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Abstract
Pharmacokinetic Study of Herbal Extracts in vivo
Phisit Khemawoot
Department of Pharmacology and Physiology,Faculty of Pharmaceutical Sciences, Chulalongkorn
University,Patumwan Bangkok, 10330
Corresponding author: phisitkhema@hotmail.com
Public interests in herbal usage for disease prevention and treatment are increasing recently
due to public awareness of healthy lifestyle and advancement in pharmacognosy research. Major
findings of active constituents in various herbs with confirmation of pharmacological effects can
improve confidence in herbal usage. Herbal usage in the past is developed for household con-
sumption such as fresh preparation. Meanwhile, currently available phytopharmaceutical prod-
ucts are formulated as dry powder packed in capsule. This formulation can be resulting in in-
crease of active ingredients, prolong shelf-life, and convenience in packaging and transportation.
However, changing in pattern of herbal usage may cause in increase of adverse events and side
effects from phytopharmaceutical products. Pharmacological data of existing phytopharmaceutical
products can be divided into two parts, pharmacokinetics (PK) and pharmacodynamics (PD).
Most of research articles are pharmacodynamics reports of herbal activities in biological system,
meanwhile absence of pharmacokinetic information seems to be weakness and major problems
in drug development from herbs. Relationship between PK and PD parameters cannot be deter-
mined in order to find vivo effects of herbal extract if PK data is not available. In Thailand, there
is no herbal extract which complete information of PK data, although more than thousand herbs
were explored from this tropical area. Therefore, the objective of this article is to determine some
major obstacles of PK studies of herbal extract in vivo. This article will be useful information to
develop PK and PD research for phytopharmaceutical products and herbal industry in Thailand.
Key words: Pharmacokinetics, Herbal extract, in vivo