, except those whose replacement would affect the nature of the characteristic groups present, have been replaced by fluorine atoms in the silicone compounds. Preferably perfluorosilicone copolymers are used in a composition according to the present invention represented by FORMULA HI: [2 qe p (CH), 5 | 4 Bl A—Si—0 79 79 Si—A R4 R4 R4 R4 n m

FORMULA III wherein R1 has the same meaning as R1 given for formula I, and wherein R1 is preferably methyl, wherein A and n have the same meaning as given for formula I, and wherein A is preferably methyl, wherein m is selected such that m + n is equal to or up to about 15000, wherein p is an integer from about 2 to 5, and wherein F is fluorine. Perfluoro-silicone copolymers are, for example, perfluorononyldimethicone and e.g.

commercially available from Siltech Inc., under the tradename FLUOROSIL.

OPTIONAL COMPONENTS In addition to the essential components described above, the present compositions may further comprise one or more optional components known or otherwise suitable for use on human/animal hair or skin. Non-limiting examples of such optional components include, for example, a foaming agent, plasticizers and wetting agents (such as glycerol, propane-1,2-diol, polypropylene glycol and other polyhydric alcohols), free radical scavengers, viscosity regulators, dyes and dyes, perfumes and the like. In a preferred embodiment, the present composition further comprises a foaming agent. Foaming agents are agents that promote the formation of foam. Any agent with a surfactant character can be used. The surfactants may be cationic, nonionic or anionic. Examples of suitable foaming agents include, but are not limited to cetrimide, lecithin, soaps and the like, and for example anionic (based on sulfate, sulfonate or carboxylate anions): Sodium dodecyl sulfate (SDS), ammonium lauryl sulfate and other alkyl sulfate salts, Sodium lauryl ether sulfate, also known as sodium laureth ether sulfate (SLES), Alkylbenzenesulfonate Soaps or fatty acid salts (see acid salts) Cationic (based on quaternary ammonium cations): Cetyltrimethylammonium bromide (CTAB) also known as hexadecyltrimethylammonium bromide and other alkyltrimethylammonium salts, Cetylpyridinium chloride (CPOPCEA) BAC), Benzethonium Chloride (BZT) Zwitterionic (Amphoteric): Dodecyl Betaine, Dodecyldimethylamine Oxide, Cocamidopropyl Betaine, Cocoamphoglycinate Nonionic: Alkyl Poly(ethylene Oxide), Alkyl Polyglucosides including: Octyl Glucoside, Decylmaltoside, Fatty Alcohols, Cetyl Alcohol. Commercially available surfactants such as Tween(TM) are also suitable.

FORMULATION It has been demonstrated by the Applicant that the present composition comprising linear hydrocarbons can be formulated as a stable composition. Likewise, the composition comprising linear hydrocarbons and one or more linear siloxanes can be formulated as a stable composition.

In an embodiment of the present invention, the composition is preferably in the form of a liquid composition, for example a solution. It should be noted, however, that compositions of the present invention are non-aqueous compositions which do not contain an aqueous carrier, such as water.

In a preferred embodiment, the liquid composition of the present invention can be removed by rinsing with water.

One problem with high viscosity dimethicone is that it is difficult to apply and remove from skin and hair.

In particular, it does not rinse well or washes out well.

The present invention provides a liquid, non-aqueous composition that is sufficiently spreadable to be applied effectively to skin and hair.

Increasing the chain length of the hydrocarbon mixture results in a composition that cannot be applied and/or removed effectively; reducing its activity in practice.

In another embodiment, the present composition comprising linear hydrocarbons and one or more linear siloxanes can be formulated as a foamable composition to form a stable foam.

The term "foamable" as used herein refers to a composition capable of forming a foam as a result of a foaming process.

Such a foaming process may involve forcing a gas into or within the composition to trap small gas bubbles therein, thereby forming the foam.

In certain embodiments of the present invention, the terms "foam" and "foamable" are used interchangeably.

Foam is a voluminous mixture of gas bubbles in liquid that will gradually collapse into gas and liquid.

The stability of foam can be determined from the time period during which foam retains a voluminous shape, i.e. before collapsing into liquid and gas.

According to the present invention, the term "stable foam" means that the time period in which the current foam retains at least 90% of its original volume is greater than 1 second, and preferably greater than 2, 3, 4, 5, 6, 7 , 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, or 60 seconds.

Prior to the foaming process, the present composition is preferably in the form of a liquid composition, for example a solution.

It should be noted, however, that compositions of the present invention are non-aqueous compositions which do not contain an aqueous carrier, such as water.

The compositions of the present invention may be prepared using conventional mixing and formulation techniques.

In the present foamable composition or foaming composition, the linear hydrocarbon is used as the active ingredient and the siloxane is used as a foaming agent. In view of this, in another embodiment, the invention also relates to the use of a linear siloxane as defined herein as a foaming agent. To our knowledge there is no indication in the art that the linear siloxanes themselves have any foaming effect. In contrast, siloxanes are known to be used in the art for their defoaming action. In the present foamable composition or foaming composition, the mixture of saturated linear and branched hydrocarbons wherein the ratio by weight of saturated linear or branched C10-C16 hydrocarbons to saturated linear or branched C17-C2s hydrocarbons is less than 15:85, forming a foam possible. This is remarkable because a composition consisting of 96% saturated, linear Cis hydrocarbons and 4% dimethicone is not foamable.

