title: Silymarin loaded liposomes for hepatic targeting: in vitro evaluation and HepG2 drug uptake.
abstract: Silymarin has hepatoprotective properties and is used in treatment of various liver diseases, but its bioavailability from oral products is very poor. In order to overcome its poor oral bioavailability we have prepared silymarin loaded hepatic targeting liposomes suitable for parenteral administration. The liposomal formulations were composed of hydrogenated soy phosphatidylcholine and cholesterol with or without distearoylphosphoethanolamine-(polyethyleneglycol)-2000 and various amounts of β-sitosterol β-D-glucoside (Sito-G) as the hepatic targeting moiety. Increasing the amount of Sito-G in the liposomes gradually decreased drug encapsulation efficiencies from ∼70% to ∼60%; still showing promising drug encapsulation efficiencies. Addition of Sito-G to non-PEGylated liposomes clearly affected their drug release profiles and plasma protein interactions, whereas no effect on these was seen for the PEGylated liposomes. Non-PEGylated liposomes with 0.17 M ratio of Sito-G exhibited the highest cellular drug uptake of 37.5% for all of the studied liposome formulations. The highest cellular drug uptake in the case of PEGylated liposomes was 18%, which was achieved with 0.17 and 0.33 M ratio of added Sito-G. The liposome formulations with the highest drug delivery efficacy in this study showed hemolytic activities around 12.7% and were stable for at least 2 months upon storage in 20 mM HEPES buffer (pH 7.4) containing 1.5% Polysorbate 80 at 4 °C and room temperature. These results suggest that the Sito-G containing liposomes prepared in this work have hepatic targeting capability and that they are promising candidates for delivering silymarin to the liver.
authors.affiliation: Division of Biopharmaceutics and Pharmacokinetics, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, 000014 Helsinki, Finland.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Elmowafy
authors.forename: Tapani
authors.initials: T
authors.lastname: Viitala
authors.forename: Hany M
authors.initials: HM
authors.lastname: Ibrahim
authors.forename: Sherif K
authors.initials: SK
authors.lastname: Abu-Elyazid
authors.forename: Ahmed
authors.initials: A
authors.lastname: Samy
authors.forename: Alaa
authors.initials: A
authors.lastname: Kassem
authors.forename: Marjo
authors.initials: M
authors.lastname: Yliperttula
mesh_terms: D002784:Cholesterol / Q000737:chemistry; D004912:Erythrocytes / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects; D056945:Hep G2 Cells; D006801:Humans; D008081:Liposomes; D008099:Liver / Q000378:metabolism; D010713:Phosphatidylcholines / Q000737:chemistry; D010714:Phosphatidylethanolamines / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D020011:Protective Agents / Q000008:administration & dosage* / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012838:Silymarin / Q000008:administration & dosage* / Q000737:chemistry; D012855:Sitosterols / Q000737:chemistry*
chemical_list: C519184:1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-methoxy-poly(ethylene glycol 2000); D008081:Liposomes; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D020011:Protective Agents; D012838:Silymarin; D012855:Sitosterols; D012710:Serum Albumin, Bovine; D011092:Polyethylene Glycols; D002784:Cholesterol; C011015:lyoniside
keywords: HepG2; Hepatic targeting; Silymarin; Targeting liposomes; β-Sitosterol β-d-glucoside