Dermal pharmacokinetics of terpinen-4-ol following topical administration of Zingiber cassumunar (plai) oil

Abstract

The purpose of this study was to investigate dermal pharmacokinetics of terpinen-4-ol in rats following topical administration of plai oil derived from the rhizomes of Zingiber cassumunar Roxb. Unbound terpinen-4-ol concentrations in dermal tissue were measured by microdialysis. The dermal pharmacokinetic study of terpinen-4-ol was performed under non-occlusive conditions. The oil was topically applied at a dose of 2, 4, and 8mg/cm 2 plai oil corresponding to the amount of 1.0, 1.9, and 3.8mg/cm 2 terpinen-4-ol, respectively. Following topical application of the oil, terpinen-4-ol rapidly distributed into the dermis and demonstrated linear pharmacokinetics with no changes in the dose-normalized area under the concentration-time curves across the investigated dosage range. The mean percentages of free terpinen-4-ol distributed in the dermis per amount of administered were 0.39±0.06%, 0.41±0.08%, and 0.30±0.03% for 2, 4, and 8mg/cm 2 doses, respectively. The dermal pharmacokinetics of terpinen-4-ol could provide information for its further formulation development and therapy schedules. © Georg Thieme Verlag KG · Stuttgart · New York.