The present composition is applied to the body site of interest in the form of a foam and it is therefore essential that the composition undergoes a foaming process before being applied to the body. In the foaming process, gas is forced or molded into the formulation to trap small gas bubbles therein, thereby forming the foam. Any suitable gas or gas producing system can be used to produce the foam. Mention may be made of butane gas and nitrous oxide, but other gases such as air, nitrogen, hydrofluorocarbons, hydrocarbons such as propane, isopropane or a mixture thereof are also suitable. Preferably, the foam is produced using air.

By using foam for administration, a composition according to the invention can be more easily and effectively applied to a treatment area. While prior art compositions in the form of a solution usually result in uneven application over a small area, the viscosity and adhesive properties of a foaming composition as defined herein allow for even distribution over a larger area. The use of foam as a delivery system for a composition as defined herein therefore results in a more efficient treatment. Foam has the advantage over a shampoo that the treatment can last longer. After washing, a shampoo is rinsed away, while foam can remain on the treated area for about 5 minutes to 8 hours.

The occurrence of eye irritation is greater with a shampoo than with a foam. In addition, the occurrence of eye irritation is greater when using a foam compared to a lotion.

The liquid composition of the present invention showed the highest safety with regard to eye irritation.

The applicant has shown that synergistic effects are obtained when hydrocarbons are combined with a linear siloxane as defined herein in a composition according to the invention.

The Applicant discovered that the combination of one or more hydrocarbons with a linear siloxane as defined herein acts synergistically against arthropods when administered locally, in particular by means of a foamable composition.

The effect of the combination is a significant killing effect on live arthropods such as lice and eggs thereof.

Therefore, administration of the combination of one or more hydrocarbons as defined herein and a linear siloxane as defined herein provides an effective treatment against arthropods and their eggs, such as, for example, lice, including nits.

The synergistic effect refers to a greater-than-additive effect produced by a combination of two components, which is greater than that which would otherwise result from individual administration of one of the components alone.

Administration of one or more hydrocarbons as defined herein in combination with a linear siloxane as defined herein unexpectedly results in a synergistic effect in that it provides greater efficacy than would result from the use of either agent alone, particularly by producing more arthropods more quickly and killing their nits and by providing higher cure rates.

The linear siloxane as defined herein enhances the effects of the hydrocarbon.

The applicant showed that the use of a composition according to the present invention provides faster killing and allows to kill a greater number of arthropods such as lice.

In particular, a composition as defined herein is typically capable of killing live lice more than two times faster, preferably more than three times faster and more preferably more than four times faster than compositions known in the art .

The foaming ability of the composition improves the mode of application and advantageously contributes to the improved effectiveness of the composition.

In comparison to the present compositions, prior art compositions comprising hydrocarbons but no siloxane have reduced killing effects, particularly in terms of time to kill as well as the number of lice killed.

On the other hand, prior art compositions comprising siloxane but not hydrocarbons cannot be used, since such compositions have characteristics, especially high viscosity, which make their application unfeasible.

In addition, the applicant has shown that a composition of the invention wherein one or more hydrocarbons as defined herein are combined with a linear siloxane as defined herein produce a foam, whereas a composition not comprising a siloxane or a composition not comprising any hydrocarbons does not result in a useful or applicable foamable composition (see also above).

In another embodiment, the invention relates to a hair product for killing arthropods and their eggs, said arthropod being an insect or arachnid, and preferably a sucking or biting louse, comprising a composition as defined herein. The term "hair product" as used herein refers to a product used for maintaining hair hygiene. The current hair product may be suitable for use by humans or animals.

In addition to the above-mentioned hydrocarbons, siloxanes and optionally substituted siloxane polymers, hair products may preferably further comprise a number of additives, including but not limited to moisturizing agents, pH regulators, dyes, dyes, UV absorbers, fragrances, plasticizers, preservatives, antibacterial and antimicrobial resources. Such additives are well known in the art and will not be described in detail herein.

The present invention provides a composition and hair product which is highly effective against arthropods as well as their eggs. The current composition and product provide high cure rates and high killing efficiencies.

The term "rate of cure" is used herein to refer to the number (in %) of individuals in a group treated with said composition who are free of live arthropods after treatment. A 70% cure rate means that 7 out of 10 people treated are free from live arthropods after treatment. The present composition provides an in vivo cure rate of greater than 70% after only one treatment, where other lice treatments require at least two treatments to achieve a cure rate of about 70%. The present composition is characterized in that it provides a cure rate of more than 70%, and preferably of at least 75, 80, 85, 90, 95 or even 100%.

The term "arthropod killing efficiency" is used herein to refer to the amount (in %) of arthropods killed after one treatment with a composition or product as defined herein.

A kill efficiency of 70% means that 7 out of 10 arthropods are killed after one treatment.

The present composition provides an arthropod killing efficiency of greater than 70%, and preferably of at least 75%, more preferably of at least 80, 85, 90, 95 or even 100%. The term "arthropod egg killing efficiency" is used herein to refer to the amount (in %) of arthropod eggs killed after one treatment with a composition or product as defined herein.

A 70% arthropod egg killing efficiency means that 7 out of 10 arthropod eggs are killed after one treatment and thus do not hatch.

The present composition provides an arthropod egg killing efficiency of greater than 70%, and preferably of at least 75%, more preferably of at least 80, 85, 90, 95 or even 100%. Compared to the present composition, prior art compositions have a negligible effect on nits, while the present composition may even have 100% ovicidal activity, i.e. 100% killing efficiency on nits, which are also called oocytes.

