CH625121A5 - Process for preparing an insecticidal shampoo - Google Patents

Description

The present invention relates to a process for the preparation of an insecticidal shampoo comprising a wetting agent and to the use of the products obtained as parasiticides and insecticides, particularly for the treatment of dogs against ticks and fleas.

Various components are known which are capable of destroying insects such as DDT, hexachlorocyclohexane or lindane. However, these products are generally in powder form, and their high toxicity makes them dangerous to use by direct contact with the skin of mammals.

However, if we take the example of lice and fleas, these plagues preferably affect young individuals, therefore individuals particularly sensitive to toxic substances.

In addition, it is known that certain acid constituents in liquid form such as acetic acid are active against insects and parasites, in particular when these products are used in concentrated solution at a pH close to 2.

However, at these pHs, the liquid products would appreciably attack the skin so that they are forced to use them in dilute solution, which significantly reduces their effectiveness.

The object of the present invention is the process, defined in claim 1, making it possible to obtain stable products which overcome these drawbacks and whose action makes it possible, on the one hand, to effectively suppress insects and parasites and , on the other hand, to prevent the return on the treated parts.

The process according to the invention can consist in adding from 2 to 12% by volume of acetic acid, so as to adjust the pH of the whole to a value lower than 3.5, as well as 0.5 to 20%, more particularly 0.5 to 3%, by volume of insecticidal and / or parasiticidal substances derived from natural substances or obtained by synthesis, such as extracts or essences of cloves, lavender, peppermint, oregano, rosemary, lime, juniper, lemon, lemongrass, thyme, Datura stramonium, pine, pyrethrum, pyrethrin and essential oils of bark or Ceylon cinnamon leaves.

In addition, one can advantageously add an insect repellent and healing substance such as natural or synthetic camphor, in proportions by volume of between 1.5 and 5% and preferably between 0.5 and 1.5%.

To better understand the advantages and highlight the mode of action of the shampoos obtained by the process according to the invention, the following will be described examples of carrying out the process as well as the use of the products obtained.

For each formulation, it will be noted that the proportion of wetting agent is important.

Indeed, it has surprisingly been found that the insecticidal effect of acetic acid is considerably increased by the addition of wetting agents such as sodium laurylesulfates, ammonia or triethanolamine, conventional cationic bases or the nonionic products conventionally used in the field of shampoos and that the products thus obtained were remarkably stable.

This observation can be verified using the following test, carried out on weevils, ants, earwigs, lice and fleas: we dilute, in thirds by volume, the product produced in the examples described below then place a few drops on each insect caught between coverslips, so that the body of the insect is impregnated about three-quarters.

We then measure the time necessary for the insect to no longer be moved. This time is compared to that obtained using an aqueous solution of acetic acid of equivalent pH.

The results observed show that the times are on average two to five times shorter in the case of shampoo than in the case of pure acetic acid (20 to 50 seconds instead of 1 to 3 minutes).

Example 1:

Shampoo effective against lice.

The proportions are indicated by volume.

Texapant "wetting agent - N 40 (Henkel) diluted to 30% 75 to 95%

Synthetic camphor 0.5 to 1.5%

Lemongrass 0.5 to 1.5%

Acetic acid 5 to 10%

Ph 1.8 to 3.5%

The process for preparing the stable shampoo is as follows:

A solution of Texapant11 wetting agent is prepared which is diluted to 30% in water using a tank fitted with a slow speed stirrer.

The synthetic camphor and the citronella are then introduced in the proportions indicated above until complete dissolution.

Technical acetic acid is then introduced slowly, via a separating funnel, by controlling the pH, for example using a pH meter.

The addition of acetic acid is stopped when the pH is close to 3 and the stirring is stopped after 5 min.

Treatment of fleas, lice and ticks in dogs.

We used a shampoo prepared as described above, containing 6% acetic acid, 1.5% lemongrass and 1.5% clove oil, and 91% Texapant * diluted to 30% (pH adjusted to 2).

An adult dachshund dog infested with fleas is treated.

Washing with a shampoo of the above veterinary formula is carried out one morning at 8 a.m. At 12 noon the dog no longer has fleas and is no longer contaminated for 3 days despite an unfavorable environment.

A maintenance treatment consisting of spraying a lotion consisting of a 25% thyme decoction solution, 73% apple cider vinegar and 2% lemongrass prevents any return of the parasites until complete disinfection of the environment (premises and fabrics) using the products of Example 3.

5

10

15

20

25

30

35

40

45

50

55

60

65

3

625121

Example 2:

Treatment of premises and fabrics.

We used a shampoo prepared as in Example 1 and composed of 10% acetic acid, 2% citronella essence and 2% camphor (pH adjusted to 1.8).

In a room that has been vacant for some time and has been poorly closed, containing disparate objects and fabrics, a proliferation of fleas has been observed.

After storage of the objects, the carpet covering part of the floor and the tiles are sprayed with the shampoo diluted in twice its volume of water. 2 hours later, the fleas no longer show any signs of life.

Likewise, dog coats, blankets and baskets have been successfully treated by treating them with solutions of 5 cm3 of shampoo per 11 of water.

In general, the mode of action of the products obtained by the process according to the invention is as follows: shampooing of the parts to be treated is carried out using the products described above, the products are left to act for a duration generally between 1 and 10 minutes for individuals and between 5 and 20 minutes for objects.

Rinse thoroughly, resulting in acetic acid or its equivalents as well as insects and parasites.

After washing, it is found that the insect repellants remain in sufficient quantity to protect against new infections.

