Neem oil-loaded cross-linked biodegradable polymeric capsules: Its larvicidal activity against Culex quinquefasciatuss larvae

BACKGROUND: Pesticide delivery system has been formulated in the form of emulsifiable concentrates, water solutions, aerosols, or spray formulations. However, such formulations showed health hazards. Encapsulation technique is the more suitable method to reduce health hazard and to deliver and release the pesticides. Natural biopolymers have been widely studied for encapsulation of pesticide compounds, as they are biodegradable, biocompatible, and low toxic to mammalian. Neem oil has been reported for controlling of the mosquitoes and more eco-friendly insecticide than synthetic insecticides. The present study was designed to prepare a cross-linked polymeric network capsules loaded with neem oil as effective controlled release formulation against Culex quinquefasciatus larvae. MATERIALS AND METHODS: Neem oil-loaded chitosan/alginate/gelatin capsules were prepared by cross-linking method. Neem oil-loaded capsules were characterized with respect to their capsule size, scanning electron microscopy (SEM) analysis, and swelling property. In vitro larvicidal activity of neem oil-loaded polymeric capsules was studied against C. quinquefasciatus larvae. RESULTS: The cross-linking method produced spherical shape of neem oil-loaded capsules. Ultraviolet spectroscopy analysis indicated that 10% of neem oil was loaded with capsule. A swelling study indicated that swelling of the loaded capsules tends to be more stable. SEM analysis showed that loading of the neem oil with the capsules fills all pores and capsules were found with good compatibility between chitosan, alginate, and gelatin due to the uniform shape of the capsule. Formulated neem oil-loaded capsules showed potential larvicidal activity (100% of mortality) against C. quinquefasciatus larvae in an in vitro model. CONCLUSION: Formulated neem oil-loaded capsules showed a simple method of preparation and eco-friendly. These polymeric capsule containing neem oil exhibited potential larvicidal activity against C. quinquefasciatus larvae.