Vacuum pumps for the pharmaceutical industry

Vacuum pumps are among the most widely used types of equipment in the pharmaceutical industry. They are employed at all scales, from pilot to industrial production, and by all sectors, from manufacturers of intermediates to producers of Active Pharmaceutical Ingredients (APIs).

A typical process calling for vacuum technology is drying, which is a crucial step in the pharmaceutical production sequence.

Drying takes place immediately after centrifugation or filtration. It is a process that removes the moisture from a wet solid by introducing heat. This operation is performed under vacuum in order to dry heat-sensitive or hygroscopic substances at temperatures that are lower than would otherwise be possible.

In the pharmaceutical industry, drying is a batch operation and can be carried out using a variety of technologies, depending on the product involved.
Vacuum pumps for the pharmaceutical industry
Crystalline products produced by synthesis (reactors) are chiefly processed using dynamic dryers (i.e., rotary and horizontal paddle dryers). These products, in fact, must have a very specific particle size and very low humidity.

Amorphous or plant and animal based products, on the other hand, are normally processed in static dryers. Particle size is not usually a determining factor for these products, since they are subsequently ground, and the moisture content is never as strictly controlled.

Industrial vacuum pumps for dynamic drying

In a dynamic system, the drying process’s effectiveness depends not only on the system itself, but also on the vacuum unit. This is the typical case found in the production of Active Pharmaceutical Ingredients (APIs) using rotary dryers and horizontal paddle dryers. Here, the vacuum pump must cope at the same time with aggressive organic solvents such as acetone, toluene and so forth, and the potential interaction with solid powder particles (especially if they are not adequately removed by the filter systems).

The Italvacuum vacuum pump can deal with both these issues.

Where a very low final moisture content is required, dynamic dryers are often combined with pumps coupled with roots compressors. For processing purposes, these compressors must be activated at the final stage of drying in order to extract the last traces of solvent retained in pharmaceutical powders. Under these circumstances, the condenser which is always mounted upstream of the Saurus939 vacuum unit is bypassed and the positive-displacement compressor is activated. With the compressor’s help, it is possible to reach very high vacuums – at least an order of magnitude below the levels that could be reached with the vacuum pump alone – together with extremely high output (here again, the output increases by around one order of magnitude).

In drying APIs, other vacuum technologies are less effective than the Saurus939 pump. Rotary vane pumps and liquid-ring pumps have a number of shortcomings when used with aggressive solvents, including a short life cycle and limited application in severe operating conditions. Dry pumps, on the other hand, have difficulty dealing with processes involving a great deal of interaction with solid particles, as they are particularly susceptible to damage by minimum quantities of dust.

Industrial vacuum pumps for static drying

Vacuum pumps
By contrast with dynamic dryers, static dryers, which are universal systems capable of drying any product, rarely need roots compressors. In addition, this technology only sporadically requires a filter between the dryer and the vacuum unit.

An example of application consists of drying plant extracts, a typical process used in today’s booming herbal industry. This sector combines the most modern extraction technologies with the vacuum drying techniques that the pharmaceutical industry has used from its beginnings. Natural and plant-based products are subjected to solvent extraction. The batch resulting from this process is then dried in order to retain all its heat-sensitive properties without change. The vacuum pump and the condenser unit are activated during this process. Both remain active for the entire duration of the process. The double stage version of the Saurus939 vacuum pump is used with or without a roots compressor.