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Herbal Mosquito Repellents

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Abstract

ABS TRACT Herbal mosquito repellent preparations (Liquid vaporizers, Absorption base &water removable base ointments) were formulated, prepared & evaluated to study the mosquito repellent effect of citronella oil(Cymbopogon nardus) & peppermint oil (Mentha piperita). PEG 200 and deodorized kerosene oil were incorporated to study the rate of vaporization from the preparations. Vaporizers containing deodorized kero sene oil were appreciated for mosquito repellent effect. The present study deals with the preparation and evaluation of citronella and peppermint oil vaporizers and a combination of both essential volatile oils along with the preparation and evaluation of absorption base ointments and water removable base ointments. Citronella oil and peppermint oil had a good amount of vaporization. The hybrid preparation was prepared by using the combination of both vaporizers of citronella and peppermint oil. The prepared hybrid vaporizer was satisfactory, and found to have a good rate of vaporization. Absorption base ointments, when applied on the skin showed longer duration of action and were better appreciated by the volunteers than when compared to water removable base ointments. Partitioning and nonpartitioning of citronella and peppermint oil among the fatty/oily ingred ients of the absorption and water removable ointment base s was attributed for the slow release of the oils from the preparation.
Nikhil Prashant A. et al., Jour. of Sci. Res. in Phar. 2012, 1(2), 82-84
Journal of Scientific Research in Pharmacy 2012, 1(2) 82-84
Journal of Scientific Research in Pharmacy Research Article
Available online through ISSN: 2277-9469
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Herbal Mosquito Repel lents
Nikhil Prashant A*, J. V. C. Sharma, Suryakanth Naule, Shyam Sunder K, and Sundeep Reddy Ch.
Nikhil Prashant Akula, Dept. of Pharm aceutics, M.L.R. Institute of Pharmacy, Dundigal (V), Quthbullapur (M), R.R.Dist, Hyd-49.
Received on: 11-06-2012; Revised on: 11-06-2012; Accepted on: 19-06-2012
ABSTRACT
Herbal mosquito repellent prep arations ( Liquid vaporizers, Absorption base &water removable base ointments) were formulated, prepared
& evaluated to study the mosquito repellent effect of citronella oil( Cymbopogon n ardus) & peppermint oil (Mentha piperita). PEG 200 and d eodorized
kerosene oil were incorporated to study the rate of vaporization from the p reparations. Vaporizers containing deodorized kerosene oil were
appreciated for mosquito rep ellent effect. The present study d eals with the preparation and evaluation of citronella and peppermint oil vaporizers and a
combination of both essential volatile oils along with the p reparation and evaluation of absorption base oin tments and water removable base
ointments. Citronella oil and p eppermint oil had a good amount of vaporization. The hybrid preparation was prep ared by using the combination of both
vaporizers of citronella and peppermint oil. The p repared hybrid vaporizer was satisfactory, and found to have a good rate of vaporization. Absorption
base ointments, when applied on the skin showed longer duration of action and w ere better appreciated by the volunteers than wh en compared to
water removable base ointments. Partitioning and nonpartitioning of citronella and peppermint oil among the fatty/oily ingred ients of the absorption
and water removable ointment bases was attributed for the slow release of the oils from the preparation.
Key words: Ci tronella oil, peppermint oil, deodorized kerosene, Absorption ointment bases, water removable ointment bases.
INTRODUCTION
N, N diethyl-3-methylbenzamide (DEET), used by millions
of peopl e worldwide is a synthetic mosquito repellent. Inspite of its
safety profile, a number of reports have showed its toxicity against the
skin, u sually when the repellent is used incorrectly (or) in the long term
[1]. The u ndesirable effects of DEET are undesirable odour, subchronic
toxicity, mutageni city, rep roductive and neu rological toxicity [ 2, 3].
Citronella (Cymbopogon nardus) [4] is a resilient grass that is n ative to
srilanka and java. It is one of the most dominant insect rep ellent before
DDT. It is used in combination with cedar wood to produce a pleasant
swellin g as a natural repellent. It has antiseptic, antifungal [5, 6]
deodorant, insecticide and as well as stimulant medicinal properties.
Pepp ermint (Mentha piperita) [7] is native to Europe, India and North
America. Its most i mportant constituent is menthol which is used for
respiratory congestion, headache and muscle pain. It has a mild insect
repellent property and is used as a carminative, antispasmodic, antiviral
and antifungal. The major objective of the current study was to prepare
individual herbal mosquito rep ellent formulations of ci tronella oil,
peppermint oil, an d hybrid preparations and to eval uate them for their
duration of action and minimiz ation of ill effects.
