In-line high-shear mixers can be used for continuous or batch dispersion operations depending on how the pipework is arranged. In our previous work (Carrillo De Hert and Rodgers, 2017a) we performed a transient mass balance to establish the link in-between these two arrangements; however this model was limited to the estimation of the mode of dispersed phases yielding simple monomodal drop size distributions. In this investigation we expanded the previous model to account for the shape of the whole drop size distribution. The new model was tested by performing experiments under different processing conditions and using two highly viscous dispersed phases which yield bimodal drop size distributions. The results for the continuous arrangement experiments were fit using two log-normal functions and the results for the recycle arrangement by implementing the log-normal function in the previously published mass balance. The new model was capable of predicting the (d) over bar (32) for different emulsification times with a mean absolute error of 12.32%. The model presented here was developed for liquid blends, however the same approach could be used for milling or de-agglomeration operations. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.