Preparation and characterization of the inclusion complex of chlorpyrifos in cyclodextrins to improve insecticide formulations.

The chemical control of crops by organophosphate insecticide treatment is usually limited because the insecticides do not maintain their efficiency for long periods for several reasons, including environmental conditions or rapid degradation of the active ingredient. Chlorpyrifos is an organophosphate insecticide used worldwide to control a variety of soil insects and arthropods in a wide range of crops. It is easily soluble in organic solvents but shows poor water solubility. The inclusion of chrorpyrifos in cyclodextrins (CDs) improves its water solubility, bioavailability, and insecticidal activity and helps prevent overdosing, leading to more cost-effective and more environmentally friendly agricultural practices. Solubility studies of chlorpyrifos in the presence of different types of CDs show G2-beta-CDs to be the most effective CDs in the complexation process, giving 1:2 complexes, with complexation constant (Kc) values of 12.34 +/- 3.1 M(-1) for K1 and 3895 +/- 183 M(-1) for K2. These complexation constant values were corroborated by applying a fluorimetric method.