Preparation, characterisation and comparative toxicity of nanopermethrin against Anophelesstephensi and Culexpipiens

Abstract

Objectives To assess the effectiveness of nanopermethrin as a potential new formulation for pest and vector control. Methods Permethrin nanoparticles were prepared by the ionic gelation method and its structure and the formulations were designed using Box–Behnken statistical technique. The effect of independent variables (Chitosan/Permethrin ratio, tripolyphosphate quantity, sonication time) on the properties of nanoparticles was investigated to determine the optimal formulation. Results The size of the nanoparticles ranged from 135.27 ± 5.88 to 539.5 ± 24.01 nm and the insecticide entrapment efficiency per cent (EE%) ranged from 7.72 ± 1.36 to 63.59 ± 3.17%. Anopheles stephensi larvae were then bioassayed with the nanopermethrin and compared with the results of the bioassay with the mother molecule of permethrin using a standard WHO‐recommended mosquito larval bioassay kit. LC50 with permethrin and nanopermethrin on larvae of An. stephensi were 0.125 and 0.026 ppm showing a 4.8 times difference. The LC50 for permethrin and nanopermethrin on Culex pipiens were 0.003 and 0.00032 ppm, respectively, showing a 9.4‐fold difference. Conclusion Nanopermethrin is much more potent than its mother molecule against larvae of An. stephensi and Cx. pipiens.

Compounds Inhibiting Noppera-bo, a Glutathione S-transferase Involved in Insect Ecdysteroid Biosynthesis: Novel Insect Growth Regulators

“…For example, the LD 50 of DMG, which is currently the most potent Nobo inhibitor, is approximately 10 ppm against A. aegypti larvae [ 69 ]. In contrast, the LD 50 values for organophosphates and pyrethroids against mosquitoes are typically less than 0.1 ppm [ 84 , 85 ]. Therefore, a further combined approach, incorporating both in vitro and in vivo structural analysis, is required for a Nobo inhibitor with higher IGR activity.…”

Hyaluronic Acid‐Coated Chitosan/Gelatin Nanoparticles as a New Strategy for Topical Delivery of Metformin in Melanoma

“…Chitosan (CHI) and gelatin are natural polymers found in the tissues of living organisms, especially plants and animals. They are extensively used in pharmaceutical drug delivery systems because of their noncytotoxic, biocompatible, and biodegradable nature [15][16][17][18][19]. The polymers can form colloidal particles that coat the active ingredient and lead the drug to pass through the skin layers [20][21][22][23].…”