VERFAHREN ZUR HERSTELLUNG VON BIS-INDOLVERBINDUNGEN ENTHALTENDEN STABILEN WAESSERIGEN ARZNEIMITTELPRAEPARATEN

The invention relates to new aqueous pharmaceutical compositions containing as active ingredient a pharmaceutically acceptable complex of a bis-indole compound with a bi- or multivalent metal ion in a therapeutically effective amount. The invention further relates to complexes formed between a bis-indole compound and a bi- or multivalent metal ion. According to another aspect of the invention there is provided a process for the preparation of a pharmaceutically acceptable metal complex of a bis-indole compound and optionally stable aqueous pharmaceutical compositions containing said metal complex, in which a solution of a bis-indole compound or a pharmaceutically acceptable salt thereof in an aqueous medium is reacted with a non-toxic water soluble salt of a bi- or multivalent metal capable of complexation, at a pH of 3.0 to 6.0, optionally in the presence of or followed by the addition of a conventional pharmaceutical carrier and/or further additive, or, if desired, the obtained complex is isolated. The aqueous pharmaceutical compositions according to the invention have substantially increased stability.