From Ultrasonic Waves to a Jar of Face Cream: What Happens Inside the Mixing Tank?

1. What’s Inside a Jar of Cream?

To understand the role of ultrasound, we first need to understand how a cosmetic cream is formulated.

Many cream formulations are emulsions, in which oil and water are combined into a dispersed system. In an oil-in-water (O/W) emulsion, small oil droplets are distributed throughout a continuous water phase.

Depending on the formulation, the cream may also contain humectants, skincare actives, thickeners, emulsifiers, preservatives and other ingredients.

During mixing, these components must be combined in an appropriate sequence. Oil and water naturally tend to separate, so emulsification must produce dispersed droplets with a size and distribution suited to the formulation’s objectives.

2. What Happens When Oil and Water Enter the Mixing Tank?

In manufacturing, ingredient phases are typically prepared separately according to the formulation and then combined using mixing or homogenizing equipment.

Mechanical agitation brings the phases into contact and distributes them throughout the tank. Homogenization equipment applies stronger mechanical forces to form dispersed oil droplets within the water phase in an O/W system.

However, three technical challenges may arise:

These are important considerations when developing emulsion formulations. Ultrasonic technology may be investigated as an additional processing step for specific technical objectives.

4. From a Coarse Emulsion to a Cream with the Desired Structure

One technical approach worth investigating involves creating a coarse emulsion through mechanical mixing and then applying ultrasound to further process the dispersed system.

The stage at which ultrasound is introduced must be determined according to the formulation. Some systems can be processed while the emulsion still has relatively low viscosity. Others may require investigation of separate-phase treatment or recirculation through an ultrasonic flow cell.

For creams containing thickeners or ingredients sensitive to heat and mechanical stress, choosing the right processing stage is especially important.

5. Does Longer Ultrasonic Processing Always Produce Better Cream?

There is no single optimal processing time that applies to every formulation.

In some studies, emulsion droplet size decreases rapidly during the initial stage, after which the rate of change slows and approaches a limiting value. Increasing treatment time or energy further may not deliver a proportional improvement.

Ultrasound can also raise the temperature of the liquid. Therefore, process development should monitor several critical parameters:

• Vibration amplitude: influences the intensity of the probe’s mechanical action.
• Sonication time: specifies how long the sample is actually exposed to ultrasound.
• Volume and tank geometry: affect energy distribution and fluid movement.
• Temperature: must be managed to reduce undesirable changes in ingredients.
• Viscosity and composition: influence processability and equipment suitability.

In particular, when moving from a small test sample to a large production tank, simply increasing power in proportion to volume does not guarantee equivalent results.

6. How Can We Tell Whether Homogenization Is Effective?

A cream sample that looks smooth on the surface does not by itself establish the quality of the entire emulsion. Evaluation should be based on specific measurable criteria.

Comparing ultrasound-treated samples with controls produced using conventional processing helps determine which changes are attributable to ultrasound. Results should also be monitored during storage rather than assessed only immediately after treatment.

7. Ultrasonic Technology and MAI’s Cream Development Direction

Within the broader exploration of ultrasonic applications in cosmetics, the MAI brand provides a relevant context.

According to the basic ingredient list provided, MAI cream contains ingredients such as Tranexamic Acid, Alpha Arbutin, Niacinamide (Vitamin B3), Panthenol (Vitamin B5), glycerin, aloe vera extract, chamomile extract, an ingredient described as Nano White Turmeric, and Caprylic/Capric Triglyceride.

These ingredients have different physicochemical properties. Some dissolve in a suitable medium, some belong to the oil phase, and others require examination of their dispersion state.

According to MAI’s product information, ultrasonic homogenization is described as a step that supports emulsification and ingredient dispersion during cream production.

This approach also connects expertise in ultrasonic equipment with cosmetic formulation development through specific, measurable outcomes.

8. From the Mixing Tank to the Cream Jar: What Comes Next?

After homogenization, the cream system must undergo further finishing stages according to the manufacturing requirements.

Depending on the formulation, these may include temperature adjustment, adding certain ingredients at suitable stages, pH control, air-bubble management, appearance checks and confirmation of quality criteria before filling.

Microbiological control, preservative-system design, equipment hygiene and stability assessment must still meet their respective requirements. Ultrasonic processing does not automatically replace these procedures.

To deliver consistent quality from one jar to the next, manufacturers must control the entire process, from raw materials and mixing energy to packaging and storage conditions.