It is good question

you have to know your drug soulbility 

if your drug is lipophilic will precipitate due to centrifugation so it is better to use density gradient to float liposome, you can have look under microscope for any traces of drug crystal

Whil if you drug is water soluble you can run the regular method you mentioned

using gel or column are suffer from drug loss and cost,

I do really recommend you know the soulbility and use the ease method 

Tangential Flow Filtration 

You can avoid dilution (which is happening during GFC/GPC) and you can further concentrate the liposomal solution (Ultrafiltration) and you can remove untrapped drug from liposomal solution and buffer exchange with final formulation buffer.

Advantages : 

1. Avoid dilutions and you can further concentrate the liposomal solution

2. Buffer exchange or Dia-filtration : When you select the right MWCO of your TFF membrane ( Cassette / Hollow fiber) , you can retain your desired liposomal solution in retentate side and untrapped drug and other low molecular weight impurities and salt will be removed in diafiltration. You can also use and customize dia-filtration buffer wisely.

Please write me on [email protected] if you need further support.

http://www.pall.co.in/main/laboratory/tangential-flow-filtration-product-selec-53300.page

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