In other words, the present invention relates to the use of a composition as defined herein, whereby a killing efficiency for said arthropods of at least 70%, and preferably of at least 75, 80, 85, 90, 95 or even 100%. The invention also contemplates the use of a composition as defined herein, obtaining a cure rate of at least 70%, and preferably at least 75, 80, 85, 90, 95 or even 100%. The present invention also relates to the use of a composition as defined herein for killing arthropod eggs, wherein in particular a killing efficiency for said arthropod eggs of at least 70%, and preferably of at least 75, is obtained. 80, 85, 90, 95 or even 100%. The present invention further provides a method of killing arthropods and arthropod eggs, wherein the arthropod is an insect or arachnid, and preferably a sucking or biting louse, comprising applying to the arthropod and/or the arthropod egg of a composition as defined herein or a hair product as defined herein.

In particular, there is provided a method of killing arthropods and eggs of arthropods wherein said arthropods and eggs of arthropods are killed with a killing efficiency for said arthropods of at least 70%, and preferably of at least 75, 80, 85, 90, 95 or even 100%, and for said arthropods of at least 70%, and preferably of at least 75, 80, 85, 90, 95 or even 100% in a single treatment step by applying to said arthropod and said arthropod egg a composition or a hair product as defined herein.

DEVICE The invention further relates to a device comprising a foamable composition according to the invention. Preferably, the device comprises a container for containing the composition, means for forming a foam and optionally a cover and optionally a cover such as a transparent cover. The composition may be present in the container in an uncompressed or compressed state.

The current composition can be stored in any suitable container until needed. Conveniently, the container will be provided with means for foaming the composition if necessary. Preferably, the container used in accordance with the present invention to dispense the composition in a foam formulation comprises means for forming a foam such as e.g. a foam pump dispenser, including a mesh screen, which mixes the (liquid) composition with air to produce the foam, or equivalent means.

The foam dispensers and their operation are well known per se. For a description of further details of such devices and their action for foaming, reference is made, for example, to WO 2007/091882, US 5,271,530 and US 5,443,569, which are incorporated herein by reference, which documents are hereby incorporated by reference. by way of reference. Those skilled in the art would readily know what type of foam dispensing pumping device can be used in accordance with the present invention. Therefore, foam dispensing pumping devices will not be discussed in more detail here.

USE OF THE COMPOSITION According to the present invention, the compositions as defined herein are used for killing arthropods and their eggs. The term "kill" as used herein includes the shedding, reduction in number and extermination of said arthropods, e.g. ectoparasites, and/or their eggs.

The use of the present compositions for killing arthropods and/or their eggs includes prophylactic use.

The compositions of the present invention are useful in killing arthropods, especially terrestrial arthropods, especially insects and arachnids, and their eggs.

Insects include ectoparasites.

In particular, said compositions have pediculicidal activity and are therefore particularly useful for treating lice infestations in animals, including humans.

Ectoparasites include sucking and biting lice, fleas, louse flies, mites and ticks.

Sucking lice (Anoplura) and biting lice (Mallophaga) are parasites found on almost all groups of mammals, and include Haematopinus spp, Linognathus spp., Solenopotes spp.

Pediculus spp. and Pthirus spp.

Pediculus spp. include Pediculus humanus, e.g. the head louse Pediculus humanus capitis and the body or clothes louse Pediculus humanus humanus.

Pthirus spp. includes the pubic louse Pthirus pubis.

Ticks are the largest group of the Acari subclass and are obligate blood-sucking ectoparasites of terrestrial vertebrates.

Certain species are pests of pets, while another group transmit diseases to humans.

Ticks are classified into three families, all but one of the species belong to the /xodidae (hard ticks) before the Argasidae (soft ticks). The present compositions can be used to kill both soft and hard ticks.

The present compositions are also useful for the control of other terrestrial arthropods, including, for example, public health pests, e.g., cockroaches and bed bugs; nuisance arthropods such as wasps, ants, silverfish and woodlice; and structural pests, eg furniture beetles, deathwatch beetles and other wood borers.

Arthropod eggs include eggs of ectoparasites as defined herein and include, but are not limited to, eggs of sucking and biting lice, also referred to as nits or ova, eggs of fleas, louse flies, mites and ticks.

Preferably, the composition is used for the treatment of hair, i.e. for hair care.

Hair care products of the present invention can be used in conventional ways and generally comprise applying an effective amount of the hair product to the hair, preferably to dry hair.

The composition is left in/on the hair for about 5 minutes to 8 hours and is then removed by rinsing and washing the hair thoroughly. The composition is distributed throughout the hair, usually by rubbing or massaging the hair and scalp with the hands or the hands of another. An effective amount of the composition, typically from about 1 gram to about 100 grams, preferably from about 10 grams to about 30 grams, is applied.

METHOD OF USE The compositions of the present invention can be used in a conventional manner. In general, the formulation of the present invention will be applied directly to the body site of interest in the form of a liquid composition or a foam, in the case of a foam, this foam is produced from suitable equipment immediately before application. However, an amount of the formulation may be prepared and then applied to the body site by any suitable means, for example by hand or with a spatula.

An effective amount of the composition, typically from about 1 gram to about 200 grams, e.g., from about 30 grams to about 150 grams, or from about 1 gram to about 100 grams, or from about 10 grams to about 30 grams, is applied.

For example, the method of treating hair comprises the following steps: (a) applying an effective amount of the composition to the hair, (b) processing the composition in contact with the hair, (c) leaving the composition on the hair for a suitable period of time to allow killing and (d) rinsing the composition from the hair with water. Applying the composition to the hair typically involves working the composition through the hair, generally with the hands and fingers. The composition is left in contact with the hair, e.g., for about 5 or 10 minutes to 8 hours. The composition is then rinsed from the hair with water and optionally soap (for example a shampoo).

