Nano colloid mill for veterinary drug suspension

In the field of veterinary medicine, many drugs require colloid grinding to refine and improve their efficacy and stability. For example, suspension preparation, etc. Colloidal mills are composed of stainless steel and semi stainless steel colloid mills. The basic principle of colloid mills is that fluid or semi fluid materials are subjected to strong shear, friction, and high-frequency vibration through high-speed relative linkage between fixed and moving teeth, effectively crushed, emulsified, homogenized, and warmed, thereby obtaining satisfactory finely processed products. The main unit is composed of a housing, dynamic grinding, static grinding, adjustment mechanism, cooling mechanism, motor, etc. Its main components are made of stainless steel, which is corrosion-resistant and non-toxic. The user can choose different specifications and models of colloid mills according to the characteristics of different materials, production efficiency, and different purposes, in order to achieve good results. During the running in process, the running in structure used consists of two interlocking dynamic and static grinding devices.

Suspension agentSuspension refers to the non-uniform dispersion of poorly soluble solid drugs in a dispersed medium as particles. The size of dispersed phase particles is generally between 0.5 and 10 μ m, with small particles up to 0.1 μ m and large particles up to 50 μ m or larger. The dispersion medium of suspension agents is mostly water, but vegetable oil is also useful. Suspension agents belong to thermodynamically unstable coarse dispersion systems.

The situations that can be considered for making suspensions are: ① Insoluble drugs need to be made into liquid agents for application; ② The dosage of the drug exceeds its solubility and cannot be made into a solution; ③ Mixing two solutions may result in the precipitation of solid drugs or the formation of insoluble compounds due to a decrease in drug solubility Compared with solution agents, in order to achieve sustained and long-lasting drug release Compared with solid dosage forms, in order to accelerate the absorption rate of drugs and improve their bioavailability In cases where solid dosage forms have significant gastric toxicity, suspension agents may be considered. But for toxic drugs or drugs with too small doses, in order to ensure the safety of medication. It is not suitable for use as a suspension agent.

The quality requirements for suspension are: the chemical properties of the drug itself should be stable, and the drug content within the validity period should meet the requirements; The suspended particles should be fine and uniform, and the particle size should meet the requirements of the dosage form; Particles settle slowly, and the settling volume ratio of oral suspension should not be less than 0.90. After settling, there should be no clumping, and it should be able to quickly disperse after gentle shaking; The viscosity of the suspension should be appropriate, and it should not stick to the bottle wall when poured; External suspension should be easy to apply and not easily dispersed; There shall be no mold, sourness, discoloration, odor, foreign matter, gas production or other deterioration phenomena; The label should indicate 'Shake well before use'.

Suspension agents are generally liquid agents, including a dry suspension agent. It is a powder or granular medication made by mixing insoluble drugs with suitable excipients, which can be dispersed into a suspension by shaking with water before use. It is mainly beneficial for solving the stability problem of suspension during storage, simplifying packaging, and facilitating storage and carrying.

Suspension is one of the commonly used dosage forms in clinical practice, such as mixtures, liniments, detergents, injections, eye drops, ointments, suppositories, and aerosols, all of which exist in the form of suspensions.

Suspension agent - stability of suspension

There is a solid-liquid interface between the drug particles and the dispersion medium in the suspension, and the dispersion of the particles is high, which makes the suspension particles have high surface energy and therefore in an unstable state. Especially for suspensions of hydrophobic drugs, there are greater stability issues. This mainly discusses the physical stability of suspensions and measures to improve stability.

（1） Sedimentation of suspended particles

The particles in the suspension will naturally settle after standing due to gravity, and their settling velocity follows Stokes' law:

According to Stokes' law, the particle concentration in the suspension should be below 2%. But in reality, the commonly used suspension concentration is above 2%. In addition, the mutual repulsion of particle charges during the settling process hinders particle settling, so the actual settling velocity is much smaller than the calculated velocity. According to Stokes' law, the settling velocity of suspended particles is directly proportional to the square of the particle radius and the density difference between particles and the dispersion medium, and inversely proportional to the viscosity of the dispersion medium. The greater the settling velocity of suspended particles, the lower the dynamic stability of the suspension.

In order to reduce the settling velocity of particles and increase the stability of the suspension, the following measures can be taken: ① Minimize the particle radius as much as possible and use appropriate methods to grind the drug finer and better. This is an effective method.

Grinding and dispersing machine is a high-tech product composed of colloid grinding and dispersing machines.

The first level consists of three-level sawtooth protrusions and grooves with increasing precision. The stator can be infinitely adjusted to the desired distance between the rotors. Under enhanced fluid turbulence. The groove can change direction at each level.
The second stage is composed of a stator. The design of the dispersing head also effectively meets the needs of substances with different viscosities and particle sizes. The difference in the design of the stator and rotor (emulsifying head) between online and batch machines is mainly due to the requirements for conveying performance. It is particularly important to note that the difference between coarse precision, medium precision, fine precision, and other types of working heads is not only the arrangement of specified rotor teeth, but also an important difference in the geometric characteristics of different working heads. The width of the slot and other geometric features can alter the different functions of the stator and rotor working heads.

The following is a model table for reference:

Nano colloid mill for veterinary drug suspension