title: Synthesis of monomethoxypolyethyleneglycol-cholesteryl ester and effect of its incorporation in liposomes.
abstract: The objective of the present study was to synthesize monomethoxypolyethyleneglycol-5000 cholesteryl ester [PEG-CH] as a cost-effective substitute for polyethyleneglycol-phosphatidylethanolamine and to evaluate the influence of its incorporation in liposomal bilayers for surface modification. PEG-CH was synthesized and characterized by infrared (IR), proton nuclear magnetic resonance spectroscopy ((1)H NMR), and differential scanning calorimetry (DSC) studies. Influence of incorporation of PEG-CH in liposomes was evaluated on various parameters such as zeta potential, DSC, and encapsulation efficiency of a hydrophilic drug pentoxyfylline. Conventional and PEG-CH containing pentoxyfylline liposomes were formulated and their stability was evaluated at 4°C for 3 months. PEG-CH could be successfully synthesized with good yields and the structure was confirmed by IR, DSC, and (1)H NMR. The incorporation of PEG-CH in liposomes resulted in reduction of the zeta potential and broadening of the DSC endotherm. Furthermore, incorporation of PEG-CH in liposomes decreased the encapsulation efficiency of pentoxifylline in liposomes when compared to conventional liposomes. Conventional and PEG-CH containing pentoxyfylline liposomes did not show any signs of pentoxyfylline degradation when stored at 4°C for 3 months.
authors.affiliation: Department of Pharmaceutics, Bombay College of Pharmacy, Kalina, Santacruz, Mumbai, India.
authors.forename: Vinayak P
authors.initials: VP
authors.lastname: Sant
authors.forename: Mangal S
authors.initials: MS
authors.lastname: Nagarsenker
mesh_terms: D002152:Calorimetry, Differential Scanning; D002626:Chemistry, Pharmaceutical; D002788:Cholesterol Esters / Q000138:chemical synthesis*; D004337:Drug Carriers; D004339:Drug Compounding; D004355:Drug Stability; D057927:Hydrophobic and Hydrophilic Interactions; D008081:Liposomes; D009682:Magnetic Resonance Spectroscopy; D010316:Particle Size; D010431:Pentoxifylline / Q000737:chemistry; D011092:Polyethylene Glycols / Q000138:chemical synthesis*; D012995:Solubility; D013055:Spectrophotometry, Infrared; D013678:Technology, Pharmaceutical / Q000379:methods; D013696:Temperature; D013997:Time Factors
chemical_list: D002788:Cholesterol Esters; D004337:Drug Carriers; D008081:Liposomes; C570878:monomethoxypolyethyleneglycol-cholesteryl ester; D011092:Polyethylene Glycols; C028210:monomethoxypolyethylene glycol; D010431:Pentoxifylline