For example, the method of treating the skin comprises the following steps: (a) applying an effective amount of the composition to the skin, (b) leaving the composition on the skin for a suitable period of time for killing to occur, and ( c) rinsing the composition from the skin with water. The composition may remain in contact with the skin, e.g., for about 5 or 10 minutes to 8 hours.

The composition is then rinsed from the skin with water and optionally soap.

The method steps can be repeated as often as desired to achieve the desired effects.

But preferably the treatment is repeated after 7 days.

To kill the hatched lice that were not killed in the first treatment.

Examples Example 1: In Vitro Screening of Compositions of the Present Invention for Efficacy Against Lice The present invention discloses the screening of compositions according to the formulations of the invention for efficacy against lice (7richodectes canis) in vitro.

In this trial, the screened compositions were developed to affect the respiration of the lice.

These compounds have been developed to have a rapid impact on human lice infestations.

Due to the difficulty of working with human lice (safety), dog lice were used in this trial.

Both lice orders (Anoplura (sucking lice) and Mallophaga (biting lice)) have the same breathing mechanisms.

Therefore, the impact of a suffocating compound (i.e., a compound that blocks the parasites' stigmas) is believed to be the same for both Orders.

Four runs were performed with an inactive control (water), an active control and different compositions (4 in each run, 2 of which were repeated). The compositions used are shown in TABLE 1. The active control consisted of a composition comprising 96 wt% cyclomethicone and 4 wt% dimethicone, but no hydrocarbons.

Trials 1 and 2 consisted of immersion trials.

In Trial 1, efficacy was determined by immersing the lice in the controls/compositions.

In the first run of this trial, lice were exposed for approximately 30 seconds, while in the second run, the exposure was approximately 10 seconds.

In Run 2, the lice were immersed for approximately 10 seconds, after which they were rinsed with water to remove residual formulation.

Test 2 was performed in duplicate.

Trials 3 and 4 consisted of contact trials.

In Trials 3 and 4, efficacy was determined by contact with filter paper saturated with the controls/compositions.

In all Trials, the water control was performed in duplicate, with the water control being the first and last substance tested to ensure that no cross-contamination had occurred.

Material and Methods Lice For all Trials, lice (Trichodectes canis) were collected from an infested dog within 24 hours of running the trials.

To prepare the lice for the tests, 10+1 lice were placed in a 2 ml microcentrifuge tube.

Some dog hair was also placed in each tube (about 10-15 strands of hair). Each louse was checked for viability before being placed in the tube.

The louse was considered viable if it moved.

Viability assessment In all studies, efficacy was assessed by determining whether the lice were viable (dead or alive). A louse was classified as alive if it was on the move or if its legs moved.

However, lice were pushed with tweezers to encourage movement.

TABLE 1: overview of compositions and compositions thereof (in wt%) used in the present test cyclo-C13-C15 | dimethicone | dimethicone | KYartair C1S-C19 N° | methicone carbon (60000cS) (L00cS) silicone hydrocarbons polymer | hydrogens 1] 100 | Je 2) 96 V4 1 LL Ll 31 | 8 | 20 Ll Ll Ll 4l 50 | 1 50 | Ll SI | 10 | LLL |6aJ TL 95 | 4 1 1 1 LN 6b] 1 79 | 20 | Ll 1 Ll 60] | 495 | 1 495 | 1 | | ol TL LL LL LL Lo | u] TL Tt 4 1 Ll 6 |

Test I After the lice were placed in the microcentrifuge tube, 2 ml of the test composition, water or control was pipetted into the tube.

After approximately 30 sec (trial run 1) or 10 sec (trial run 2), the tube was inverted and the contents poured into a petri dish lined with filter paper.

The lice were immediately removed and placed in a clean petri dish with filter paper and assessed for viability.

After this assessment, the lice were left on the filter paper for up to 1 hour and checked again for viability.

In both runs, the test items were: water, active control and compositions 1, 2,3 and 4. Run 2 Run 2 was identical to Run 1, Run 2 with the following difference.

After inverting the tube and pouring the contents into a petri dish lined with filter paper, the aphids were transferred to fresh filter paper and washed with approximately 2 ml of water.

The lice were then transferred to a clean petri dish with filter paper and assessed for viability.

After this assessment, the lice were left on the filter paper for approximately 1 hour and checked again for viability.

The test items in this test were: water, active control and compositions 5, 6a, 6b and 6c.

Test 3 In Test 3, 1 ml of the test composition, water or control was placed on filter paper.

Excess liquid was shaken off the paper so that the paper was saturated but no liquid was collected.

The paper was then placed in a petri dish.

The lice in the microcentrifuge tubes were poured onto the filter paper and assessed for viability every minute from 2 minutes to 10 minutes.

The time when at least 1 louse was alive was recorded and the time when all lice were dead was recorded.

If not all lice had died after 10 minutes, the number of live lice was recorded after 1 hour.

The test items in Test 3 were: water, active control and compositions 1, 2, 3, 4, 5, 6a, 6b and 6c.

Run 4 Run 4 was identical to Run 3. However, all samples were run in duplicate.

In addition, the number of dead lice was recorded every minute from 1 minute to 10 minutes.

The test items in Test 4 were: water, active control and compositions 2, 5, Yen ll.

Results Ten aphids were used in the trial runs of Experiment 1.

For all test compositions and the active control, all lice were considered dead immediately after exposure.

