Microemulsion: New Insights into the Ocular Drug Delivery

Table 2

List of surfactants commonly used in ophthalmic microemulsion.

General class	Examples
Lecithin and lecithin derivatives	Pure phospholipids (e.g., soya phosphatidyl choline) and mixed phospholipids, sodium cholate; Hydroxylated phospholipids/lecithin
Glycerol fatty acid esters	Polyglycerol fatty acid esters; Polyglycerol polyricinoleate; Propylene glycol fatty acid esters; (e.g., polyoxyethyleneglycerol triricinoleate,; cremophor EL (macrogol-1500-glyceroltriricinoleate); monobutyl glycerol)
Sorbitan fatty acid esters	Span 20 (sorbitan monolaurate); Span 80 (sorbitan monooleate)
Polyoxyethylene sorbitan fatty acid esters	Tween 20 (polyethylene glycol sorbitan monolaurate); Tween 80 (polyethylene glycol sorbitan monooleate)
Others (potential cosurfactants)	Propylene glycol; PEG 200