What is the main characteristic of a ready-to-mix system in pharmacy?

The main characteristic of a ready-to-mix system in pharmacy is that it requires no additional preparation. This convenience allows healthcare providers to quickly utilize the medication without needing to measure, mix, or prepare it further. Ready-to-mix systems are designed to streamline processes and reduce the chances of errors associated with preparation, making them particularly valuable in settings where efficiency and accuracy are crucial, such as hospitals and emergency situations.

In contrast to the other options, which describe various attributes that may not apply to all ready-to-mix systems, the defining feature is the elimination of the need for further preparation. While some ready-to-mix systems may allow for mixing at any time or may be used intravenously, these characteristics are not universal to all systems. Furthermore, having a fixed volume is not a necessary aspect of all ready-to-mix preparations, as they can come in various volumes depending on the medication and intended use. Thus, the focus on requiring no additional preparation distinctly highlights the efficiency and practicality of ready-to-mix systems in pharmacy practice.