MATERIALS AND METHODOLOGY
Citronella grass and peppermint were obtained from the
medicinal plant garden of dhulapally forest academy, hyd. The fresh
leaves were subjected to trituration and steam d istillation in Cleveng er
type apparatus [ 8]. After 3 hours of distillation, the essential oils were
extracted and were sealed in gl ass vial s an d stored for fu rther use. The
reagents used were of analytical grade.
METHOD OF PREPA RATION: [9]
Mosquito Repellent Vaporizers - 6 vaporizers were formulated and
prepared for their rate of vaporization and mosquito repellent effect.
Citronella oil was diluted with PEG200 and deodorized kerosene to get
*Correspond ing author:
Nikhil Prashant A
Dept. of Pharmaceutics, M.L.R. Institute of Pharmacy, Dundigal (V),
Quthbullapur (M), R.R.Dist, Hyderabad-49. Telephone: 9177534383.
*E-Mail: nikhilprashant@gmail.com
desired effect of repellency and rate of vap orization and vice versa with
peppermint oil. The homogeneous mixture obtained was transferred into
vaporizers.
Hybrid Preparation - The best p reparation from citronell a oil and
peppermint oil was selected an d a hybrid was prepared. This
preparation contains a combination of citronella and peppermint oils,
dilu ted by using PEG200 and deodorized kerosene. This homogenous
preparation was transferred into vaporizers and evaluated.
Evaluation:
The liquid vaporizers were evaluated by reported method [10] .
The prepared liquid vaporizers (25ml) were d istributed amongst six
volunteers and were informed to use this preparation in their rooms
with time duration of 7 h ours/day for 45 days without opening the
wind ows. Th ey were asked to switch on the ceilin g fan while using the
preparation for proper air flow in the room. Th e volunteers appreciated
the preparation for its mosquito repellent effect as well as its rate of
vaporization.
Preparation of Ointments:
Four ointment fo rmulations of citronella an d peppermint oil
were prepared by fusion method [ 11] u sing absorption bases and water
removable bases in differen t proportions. (Tables IV, V, VI & VI I) All
aqueous p hase ingredients (parabens and water) w ere kept in a beaker
and mix them until they get dissolved completely. Wh ile oil phase
ingredients were kep t in a porcelain dish or glass beaker and heated on
the water bath up to 70oc. On other hand, aqueous phase ingredients
were al so kept at the same temperature an d then aqueous phase
componen ts are mixed , combined, melted together with oil p hase
componen ts at 72oc and cooled, then drug is added at 45 -50oc with
constant stirring un til congealing occurs and a homogenous mixture is
formed. Once congealed, the ointment may be further levigated on the
ointment slab. Then the preparation was transferred into the container.
keep all water soluble ingredients (PE G, parabens and water)
in a beaker and mix them until they get dissolved compl etely whil e oil
soluble ingredients were kept in a p orcelain dish or glass beaker and
heated on the water bath at 7 0-75oc. On other hand, water soluble
ingredients were also kept at the same temperature and then w ater
soluble components are mixed, combined, melted together with oil
soluble components and cooled, then drug is added at 45-50oc with
constant stirring un til congealing occurs and a homogenous mixture is
formed. Once congealed, the ointment may be further levigated on the
ointment slab or if a large volume is being prepared, a commercial mill
can be used. Then the preparation was transferred in to container.
Nikhil Prashant A. et al., Jour. of Sci. Res. in Phar. 2012, 1(2), 82-84
Journal of Scientific Research in Pharmacy 2012, 1(2) 82-84
Evaluation of Ointments:
The mosquitoes were kept fas ting for overnight and
transferred in a transparent glass chamber which has an opening for the
insertion of forearm in order to take the readings. P repared ointments
were applied on the hand which is covered w ith the gl oves and a small
area of the gloves was cut (3 "diameter) from the centre p ortion to
expose that portion for the mosquitoes and then inserted in the glass
chamber. It was observed that the hun gry mosquitoes struck the hand as
soon as it entered the glass chamber. It was observed that the hungry
mosquitoes struck the hand as soon as it entered the glass chamber.
Evaluation was performed by counting the number of stings per minute
on the part of the forear m exposed. Th e prepared oin tments were
appl ied to the exposed area of the forearm. The effec t was performed for
3 hrs at 1 hr time intervals. The same process was repeated for the
evaluation studi es of the next ointment. Absorption and water
removable ointment bases without citronella and peppermint oil were
used as controls.
