In the case of suppositories, a distinction is made between water-soluble and aliphatic (fatty) preparations. The aliphatic preparations are the most familiar form. In production with aliphatic bases, hard fat is usually used as the starting substance, the melting range of which is close to the human body temperature.  The hard fat must possess defined emulsifying and melting properties in order to be used as a starting substance in the production of suppositories.

An important property of aliphatic suppositories is the melting point which is close to body temperature, so that the suppository can dissolve in the area of application. The water-soluble suppositories do not melt at a certain temperature, but dissolve in the water present in the area of application and then release the active ingredient. The small amount of liquid present, for example in the rectum, in which the suppository is supposed to dissolve, is problematic. Mixtures of various polyethylene glycols, as well as gelatine and glycerol, are used in the preparation of suppositories. Suppositories are produced from emulsions, suspensions or solutions of different active substances and hard fats.

In addition to sterile preparation, the handling of a wide range of viscosities must be considered in the production of suppositories. Innovative homogenising mixers are extremely flexible and efficient machines to be employed in production. Numerous installation and equipment options for the homogenising chamber and re-circulation lines, as well as in the cover area, are useful in order to ensure efficient suction, mixing and dosing. Pressure and vacuum-proof sealing of the agitating and homogenising machines enables processing of pharmaceutical products  with different viscosities under sterile conditions in one homogenising step. Furthermore, efficient radial and vertical mixing must be guaranteed in the case of high-viscosity products like suppositories. The process can also be facilitated by special processes for easy suction and dispersion of powders or, for example, wax pellets. Many suppository masses can be produced completely without an anchor agitator with scrapers; so-called circulation agitators or similar can be employed for this purpose.

By means of a circulating agitator, fat phases can be melted, wax incorporated and the product can be kept under constant turbulence, whereby, if desired, only minimal shear occurs with high mixing.

The aseptic construction of many fittings is designed to lie within the norm and makes these systems ideal for the production of pharmaceuticals of every kind.   

An accurate and infinitely variable temperature control is intended to ensure an exact and precisely timed heating or cooling phase at the plants. All parts of the plant in contact with the product must be temperature-controllable, in order to guarantee optimal production.

In addition, all production steps must be recorded, documented, stored and retrievable at all times.