A ZX3 vortex mixer (40 Hz) from VELP Scientifica (Usmate Velate, Italy) was used to ease the liquid–liquid extraction in the preparation of fat-soluble and cosmetic cream samples and an EBA 21 centrifuge from Hettich (Tuttlingem, Germany) was used for phase separation.
A Basic 20 pH meter from Crison (Alella, Spain) was used for the pH adjustments.