ANILINE X-RAY AGENT AND BUFFER WHOSE PH DECREASES WITH TEMPERATURE

摘要

A process for the preparation of a sterile iniectable physiologically acceptable solution of an X-ray contrast agent and solutions of the X-ray contrast agent and a buffer Sterile, injectable, physiologically acceptable solutions of an X-ray contrast agent are prepared by autoclaving a solution-of a m-carboxamido-o-iodo-N-(.beta.-hydroxyalkyl)aniline X-ray contrast agent in the presence of a physiologically acceptable buffer system the pH of which decreases with increasing temperature. The presence of a temperature dependent buffer, preferably an amine, enables X-ray contrast agents to be sterilized by autoclaving without significant decomposition. Examples of the autoclaving processes are given and solutions for autoclaving containing a mcarboxamido-o-iodo-N-(.beta.-hydroxyalkyl)aniline X-ray contrast agent and a physiologically acceptable buffer system the pH of which decreases with increasing temperature are described and claimed.