Influence of membrane components on the stability and drug release properties of reverse phase evaporation vesicles (REVs): light sensitive all-trans retinal, negatively charged phospholipid dicetylphosphate and cholesterol.
Incorporation of a negatively charged phospholipid, dicetylphosphate, initially increased encapsulation efficiency (from 12 to 24%) but beyond 5% (molar) a detrimental effect was observed. Rate of drug release from REVs was, for most cases, found to be bi-phasic implying partitioning between the lipid bilayer and the aqueous compartment. It was not possible to prepare liposomes with more than 1% (molar) all-trans retinal (ATR) as a membrane component. When ATR was reduced to 0.5% (molar), encapsulation efficiency increased to 7.76%. Upon exposure to long wave UV (365 nm), release from ATR containing REVs was increased and this was attributed to the formation of 13-cis isomer as indicated by HPLC and UV spectroscopy data.
Gürsel
M
M
Middle East Technical University, Department of Biological Sciences, Ankara, Turkey.
Hasirci
V
V
D002626:Chemistry, Pharmaceutical / Q000379:methods; D002784:Cholesterol / Q000737:chemistry*; D004337:Drug Carriers; D004355:Drug Stability; D005452:Fluoresceins / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D007700:Kinetics; D008081:Liposomes / Q000737:chemistry* / Q000528:radiation effects*; D010755:Organophosphates / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000737:chemistry; D011836:Radiation Tolerance; D012172:Retinaldehyde / Q000737:chemistry* / Q000528:radiation effects*; D013696:Temperature; D014466:Ultraviolet Rays
D004337:Drug Carriers; D005452:Fluoresceins; D005456:Fluorescent Dyes; D008081:Liposomes; D010755:Organophosphates; D010713:Phosphatidylcholines; C002290:dicetylphosphate; C024098:6-carboxyfluorescein; D002784:Cholesterol; D012172:Retinaldehyde