WO2009108038A1

WO2009108038A1 - Insect repellent

Info

Publication number: WO2009108038A1
Application number: PCT/MY2009/000034
Authority: WO
Inventors: Awang Soh@ Yusoff Mamat; Anuar Abd. Ghani; Engku Ismail Engku Ahmad
Original assignee: Universiti Malaysia Terengganu
Priority date: 2008-02-29
Filing date: 2009-02-26
Publication date: 2009-09-03
Also published as: MY154980A

Abstract

A controlled release insect repellent composition comprising a mixture of 70% to 95% by weight of polyethylene glycol and 5% to 30% by weight of essential oil derived from plant parts of Ocimum basilicum.

Description

INSECT REPELLENT

FIELD OF THE INVENTION

The present invention relates to insect repellent composition which the active agent for eliminating the insects is derived from a sustainable natural source. In more particular, the active agent mentioned herein is essential oil extracted from the plant parts of Ocimum basilicum.

BACKGROUND OF THE INVENTION Demand for natural products is gaining momentum due to their safety and environmental friendly characteristics. Numerous researches have been engaged in identifying potential plant-based compounds to be used for either medical treatment or industrial applications. Moreover, some of the plant-based compounds are identified to be useful as insect repellent, or even as insecticides. It is important to be noted that insect repellent or insecticide are not only used in domestic household solely for eradicating unwanted insects, but also been applied in the field of agriculture for pest control. Therefore, efficiency and safety issues of the insect repellent or insecticides used have always been the major concern to ensure the living environment or agricultural products are not contaminated by harmful chemical remnants.

In France patent publication no. 2670386, essential oil of Ocimum basilicum is employed in a skin preparation for repelling mosquitoes. In the disclosure of this France application, the essential oil is suggested to be prepared in the form of milk, cream, or pulverizing liquid for applying onto the skin.

Another United Kingdom patent publication no. 633676 is related to an insect repelling mixture containing eucalyptus oil, juniper berry oil, basil oil and camphor oil. The disclosed mixture mainly constituted of about 50% of eucalyptus oil as the active compounds for repelling the insects.

Japan patent publication no. 2003183109 claims a mosquito repellent coil incorporated with an anti-fungal agent which is dried herb matters chosen from basil, thyme, clove or cassia. The coil incorporated with the abovementioned herb dried matters is claimed to be resistance to mildewproof.

For preventing insect infestation on grain products, Japan patent application discloses an insect controlling agent containing one or any two combinations of the essential oil extracted from the plants of sage, rosemary, basil, caraway, eucalyptus, citronella, anise, orange and lavender as the active ingredient. The disclosed controlling agent in this Japan application is in solid preparation.

SUMMARY OF THE INVENTION

The present invention aims to disclose an insect repellent composition which the active ingredient of the disclosed composition is of plant-based compounds, namely essential oil of plant parts of Ocimum basilicum, which maybe further incorporated with essential oil of plant parts of Chromolaena odorata.

Another object of the present invention is to provide an eco-friendly insect repellent composition that incurs no deleterious effect towards the users or the surrounding environment while being exposed to the disclosed composition.

Further object of the present invention is to offer a highly effective insect repellent composition that is prepared in the form of high pressure spray, aerosol or solid controlled release system.

Still another object of the present invention is to provide an insecticide composition which contains high dosage of the active ingredient to be used for eradicating undesirable insects.

At least one of the preceding objects is met, in whole or in part, by the present invention, in which one of the embodiments of the present invention is a controlled release insect repellent composition comprising a mixture of 70% to 95% by weight of polyethylene glycol and 5% to 30% by weight of essential oil derived from plant parts of Ocimum basilicum. According to another preferembodiment, the controlled release insect repellent composition may further comprises 0.5% to 15% by weight of essential oil derived from plant parts of Chromolaena odorata to enhance efficiency of the composition.

For acquring the essential oil with the desired insect repelling property, the plant parts of Ocimum basilicum employed for extraction of the essential oil are leaves, while the plant parts of Chromolaena odorata are stems and/or leaves.

Another embodiment of the present invention includes also a volatile insect repellent composition comprising an isotropic mixture of 40% to 75% by weight of an emulsifϊer and/or stabilizing agent; 15% to 40% by weight of volatile hydrocarbon; and 5% to 20% by weight of essential oil derived from plant parts of Ocimum basilicum.

