A natural nanogel with higher efficacy than a standard repellent against the primary malaria mosquito vector, Anopheles stephensi Liston

Personal protective repellent is a practical approach to evade mosquitoes’ bites and control mosquito-borne diseases like malaria in endemic regions. However, due to the relative allergy and neurotoxicity of synthetic repellents such as N, N -diethyl-meta-toluamide (DEET), attempts have focused on developing natural repellents. In this study, nanoemulsion-based nanogels of Elettaria cardamomum and Zataria multiflora essential oils were first prepared. The median complete protection times (CPTs) of the prepared nanogels were then evaluated using the arm-in-cage (AIC) method compared to DEET against the primary malaria vector, Anopheles stephensi . The topical repellent effect of nanogel of Z. multiflora essential oil with a droplet size of 8 ± 1 nm, droplet size distribution (SPAN) 0.89, and a minimum CPT of 600 min outperformed all other samples ( P < 0.001). However, the nanogel of E. cardamomum essential oil with a droplet size of 86 ± 5 nm, droplet size distribution 0.97, and 63 ± 15 min CPT showed significantly less efficacy ( P < 0.001) than DEET (242 ± 12 min). The promising efficacy, natural constituents, straightforward, and repeatable preparation procedure are some of the advantages of the Z. multiflora nanogel as a new potential repellent.