title: Topical formulation and dermal delivery of active phenolic compounds in the Thai medicinal plant--Clerodendrum petasites S. Moore.
abstract: OBJECTIVE
  To develop topical formulations of Clerodendrum petasites S. Moore (CP), and to optimize the skin permeability and topical bioavailability of the active phenolic compounds therein.
  
  
  METHODS
  The skin uptake and delivery of active compounds from two formulations, an oil-in-water cream and a lotion (both containing 10% w/w CP extracts), were examined (a) invitro using pig skin, and (b) invivo in human volunteers. Stratum corneum (SC) was collected by tape stripping and the compounds were detected and quantified by high performance liquid chromatography coupled with either mass spectrometry (HPLC-MS) or ultraviolet and photodiode array (HPLC-UV-PDA) detection.
  
  
  RESULTS
  From the invitro results, vanillic acid, verbascoside, nepetin and hispidulin, were chosen as potential phenolic actives for topical delivery optimization from the formulations. Invivo, vanillic acid, nepetin and hispidulin were appreciably taken up into the SC within 6h, while verbascoside did not penetrate beyond the most superficial layers. No significant differences in delivery were observed between the two formulations, both of which were well tolerated.
  
  
  CONCLUSIONS
  The detected topical absorption of hispidulin, nepetin, and vanillic acid, from the cream and lotion vehicles investigated, suggest that these compounds are potentially active compounds in Thai traditional medicine for the treatment of a wide range of skin diseases.
authors.affiliation: University of Bath, Department of Pharmacy & Pharmacology, Bath BA2 7AY, England, United Kingdom; Center of Applied Thai Traditional Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, 2, Wanglang Road, Bangkoknoi, Bangkok 10700, Thailand. Electronic address: premrutai@gmail.com.
authors.forename: Premrutai
authors.initials: P
authors.lastname: Thitilertdecha
authors.affiliation: University of Bath, Department of Pharmacy & Pharmacology, Bath BA2 7AY, England, United Kingdom.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Rowan
authors.affiliation: University of Bath, Department of Pharmacy & Pharmacology, Bath BA2 7AY, England, United Kingdom.
authors.forename: Richard H
authors.initials: RH
authors.lastname: Guy
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D000818:Animals; D002626:Chemistry, Pharmaceutical; D032409:Clerodendrum; D005260:Female; D006801:Humans; D008297:Male; D010636:Phenols / Q000493:pharmacokinetics*; D010936:Plant Extracts; D010946:Plants, Medicinal; D012867:Skin / Q000378:metabolism*; D012869:Skin Absorption; D063465:Skin Cream; D013552:Swine
chemical_list: D010636:Phenols; D010936:Plant Extracts
keywords: Clerodendrumpetasites S. Moore; Hispidulin; Hispidulin (PubChem CID: 5281628); Mass spectrometry; Nepetin (PubChem CID: 5317284); Skin permeation; Topical bioavailability; Vanillic acid (PubChem CID: 8468); Verbascoside (PubChem CID: 5281800)