Abstract

Water-reduced moist granulation technique by the addition of liquid acids / An innovative, energy-saving pharmaceutical technology which is working without any expensive physical drying step

This technological communication is reporting on an economical as well as ecological innovative and primarily energetically simplified, pharmaceutical technology of wet granulation. The decisive change of this technology is the application of liquid pharmaceutical accepted acids instead of the relatively large amounts of water, as it is performed up to date. By this new chemical art the usually required and from the energy point of view very expensive physical drying steps can be absolutely omitted.

Most suitable acids to realize this new technology are the racemic lactic acid because of its low melting point of 17 °C and the highly concentrated aqueous ortho-phosphoric acid (85 %, Ph.Eur.). Both of these acids show a liquid physical state at the normal room or working temperature of around 25 °C.

The chemical change, playing an important part in this new technology, is first of all the formation of corresponding salts after the reaction of the suitable acids with the earthalkali oxides incorporated within the powdery part of the formulation. During these binding salt formations the direct and extremely economic way of energy-saving, self-solidifying formulations as dry, granular-like, agglomerated products are accomplished. Sometimes these processes also lead to additional formations of hydrates. In each case it is quite easy to produce dry granule-like formulations with this energy-saving and self-solidifying technology.

The basic reason is the removal of the actually used and very expensive physical drying steps by a simple dry salt formation. By the following steps these granules can be worked up into e.g. tablets or capsule fillings by well-known ways. Particularly interesting and worth mentioning are the possibilities to produce very fast disintegrating oral dosage forms (ODTs) for instant by the use of highly active dispersing agents. Nevertheless, these technologies are still not developed to be marketable. But meanwhile there were performed some preformulation studies with placebo mixtures – in very small beaker batches or by small starmix-like devices. The results confirm principally good functions of the intended processes.

Korrespondenz:

Prof. emer. Dr. Kurt H. Bauer, Augustinum Freiburg-St. Georgen, App. 1302, Weierweg 10, 79111 Freiburg, Germany; e-mail: bauer.kurt.freiburg@t-online.de