RESUL TS
When the vap orizers were evaluated for their mosquito
repellent effect and rate of vaporization, it was found (Table 1 & 2) that
V-3 preparation showed satisfactory results.V -1 showed intermediate
effect and V-2 d idn’t did not show any effect n or an y increased duration
of action. Vap orizers containing PEG 200 and deodorized kerosene were
used as control and were devoid of mosquito repel lent property. The
best vap orizer formulation V-3 of both citronella and peppermint oil
were selected, combined and named as hybrid wh ich was appreciated
for its mosquito repel lent effect and rate of vap orization. (Table 3)
When the ointments were ap plied on the hand and were inserted into
the chamber (T able 8 & 9) it was noticed that absorption base
ointments showed noticeable effect and an increased duration of action
whereas the action was short for water removable base ointments.
Table No.1: Different v aporizer formulations of Citronella oil
Table No. 2: Different vaporizer formulations of peppermint oil
Ingredients
V1 (%)
V2 (%)
V3 (%)
Peppermint oil
10 %
10 %
10 %
PEG-200
5 %
Q.S
---
Deodorized kerosene
Q.S
---
Q.S
Vaporization (ml/hr/day)
0.008
---
0.070
Table No. 3: Hybrid Vaporizer formulation
Ingredients
V (%)
Peppermint oil
5
Citronella oil
5
Deodorized Keros ene
Q.S
Rate of vaporization
0.05
Table No. 4: Different formulations of absorption and water removable base ointments
WR-I
6ml
0.75 gm
3.75 ml
5ml
14.5 gm
5gm
15ml
Table No. 5: Different for mulations of Absorption base ointments of citronella oil
INGREDIENTS
AB-I
AB-II
Citronella oil
5 ml
5 ml
Methyl paraben
0.15 g
0.15 g
Lanolin
1 g
1 g
Propylene glycol
6 ml
7.5 ml
Stearyl alcohol
12.5 g
11.5 g
White petrolatum
11.5 g
12.5 g
Purified water
13.85 ml
12.35 ml
Table No. 6: Different formulations of water removable base ointments of peppermint oil
INGREDIENTS
WR-I
WR-II
Peppermint oil
6ml
6ml
Methyl paraben
0.75 gm
0.75 gm
PEG-200
3.75 ml
5ml
Propylene glycol
5ml
6ml
Stearyl alcohol
14.5 gm
13gm
White petrolatum
5gm
4.25 gm
Purified water
15ml
15ml
Ingredients
V1 (%)
V2 (%)
V3 (%)
Citronella oil
10 %
10 %
10 %
PEG-200
5 %
Q.S
---
Deodorized kerosene
Q.S
---
Q.S
Vaporization rate (ml/hr/day)
0.00 7
---
0.051
Nikhil Prashant A. et al., Jour. of Sci. Res. in Phar. 2012, 1(2), 82-84
Journal of Scientific Research in Pharmacy 2012, 1(2) 82-84
Table No. 7: Different formulations of Absorption base ointments of peppermint oil
INGREDIENTS
AB-I
AB-II
Peppermint oil
5 ml
5 ml
Methyl parab en
0.15 g
0.15 g
Lanolin
1 g
1 g
Propylene glycol
6 ml
7.5 ml
Stearyl alcohol
12.5 g
11.5 g
White petrolatum
11.5 g
12.5 g
Purified water
13.85 ml
12.35 ml
Table No. 8: Evaluation of Absorpt ion & Water removable base ointments of Citronella oil
Number of stings/minute.
Time (hr)
Control
Absorption base ointment
Water removable base ointment
I
II
I
II
1
15
0
0
0
1
2
3
2
1
3
3
6
7
5
4
Table No. 9: Evaluation of Absorpt ion & Water removable base ointments of Peppermint oil
Number of stings/hour.
Time (hr)
Control
Absorption base ointment
Water removable base ointment
I
II
I
II
1
15
0
0
0
0
2
1
3
2
1
3
4
6
7
4
DISCUSSION
Onl y V-3 vaporizers formulations from both the oils showed
desired rate of vaporization an d mosquito repellen t effect whereas V-1
and V-2 vaporizer formulations didn’t showed the desired effect. The
hybrid preparation was appreciated for its mosquito repellen t effect and
rate of vaporization. When PEG 200 was added, the rate of vaporization
was decreased and the bound ary layer thickness was increased which
was overcome by the surface molecules of both the oils to leave the
surface in indi vidual and hybrid preparations.V-2 preparation, showed
least effect and V-1 showed intermediate effect. All the volun teers
appreciated the ointments prepared from absorption bases and water
removable bases. Absorption base s were sticky and less irritating but
showed desired du ration of action. C itronella and peppermint oils
partition between the in gredients of the absorption bases and oil
releases slowly showing increased duration of action. AB II f ormulation
was best amongst a bsorption base ointments.
