DƯỢC LÍ Goodman & Gilman's The Pharmacological Basis of Therapeutics 12th, 2010

Table 64–8
Vitreous Substitutes a
VITREOUS SUBSTITUTE CHEMICAL STRUCTURE CHARACTERISTICS (duration or viscosity)
Nonexpansile gases
Air
Duration of 5-7 days
Argon
Carbon dioxide
Helium
Krypton
Nitrogen
Oxygen
Xenon
Duration of 1 day
Expansile gases
Sulfur hexafluoride (SF 6
)
Duration of 10-14 days
Octafluorocyclobutane (C 4
F 8
)
Perfluoromethane (CF 4
)
Duration of 10-14 days
Perfluoroethane (C 2
F 6
)
Duration of 30-35 days
Perfluoropropane (C 3
F 8
)
Duration of 55-65 days
Perfluoro-n-butane (C 4
F 10
)
Perfluoropentane (C 5
F 12
)
Silicone oils
Nonfluorinated silicone oils (CH 3
) 3
SiO[(CH 3
) 2
SiO] n
Si(CH 3
) 3
Viscosity range from 1000-30,000 cs
Fluorosilicone (CH 3
) 3
SiO[(C 3
H 4
F 3
)(CH 3
)SiO] n
Si(CH 3
) 3
Viscosity range from 1000-10,000 cs
“High-tech” silicone oils (CH 3
) 3
SiO[(C 6
H 5
)(CH 3
)SiO] n
Si(CH 3
) 3
May terminate as trimethylsiloxy (shown)
or polyphenylmethylsiloxane; viscosity
not reported
a
See Parel and Villain, 1994, and Chang, 1994, for further details. cs, centistoke (unit of viscosity).