Thiacloprid suspension formula optimization by a response surface methodology

Abstract

A model thiacloprid 25% suspension concentrate was prepared using Tersperse2700 (X₁), AE1601 (X₂), xanthan gum (X₃) and Veegum (X₄). A response surface methodology (RSM) was used to evaluate the influences of four experimental factors on the aqueous separation ratio (R₁), centrifugal sedimentation ratio (R₂) and viscosity (R₃). The results show that the main factors influencing the three responses were X₃, X₄ and X₂ followed by X₁; moreover, several interactions were also significant. Multiple-response optimization was performed based on a desirability function, considering the minimum R₁, R₂, and R₃ as well as the financial cost. The integrated optimum conditions were X₃ = 0.24%, X₄ = 1.33%, X₂ = 0.50%, and X₁ = 2.90% (mass fraction). A verification experiment demonstrated that the optimized formula R₁, R₂, and R₃ were 1.69%, 2.63% and 257.74 mPa s with the average relative predicted value errors 7.69%, 4.18% and −1.41%, respectively. The response surface methodology is an effective approach for optimizing the suspension concentrate formula with comprehensive advantages.