1.Normal phase EW Process (O/W)
Advantages of normal phase process
1)One-step emulsification – simple & efficient
2)Suitable for continuous production (best for low oil phase content)
3)Suitable for preparing low-loading EW
4)For medium to high loading EW, the use of the normal-phase process eliminates the risk of phase inversion failure.
Disadvantages of normal phase process
1)Poor stability → wide droplet size distribution, leading to storage issues like stratification/oil separation
2)Inefficient shear → extended processing time to reach proper particle size
2.Reversed phase EW Process (W/O→O/W)
Advantages of reversed phase process
1)Highly efficient shearing process
2)Controlled stepwise emulsification
3)Uniform particle size distribution
4)Enhanced storage stability
5)Ideal for medium-to-high oil phase content
6)First choice for preparing high-loading EW (If certain product fail to realize phase reversion, use normal phase process )
Disadvantages of reversed phase process
1)Complex process - critical control of Reversion parameters(T./ Shear speed/Speed of water addition )
2)Some products carry the risk of phase reversion failure, demand for formulation optimization