With the recent changes to Chapter <621> of the USP guidelines for chromatography, changes to the column particle type, size, and dimension are allowed without the need for revalidation. With the harmonisation efforts, the changes are also allowed for EP, BP, and JP gradient methods.
Many methods were developed on older column types and using HPLCs limited to 400 bar. Modernisation of the methods by moving them to smaller particle size, shorter column length, and smaller ID is beneficial for time savings as well as solvent savings.
The time and solvent savings combine for cost savings since the laboratory can increase both their efficiency and throughput.
Example: (For further reference see Tech Report below)
The USP method for organic impurities of acetaminophen is 73 minutes long and is run at a flow rate of 0.9 mL/min on a FPP C8, 5 μm, 4.6 x 250 mm column.
Optimizing the method to use a HALO® C8, 2.7 μm, 4.6 x 150 mm with column run at 1.667 mL/min for 21.68 minutes reduces the solvent consumption by 45% and reduces the time required to run an entire batch by 70%.
Further readings: