Development of a droplet size prediction tool for manufacture of emulsion creams

A practical computational tool was designed to estimate droplet size distributions in process equipment for ointment manufacturing, thereby providing guidance in selecting optimal equipment operating parameters for producing emulsions with desired characteristics. For simplicity and computational tractability, hydrodynamics are simulated using a compartment model, which allows for consideration of multiple hydrodynamic environments. The simulation tool employs a general coagulation-breakage population balance equation, using established expressions for coagulation and breakage kernels and a robust method for discretizing the model equations. Experiments were conducted to assess the accuracy of the simulation tool, including tests with two types of non-Newtonian emulsions: petrolatum in water as well as polyacrylic gelling polymer in water formulations representative of topical ointments. Simulation predictions for droplet size distribution demonstrated good agreement with experimental results using only a few adjustable parameters.