Fig. 2.

Electron microscopy images of phospholipid-based particles of ciprofloxacin. a SEM image of spray-dried particles (CIP) comprising ciprofloxacin betaine crystals coated with a porous layer of phospholipid [33]. The bar represents a length of 2 µm. Reproduced with permission from Respiratory Drug Delivery 2016, Virginia Commonwealth University; b schematic of small unilamellar vesicles loaded with ciprofloxacin, showing a single bilayer of phospholipid, with drug (red circles) encapsulated within the aqueous core [80]; c Cryo-TEM image of small unilamellar vesicles containing ciprofloxacin. The bar represents a length of 100 nm [80]. Reproduced with permission from Elsevier