RL 500 ML IV is a solution that is isotonic with blood. It is intended for intravenous administration in humans.Ringer's lactate solution is grouped with intravenous fluids known as "crystalloids", which include saline and dextrose solutions (compared to the "colloids" which contain larger molecules such as starch or gelatine). Ringer's lactate solution is abbreviated as "LR", "RL" or "LRS". It is also known as lactated Ringer's solution (although Ringer's solution technically refers only to the saline component, without lactate). It is very similar, though not identical, to Hartmann's solution, which is more commonly found in British and Irish hospitals and has slightly different ionic concentrations.