How High Pressure Homogenisers Help Produce Stable Emulsions

Emulsions are widely produced for a variety of industrial and pharmaceutical products, and are often defined as a combination of two immiscible liquids, whereby one liquid (the dispersed phase) is in the form of microscopic droplets dispersed in the other liquid (the continuous phase).

The majority of emulsions are thermodynamically unstable, and tend to break down over time via creaming, flocculation, phase inversion or coalescence. In cases of food or pharmaceuticals, it is important to minimise these processes and facilitate the longest possible shelf life.

The droplet size in the dispersed phase can affect the stability of the emulsion. Generally, the smaller the droplet size; the more stable the emulsion. More energy input is required to achieve smaller droplets, and so high-pressure homogenisation is often utilised to meet this as it can reduce droplet sizes to less than 1µm.

Avestin’s range of high pressure homogenisers from BPS Crowthorne allow adjustable pressures of up to 30,000psi, forcing a sample through a narrow orifice within the unique, dynamic homogenising valve. Performing multiple passes through the homogenising valve can have benefits in reducing particle sizes and narrowing the overall droplet size distribution.

Exposure to higher temperatures can also impact the stability of an emulsion, as it has the ability to affect the physical properties of oil, water, interfacial films and surfactant solubility. As the temperature of emulsions increases; its viscosity decreases. This can accelerate the rate of particle collisions making the emulsion less stable.

Avestin’s systems utilise a triplex pump design, whereby the pumps work intermittently to facilitate negligible pressure pulsation, and high throughput. This can aid in producing a more stable emulsion, with reduced wear on impact parts within the product pathway making them the systems of choice at every manufacturing scale. Read the full article by here.