All lice in the water control were alive.

One hour later, no lice in the trial and active control treatments had recovered and all lice in the water control were still alive.

In Experiment 2, the following number of lice was used (Table 2): Table 2 Number of lice Repeat 1 Repeat 2 | compound | 11 |9 | aso 8 6a composition ammo on =p 11 6c

As in Test 1, all lice exposed to the test compositions and the active control were considered dead immediately after exposure.

All lice in the water control were alive.

One hour later, no lice in the trial and active control treatments had recovered and all lice in the water control were still alive.

The results of Trial 3 are shown in Table 3. Table 3 Number 2. I Time 2 (all 1) lice Time 1 (1 live) dead)! 1 hour 3.5 7 life Control | 10 | l0mimuten | _ - | Olive | |_composition 2° | 9 | N/A | 3minutes | Olive | | composition3 | 9 | 2minutes | Sminutes | Olive | | composition4 | 9 | mvt | Tmminutes | Olive |

1 Time 1 is the time when no more than 1 louse was still alive. Time 2 was the time no lice were alive with controls up to 10 minutes. 2 n.a. = not applicable. 3 Two samples of water were tested. The results were the same for both. 4 After 10 minutes, 5 were still alive. 5 These samples were run in duplicate. In some cases, all lice died between controls and there was no time when a louse was still alive (eg samples 2, 6a and 6c). The results for Trial 4 are shown in Table 4. Table 4 Number Number of dead (time in minutes | hours of lice | 1 |2 [3 [4 5 [61 78 [9/10] Water (1) 11 All alive Water ( 2) All alive | Control (1) | 9 |9|=-|-|-|=-|- |" || = | = | Alive | | Control (2) | 10 |6|9|10| -|-|-|=-|=-|=-|=-| composition 2 (1) | 9 |819|—-|-|=-|=|=-|=|-|= | Olive | composition ? (2) | 10 | 7 |10 | -- | -- | -— |-— |-- | -- | -- | |Olive | composition 5 (1) | 9 |3|4|8|9 -|- |-|--|-— |-- | Olive | composition 5 (2) | 10 |3[|5|7|7|9|9|9|9[|9[|9 |Olive | composition 9 (1) | 10 | 10 | -- | -- |-- | -— | -— | -- | -- | -- | |living | composition 9 (2) | 10 |6|747|10 |-|=-|-|-|=-|=-| = | composition 11 1 0 alive En lem The order in which the samples were taken was: water, control, 9, 11, 2, 5, 9, 11, 2, 5, control, water Figures 1 and 2 illustrate the absolute and relative effects of tested compositions compared to controls (water and active co checks) for trial

4. Discussion

All test compositions and the active control were effective against the lice in the immersion test (Tests 1 and 2). Water immersion did not affect the viability of the lice, so drowning from water exposure was not the cause of death. The compositions tested showed comparable efficacy to the active control in Experiments 1 and 2. All test compositions and the active control showed activity against lice in the contact trial (Tests 3 and 4). In the contact test, some differences can be explained by the viscosity of the composition. For example, in compositions 5 and 9, the lice were allowed to walk on the filter paper for a period of time, while in other compositions (e.g., 2 and 11) the lice stopped walking immediately. In addition, the actual contact time was shorter than indicated if the louse was attached to a hair. In particular, if a louse was attached to a hair and the liquid did not go up the hair, the louse could avoid contact for a period of time. To reduce this, all hairs were pressed against the filter paper with tweezers. However, this resulted in a contact delay of up to 1 minute.

In Run 3, all compositions except composition 5 showed high activity against lice. There were some differences in the speed of operation. Compositions 1, 2 and 6c showed the fastest action and composition 6b and the control showed the slowest action.

From Run 4 (see also FIGS. 1-2) it can be noted that the active control, compositions 2 and 11, consisting of a combination of hydrocarbons and a linear siloxane, exhibited faster effects against the lice compared to a composition comprising hydrocarbons. , but no siloxane.

It can be concluded from this test that compositions comprising linear hydrocarbons, as used herein, exhibit anti-lice and lice-killing effects. In addition, compositions comprising a combination of linear hydrocarbons and a linear siloxane, as used herein, gave better results, a faster killing effect on the lice and a greater number of lice killed, compared to a composition comprising only hydrocarbons. In addition, compositions of the invention comprising linear hydrocarbons and a linear siloxane exhibited a parasiticidal effect comparable to an active control known in the art.

Example 2: In Vitro Screening of Compositions of the Present Invention for Efficacy Against Lice Using Contact Tests This test is similar to Runs 3 and 4 of Example 1, wherein an inactive control (water), an active control, a composition of the invention, olive oil produced according to the British Pharmacopeia and two prior art compositions, a first with neem oil as active ingredient (Bioforce Neemcare Riddance) and a second with permethrin as active ingredient (Lyclear cream rinse, containing 1% permethrin). The screened compositions all affect the respiratory mechanism of lice. A composition according to the invention comprises 4 wt% dimethicone 60,000 centistokes at 25°C, 48 wt% C13 -C15 hydrocarbons and 48 wt% C18 -C19 hydrocarbons. The active control consisted of a composition comprising 96 wt% cyclomethicone and 4 wt% dimethicone (60,000 centistokes at 25°C), but no hydrocarbons. The results of this trial are presented in TABLE

5.

