Influência da temperatura e conservantes no encapsulamento e estabilidade de formulações contendo óleo essencial da Piper nigrum para controle larvicida de Anopheles aquasalis

Abstract

Alternative low toxicity bioactives to combat urban pests are being commonly used in research. With the problem of pesticide substitution, studies can use plant extracts with characteristics capable of eliminating urban pests from their larval stage. Thus, this research aimed to develop formulations of biopolymeric nanoparticles loaded with Piper essential oil that include bioinsecticide application, considering the influence of temperature (35° C) and preservatives. Stability analyzes were performed to characterize formulations at 35 ° C under short (120 days) and long term (12 months). The reported stability statistics include the conservative NE as the best long-term performance. The stability parameters indicate that the formulations evaluated for a short period remain stable for 120 days (data of regular validity of the products in use) and a long term, for 5 months. In larvicidal tests in semi-field conditions with essential oil, nature was observed with variation in larval mortality in different variations. In the first 24 h, there was a linear progress between the mortality values, becoming less pronounced after 48 h and remaining constant for 72 h. From the values selected in the semi-field experiment, such as LD50 and DL90 were calculated. In the first 24 h, a DL50 and DL90 recorded values of 229μg.mL-1 and 628 μg.mL-1, respectively. In 48 h, these values decrease to 166 μg.mL-1 and 370 μg.mL-1 and, finally, in 72 h, 74 μg.mL-1 and 356 μg.mL-. As nanoparticles loaded with essential oil, they are shown in 48h at 300 and 500 μg.mL-1 of mortality above 90%, corroborating the results of controlled activation. Therefore, it is believed to contribute to this research through the development of an effective and low toxicity toxin with bioinsecticidal properties.