Handbook of Solvents - George Wypych - ChemTech - Ventech!

984 Michel Bauer, Christine Barthélémy
• From time to time the solvent can react in lieu of the reagent.
In a synthesis aimed to prepare 3-chloro-1-methoxy-2-propan-2-ol starting from
chloromethyloxirane and methanol, traces of ethanol present in methanol gave the corresponding
ethoxylated compound:
Another and final example concerns the preparation of a urea derivative using the
reaction of an amine and isocyanate in presence of isopropanol:
Other examples could be found. These obvious examples stress the need for close collaboration
between chemists and analysts when elaborating chemical syntheses and corresponding
quality control monographs.
14.21.1.2.2 Drug products 11,12
14.21.1.2.2.1 General points
Because ultimately it is the DP which is administered to the patient, it is necessary to have
the quality of the solvents potentially used in the design of pharmaceutical formulations under
control.
14.21.1.2.2.2 Areas of utilization
Solvents including water are used in different ways in pharmaceutical formulation:
• either as a part of the final drug product:
injectables,
drinkable solutions,
patches, sprays,
microemulsions
• or used as an intermediary vehicle which is removed at the end of the process:
granulation
coating
sugar coating
microencapsulation