Although Prep Chromatography or Preparative Chromatography is not simple and has many different aspects and uses and therefore is really specific for each need, there are some generalities that should be considered if you are thinking of working with HPLC for purifications.
A higher surface area generally leads to more load-ability. But this is also related to solubility of the compounds to be prepped and the mobile phase. However, if you are preparing protein then you made need to go to a 300A material and the surface area will drop but of greater importance in preparation is selectivity. If you have good selectivity between the target compounds and others in the mixture, you can greatly overload the column without fear of contamination and hence prepare much more material per run.
For many customers they discovered that the unique selectivity of the Cogent TYPE-C™ columns has favorable Selectivity and are used from analytical to prep or even production scale.