Dispersible concentrate (DC)

There are four key areas to consider when developing a DC formulation:

1. Active ingredient selection
A suitable active ingredient is of high-purity, stable against hydrolysis, fully soluble within the solvent system and insoluble within water.

2. Polar solvent selection
A polar solvent or blend of sufficiently polar solvents should solvate all active ingredients and dissolve all additional co-formulants.

3. Surfactant system selection
A DC formulation’s surfactant system contains an aqueous dispersant to stabilise active ingredient crystals on dilution, while additional surfactants such as high or low HLB surfactants controls the initial growth of active ingredient crystals. Croda offer a range of recommended surfactants suitable for use within DC formulations (see below).

4. Appropriate formulation testing
Typical CIPAC testing is carried out after development to evaluate formulation stability and performance. This includes characterisation of particle size, dispersibility, and rheology, which are critical for ensuring long-term stability and ease of application.

Benefits

• Simple to manufacture
• Good physical stability equal to emulsifiable concentrate (EC) formulations 
• Low melting point active ingredients can be dispersed 
• High biological activity
• Good chemical stability
• Water-free formulation
• Biocide free
• Good long-term physical stability compared to oil dispersion (OD) / suspension concentrate (SC) formulations

Limitations

• Limited number of active ingredients dissolve in polar solvents
• Moderately low active content: <350 g/L typical
• Requires water-free solvents and surfactants to avoid active degradation
• Solvent odour/toxicity
• Complex solvent selection to maintain high active loading and surfactant miscibility
• Requires water-insoluble active ingredients
• Requires good in-tank mixing
• Robust surfactant system to effectively control particle size on dilution