The effect of oil components on the physicochemical properties and drug delivery of emulsions: tocol emulsion versus lipid emulsion.
An emulsion system composed of vitamin E, coconut oil, soybean phosphatidylcholine, non-ionic surfactants, and polyethylene glycol (PEG) derivatives (referred to as the tocol emulsion) was characterized in terms of its physicochemical properties, drug release, in vivo efficacy, toxicity, and stability. Systems without vitamin E (referred to as the lipid emulsion) and without any oils (referred to as the aqueous micelle system) were prepared for comparison. A lipophilic antioxidant, resveratrol, was used as the model drug for emulsion loading. The incorporation of Brij 35 and PEG derivatives reduced the vesicle diameter to <100nm. The inclusion of resveratrol into the emulsions and aqueous micelles retarded the drug release. The in vitro release rate showed a decrease in the order of aqueous micelle system>tocol emulsion>lipid emulsion. Treatment of resveratrol dramatically reduced the intimal hyperplasia of the injured vascular wall in rats. There was no significant difference in this reduction when resveratrol was delivered by either emulsion or the aqueous micelle system. The percentages of erythrocyte hemolysis by the emulsions and aqueous micelle system were approximately 0 and approximately 10%, respectively. Vitamin E prevented the aggregation of emulsion vesicles. The mean vesicle size of the tocol emulsion remained unchanged during 30 days at 37 degrees C. The lipid emulsion and aqueous micelle system, respectively, showed 11- and 16-fold increases in vesicle size after 30 days of storage.
Hung
Chi-Feng
CF
School of Medicine, Fu-Jen Catholic University, Taipei, Taiwan.
Fang
Chia-Lang
CL
Department of Pathology, College of Medicine, Taipei Medical University, Taipei, Taiwan.
Liao
Mei-Hui
MH
Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, 259 Wen-Hwa 1st Road, Kweishan, Taoyuan 333, Taiwan.
Fang
Jia-You
JY
Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, 259 Wen-Hwa 1st Road, Kweishan, Taoyuan 333, Taiwan. Electronic address: fajy@mail.cgu.edu.tw.
D000818:Animals; D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology; D001713:Biphenyl Compounds; D016893:Carotid Stenosis / Q000473:pathology / Q000517:prevention & control; D002626:Chemistry, Pharmaceutical; D000074263:Coconut Oil; D004195:Disease Models, Animal; D004337:Drug Carriers; D004339:Drug Compounding; D004655:Emulsions; D006461:Hemolysis / Q000187:drug effects; D008297:Male; D008823:Micelles; D009821:Oils / Q000737:chemistry* / Q000633:toxicity; D010316:Particle Size; D010713:Phosphatidylcholines / Q000737:chemistry; D010851:Picrates / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry* / Q000633:toxicity; D051381:Rats; D017207:Rats, Sprague-Dawley; D000077185:Resveratrol; D012995:Solubility; D013267:Stilbenes / Q000737:chemistry* / Q000494:pharmacology; D013501:Surface-Active Agents / Q000737:chemistry* / Q000633:toxicity; D013678:Technology, Pharmaceutical / Q000379:methods*; D013997:Time Factors; D014810:Vitamin E / Q000737:chemistry
D000975:Antioxidants; D001713:Biphenyl Compounds; D004337:Drug Carriers; D004655:Emulsions; D008823:Micelles; D009821:Oils; D010713:Phosphatidylcholines; D010851:Picrates; D010938:Plant Oils; D013267:Stilbenes; D013501:Surface-Active Agents; D014810:Vitamin E; D011092:Polyethylene Glycols; C004931:1,1-diphenyl-2-picrylhydrazyl; D000077185:Resveratrol; D000074263:Coconut Oil