Formulation and Effectiveness of Coconut Shell Potassium-Based Piper betle L Essential Oil Soap Repellent Against Aedes aegypti

Abstract

Serious concerns include mosquito bites and the risk of mosquito-borne diseases. The search for safe, natural substitutes for chemical insecticides is motivated by the effectiveness of skin repellents as a preventative measure. Essential oils from the betel plant (Piper betle) produce a unique smell that mosquitoes find repulsive. A useful invention for avoiding bites during everyday activities or bathing is to formulate a repellent as a soap. The purpose of this study was to assess the mosquito-repelling effectiveness of a betel-based soap formulation using the human-arm-bait method. Five dosage levels and four observation intervals (30 minutes, 1 hour, 2 hours, and 3 hours) were used in the randomized design experiment, with six replicates for each condition. Two-Way ANOVA, Tukey HSD post hoc tests, and Probit regression were used to analyze data on the number of mosquitoes landing to calculate Lethal Time (LT₅₀ and LT₉₀) values. Mosquito landing intensity was significantly influenced (p < 0.001) by dosage, observation time, and their interaction, according to two-way ANOVA results, with an R-squared value of 94.2%. A consistent and significant decrease in repellent efficacy over time (p < 0.05) was confirmed by Tukey HSD post-hoc tests; the average number of mosquito landings increased from 9.12 (at 30 minutes) to 17.56 (at 3 hours). With a mean difference of 4.00 landings, the most significant decline in repellent efficacy happened between the 2- and 3-hour intervals. The formulation's LT50 was estimated by Probit modeling to be 1.257 hours (roughly 1 hour and 15 minutes), while the theoretical LT90 was determined to be 19.342 hours. In summary, the tested repellent formulation provides robust protection, but its effectiveness diminishes markedly with prolonged skin exposure