Disclosed are storage stable aqueous infusible or injectable solutions containing an active substance of general formula (I) wherein the groups L, R<；SUP>；1<；/SUP>；, R<；SUP>；2<；/SUP>；, R<；SUP>；3<；/SUP>；, R<；SUP>；4 <；/SUP>；and R<；SUP>；5 <；/SUP>；have the meanings given in the claims and in the specification, and an amount of a physiologically acceptable acid or mixture of acids sufficient to dissolve the active substance and act as a stabiliser, optionally together with other formulating excipients suitable for parenteral administration, and a process for preparing the infusible or injectable solutions according to the invention.
