Original sentence: With weak membrane -life]], therefore must be taken at least twice daily or as a Slow-release preparation
Edited sentence: Because of this metoprolol is always manufactured in a salt-based solution, as drugs with melting points below 100 degrees Celsius are difficult to work with in a manufacturing environment.Metoprolol has a very low melting point, around 45 degrees Celsius (as determined by Differential scanning calorimetry).Short half-life, therefore must be taken at least twice daily or as a Slow-release preparation.The free base exists as a waxy white solid, where the tartrate salt is finer crystalline material.With weak membrane stabilizing activity