Formulation and Evaluation of Polyherbal Mosquito Repellent Cream

Mosquitoes such as Aedes, Anopheles, and Culex are a serious threat to the public health as they are known vectors for various protozoans, viruses, and bacteria which result in many life- threatening diseases like malaria, filariasis, yellow fever, Japanese encephalitis, chikungunya, and dengue. These vectors have been considered as a major obstacle to socioeconomic development of developing countries particularly in the tropical region. Despite considerable efforts in recent years to control vector-borne diseases, malaria alone produces 250 million cases per year and 800,000 deaths including 85% children under five years (WHO, 2010). Therefore, the prevention of mosquitoes could be better than the cure of vector-borne disease. Hence, use of the mosquito repellents on exposed skin area is strongly recommended. Insect repellents usually work by providing a vapor barrier deterring the arthropod from encountering the skin surface. Most of the commercial mosquito repellents are prepared using nonbiodegradable, synthetic chemicals like N, N-diethyl-3-methylbenzmide (DEET), dimethyl phthalate (DMP), and allethrin, which may lead to their higher exposure to the environment and, hence, the unacceptable health risks. With an increasing concern on public safety, a renewed interest on the use of natural products of plant origin is desired because natural products are effective, environment friendly, biodegradable, inexpensive, and readily available. Many plant extracts have been identified as having insect-repellent effects and there has been increasing research in the last decade proving plant-based mosquito repellents are just as, if not more effective than DEET like Citronella Oil, Neem Oil etc. Plant products are emerging as a potential source of mosquito control and among them essential oils have special interest due to their insecticidal or repellent properties. Essential oils are volatile, naturally occurring, complex compounds characterized by a strong odour and are formed by aromatic plants as secondary metabolites. They are liquid, volatile, rarely coloured, lipid soluble and soluble in organic solvents with a density generally lower than that of water. There are 17,500 aromatic plant species among higher plants and approximately 3,000 essential oils are known out of which 300 are commercially important for pharmaceuticals, cosmetics, and perfume industries apart from pesticide or repellent potential. Owing to the attraction for natural products like essential oils, despite their wide use and being familiar to us as fragrances, it is important to develop a better understanding of their mode of biological action for new applications in human health, agriculture, and the environment. Some of them constitute effective alternatives or complements to synthetic compounds of the chemical industry without showing the same secondary effects. In nature essential oils play an important role in the protection of the plants as antibacterial, antiviral, antifungal, and insecticides. Hence the present study aims to develop an ecofriendly mosquito repellent, a substitute for chemical repellent by using different essential oils and to produce the natural repellent which is more cost effective, cheap and keeps the environment pleasant and health friendly. The aim of the present study is to formulate and evaluate a polyherbal mosquito repellent cream. The main objective of the study is to formulate a polyherbal mosquito repellent cream consisting of various herbal constituents such as Citronella oil, Eucalyptus oil, Tulsi oil, clove oil, neem oil, Sweet orange extract, Turmeric extract, etc. which exhibit mosquito repelling character.

Drug Profile

Cymbopogon nardus (Citronella)

Figure 1: Cymbopogon nardus.

Kingdom: Plantae

Order: Poales

Family: Poaceae

Genus: Cymbopogon

Species: C. nardus

Cymbopogon nardus or Citronella grass (S. Pengiri) is a coarse and clump-forming tropical grass native to Sri Lanka. Citronella grass can grow up to 1.5-1.8 m tall and citronella stems are like canes. Citronella essential oil is extracted by steam-distillation of citronella leaves. Citronella essential oil is used as an insect repellent and it can be found in dozens of registered pesticide products such as sprays, lotions, and candles. Due to its antifungal properties, citronella oil is also used to treat insect bites. Additionally, citronella essential oil is one of the most common oils used in aromatherapy as it has an ability to treat and prevent fever and headache. Because of citronella oil’s antiseptic properties, it is used in soaps, household cleaners and detergents. The main components of citronella essential oil are monoterpene hydrocarbons and alcohols such as geraniol (18-20%), citronellal (5-15%), citronellol (6.4- 8.4%), limonene (9-11%) and geranyl acetate (2%). Additionally, methyl eugenol, camphene, nerol, borneol, citronellic acid and citral are also present in citronella essential oil.

Eucalyptus globulus