High-shear emulsifying pumps, small pharmaceutical emulsifying machines, inline emulsifying machines, and pharmaceutical formulation emulsifying machines adopt frequency conversion speed regulation. They come in various specifications, operate stably and powerfully, and are suitable for various viscosities; featuring both hydraulic and mechanical lifting forms, they can lift and rotate freely, adapting to various positions; with both ordinary and explosion-proof configurations, they are safe and reliable with simple operation and maintenance; they have strong production continuity, can rapidly disperse and dissolve materials, have good dispersion effects, high production efficiency, stable operation, and simple installation. There are different powers and models for different material viscosities and processing capacities. Now, let's explore the application of high-shear emulsifying pumps in fat emulsion injections!
Fat emulsion injection is an oil-in-water (O/W) emulsion, typically composed of vegetable oil, emulsifier, glycerin, and water. The preparation steps using a high-shear emulsifying pump are as follows: certain substances (such as lecithin) are added to the oil phase and stirred to dissolve under 75°C water bath conditions. Then, the remaining materials are mixed with glycerin and other materials to prepare the aqueous phase. After mixing the oil and aqueous phases uniformly, they are sequentially placed into a high-speed emulsifying device for inline high-shear emulsification to produce a uniform and stable emulsion.
Production Challenges of High-Shear Emulsifying Pumps: Emulsification Fineness and Shearing Degree
The physical differences in pharmaceutical formulations such as fat emulsion injections are manifested in emulsion creaming, coalescence, and the micronization of particles in suspensions. Generally, physical instability issues only alter the physical properties of the drug without changing its chemical structure. Smaller particle sizes lead to larger reaction areas and more pronounced effects.
The crucial principle of high-shear emulsifying pumps' high-speed shearing lies in a pair of mutually "meshing" stator and rotor. The high-speed rotation of the rotor draws the material from the bottom into the narrow shearing "working zone" between the stator and rotor. The micronization of emulsions requires powerful shear forces to achieve maximum micronization while maintaining the material's properties.
Droplet Rupture in Laminar Flow:
In laminar flow, the deformation and rupture of dispersed phase droplets can be represented by a functional relationship between shear stress (from the equipment's shear gap) and surface tension, which Taylor defines as the modified Weber number. Droplet rupture depends on the critical deformation value, i.e., the critical Weber number.
Droplet Rupture in Turbulent Flow:
In turbulence, droplets are controlled by the continuously changing flow velocity and the pulsating pressure resulting from it, generating tensile forces that split the droplets, commonly known as "apparent turbulent tension." In turbulent flow, the primary cause of droplet rupture is the pulsating force generated by turbulence. Meanwhile, the shearing action in turbulent flow is determined by turbulence intensity.
In summary, to achieve good dispersion of liquid materials, it is necessary to introduce a sufficient shear force field, and ultra-shear technology can be introduced during the dispersion and micronization process of fat emulsion injections.
Features of High-Shear Emulsifying Pumps:
1.Traditional high-shear emulsifying machines are single-stage emulsifying machines, which means they have one set of fixed stator and rotor (emulsifying head). Single-stage emulsifying machines have significant limitations in terms of material shear force and production efficiency. However, they can achieve material particle sizes at the nanometer level, making the system more uniform.
2.High-shear emulsifying pumps have also seen significant improvements in high-speed operation. High rotational speeds and shear rates are crucial for obtaining ultrafine suspensions. According to specific requirements in some industries, their shear speeds exceed 10,000 rpm, with rotor speeds reaching up to 40 m/s. Within this speed range, motors specifically developed based on shear force-induced turbulent coupling can reduce particle size ranges to the nanometer level. With stronger shear forces, the emulsion particle size distribution becomes narrower.