TABLE 5 Number of deaths (time in minutes) | hours of lice | 1 [2 [3 | 4|5|617|819[10]| warw | # [0[0|0 [0 [0[0[0/0|0 0 teen alive va | u [0 [010 0 j0[ele 0/0 0 Mi alive | Active control (1) | 10 | 8 | 9 | 10 | 10 |-—- |-|-|- |-- | = | Living | | Active Control (2) | 10 | 7 |9|10|-|=-|-| =|=|=| = | Olive | Composition according to the 0 living invention Olive oil (1 | 9 |0|0|5|5|5|/5|5|5|5| 5 | 4live | Olive oil (2) | 11 | O0 |0|1|1|1|1|2|2|2 | 2 | 9alive | First prior art composition 10 10 0 prior art composition Second prior art composition 11 4 4 7 3 prior art A composition according to the invention, the active controls (2 tests) and a first composition according to the prior art were all effective against the lice in the contact test, and showed rapid killing of live lice.

(see also FIG. 3) clearly show that active controls (both tests), a first prior art composition and a composition of the invention rapidly killed live lice compared to a second prior art composition and olive oil.

Figure 3 illustrates the absolute effects of the tested compositions compared to controls (water and active controls) in this test.

From this test it can be concluded that a composition according to the invention comprising a combination of linear hydrocarbons and a linear siloxane gives better results, in particular a faster killing effect on lice and a higher number of lice killed, compared to compositions from the prior art. of technology.

In addition, a composition of the invention exhibited a two-fold faster killing effect compared to prior art compositions.

Example 3: Evaluating the Foamability of a Range of Compositions of the Present Invention In this trial, a range of compositions of the invention were screened for their foamability.

The compositions used are shown in TABLE 6. To evaluate the foaming ability of the compositions, a container was filled with the composition.

A foam pump was attached to the container and the apparatus was shaken.

After this, the number of dispenser strokes required to obtain a volume of 0.04 liters of foam was determined.

The foaming capacity can be assessed in this way, as maximum foam volume must be obtained with a minimum number of strokes.

Poorer foam quality is indicated by a large number of strokes required to obtain the volume.

TABLE 6: Overview of compositions according to the invention and compositions thereof (in % by weight) used in the present test

S —_ S 025 ES || 2/75 2531812121 2/ 2 398838 8966615 SE] EYES ES e  SL ST 2 |1196|4 | | | LL LLL LLL 2 141 | | LLL 1961 | | | | - | 3] | 4 | 1961 VU UT | | —- | A| 141 | 1961 | | | LLL | | —- | st |4 | | | fate | [| | | | | | | 161 | | | | 1961 | | | | | | + | 7) 141 | | | | ls | | | | | + | 38) 141 | | | | LL 1961 | | | + | ol A| | | | | LLL 1961 | [| + | 0) 41 LL | | LL LL lo] [| + | il 14 LL LL Lt LLL la] - | 12] | |4| | | | ls | | | | | + | Bt | 141 | | | | 1961 | | | + | 4] | |4| | | LL | | 1961 | [| + | ist | A| | | LLL | | lo] [| + | 6] | 141 | I LL I | | | la] - | '+ indicates the ability to form stable foam '- indicates that there is no foaming Compositions 6, 7, 8, 9, 10, 12, 13, 14 and 15 formed a stable foam as defined herein.

Unstable foam was obtained with compositions 2, 3, 4, 5, 11 and 16. No foaming occurred for composition 1.

The test showed that hydrocarbons are necessary to obtain foam, as composition 1 did not generate foam.

The lowest number of strokes required to obtain a volume of 0.04 liters was observed for compositions containing C11, C12, C13, C4 or C15 hydrocarbons, while for compositions containing Cs, Cs, C10 or C16 hydrocarbons, a large number of strokes were required to obtain a volume of 0.04 liters and insufficient foam was obtained.

In addition, the foam formed for compositions containing Cs, Cs, C10,C18 hydrocarbons was unstable and therefore unsuitable for use.

In addition, results indicate that the use of branched hydrocarbons in a composition of the invention (e.g. composition 2) generates less foam.

Foam formed from compositions containing C11, Co, C13, C14 or C1 hydrocarbons and dimethicone further remained stable for a period as defined herein long enough to apply sufficient foam to the area to be treated. Example 4: In Vivo Test to Evaluate the Healing Rate of a Composition In this trial, a trial was conducted in humans to evaluate the effectiveness of a composition of the invention. A composition according to the invention comprising 4 wt% dimethicone 60,000 centistokes at 25°C, 6 wt% C19-C15 hydrocarbons and 90 wt% C16-C25 hydrocarbons and a prior art composition containing permethrin as active ingredient (NIX, 1 % permethrin) were screened.

During the trial, a total of 30 patients with head lice were treated, 15 patients with a composition of the invention and 15 patients with the prior art composition. The trial consisted of two consecutive treatments with the compositions, with the second treatment taking place 7 days after the first treatment. To determine the effectiveness of the treatment, the number of live lice and nymphs was counted at four time points: on day 1 before treatment (time 1), on day 1 after the first treatment (time 2), on day 7 before the second treatment (time 3) and on day 7 after the second treatment (time 4). The cure rates were then calculated as the percentage of individuals who were free of live lice in each group. Complete eradication was assumed when no live lice or nymphs were found in the patient. The results of this study are presented in TABLE 7.

TABLE 7 Technique This trial showed that the effectiveness of a composition of this invention is much better than treatment with a prior art composition. After a first treatment, no live lice were obtained in patients treated with a composition according to the invention, while in patients treated with a prior art composition, only 27% showed no live lice. At time 2, 76% showed no occurrence of live lice when treated with a composition of the invention, while only 33% showed no occurrence of live lice when treated with a prior art composition. From these results, it is clear that after a first treatment, the efficacy of a composition of the present invention is much higher than that of a prior art composition, since a cure rate of 76% can be obtained.