It is in the most preferred embodiment that 0.5% to 15% by weight of essential oil derived from plant parts of Chromolaena odorata is incorporated into the volatile composition.

Moreover, the stabilizing agent employed in the volatile composition is any one or combination of beta glucan, alginic acid, dammar gum, gellan gum, gum Arabic, guar gum, locust bean gum, sodium alginate and xanthan gum to stabilize emulsion formed within the volatile composition.

In the more preferred embodiment, volatile hydrocarbon utilized for preparing the volatile composition is any one or combination of methanol, propane, n-butane, isobutene, dimethyl ether, and methyl ethyl ether. Nonetheless, other short chain alcohol can be used in the present invention too.

As mentioned above, the plant parts for acquiring the Ocimum basilicum essential oil are leaves and plant parts for acquiring the Chromolaena odorata essential oil are leaves and/or stems. BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is a graph showing effects of Ocimum basilicum essential oil concentration to the survival number of flies by using spraying method. From the expreriment, it was found that concentration of Ocimum basilicum at 50 ppm killed the highest amount of flies. The number of flies strictly reduced to about 5- 8 after 16 minutes in this concentration compared to other treatment;

Figure 2 is a graph showing effects of Ocimum basilicum essential oil concentration to the survival number of flies by using vaporation method. From the expreriment, it was found that concentration of Ocimum basilicum at 50 ppm killed the highest amount of flies. The number flies decreased from fifteen to zero after 8 minutes application of vaporation method compared to other treatment;

Figure 3 is a graph showing effects of Ocimum basilicum essential oil concentration to the survival number of mosquitoes by using sprayer method. Generally, number of mosquitoes decreased in all concentration of Ocimum basilicum. However, it was found that concentration at 50 ppm give the best treatment and we choose this concentration because it's killed all the mosquitoes after 12 minutes compared to other concentration; and

Figure 4 is a graph showing effects of Ocimum basilicum essential oil concentration to the survival number of mosquitoes by using vaporation method. This technique gives the best results as compared to sprayer method. The concentration of 50 ppm killed all the mosquitoes after 4 minutes whilst sprayer method takes about 12 minutes to kill all the mosquitoes DETAILED DESCRIPTION OF THE INVENTION

The present disclosure includes as contained in the appended claims, as well as that of the description herein. Although this invention has been described in its preferred form with a degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangements of parts may be resorted to without departing from the scope of the invention.

On of the embodiment of the present invention relates to a controlled release insect repellent composition comprising a mixture of 70% to 95% by weight of polyethylene glycol and 5% to 30% by weight of essential oil derived from plant parts of Ocimum basilicum. It is imporant to be noted that essential oil contained within the controlled release insect repellent composition will be released or sublimated out of the composition to perform the insect repelling effect. The sublimation or release rate of the active agent, essential oil derived from plant parts of Ocimum basilicum, can be controlled by adjusting concentration of the essential oil contained within the compositon and surface area esposed to the surrounding environmnet of the composition. In more specific, greater the exposing surface area of the composition higher the essential oil release rate to attain better insect repelling effect. Similarly, lower ratio of the essential oil to the polyethylene glycol shall render the sublimation rate of the essential oil lower.

It was found by the inventors of the present invention that essential oil derives from Chromolaena odorata can further improve the repelling effect. Thus, in the most preferred embodiemnt, the controlled release insect repellent composition may further comprise 0.5% to 15% by weight of essential oil derived from plant parts of Chromolaena odorata.

Preferably, the plant parts for acquiring the essential oil which to be used as the active ingredients in the controlled release insect repellent composition are leaves of

Ocimum basilicum. Likewise, the plant parts to obtain essential oil of Chromolaena odorata are stems and/or leaves. Apparently, the essential oil can be acquired via different known methods in the art thus modification thereon shall then contain within the scope of the present invention.

In the present invention, the polyethylene glycol employed in the controlled release insect repellent composition serves as a carrier to accommodate the Ocimum basilicum essential oil. Nevertheless, one skilled in the art shall appreciate the possibility to employ other carrier types to perform the same task in releasing effective amount of active agent to repell the insect. For example, the essential oil derived from plant parts of Ocimum basilicum and/or essential oil derives from Chromolaena odorata can be carried by other solid support such as, but not limited to, nonwoven fabric, silica, talc, activated carbon, silica gel, zeolite, cellulose bead, activated carbon, ceramics and the like. The essential oil may also be incorporated with other insect repelling agent such as naphthalene, 1,4 dichlorobezne and the like to form a repelling composition alike to mothballs. Yet, the controlled release insect repellent composition in the most preferred embodiment is produced in a moldable strip.

