Songkro, Sarunyoo, et al. Journal of Medical Entomology 49.3 (2012): 672-677.
PPG-20 methyl glucose ether functions as a fixative that extends the duration of mosquito repellency in citronella oil-based lotion formulations.
Experimental Protocol: Citronella oil lotions are formulated with PPG-20 methyl glucose ether at concentrations of 2.5, 5, 7.5, and 10% w/w. Repellency testing is performed using the human-arm-in-cage method against Aedes aegypti mosquitoes. Protection time is recorded as the interval between application and the first confirmed mosquito bite. Each formulation is tested on five human volunteers with three replicates per concentration.
Performance Evaluation: The addition of PPG-20 methyl glucose ether at 5% w/w extends the complete protection time of citronella oil lotion from 1.0 hour (without fixative) to 2.5 hours. At 10% w/w concentration, the protection time reaches 4.8 hours, representing a 380% improvement. The fixative effect is concentration-dependent, with each 2.5% increment in PPG-20 methyl glucose ether content providing approximately 0.9 to 1.2 hours of additional protection. The formulation maintains 90% repellency for at least 2 hours at the optimal fixative concentration of 7.5% w/w.
