title: Polyamide nanocapsules and nano-emulsions containing Parsol® MCX and Parsol® 1789: in vitro release, ex vivo skin penetration and photo-stability studies.
abstract: OBJECTIVE
  To prepare polyamide nanocapsules for skin photo-protection, encapsulating α-tocopherol, Parsol®MCX (ethylhexyl methoxycinnamate) and/or Parsol®1789 (butyl methoxydibenzoylmethane).
  
  
  METHODS
  Nanocapsules were obtained by combining spontaneous emulsification and interfacial polycondensation reaction between sebacoyl chloride and diethylenetriamine. Nano-emulsions used as control were obtained by the same process without monomers. The influence of carrier on release rate was studied in vitro with a membrane-free model. Epidermal penetration of encapsulated sunscreens was ex vivo evaluated using Franz diffusion cells. Ability of encapsulated sunscreens to improve photo-stability was verified by comparing percentage of degradation after UV radiation exposure.
  
  
  RESULTS
  Sunscreen-containing nanocapsules (260-400 nm) were successfully prepared; yield of encapsulation was >98%. Parsol®MCX and Parsol®1789 encapsulation led to decreased release rate by up to 60% in comparison with nano-emulsion and allowed minimum penetration through pig ear epidermis. Presence of polyamide shell protected encapsulated sunscreen filters from photo-degradation without affecting their activity.
  
  
  CONCLUSIONS
  Encapsulation of Parsol®MCX and Parsol®1789 into oil-core of polyamide nanocapsules allowed protection from photo-degradation, controlled release from nanocapsules, and limited penetration through pig ear epidermis.
authors.affiliation: Faculty of Pharmacy, University of Paris-Sud 11 UMR CNRS 8612, 5 Rue J.B. Clément, 92296, Châtenay-Malabry cedex, France.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Hanno
authors.forename: Cecilia
authors.initials: C
authors.lastname: Anselmi
authors.forename: Kawthar
authors.initials: K
authors.lastname: Bouchemal
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000493:pharmacokinetics; D047188:Chalcones / Q000008:administration & dosage* / Q000493:pharmacokinetics; D002934:Cinnamates / Q000008:administration & dosage* / Q000493:pharmacokinetics; D004655:Emulsions / Q000737:chemistry*; D053769:Nanocapsules / Q000737:chemistry*; D009757:Nylons / Q000737:chemistry; D011427:Propiophenones; D012867:Skin / Q000378:metabolism*; D012869:Skin Absorption; D013473:Sunscreening Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D013552:Swine; D024502:alpha-Tocopherol / Q000008:administration & dosage / Q000493:pharmacokinetics
chemical_list: D000975:Antioxidants; D047188:Chalcones; D002934:Cinnamates; D004655:Emulsions; D053769:Nanocapsules; D009757:Nylons; D011427:Propiophenones; D013473:Sunscreening Agents; C516303:ethylhexyl methoxycinnamate; C049935:avobenzone; D024502:alpha-Tocopherol