Another embodiment disclosed in the present invention includes a volatile insect repellent composition comprising an isotropic mixture of 40% to 75% by weight of an emulsifϊer and/or stabilizing agent; 15% to 40% by weight of volatile hydrocarbon; and 5% to 20% by weight of essential oil derived from plant parts of Ocimum basilicum. Preferably, the volatile insect repellent composition mentioned herein is embodied in the form of high presure spray, aerosol and the like to be applie onto the the area where the relevant insects are not welcoming.

In the most preferred embodiment of the disclosed volatile insect repellent composition, 0.5% to 15% by weight of essential oil derived from plant parts of Chromolaena odorata is further included into the isotropic mixture thus improving the efficiency of the insect repelling capability.

Preferably, the isotropic mixture of the volatile hydrocarbon and the essential oil of Ocimum basilicum, possibly with the essential oil of Chromolaena odorata, should form an emulsion which may be stabilized using a stabilizing agent with or without the use of an emulsifϊer. It is preferred that the stabilizing agent employed is derived from natural sources such as, but not limited to, any one or combination of beta glucan, alginic acid, dammar gum, gellan gum, gum Arabic, guar gum, locust bean gum, sodium alginate and xanthan gum.

For preparing the volatile insect repellent composition, volatile hydrocarbon used in the present invention can be any one or combination of methanol, propane, n-butane, isobutene, dimethyl ether, and methyl ethyl ether. Yet, it is most preferred that methanol is used.

As mentioned in the foregoing, the plant parts for acquiring the essential oil of Ocimum basilicum are leaves and the plant parts for obtaining Chromolaena odorata essential oil are stems and/or leaves.

It is important to be noted that the disclosed volatile insect repellent composition at its optimal dosage can serve as insecticide as shown in the appended experiment results below.

The following example is intended to further illustrate the invention, without any intent for the invention to be limited to the specific embodiments described therein.

Example 1

The whole plants included leaves, stems and roots were collected. The steam distillation technique was done to obtain essential oil and water extract. The essential oil was then separated from the water extract.

In this experiment, 40 flies and 40 mosquitoes were used respectively. The different concentrations of Ocimum basilicum essential oil at concentration of 10 ppm, 20 ppm, 30 ppm, 40 ppm and 50 ppm were tested on the insects via two different methods, spraying method and evaporation method. Results of the conducted experiments are as shown in Figure 1, Figure 2, Figure 3 and Figure 4. One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiment describes above is not intended as limitations on the scope of the invention.

Claims

CLAIMS:

1. A controlled release insect repellent composition comprising a mixture of 80% to 95% by weight of polyethylene glycol and 5% to 30% by weight of essential oil derived from plant parts of Ocimum basilicum.

2. A controlled release insect repellent composition according to claim 1 further comprising 0.5% to 15% by weight of essential oil derived from plant parts of Chromolaena odorata.

3. A controlled release insect repellent composition according to claim 1 or 2, wherein the plant parts of Ocimum basilicum are leaves.

4. A controlled release insect repellent composition according to claim 2, wherein the plant parts of Chromolaena odorata are stems and/or leaves.

5. A volatile insect repellent composition comprising an isotropic mixture of

(a) 40% to 75% by weight of an stabilizing agent and/or emulsifier;

(b) 15% to 40% by weight of volatile hydrocarbon; and (c) 5% to 20% by weight of essential oil derived from plant parts of

Ocimum basilicum.

6. A volatile insect repellent composition according to claim 5 further comprising 0.5% to 15% by weight of essential oil derived from plant parts of Chromolaena odorata.

7. A volatile insect repellent composition according to claim 5 or 6, wherein the stabilizing agent is any one or combination of beta glucan, alginic acid, dammar gum, gellan gum, gum Arabic, guar gum, locust bean gum, sodium alginate and xanthan gum.

8. A volatile insect repellent composition according to claim 5 or 6, wherein the volatile hydrocarbon is any one or combination of methanol, propane, n- butane, isobutene, dimethyl ether, and methyl ethyl ether.

9. A volatile insect repellent composition according to claim 5 or 6, wherein the plant parts of Ocimum basilicum are leaves.

10. A volatile insect repellent composition according to claim 6, wherein the plant parts of Chromolaena odorata are stems and/or leaves.