title: Exploring the co-loading of lidocaine chemical forms in surfactant/phospholipid vesicles for improved skin delivery.
abstract: OBJECTIVE
  The present study was aimed at targeting the skin to deliver lidocaine loaded in surfactant/phospholipid vesicles tailored for improved local delivery. The influence of different formulation parameters was explored to maximise drug efficacy.
  
  
  METHODS
  The vesicles were prepared using a mixture of soy lipids (Phospholipon 50) and a surfactant with penetration-enhancing properties (Oramix CG110, Labrasol, Labrafac PG or Labrafac CC), and loaded with lidocaine. The formulations were analysed in detail by cryo-TEM, SAXS, Turbiscan Lab, and tested in permeation experiments through new born pig skin, as a function of the chemical form and concentration of lidocaine (i.e. free base or salt, 12.5 or 25 mg/ml).
  
  
  RESULTS
  Small, spherical vesicles with good entrapment efficiency and exceptional long-term stability were produced. The lamellar organisation was affected by either the surfactant or the lidocaine form used. Permeation studies highlighted that the co-incorporation of lidocaine base + hydrochloride allowed the achievement of a superior deposition in the skin layers, especially when surfactant vesicles were used, as their content was presumably saturated with the maximum amount of loadable anaesthetic.
  
  
  CONCLUSIONS
  The proposed systems based on surfactant/phospholipid vesicles co-loaded with both lidocaine forms are an effective approach for improving its local delivery.
authors: Department Scienze della Vita e dell'Ambiente, Sezione di Scienze del Farmaco, University of Cagliari, Cagliari, Italy.
authors: Carla
authors: C
authors: Caddeo
authors: Department Scienze della Vita e dell'Ambiente, Sezione di Scienze del Farmaco, University of Cagliari, Cagliari, Italy.
authors: Donatella
authors: D
authors: Valenti
authors: Department of Pharmacy and Pharmaceutical Technology, University of Valencia, Valencia, Spain.|Instituto de Reconocimiento Molecular y Desarrollo Tecnológico, Centro Mixto Universidad Politécnica de Valencia-Universidad de Valencia, Valencia, Spain.
authors: Amparo
authors: A
authors: Nácher
authors: Department Scienze della Vita e dell'Ambiente, Sezione di Scienze del Farmaco, University of Cagliari, Cagliari, Italy.
authors: Maria
authors: M
authors: Manconi
authors: Department Scienze della Vita e dell'Ambiente, Sezione di Scienze del Farmaco, University of Cagliari, Cagliari, Italy.
authors: Anna Maria
authors: AM
authors: Fadda
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D002626:Chemistry, Pharmaceutical / Q000379:methods; D004337:Drug Carriers / Q000008:administration & dosage / Q000737:chemistry; D004355:Drug Stability; D005989:Glycerides / Q000008:administration & dosage / Q000737:chemistry; D008012:Lidocaine / Q000008:administration & dosage* / Q000737:chemistry*; D010539:Permeability; D010743:Phospholipids / Q000008:administration & dosage* / Q000737:chemistry*; D012867:Skin / Q000378:metabolism*; D012869:Skin Absorption / Q000502:physiology; D013501:Surface-Active Agents / Q000008:administration & dosage* / Q000737:chemistry*; D013552:Swine
chemical_list: D004337:Drug Carriers; D005989:Glycerides; D010743:Phospholipids; D013501:Surface-Active Agents; C440220:Labrasol; D008012:Lidocaine
keywords: accelerated stability; lamellar structure; lidocaine; skin delivery; surfactant/phospholipid vesicle