title: An investigation into the characteristics and drug release properties of multiple W/O/W emulsion systems containing low concentration of lipophilic polymeric emulsifier.
abstract: Multiple W/O/W emulsions with high content of inner phase (Phi1=Phi2=0.8) were prepared using relatively low concentrations of lipophilic polymeric primary emulsifier, PEG 30-dipolyhydroxystearate, and diclofenac diethylamine (DDA) as a model drug. The investigated formulations were characterized and their stability over the time was evaluated by dynamic and oscillatory rheological measurements, microscopic analysis and in vitro drug release study. In vitro release profiles of the selected model drug were evaluated in terms of the effective diffusion coefficients and flux of the released drug. The multiple emulsion samples exhibited good stability during the ageing time. Concentration of the lipophilic primary emulsifier markedly affected rheological behaviour as well as the droplet size and in vitro drug release kinetics of the investigated systems. The multiple emulsion systems with highest concentration (2.4%, w/w) of the primary emulsifier had the lowest droplet size and the highest apparent viscosity and highest elastic characteristics. Drug release data indicated predominately diffusional drug release mechanism with sustained and prolonged drug release accomplished with 2.4% (w/w) of lipophilic emulsifier employed.
authors.affiliation: Department of Pharmaceutical Technology and Cosmetology, Faculty of Pharmacy, Belgrade University, Vojvode Stepe 450, 11221 Belgrade-Kumodraz, Serbia and Montenegro. vasilj@pharmacy.bg.ac.yu
authors.forename: Dragana
authors.initials: D
authors.lastname: Vasiljevic
authors.forename: Jelena
authors.initials: J
authors.lastname: Parojcic
authors.forename: Marija
authors.initials: M
authors.lastname: Primorac
authors.forename: Gordana
authors.initials: G
authors.lastname: Vuleta
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations; D004008:Diclofenac / Q000737:chemistry; D004058:Diffusion; D004355:Drug Stability; D045703:Emulsifying Agents / Q000737:chemistry*; D004655:Emulsions; D007700:Kinetics; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry*; D012212:Rheology; D012995:Solubility; D013228:Stearates / Q000737:chemistry*; D014783:Viscosity
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D003692:Delayed-Action Preparations; D045703:Emulsifying Agents; D004655:Emulsions; D013228:Stearates; D004008:Diclofenac; D011092:Polyethylene Glycols