title: Development and Assessment of a Gas Chromatographic Based Method for the Quantification of Thymol from Cream Based Formulation.
abstract: Herbal medicines have been used for different illnesses. However, standardization of these medicaments should be done before introducing for treatment purposes. Ajwain an essential oil, is traditionally used for neuropathic pain.
  
  
  
  To develop and assess a gas chromatographic-based method for the quantification of thymol in Ajwain essential oil, current work was performed.
  
  
  
  Both pure thymol and Ajwain creams were prepared and subjected to hydrodistillation method under temperature-controlled procedure to re-extract the applied essential oil and pure thymol. Previously, Ajwain seeds essential oil composition was analyzed and identified using GC/MS. After re-extraction, GC/FID was applied quantitatively to determine the thymol content in the Ajwain and thymol creams. The parameters represented in International Conference on Harmonization (ICH) guidelines were considered for the determination.
  
  
  
  Thymol content in a 50 g laminated tube of Ajwain cream was calculated as 2.34 g ± 0.02. Regarding the total thymol content of a 50 g laminated tube of Thymol cream (2.43 g), recovery percent for Ajwain cream was calculated as 96.29 %.
  
  
  
  Using hydrodistillation for an essential oil- containing cream sample via Clevenger proved to be a simple and convenient method to work up and extract active volatile components of such semisolid formulation. However, the extraction yield was profoundly related to the condenser temperature. The current employed determination method is introduced as a rapid and reliable method and thus, can be suggested for the quality control assessment of phytopharmaceutical semisolid preparations containing thymol and similar volatile constituents.
authors.forename: Soliman Mohammadi
authors.initials: SM
authors.lastname: Samani
authors.forename: Mahmoodreza
authors.initials: M
authors.lastname: Moein
authors.forename: Peyman
authors.initials: P
authors.lastname: Petramfar
authors.affiliation: Department of Phytopharmaceuticals (Traditional Pharmacy), School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran. zarm@sums.ac.ir.
authors.forename: Mohammad M
authors.initials: MM
authors.lastname: Zarshenas
mesh_terms: D029974:Carum; D004304:Dosage Forms; D008401:Gas Chromatography-Mass Spectrometry; D009822:Oils, Volatile / Q000032:analysis*; D012639:Seeds / Q000737:chemistry; D013943:Thymol / Q000032:analysis*
chemical_list: D004304:Dosage Forms; D009822:Oils, Volatile; D013943:Thymol