PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Insect Repellents”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed1990

Development & evaluation of controlled release formulations of DEPA, an insect repellent.

Three controlled release formulations of the insect repellent DEPA (N, N-Diethyl phenylacetamide), Depa-A, Depa-B and Depa-C have been developed and tested on human subjects against Aedes aegypti adult mosquitoes for repellency and the results were compared to those of a solution of DEPA (Depa-0). The increase in the protection time of the formulations, as compared to Depa-0 was compared. Depa-B was found to be effective with a protection time of 7.13 and 6.15 h and percentage increase in protection time of 44.5 and 38.2 at the two application rates of 0.5 and 0.25 mg/cm2 of the repellent. This observation agreed with the studies carried out on the evaporation of the repellent formulations on two models, on adsorbing and nonadsorbing surfaces for the relative adsorption and evaporation by analysing the repellent concentrations, using an infrared spectrophotometer.

Acetamides↗
PubMed1997

Insect repellents: an overview.

The optimal management of arthropod bites is prevention, and many over-the-counter insect repellents are available. Since first marketed in 1956, deet has remained the most effective repellent against mosquitoes, biting fleas, gnats, and chiggers. Permethrin is applied to clothing rather than to skin, and it is a better repellent against ticks than deet. The risk of serious side effects with the use of deet is slight; nevertheless, the lowest effective concentration should be used. The current, popular repellent agents (for adults and children) and their active ingredients are discussed. In addition, the Environmental Protection Agency guidelines for the safe use of insect repellents are supplied.

Adult↗
PubMed2002

Comparative efficacy of insect repellents against mosquito bites.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Animals↗
PubMed1994

Retrospective analysis of calls to poison control centers resulting from exposure to the insect repellent N,N-diethyl-m-toluamide (DEET) from 1985-1989.

This study analyzed 9,086 human exposures involving N,N-diethyl-m-toluamide--containing insect repellents that were reported to Poison Control Centers from 1985-1989. Nearly two-thirds of those exposed had no adverse effects or only experienced minor symptoms that resolved rapidly. Symptoms were more likely to occur after ocular or inhalation exposures and least likely to occur if the product was ingested. The only reported death occurred in a patient who suicidally ingested 8 oz of an insect repellent containing N,N-diethyl-m-toluamide. Five patients may have experienced a serious or potentially life-threatening effect but the poison center record did not provide unequivocal substantiation of the effect or clearly establish N,N-diethyl-m-toluamide as the causative agent. From the analysis of those patients calling Poison Control Centers, it appears the risk of serious medical effects with the labeled use of N,N-diethyl-m-toluamide-containing insect repellents is low in comparison with its reported annual use by about 30% of Americans. For patients contacting Poison Control Centers, the occurrence of adverse effects appears to be related to the route of exposure rather than age or gender of the patient or the concentration of N,N-diethyl-m-toluamide in the product.

Adolescent↗
PubMed2001

Laboratory and field evaluations of the insect repellent 3535 (ethyl butylacetylaminopropionate) and deet against mosquito vectors in Thailand.

The insect repellents 3535 (ethyl butylacetylaminopropionate or IR3535) and deet (N,N-diethyl-3-methylbenzamide) were prepared as 20% solutions in absolute ethanol and evaluated for repellency against many mosquito species in Thailand under laboratory and field conditions using human subjects. In the laboratory, 0.1 ml was applied per 30-cm2 of exposed area on a volunteer's forearm (0.66-0.67 mg active ingredient [AI]/ cm2), whereas in the field, volunteers' legs (from knee to ankle, with a surface area of about 712-782 cm2) were treated with 3 ml per exposed area (0.76-0.84 mg AI/cm2). In the laboratory, both IR3535 and deet showed equal repellency (P > 0.05) for 9.8 and 9.7 h against Aedes aegypti, for 13.7 and 12.7 h against Culex quinquefasciatus, and for 14.8 and 14.5 h against Cx. tritaeniorhynchus, respectively. Anopheles dirus was significantly less sensitive to IR3535 than to deet (P < 0.05), with a mean protection time of 3.8 and 5.8 h, respectively. Under field conditions, both IR3535 and deet provided a high degree of protection against various mosquito vectors ranging from 94 to 100% during the test periods. Both repellents provided a high level of protection for at least 8 h against Ae. albopictus and for at least 5 h against Cx. gelidus, Cx. tritaeniorhynchus, Cx. quinquefasciatus, Mansonia dives, Ma. uniformis, Ma. annulata, Ma. annulifera, Anopheles minimus, and An. maculatus. This study clearly documents the potential of IR3535 for use as a topical treatment against a wide range of mosquito species belonging to several genera.

