[On the action of various factors on the liberation from suppositories (author's transl)]

The authors deal with the effects of five suppository bases on the liberation of aminophenazone, codeine phosphate, phenobarbital natrium and trapidil from suppositories, with regard to the physical properties (melting time, melting range, melting point, viscosity) and the chemical properties (acid number, hydroxyl value, composition of the bases) of the bases and the suppositories as well as of the drugs used (solubility, particle size). The grouping of the causative factors indicated, which must be weighted differently, leads to the characterization of the mechanisms of liberation and to the interpretation of the considerable differences in liberation.