title: Effect of diclofenac and glycol intercalation on structural assembly of phospholipid lamellar vesicles.
abstract: The aim of the current study was to improve the knowledge of drug-glycol-phospholipid-interactions and their effects in lamellar vesicle suitability as drug delivery systems. Liposomes were prepared using hydrogenated soy phosphatidylcholine (P90H, 60 mg/ml) and diclofenac sodium salt at two concentrations (5-10 mg/ml). To obtain innovative vesicles two permeation enhancers with glycol group, diethyleneglycol monoethyl ether and propylene glycol, were added to the water phase at different ratios (5%, 10%, and 20%). Vesicle organization was deeply investigated by physico-chemical characterization, including differential scanning calorimetry and small-angle diffraction signal analysis while macroscopic structure behavior was evaluated by rheological studies. Results evidenced that the presence of the penetration enhancer and diclofenac sodium salt led to structural rearrangements within and among vesicles forming a tridimensional and complex architecture in which vesicles were closely packed and interconnected. This new design allowed a change in the physical state of dispersions that became highly viscous liquid or soft-solid-like, thus forming an ideal system for topical application able of both adhering to the skin and delivering the drug.
authors.affiliation: Dept. Scienze della Vita e dell'Ambiente, Sez. Scienze del Farmaco, CNBS, University of Cagliari, Cagliari, Italy.
authors.forename: Ines
authors.initials: I
authors.lastname: Castangia
authors.forename: Maria Letizia
authors.initials: ML
authors.lastname: Manca
authors.forename: Pietro
authors.initials: P
authors.lastname: Matricardi
authors.forename: Chiara
authors.initials: C
authors.lastname: Sinico
authors.forename: Sandrina
authors.initials: S
authors.lastname: Lampis
authors.forename: Xavier
authors.initials: X
authors.lastname: Fernàndez-Busquets
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Fadda
authors.forename: Maria
authors.initials: M
authors.lastname: Manconi
mesh_terms: D002152:Calorimetry, Differential Scanning; D004008:Diclofenac / Q000737:chemistry*; D004339:Drug Compounding; D005026:Ethylene Glycols / Q000737:chemistry*; D007364:Intercalating Agents / Q000737:chemistry*; D008081:Liposomes; D010713:Phosphatidylcholines / Q000737:chemistry*; D019946:Propylene Glycol / Q000737:chemistry*; D012212:Rheology; D014961:X-Ray Diffraction
chemical_list: D005026:Ethylene Glycols; D007364:Intercalating Agents; D008081:Liposomes; D010713:Phosphatidylcholines; D004008:Diclofenac; D019946:Propylene Glycol; C010111:carbitol
keywords: Cryo-TEM; DSC; Glycols; Phospholipid vesicles; Rheology; SAXS