However, in many cases, it is advantageous to continue the treatment with successive washes spaced until the larvae have completely disappeared, as well as to apply a maintenance treatment comprising sprays or sprays of the different species of insecticide or parasiticide products mentioned. above, with or without camphor but preferably without acetic acid, that is to say, lemon grass, clove oil, lavender, peppermint, oregano, rosemary, lime, juniper, lemon, thyme, Datura stramonium, pyrethrum or Ceylon cinnamon essential oil.

These sprays durably protect the subjects between each shampoo.

We also compared the insecticidal action of the shampoo in accordance with that used in case 1 of Example 1 with respect to a preparation of lindane powder at 15% by weight as follows:

1. Tests on an adult louse:

In a dish, put 5 cm3 of pure shampoo, then place 5 lice (Pediculus humanus) in it. Death is immediate. In order to be certain of the result, another test was made by leaving the lice in the shampoo for only 10 s and removing them with a wooden stick. We put them under a magnifying glass and we note the actual death of lice.

The operation is carried out in the same way with the shampoo diluted to 50% then to 25%, in order to approach the use concentrations which vary from 25 to 100%.

Lice death is slower with these two dilutions, and the lice recovery test shows that after 30 s the lice do not come back to life.

The same tests are carried out on the species Phtiriuspubis with the same percentage of mortality of 100% after 30 s. These tests are repeated in comparison with a 1.5% powdered lindane preparation.

(Table at the top of the next column)

The same test was carried out on adults of Phtirius pubis with identical results.

The product is therefore more active than a 1.5% lindane formulation.

The table below summarizes the results obtained. Tests on adult Pediculus humanus:

Percentage of mortality

After 10 s

After 30 s

After 2 h

R.S. 206 pure

100%

100%

100%

R.S. 206 diluted to 50%

20%

100%

100%

R.S. 206 diluted to 25%

0%

100%

100%

Lindane powder

at 1.5%

0%

0%

50%

The 0.4 and 0.8% Lindane formulations have insufficient action to be used as a comparison.

In addition, the bacteriostatic action of the products by the process according to the invention has been verified, and this although they do not contain any of the bactericides usually used such as methyl paraoxyben-zoate, but various tests have shown that no bacteria only developed in the pure product or diluted to 50%.

The study made to verify that the preparation was free of bacteria was continued in front of the interesting results obtained.

The technique used was as follows, with the shampoo prepared according to Example 1:

1) inoculation on ordinary agar,

2) storage in an oven at 37 ° C for 48 h and then for 7 days.

Results:

After 48 h After 7 days

Pure shampoo 0 colony 0 colony

Shampoo diluted to 50% 0 colony 0 colony

After seeding with Escherichia coli:

After 48 h After 7 days

Pure shampoo 0 colony 0 colony

Shampoo diluted to 50% 0 colony 0 colony

Finally, the toxicities noted can vary significantly, which reinforces the interest of the acetic acid associated in synergy with a wetting agent, giving it an increased insecticidal power while maintaining its toxicity within limits entirely compatible with its use in contact with sensitive skin.

Indeed, the F.O. obtained by administration of the shampoo in accordance with Example 1 to male river mice, of average weight: 25 g, indicates for maximum tolerated dose 24 ml / kg and for lethal dose 100, a value of 40 ml / kg.

The results do not allow a lethal dose 50 to be evaluated. By comparison, it may be recalled that the lethal dose 50 for lindane, observed with aqueous preparations administered orally to mice, is approximately 300 mg / kg.

Finally, the study of local skin tolerance made it possible to determine a primary irritation index of 0.3, therefore low; the repeated application tests on the mouse ear made it possible to conclude that the shampoo was not irritating, and the repeated applications on the rabbit's coat showed excellent tolerance.

Only eye tests suggest that the shampoo may be irritating but that this irritant action is very weak after dilution corresponding to the use of the product.

Other applications and variants of the invention will be easily carried out by those skilled in the art without departing from the scope of the invention, in particular by substituting equivalents with the various products described above, for example by replacing the acetic acid by homologous acids, but it was found that the results obtained could be significantly lower, in particular with propionic and caprilic acids.

5

10

15

20

25

30

35

40

45

50

55

60

65

R

Claims (9)

625121 1. Process for the preparation of an insecticidal shampoo comprising a wetting agent, characterized in that at least one organic acid having from 2 to 8 atoms is introduced into the mixture, in a proportion by volume of between 1 and 25% carbon, so as to bring the pH of the whole to a value lower than 4.5. 2. Method according to claim 1, characterized in that from 2 to 12% by volume of acetic acid is added so as to bring the pH of the whole to a value less than 2.5. 2 3. Method according to one of claims 1 or 2, characterized in that 0.5 to 20% by volume of substances, natural or synthetic, insecticides and parasiticides belonging to the class consisting of extracts or essences are added. cloves, lavender, peppermint, oregano, rosemary, linden, juniper, lemon, lemongrass, thyme, Datura stramonium, pine, pyrethrum and pyrethryne, and the essential essences of bark or Ceylon cinnamon leaves. 4. Method according to claim 3, characterized in that from 0.5 to 3% by volume of citronella is added. 5. Method according to one of claims 1 to 4, characterized in that synthetic or natural camphor is added in proportions of between 0.5 and 5% by volume. 6. Method according to claim 5, characterized in that 0.5 to 1.5% by volume of camphor is added. 7. Method according to one of claims 1 to 6, characterized in that sodium lauryl sulfate is used as the wetting agent. 8. Use of the products obtained by the process according to claim 1 as parasiticides and insecticides. 9. Use according to claim 8 for the treatment of dogs against fleas and ticks.