FPGEE 2025 Practice Exam for NABP – The Complete All-in-One Guide to Exam Success!

In the context of emulsions and their classification, a coarse dispersion typically refers to a system where the dispersed droplets are larger in size. The acceptable droplet diameter range for classifying an emulsion as a coarse dispersion falls between 0.1 micrometers (μm) and 10 micrometers (μm). This range is significant because emulsions within this size bracket exhibit distinct physical properties and behaviors, often leading to their separation over time due to gravitational forces.

Emulsions with droplet sizes smaller than 0.1 μm are typically classified as fine or micro-emulsions, and sizes below 1 nanometer are classified as molecular dispersions, which involve solubilized substances rather than true emulsions. On the upper end, droplets larger than 10 μm would not typically be classified as emulsions, as they can lead to more pronounced sedimentation and separation, thus altering the intended application of the emulsion.

This classification is crucial in various pharmaceutical and cosmetic formulations, as it influences the stability, delivery, and overall effectiveness of the product. Therefore, the range of 0.1 μm to 10 μm accurately reflects the typical characteristics and behaviors of coarse dispersions in emulsions.