A liposome is a spherical vesicle having at least one lipid bilayer. The liposome can be used as a vehicle for administration of nutrients and pharmaceutical drugs. Liposomes may be seen as the frontrunners of the nanomedicines family, e.g. polymeric micelles and colloidal gold dispersions. Therefore, much of the experience gained with these carrier systems may be applied to other nanomedicines.

FDA does not formerly recognize NBCDs, with originators required to follow the new drug application (NDA) route and follow-on NBCDs using the generics – abbreviated new drug application (ANDA) – route. The agency has, however, issued draft guidance documents for certain NBCD families, e.g. liposomes, different iron carbohydrates (iron sucrose, iron gluconate, ferumoxytol) and cyclosporine ophthalmic emulsions [1].

In contrast to the 2002 draft guidance for liposomes, the new (2015) draft guidance now notably includes information for follow-on products.

Liposome Drug Products
Date: October 2015 
http://www.fda.gov/downloads/drugs/guidancecomplianceregulatoryinformation/guidances/ucm070570.pdf 

The guidance discusses chemistry, manufacturing and controls (CMC), human pharmacokinetics and bioavailability or, in the case of an ANDA, bioequivalence, as well as labelling in NDAs and ANDAs.

The guidance also states that in connection with ANDA submissions, recommendations in any product-specific bioequivalence guidances should be considered. The only product-specific guidance for liposomes to date is the draft guidance for doxorubicin, which gives recommendations for clinical andin vitrostudies to demonstrate bioequivalence [2].

Related article
EU guidelines for follow-on NBCDs 

References
1.  GaBI Online - Generics and Biosimilars Initiative. Regulations for follow-on NBCDs [www.gabionline.net]. Mol, Belgium: Pro Pharma Communications International; [cited 2016 Feb 26]. Available from: www.gabionline.net/Non-Biological-Complex-Drugs/Reports/Regulations-for-follow-on-NBCDs  
2.  GaBI Online - Generics and Biosimilars Initiative. US guidelines for follow-on NBCDs [www.gabionline.net]. Mol, Belgium: Pro Pharma Communications International; [cited 2016 Feb 26].