You can make emulsions by combining two immiscible liquids (oil and water, for example) in a suspension through the use of force. The use of emulsifiers is necessary to keep this mixture stable and permanent.
Tell us about your production challenge
Emulsifying equipment and manufacturing processes to know about
To mix two immiscible substances, you first need to break down one of them into millions of tiny droplets. You can then suspend these droplets in the other substance by blending both with an industrial blender. The droplets become known as the dispersed phase, while the other liquid becomes the continuous phase.
Emulsions can be either oil-in-water (O/W) and water-in-oil (W/O). To form oil-in-water emulsions, the dispersed phase must be oil and the continuous phase, water. For water-in-oil emulsions, the phases are the opposite. However, these substances will not stay mixed for long on their own, and this is where the use of emulsifiers becomes necessary. Emulsifying equipment such as shear mixers and high-speed agitators are essential to prevent separation.
Emulsions for cosmetic, food, and pharmaceutical purposes
Some of the most common food items and sauces such as Hollandaise, mayonnaise, and salad dressings are emulsions. Cosmetic products such as shampoos, creams, conditioners, and lotions are also emulsions. Similarly, in healthcare circles, emulsions deliver vitamins, supplements, and other bioactive compounds.
Oil-in-water emulsions are more suitable for products meant for internal use. This is why food sauces and drug supplements are mostly oil-in-water emulsions. On the flip side, products meant for external use, such as creams and lotions, work better with water-in-oil emulsions.
What are the regulations for different emulsions?
The Good Manufacturing Practices (GMP) from the World Health Organization (WHO) guide the food, cosmetic and pharmaceutical emulsions production. While the institution encourages these regulations, they are not enforceable.
In the US, the FDA regulates pharmaceutical emulsions, and products that don’t meet these regulations are marked adulterated. In Europe, it’s the decentralized European Medicines Agency (EMA) that enforces EudraLex, in collaboration with regional regulatory agencies in the European Union. EudraLex is the collection of rules and regulations governing medicinal products in the EU. In the ASEAN region, marketing authorizations for drugs are country-specific, although pharmaceuticals production regulations are largely based along PIC/S recommendations.
A few words about filling and packaging of emulsions
For starters, packaging laws in several countries oblige you to clearly state whether products are suitable for internal or external use on their labels. You should also use wide-mouthed bottles for viscous emulsions and state clearly on the label that the product should be shaken thoroughly before use. Finally, low temperatures can contribute to the demulsification of emulsions, so you should avoid refrigerating them.