In the industrial manufacture of gel for the pharmaceutical sector many raw materials and active ingredients are used. The polyacrylic acid Carbopol frequently serves as a versatile thickener.
Carbopol as a thickener
Carbopol can thicken a wide range of solvents and even non-polar systems. It can also be applied in a well-controlled manner. Nevertheless, numerous factors must be taken into account during mixing so that production runs sterile and efficiently.
Incorporating Carbopol in powder form requires a multi-stage mixing process. In addition, specific speeds must be maintained and air entrainment avoided.
Requirements for the homogenising mixer
For drawing in and homogenising to run conveniently and without disruption, the mixer must incorporate and wet powder uniformly. The following are particularly important:
- Powder feeds that prevent lump formation
- Low speed during the addition of powders to the liquid phase, so that no air enters the gel
- Infinitely variable speed adjustment of agitator and homogeniser for efficient stirring and homogenising
- Vacuum-controlled drawing-in of liquids and powders into the circulation flow below the liquid level
Vacuum-controlled drawing-in significantly shortens process times and reduces air entrainment. At the same time, product quality increases.
Frequently asked questions about manufacturing gels
Which thickener is often used for pharmaceutical gels?
Frequently the polyacrylic acid Carbopol, as it can thicken a wide range of solvents and even non-polar systems and is easy to control.
What must be considered when incorporating Carbopol?
A multi-stage mixing process, specific speeds and the avoidance of air entrainment. The speed should be low when adding powder, and suitable powder feeds prevent lumps.
How can air entrainment in the gel be avoided?
By drawing powders and liquids into the circulation flow below the liquid level under vacuum control. This shortens the process time and improves product quality.
What equipment should the homogenising mixer have?
Infinitely variable speed adjustment of agitator and homogeniser, suitable powder feeds and vacuum control.