To select the appropriate HPLC column for biorelevant experiment the column compatibility with the drug (analyte) and mobile phase should be considered. Generally, C18 columns (particle size 5μm and 3μm) with a length of 15mm and internal diameter of 4.6mm can typically be used. In combination with the appropriate mobile phase, the column stationary phase can be altered to achieve the desired resolution and selectivity. 

For example, when analysing a basic drug molecule using C18 ODS (Octadecylsilane) column, peak tailing may appear due to interaction between the basic functional group(s) of drug and silanol groups present on the surface of silica particles in ODS columns. 

It is first recommended to modify the mobile phase composition, such as changing in the aqueous phase to reduce the peak tailing. However, if peak tailing still persists despite these adjustments, instead of using the C18 ODS (Octadecylsilane) column, use of a BDS (Base Deactivated Silica) column is typically suggested. BDS columns are designed to reduce silanol activity and peak tailing, specifically when mobile phase alteration individually is insufficient (depends on analyte/drug).