Animals↗
PubMed2004

In-vitro permeation of the insect repellent N,N-diethyl-m-toluamide (DEET) and the sunscreen oxybenzone.

The permeation behaviours of the insect repellent N,N-diethyl-m-toluamide (DEET) and the sunscreen oxybenzone were assessed in a series of in-vitro diffusion studies, using piglet skin and poly (dimethylsiloxane) (PDMS) membrane. The transmembrane permeability of DEET and oxybenzone across piglet skin and PDMS membrane was dependent on dissolving vehicles and test concentrations. An enhanced permeation increase across piglet skin was found for DEET and oxybenzone when both compounds were present in the same medium (DEET: 289% in propylene glycol, 243% in ethanol and 112% in poly(ethylene glycol) (PEG-400); oxybenzone: 139% in PEG-400, 120% in propylene glycol and 112% in ethanol). Permeation enhancement was also observed in PDMS membrane (DEET: 207% in ethanol, 124% in PEG-400 and 107% in propylene glycol; oxybenzone: 254% in PEG-400, 154% in ethanol and 105% in propylene glycol). PDMS membrane was found to be a suitable candidate for in-vitro diffusion evaluations. This study shows that the permeations of the insect repellent DEET and the sunscreen oxybenzone were synergistically enhanced when they were applied simultaneously.

Administration, Cutaneous↗
PubMed1991

Acute and subacute inhalation toxicity studies of a new broad spectrum insect repellent, N,N-diethylphenylacetamide.

N,N-Diethylphenylacetamide (DEPA) is an inexpensive, long-acting and broad spectrum insect repellent. The acute LC50 for a 4-h exposure of DEPA aerosol was found to be 1.451 mg l-1 (1.290-1.633) in male and 1.375 mg l-1 (1.307-1.447) in female rats. DEPA did not cause delayed deaths. Acute exposure to 0.9 LC50 revealed that liver might be a target organ for DEPA toxicity. On subacute exposures to 0.2, 0.6 and 0.8 LC50 for 6 h per day, 5 days a week for 2 weeks, there was no significant change in the 0.2 LC50 group, as evaluated by the body weight gain and organ body weight ratio. The minimal changes observed in the 0.6 LC50 group were of reversible type as the animals recovered on cessation of exposure. A massive concentration of 0.8 LC50 produced lethal effects. The study shows that DEPA has a low mammalian toxicity by inhalation as was found earlier with cutaneous application of the insect repellent.

Acetamides↗
PubMedDate not supplied

Human Exposures to N,N-diethyl-m-toluamide insect repellents reported to the American Association of Poison Control Centers 1993-1997.

This study analyzed 20,764 exposures involving insect repellants containing N,N-diethyl-m-toluamide (DEET) that were reported to poison control centers from 1993 to 1997. Nearly 70% of the cases reported no symptoms related to the exposure. The occurrence of symptoms was related to the route of exposure, with the highest rates associated with ocular exposures, followed by inhalation, multiple exposure routes, dermal, and ingestion. Two deaths were reported, one in a 26-year-old male and one in a 34-year-old female, both following a dermal exposure. Twenty-six subjects experienced major effects. The greatest number of reported exposures involved infants and children, but this group experienced lower rates of adverse effects than teens or adults. There was no clear relationship between DEET concentration and presence or severity of clinical effects. For the cases reported to poison control centers and included in this analysis, the risk of serious medical effects for labeled use of insect repellants containing N,N-diethyl-m-toluamide appears to be low.

Adolescent↗
PubMed2003

Laboratory evaluation of toxicity of 16 insect repellents in aerosol sprays to adult mosquitoes.

Sixteen commercial insect repellents (6 botanical and 10 synthetic organic products) in spray formulations were evaluated in the laboratory for adult knockdown (KD) and mortality of laboratory-reared female Aedes aegypti, Aedes albopictus, and Anopheles quadrimaculatus. All tested products produced significant posttreatment KD and 24 h mortality of all 3 mosquito species. In our study, the synthetic organic repellents induced faster KD and KD of higher magnitude in adult mosquitoes than the botanical product repellents except geraniol-based MosquitoSafe. All tested formulations except 2 botanical repellent products caused 100% 24 h mortality of Ae. aegypti and all but 1 caused 100% 24 h mortality of Ae. albolpictus and An. quadrimaculatus.

Aerosols↗
PubMed2004

Evaluation of the sensitivity of Aedes aegypti and Anopheles gambiae complex mosquitoes to two insect repellents: DEET and KBR 3023.

We conducted laboratory tests to assess the sensitivity to the insect repellent 1-piperidinecarboxylic acid, 2-(2-hydroxyethyl)-, 1-methylpropylester (known as KBR 3023 or Picaridin, trade name Bayrepel) of West African strains of the yellow fever mosquito Aedes aegypti and of malaria vectors of the Anopheles gambiae complex, in comparison with the standard repellent N,N-diethyl-3-methyl-benzamide (DEET). Test mosquitoes were exposed according to a 'separate arms' protocol to logarithmic dose increments applied on one arm of human subjects to evaluate the relative potency, and the median effective dosages (ED50 and ED90). According to a logistic regression model fitted to the experimental data, the dose-response relationship for the two repellents was the same within each species, thus pooled ED values were assessed for each mosquito separately. The median ED of KBR 3023 and DEET was estimated at 0.78 (95% confidence limits (CI): 0.57-1.04) and at 0.018 microg/cm2 (0.004-0.052) for mosquitoes of the An. gambiae complex and Ae. aegypti, respectively. ED90 values were 125.6 (81.4-201.3) and 24.0 microg/cm2 (5.7-208.5) for An. gambiae s.l. and Ae. aegypti, respectively. The relative potency of KBR 3023 was not significantly different from that of DEET for An. gambiae s.l. (95% confidence limits 0.7-1.0), whereas in the case of Ae. aegypti it was with 95% probability 1.1-2.0 times more potent than DEET. On the basis of available evidence, KBR 3023 represents a promising alternative to DEET for personal protection against bites of these important vectors of disease in the Afrotropical region.

Aedes↗
PubMed1993

Compatibility of army face paint and insect repellent formulation.

The compatibility studies of a new controlled-release repellent formulation (NSN 6840-01-284-3982, insect repellent personal application) and a new camouflage face paint (NSN 6850-01-262-0635) indicated that the repellent did not interfere with the use of face paints when repellent was applied first, and the face paints did not reduce the effectiveness of the repellent against mosquitoes.

Aedes↗
PubMed2004

Field evaluation of the efficacy and persistence of insect repellents DEET, IR3535, and KBR 3023 against Anopheles gambiae complex and other Afrotropical vector mosquitoes.

