title: Pre-treatment with Aloe vera juice does not enhance the in vitro permeation of ketoprofen across skin.
abstract: OBJECTIVE
  The potential of pre-treating skin with Aloe vera juice as a penetration enhancer was evaluated in vitro using ketoprofen as model permeant.
  
  
  METHODS
  To excised porcine skin mounted in Franz diffusion cells was applied either: (1) commercial Aloe vera; (2) commercial Aloe vera followed by massaging; (3) previously boiled commercial Aloe vera; (4) water (negative control); (5) tea tree oil (positive control). After 1 h, the pre-treatment was removed and the skin dosed with a saturated solution of ketoprofen in polyethylene glycol 400; the appearance of drug in the receptor phase was then monitored by HPLC.
  
  
  RESULTS
  No statistically significant differences in the transdermal delivery of ketoprofen were observed between water and all the Aloe vera pre-treatments (p > 0.05). The tea tree oil pre-treatment was significantly different to all others (p < 0.05).
  
  
  CONCLUSIONS
  Aloe vera appears to have no value as a penetration enhancer when used as a pre-treatment, although the data indirectly support the mechanism of action proposed previously, work when used 'within-vehicle'. Handling household products containing Aloe vera appears not to leave the user at elevated risk of subsequent absorption of exogenous chemicals.
authors.affiliation: Welsh School of Pharmacy, Cardiff University, Cardiff, UK.
authors.forename: L
authors.initials: L
authors.lastname: Ballam
authors.forename: C M
authors.initials: CM
authors.lastname: Heard
mesh_terms: D000504:Aloe / Q000737:chemistry*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D015194:Diffusion Chambers, Culture; D005079:Excipients / Q000737:chemistry; D007660:Ketoprofen / Q000493:pharmacokinetics*; D010936:Plant Extracts / Q000494:pharmacology*; D011092:Polyethylene Glycols / Q000737:chemistry; D012867:Skin / Q000187:drug effects / Q000378:metabolism; D012869:Skin Absorption / Q000187:drug effects*; D013552:Swine; D020947:Tea Tree Oil / Q000494:pharmacology
chemical_list: D005079:Excipients; D010936:Plant Extracts; D011092:Polyethylene Glycols; D020947:Tea Tree Oil; D007660:Ketoprofen