After a second treatment, no live lice were obtained in patients treated with a composition according to the invention, while in patients treated with a prior art composition, 73% showed no live lice.

Moreover, a cure rate of 76% at the second time point in the group treated with a composition according to the invention further inherently indicates that the present composition has ovicidal activity, and allows effective killing of nits.

In comparison with a composition according to the prior art, a composition according to the invention shows a better efficiency: a higher and faster killing rate and higher killing efficiency is obtained with a composition according to the invention. In this example, a preparation according to the invention showed a four times more effective kill of live lice in the short term immediately after the treatment compared to a composition according to the prior art, while in the long term a two to three times more effective treatment was obtained with a composition according to the invention.

Example 5: Preferred Examples of Compositions of the Invention The following examples illustrate various embodiments of compositions of the invention.

A first composition comprises: A) 2-6 wt% dimethicone, more preferably about 4 wt% dimethicone, e.g. from 20,000, 40,000, 60,000 or 80,000 centistokes at 25°C, and preferably from 60,000 or

80,000 centistokes at 25°C, and

B) 65 to 96 wt% of a mixture of saturated linear or branched hydrocarbons selected from the group consisting of C10, C11, C12, C13, C14, C18, C18, C17, C18, C1, Coo, Cz1, C12, C23 , C24 and C:5 hydrocarbons, and preferably - from 0.0 to 15.0 wt% C10, C11, C12, C13, C14, and/or C15 hydrocarbons, preferably from 0.0 to 10.0 wt% C10, Ci, C2Z, C2Z, C14, and/or C18 hydrocarbons and more preferably less than 9.0 wt% C19, Ci, Cn, C2z, C14, and/or C15 hydrocarbons, and more preferably less than 8, 0 wt% C10, Ci, Co, Cis, Cu, and/or C18 hydrocarbons, and more preferably less than 7.0 wt% C19, C11, Co, C23, C14, and/or C18 hydrocarbons, and more preferably less than 6.0 wt% C10, C11, Cnz, C13, C14, and/or C18 hydrocarbons, and more preferably less than 5.0 wt% Co, C1, Co, C13, C14, and/or C15 hydrocarbons, and more preferably less than 4.0 wt% C10, C1, Co, C13, C14, and/or C15 hydrocarbons, and more preferably less than 3.0 wt% Co, C1, Co, C13, C14, and/or C18 hydrocarbons, and more preferably less than 2.5 wt% C10, Ci, Cn, Ci, C14, and/or C15 hydrocarbons, and most preferably less than 2 wt% C10, Ci, Cn, C13, C14, and/or C15 hydrocarbons, and - from 0 to 20 wt% C18 hydrocarbons, preferably from 1 to 15 wt% C18 hydrocarbons and more preferably from 1 to 10 wt% C16 hydrocarbons, more preferably from 2 to 8 wt% C18 hydrocarbons, more preferably from 3 to 7 wt% C18 hydrocarbons, more preferably about 5 wt% C16 hydrocarbons, - from 0 to 30 wt% C17 hydrocarbons, preferably from 1 to 20 wt% C17 hydrocarbons and more preferably from 5 to 15 wt% C17 hydrocarbons, most preferably about 10 wt% C17 hydrocarbons, - from 0 to 30 wt% C18 hydrocarbons, preferably 1 to 20 wt% C18 hydrocarbons and with more preferably from 5 to 15 wt% C18 hydrocarbons, most preferably about 12 wt% C18 hydrocarbons, - 0 to 30 wt. w% C19 hydrocarbons, preferably 1 to 20 wt% C19 hydrocarbons and more preferably 5 to 20 wt% C19 hydrocarbons and/or more preferably 10 to 20 wt% C19 hydrocarbons, most preferably about 16 wt% C19 hydrocarbons, - from 0 to 70 wt% C2 + hydrocarbons, preferably from 20 to 65 wt% C20 + hydrocarbons and more preferably from 30 to 60 wt% C20 + hydrocarbons, and more preferably from 40 to 60 wt% C20 + hydrocarbons, most preferably about 55 wt% C20+ hydrocarbons. C) optionally between 0.1 wt% and 2 wt% of a quaternary silicone copolymer, said wt% being based on the composition.

Another preferred composition according to the invention consists of 4 wt% dimethicone

60,000 centistokes at 25°C and a residual fraction comprising saturated linear or branched hydrocarbons, and in particular less than 0.1 wt% C10 less than 0.1 wt% C11, less than 0.1 wt% C12, less than 0 .1 wt% C13, 0.5 wt% C14, 1.7 wt% Cis, 3.7 wt% Cis, 7.6 wt% C17, 9.9 wt% Cis, 16.9 wt% C19, 12, 6 wt% Cx saturated linear and/or branched hydrocarbons, 10.6 wt% C:1 saturated linear and/or branched hydrocarbons, 10.2% C+ saturated linear and/or branched hydrocarbons, 21.9% C23+ saturated linear and/or or branched hydrocarbons where the weight percent is based on the composition.

Example 6: In Vitro Evaluation of a Composition of the Present Invention for Efficacy Against Pediculus Nits Using an Immersion Test In this experiment, ten nits were immersed for 15 minutes in a composition of the present invention and placed in an incubator suitable for to hatch nits. Hatching was monitored daily for 15 days. Of the ten nits submerged, no nits emerged upon exposure to the composition, demonstrating an ovicidal efficacy of approximately 100%.