Synthetic insect repellents, IR3535 and KBR 3023 (also known as picaridin, or by the trade name Bayrepel, were tested in Burkina Faso against mosquito vectors of disease to compare their relative efficacy and persistence profiles to those of the 'gold standard' DEET. Collection of >49000 mosquitoes (approximately 95% belonging to the Anopheles gambiae complex) showed that after an exposure of 10h, KBR 3023 produced the highest protection against anophelines, followed by DEET, then IR3535. The response of aedines was more variable. By fitting a logistic plane model we estimated 95% effective dosages (ED95) for An. gambiae s.l., as well as a decay constant characterizing the exponential loss of repellent from the skin, with time. The ED95 values for DEET, IR3535, and KBR 3023 were 94.3, 212.4, and 81.8 microg/cm2 respectively. The decay constants were estimated at -0.241, -0.240, and -0.170 h(-1) respectively. The corresponding estimates of half-life were 2.9, 2.9, and 4.1h. Immunoenzymatic detection of the circumsporozoite protein (CSP) of Plasmodium falciparum in 842 An. gambiae s.l. showed that CSP-positive mosquitoes were equally frequent in treated and control subjects, indicating that the repellents could produce a reduction in the number of malaria infectious bites.

Administration, Topical↗
PubMed1978

Dermal penetration of three topical insect repellents in dogs and rabbits.

Three (14)C-labeled candidate insect repellents, cyclohexamethylene carbamide, n-butylsufonimidocyclohexamethylene and 2-hydroxyethylcyclohexane carboxylate were evaluated for skin penetration in dogs and rabbits. Absorption of the repellents was determined by monitoring excreted urine daily for seven days following topical application. Significant percutaneous absorption of all three repellents occurred within 24 hours. (14)C-cyclohexamethylene carbamide showed the greatest absorption. Measurable amounts of radioactivity persisted at the application site for both species after seven days.

Administration, Topical↗
PubMed2005

Simultaneous analysis of insect repellent DEET, sunscreen oxybenzone and five relevant metabolites by reversed-phase HPLC with UV detection: application to an in vivo study in a piglet model.

N,N-Diethyl-m-toluamide (DEET) and oxybenzone are two essential active ingredients in insect repellent and sunscreen preparations. We developed and validated a simple, sensitive, and selective HPLC assay to simultaneously measure DEET, oxybenzone and five primary metabolites of DEET and oxybenzone in biological samples including plasma, urine and skin strips. The compounds were separated on a reversed-phase C18 column using three-stage gradient steps with methanol and water. DEET and two relevant metabolites were detected at 254 nm, while oxybenzone and three relevant metabolites were detected at 289 nm. The limit of detection was 0.6 ng for DEET and 0.5 ng for oxybenzone, respectively. The developed method was further applied to analyze various biological samples from an in vivo animal study that evaluated concurrent use of commercially available insect repellent and sunscreen preparations.

Animals↗
PubMed1991

In vivo experimental model to evaluate the insect repellent N-N, diethylphenylacetamide in Periplaneta americana Linn.

The responsiveness of insect antennae to bornyl acetate (BA), a sex pheromone mimic and N,N-diethyl phenylacetamide (DEPA), a multi-insect repellent has been studied. Electrical activity from the antennal lobe was quantified to observe the alterations in power and frequency spectrum in P. americana Linn. following exposure to these chemicals. Two distinct patterns of responses were exhibited on exposure to BA and DEPA, the former producing a marked excitation and the latter inhibition of electrical discharge during the exposure to these compounds at a concentration of 200 micrograms.

Acetamides↗
PubMed2005

Citronella as an insect repellent in food packaging.

Of five commercial plant extracts (citronella, garlic oil, neem extract, pine oil, and pyrethrum), citronella was found to be effective in deterring the infestation of cartons containing muesli and wheat germ by red flour beetles. The chemical components were applied as part of a coating on the carton board. In an experimental set up that accelerates infestation over a 2 week period, citronella-treated cartons (0.2 g/m2 of carton board) reduced beetle infestation to approximately 50% of the level observed in control cartons. Evidence was provided to indicate that an insect repellent effect persists for at least 16 weeks. Additional work on the controlled release of the insect repellent would be required to prolong the effect.

Animals↗