Emulsiovoiteet

Emulsiovoiteet (Finnish for emulsion creams) are semisolid formulations in which two immiscible liquid phases—typically oil and water—are dispersed with the help of emulsifying agents. They are widely used in cosmetics, dermatology and topical pharmaceuticals to deliver moisture, active ingredients and protective lipids to the skin.

Common types include oil-in-water (O/W) emulsions, where oil droplets are dispersed in a continuous aqueous phase, and water-in-oil (W/O) emulsions, where water droplets are dispersed in an oil phase. More complex forms include multiple emulsions (W/O/W), microemulsions and nanoemulsions, which can alter release properties and stability.

Typical composition comprises an oil phase (plant or synthetic oils, waxes), an aqueous phase (water, humectants like glycerin), emulsifiers (surfactants or polymeric stabilizers), rheology modifiers (thickeners), preservatives and optional active ingredients (vitamins, sunscreens, drugs). Manufacturing generally involves heating, mixing and high-shear homogenization to produce a stable droplet size distribution.

Stability concerns include phase separation, creaming, coalescence and microbial growth; formulators address these through emulsifier choice, droplet size control, pH adjustment and antioxidants. Emulsion creams offer good skin feel, evaporative cooling and ease of application, but may cause irritation or allergic reaction in sensitive individuals depending on ingredients. Regulatory requirements for safety, labeling and preservative efficacy vary by region, and shelf life is influenced by formulation and storage conditions.