Photoprotection and release study of spinosad biopolymeric microparticles obtained by spray drying

Microparticles containing the photosensitive spinosad (SP) were obtained using a combination of chitosan (CH) and sodium lignosulfonate (SL) as encapsulating materials to develop a photoprotective system for intake administration. The microparticles were obtained by a spray drying technique and were characterized in terms of morphology (scanning electron microscopy - SEM) and particle size. In vitro release studies showed an initial burst effect that fits very well with the zero order kinetic model and then a slow release of the bioinsecticide, which fits best with the first order model. The results of this work demonstrate that the bioinsecticide carrier system developed with natural polymeric materials presents high stability to photodegradation and adequate insecticide release for use as a strategy to reduce negative impacts on the environment in agronomic practices.