Stability of drug-carrier emulsions containing phosphatidylcholine mixtures.
Lipid emulsion particles containing 10% of medium chain triglycerides were prepared using 2% w/w of a mixture 1:1 w/w of purified soya phosphatidylcholine and 2-hexanoyl phosphatidylcholine as emulsifier mixture, for use as drug carriers. The mean droplet sizes of emulsions, prepared using an Ultra Turrax or a high-pressure homogenizer, were about 288 and 158 nm, respectively, compared with 380 and 268 nm for emulsions containing lecithin, or 325 and 240 nm for those containing 6-phosphatidylcholine. The stability of the emulsions, determined by monitoring the decrease of a lipophilic marker at a specified level within the emulsion, and observing coalescence over time, was also greatly increased using the emulsifier mixture. The emulsion stability did not notably change in the presence of a model destabilizing drug, indomethacin. The use of a second hydrophilic surfactant to adjust the packing properties of the lecithin at the oil-water interface provided an increase in the stability of lipid emulsions, and this may be of importance in the formulation of drug delivery systems.
Trotta
Michele
M
Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Turin, Italy. trotta@pharm.unito.it
Pattarino
Franco
F
Ignoni
Terenzio
T
D004337:Drug Carriers / Q000737:chemistry; D004355:Drug Stability; D004655:Emulsions; D007700:Kinetics; D008244:Lysophosphatidylcholines / Q000737:chemistry; D010713:Phosphatidylcholines / Q000737:chemistry*; D013678:Technology, Pharmaceutical / Q000379:methods
D004337:Drug Carriers; D004655:Emulsions; D008244:Lysophosphatidylcholines; D010713:Phosphatidylcholines