ABSTRACT: The main objective of the work was to extract the active ingredient in Cymbopogon citratus leave and to formulate a mosquito repellent cream naturally obtained from medicinal plants instead of commonly available synthetic repellents and insecticides such as N-Diethyl-3methylbenzamide (DEET), which are carcinogenic and non eco-friendly. The formulation of cream have smooth texture with a pH 7.30 which is non-irritant and suitable for the skin. The efficacy of the extract of Lemon grass (Cymbopogon citratus) was investigated on mosquito in this research using different concentrations of the oil extract. The sample (cream) with the highest concentration of the active ingredient extracted was found to be most effective in repelling mosquitoes. Ethanol and Hexane were used to extract the essential oil and Gas chromatography-mass spectrophotometer (GC-MS) was used to analyse the constituents in the extracted active oil. The most abundant constituents observed in the hexane extract are cyclotetracosane (4.05%) and naphthalene (5.03%). Hexane proved to be a better solvent by giving a percentage yield of 7.8% of essential oil while ethanol a percentage of 2.9%