Example 7 In this test, a series of compositions consisting of 96 wt% hydrocarbons and 4 wt% dimethicone (60,000 cS) were tested for skin sensitivity and irritation. These compositions were scored from 0 (no irritation noted) to 4 (maximum irritation) in live piglets. The compositions were also tested for rinseability. The results are shown in Table 8.

TABLE 8 I= TT

Sn 2 IT on Ss |< © © O = a © ! en + mn © > co a > - N + N S S| © ©) D | D D D D D D D D © 5 sv E 2 = 183 un |17| 4 |<1|01|05| 17 | 37 | 76 | 99 |17.9|12.6|116|11.2|19.1| 0 | + | |18| 4 | 20 |15.2|37.6/25.4| 94 | 6.6 | 08|07|03| 0 [0 | 0 | 3 | + | |19| 4 [<1[01 [3.5 | 89 |18.7/274|214|112|40|05|02| 0 | 2 | + | |20| 4 |07|04|07| 12 | 78 |13.2|11.6|13.8/25.2| 98 | 47 |69 | 0 | + | |21| 4 |<1|<1|<1|01 0.1 | 0.5 | 3.5 |10.2|198|28.6/223|10.6| 0 | - | |22| 4 |48 | 0 |4|0|0|0|0|0|0|/0|0|0]| 4 | + | |24| 4 | 0 |0|4|0|48|0|0|0|0|/0|0|0]| 3 | + | |25| 4 | 0 |0|0|0|4|0|4|0|0/0|0|0| 1 | - | |26| 4 |0|10|0|0|0|0|4|0|4|0|0|0| 0 | - | ‘+ indicates the ability to apply said composition and then rinse it from both hair and scalp. "-" indicates problems with application or removal of said composition.

This trial showed that the effectiveness of a composition of this invention is much better than a composition consisting of 96 wt% hydrocarbons and 4% dimethicone which are outside the scope of the present invention.

This test shows that only hydrocarbon mixture compositions of the present invention (Composition 17 and 20) have the combination of low irritation and sufficiently high flushability.

Hydrocarbon mixtures with too many low molecular weight hydrocarbons (Cis-) have problems with skin irritation and sensitivity.

Hydrocarbon mixtures with too many high molecular weight hydrocarbons (Cıs+) have problems with flushability and/or skin irritation.

In particular, compositions comprising high molecular weight dimethicone and high molecular weight hydrocarbon mixtures are increasingly difficult to distribute evenly on the scalp and hair, and also to remove adequately from the scalp and/or hair.

Claims (15)

Conclusions An arthropod killing composition, said composition comprising at least 65% by weight of a mixture of saturated linear or branched hydrocarbons, said hydrocarbons being a mixture of saturated linear or branched C10-C16 hydrocarbons and saturated linear or branched C17 hydrocarbons C25 hydrocarbons wherein the ratio by weight of saturated linear or branched C10-C18 hydrocarbons to saturated linear or branched C17-C25 hydrocarbons is less than 15:85. The composition of claim 1, wherein the composition further comprises between 0.01 and 10% by weight of dimethicone having a viscosity of at least 20,000 centistokes at 25°C, preferably at least 40,000 centistokes at 25°C. A composition according to any one of claims 1-2, wherein the ratio by weight of saturated linear or branched C10-C16 hydrocarbons to saturated linear or branched C17-C25 hydrocarbons is less than 10:90. A composition according to any one of claims 1 to 3 wherein the ratio by weight of saturated linear or branched C10 -C16 hydrocarbons to saturated linear or branched C17 -C25 hydrocarbons is less than 5:95. A composition according to any one of claims 1-4, wherein the hydrocarbons comprise a mixture of saturated linear or branched C10-C15 hydrocarbons and saturated linear or branched C18-C19 hydrocarbons, wherein the ratio of saturated linear or branched C10-C15 hydrocarbons to saturated linear or branched C16-C19 hydrocarbons by weight between 1:100 and 1:10. A composition according to any one of claims 1-5, wherein the ratio of saturated linear or branched C10-C15 hydrocarbons to saturated linear or branched C16-C19 hydrocarbons by weight is 1:20. A composition according to any one of claims 1-6, wherein the hydrocarbons comprise a mixture of saturated linear hydrocarbons and saturated branched hydrocarbons, wherein the ratio of saturated linear hydrocarbons to saturated branched hydrocarbons is between 1:4 and 1:2. Use of a composition according to any one of claims 1-7, wherein said arthropod is an insect or arachnid, and preferably a sucking or biting louse. Use of a composition according to any one of claims 1-7, wherein a killing efficiency for said arthropods of at least 70%, and preferably of at least 75% is obtained. Use of a composition according to any one of claims 1-7, wherein a cure rate of at least 70%, and preferably of at least 75% is obtained. Use of a composition according to any one of claims 1-7 for killing arthropod eggs. Use according to claim 11, wherein a killing efficiency for said arthropod eggs of at least 70%, and preferably of at least 75% is obtained. A hair product for killing arthropods and eggs of arthropods, wherein said arthropod is an insect or arachnid, and preferably a sucking or biting louse, comprising a composition as defined in any one of claims 1 7. A device comprising a composition according to any one of claims 1-7 or a hair product according to claim 13 and means for distributing said composition or hair product. A method of killing arthropods and eggs of arthropods, wherein the arthropod is an insect or arachnid, and preferably a sucking or biting louse, comprising applying to the arthropod and the egg of the arthropod a composition as defined in any one of claims 1-7 or a hair product as defined in claim 13.