Water removable bases are O/W type emulsions and were
easily removed by water, but thei r duration of action was n ot as long as
absorption bases. The oin tment bases containing both the oils didn’t
partition among the water removable bases and escaped out from the
base when applied on the skin, thus, showing short duration of action.
WR1 p reparation was found to be best amongs t w ater removable base
ointments.
CONCLUSION
It is conclud ed that deodorized kerosene red uced the rate of
vaporization and hybrid preparation of the oils was m ost effective.
Absorption an d Water removable bases were equally effective but
Absorption bases showed longer du ration of action.
ACKNOWLEDGEMENTS:
Authors are thankful to Prof. JVC Sharma, H.O .D
(Pharmacognosy dept.) of M.L.R Insti tute of Pharmaceutical S ciences i n
guid ing us to do our research work.
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Source of support: Nil, Conflict of interest: None Declared
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Article
This review is intended to provide the reader with an overview of the all-purpose topical insect repellent N,N-diethyl-3-methylbenzamide (deet), with emphasis on its pharmacokinetics, formulation, and safety aspects. N,N-diethyl-3-methylbenzamide is effective against a variety of mosquitoes, flies, fleas, and ticks, and its protection efficacy depends on factors such as type of formulation, application pattern, physical activity of the user, environment, and species and feeding behavior of the insects. It offers an inexpensive and practical means of preventing the attack of biting insects and, more importantly, the transmission of vector-borne diseases. In both humans and animals, deet skin penetration and biodistribution are rapid and extensive, and metabolism and elimination appear to be complete. As evidenced by over 4 decades of human experience and rigorous animal testing, deet is generally safe for topical use if applied as recommended, although it has occasionally been related to side effects such as toxic encephalopathy, seizure, acute manic psychosis, cardiovascular toxicity, and dermatitis, along with a few cases of death due to extensive skin absorption. N,N-diethyl-3-methylbenzamide may compete in metabolism with and alter the biodistribution properties of other compounds to which a subject is simultaneously exposed, resulting in an added risk of side effects. The appropriate use of formulation techniques and new formulation excipients not only offers a way to extend the duration of protection, but also reduces deet skin penetration. In addition to extended repellency, minimal skin penetration of deet should be an important consideration in the evaluation of a deet formulation during new product development.
Article
The worldwide threat of arthropod-transmitted diseases, with their associated morbidity and mortality, underscores the need for effective insect repellents. Multiple chemical, botanical, and "alternative" repellent products are marketed to consumers. We sought to determine which products available in the United States provide reliable and prolonged complete protection from mosquito bites. We conducted studies involving 15 volunteers to test the relative efficacy of seven botanical insect repellents; four products containing N,N-diethyl-m-toluamide, now called N,N-diethyl-3-methylbenzamide (DEET); a repellent containing IR3535 (ethyl butylacetylaminopropionate); three repellent-impregnated wristbands; and a moisturizer that is commonly claimed to have repellent effects. These products were tested in a controlled laboratory environment in which the species of the mosquitoes, their age, their degree of hunger, the humidity, the temperature, and the light-dark cycle were all kept constant. DEET-based products provided complete protection for the longest duration. Higher concentrations of DEET provided longer-lasting protection. A formulation containing 23.8 percent DEET had a mean complete-protection time of 301.5 minutes. A soybean-oil-based repellent protected against mosquito bites for an average of 94.6 minutes. The IR3535-based repellent protected for an average of 22.9 minutes. All other botanical repellents we tested provided protection for a mean duration of less than 20 minutes. Repellent-impregnated wristbands offered no protection. Currently available non-DEET repellents do not provide protection for durations similar to those of DEET-based repellents and cannot be relied on to provide prolonged protection in environments where mosquito-borne diseases are a substantial threat.
Antibacterial and antifungal activity of ten essential oils in vitro
  • S Patnaik
  • V R Subramanyam
  • C Kole
Patnaik S., Subramanyam V. R., Kole C. "Antibacterial and antifungal activity of ten essential oils in vitro", Microbios. 2006: Vol. 86(349); pp237-246.
Hydro-distillation of oils from aromatic herbs, Perfum Flavor
  • E F K Denny
Denny E.F.K. Hydro-distillation of oils from aromatic herbs, Perfum Flavor. 1989; 14: 57-63.