title: Transdermal absorption of natural progesterone from alcoholic gel formulations with hydrophilic surfactant.
abstract: OBJECTIVE
  The aim of this study was to evaluate the in vitro skin permeation and in vivo transdermal absorption of natural progesterone (Prog) from alcoholic gel-based transdermal formulations containing Prog dissolved stably at a concentration of 3%.
  
  
  METHODS
  3% Prog dissolved gel formulations were prepared containing with water, ethanol, 1,3-butylene glycol, carboxyvinylpolymer, diisopropanolamine, polyoxyethylene (2) oleylether and benzyl alcohol. The gel formulations added different hydrophilic surfactants and isopropyl myristate or propylene glycol dicaprylate (PGDC) as oily solvents were applied in vitro permeation study through excised rat skin on unocclusive condition. The gel formulations added polyoxyethylene (20) oleylether (Oleth-20) as hydrophilic surfactant and PGDC were applied in vivo single- and repeated-dose transdermal absorption study of rat on unocclusive condition.
  
  
  RESULTS
  The results of evaluation of the gel formulations by an in vitro skin permeation study revealed a high flux of Prog from the formulation containing Oleth-20 and Oleth-20 with PGDC. The results of single and repeated in vivo transdermal absorption studies confirmed that good plasma levels of Prog were achieved and maintained by Oleth-20 and PGDC containing gel formulation.
  
  
  CONCLUSIONS
  The Oleth-20 and PGDC containing ethanolic gel formulation seemed to have the ability to maintain a high activity of Prog and high diffusivity or solubility of Prog in the epidermis on the practical formulation application.
authors: Innovative Science Research and Development Center, Shiseido Co., Ltd. , Yokohama , Japan and.
authors: Rakan
authors: R
authors: Matsui
authors: Osamu
authors: O
authors: Ueda
authors: Shinya
authors: S
authors: Uchida
authors: Noriyuki
authors: N
authors: Namiki
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D002210:Caprylates / Q000737:chemistry; D002626:Chemistry, Pharmaceutical / Q000379:methods; D000431:Ethanol / Q000737:chemistry*; D005079:Excipients / Q000737:chemistry*; D005782:Gels; D057927:Hydrophobic and Hydrophilic Interactions; D008297:Male; D009226:Myristates / Q000737:chemistry; D011374:Progesterone / Q000008:administration & dosage* / Q000493:pharmacokinetics; D019946:Propylene Glycol / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D012869:Skin Absorption; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D002210:Caprylates; D005079:Excipients; D005782:Gels; D009226:Myristates; D012997:Solvents; D013501:Surface-Active Agents; C008205:isopropyl myristate; D000431:Ethanol; D011374:Progesterone; D019946:Propylene Glycol
keywords: Gel formulation; hormone replacement therapy; natural progesterone; surfactant; transdermal absorption