Ocular drug delivery systems: An overview

Table 2 Recent advancements in liposomal ocular drug delivery

Drug	Type of Liposomes	Result
Acetazolamide	Multilamellar, unilamellar	Multilamellar liposomes produced a more significant lowering in IOP in comparison with REVs liposomes[72]
Ciprofloxacin	Multilamellar	The mean residence time of ciprofloxacin was three fold higher for the CS-coated liposomes (3.85 h) compared to commercially available eye drops Ciprocin® (1.39 h)[73]
Cytochrome C		The cytochrome C loaded freeze-dried liposomes exhibited significant efficacy in retarding the onset and progression of cataract formation in rat eye[74]
VIP	Pegylated liposomes	After intravitreal injection, VIP concentration in ocular fluids was 15 times higher for liposomal formulation (155 ± 65 ng/mL) than the solution (10 ± 1 ng/mL), at 24 h[75]
Coumarin-6	Multilamellar	After topical administration in mice, the intensity of coumarin-6 in the retina was much higher with PLL modified liposomes[76]
Bevacizumab (Avastin)		Vitreous concentration of bevacizumab after 42 d of administration was 16 and 3.3 μg/mL in the eyes for liposomal and non-liposomal bevacizumab, respectively. The AUC (conc vs time) for liposomal bevacizumab was 1.5 fold higher compared with non-liposomal bevacizumab[77]
Fluorescence probe (coumarin-6)	Submicron-sized liposomes (ssLips) and multilamellar	After topical instillation of submicron-sized liposomes (ssLips), drug was delivered to the posterior segment ocular tissues including retina[78]
Fluconazole		Antifungal activity of fluconazole in liposomal formulation was better than that of fluconazole solution[79]
Edaravone	Submicron-sized liposomes	Topical administration of edaravone-loaded ssLips protected retina against light-induced dysfunction in mice eye while there was no marked protection found in the group treated with free edaravone[80]
Diclofenac	Multilamellar	Topical administration of diclofenac loaded PVA-R modified liposomes lead to improved retinal delivery in rabbit eye. Concentration of diclofenac in the retina–choroid was enhanced by 1.8 fold in case of drug loaded PVA-R modified liposome compared to that of the diclofenac solution[81]

REVs: Reverse phase evaporation; PLL: Poly-L-lysine; VIP: Vasoactive intestinal peptide; PVA: Polyvinyl alcohol; IOP: Intraocular pressure; AUC: Area under the curve.