title: Dermal delivery of selected hydrophilic drugs from elastic liposomes: effect of phospholipid formulation and surfactants.
abstract: The effect of phospholipid formulation and choice of surfactant on skin permeation of selected hydrophilic drugs from elastic liposomes across human epidermal membrane has been studied. Sodium cholate and various concentrations of phosphatidylcholine were used for the preparation of liposomes namely hydrogenated phosphatidylcholine 90% (Phospholipon 90H), phosphatidylcholine 95% (Phospholipon 90G), phosphatidylcholine 78.6% (Phospholipon 80), and phosphatidylcholine 50% (Phosal PG). To investigate the effect of the surfactant, liposomes were prepared from 95% phosphatidylcholine (Phospholipon 90G) and various surfactants (sodium cholate, sodium deoxycholate, Span 20 (sorbitan monolaurate), Span 40 (sorbitan monopalmitate), Span 60 (sorbitan stearate) and Span 80 (sorbitan monooleate)). The vesicles were prepared by the conventional rotary evaporation technique. The film was hydrated with phosphate-buffered saline (10 mL) containing 9, 2 and 2.5 mg mL(-1) of methotrexate, idoxuridine and aciclovir, respectively. All formulations contained 7% ethanol. Homogenously-sized liposomes were produced following extrusion through 100-nm polycarbonate filters using Lipex Extruder. Particle size was characterized by transmission electron microscopy. Vertical Franz diffusion cells were used for the study of drug delivery through human epidermal membrane. For the three drugs, the highest transcutaneous fluxes were from elastic liposomes containing 95% phosphatidylcholine. In general, a higher flux value was obtained for liposomes containing sodium cholate compared with sodium deoxycholate. For the liposomes containing sorbitan monoesters, there was no clearly defined trend between alkyl chain length and flux values. Overall, transcutaneous fluxes of liposomal preparations of hydrophilic drugs were comparable with those from saturated aqueous solutions (P > 0.05).
authors: Unit for Drug Research and Development, North-West University, Potchefstroom Campus, Potchefstroom 2520, South Africa.
authors: Kevin B
authors: KB
authors: Ita
authors: Jan
authors: J
authors: Du Preez
authors: Majella E
authors: ME
authors: Lane
authors: Jonathan
authors: J
authors: Hadgraft
authors: Jeanetta
authors: J
authors: du Plessis
mesh_terms: D000212:Acyclovir / Q000008:administration & dosage*; D000279:Administration, Cutaneous; D002626:Chemistry, Pharmaceutical; D002851:Chromatography, High Pressure Liquid; D004058:Diffusion; D004548:Elasticity; D004817:Epidermis / Q000378:metabolism; D006801:Humans; D007065:Idoxuridine / Q000008:administration & dosage*; D008081:Liposomes; D008727:Methotrexate / Q000008:administration & dosage*; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D010539:Permeability; D010713:Phosphatidylcholines / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry*; D012867:Skin; D012869:Skin Absorption; D013329:Structure-Activity Relationship; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D008081:Liposomes; D010713:Phosphatidylcholines; D010743:Phospholipids; D013501:Surface-Active Agents; D007065:Idoxuridine; D000212:Acyclovir; D008727:Methotrexate