ABSTRACT
Pesticides are considered as one of the critical inputs for securing global food production. A controlled release (CR) formulation is considered to be diffusion controlled when the diffusion of through the polymeric matrix or membrane controls the release rate. Diffusion CR of pesticides from a polymeric matrix, either a monolithic or a reservoir system, has been known for a long time. In the 1960s, a number of polymeric systems were tested for controlled delivery of aquatic herbicides. A polymeric matrix that erodes from the surface can lead to a zero-order release rate if the surface area remains constant. A polymer matrix in which there is a change of polymer morphology on interaction with the release medium follows the swelling CR phenomenon. The CR mechanism involves slow release of the target site, which can be regulated by employing different release mechanisms such as diffusion, erosion.
