Extraction Technologies for Medicinal and Aromatic ... - Capacity4Dev

EXTRACTION TECHNOLOGIES FOR MEDICINAL AND AROMATIC PLANTS
11 Process-scale High Performance Liquid
Chromatography for Medicinal and
Aromatic Plants
Abstract
M. M. Gupta and K. Shanker
High performance liquid chromatography (HPLC) is widely used by chromatographers
and by the pharmaceutical industry for the accurate and precise analysis of chemicals
and drugs of diverse nature. The systematic scale-up from analytical to preparative
and process scale and further scale-up to industrial scale can be used in the medicinal
and aromatic plant industry for the isolation and purifi cation of phytomolecules of
therapeutic and commercial interest. Due to the gradual increase in the demand for
phytomolecules, the importance of process-scale HPLC as a purifi cation tool has been
increasing. In this article, we discuss the practical aspects of process-scale HPLC and
focus on terminology, operational problems, advantages and applications of this technology
to medicinal and aromatic plants.
11.1 Introduction
The term liquid chromatography (LC) refers to a range of chromatographic
systems, indicating liquid-solid, liquid-liquid, ion-exchange and
size exclusion chromatography. Glass column chromatography is an example
of classic liquid column chromatography in which the mobile phase percolates
under gravity through a glass column fi lled with a fi nely divided stationary
phase. Liquid chromatography has overtaken gas chromatography,
as high performance liquid chromatography (HPLC) systems now provide
features such as:
i)
ii)
iii)
iv)
v)
High resolving power
Fast separation
Continuous monitoring of column effl uent
Qualitative and quantitative measurements and isolation
Automation of analytical procedures and data handling
There has been tremendous growth in this technique since
1964 when the fi rst HPLC instrument was constructed by Csaba Horvath
at Yale University. For the isolation of compounds, preparative mode HPLC
(prep-HPLC) can be used in pharmaceutical development for trouble-shooting
purposes or as part of a systematic scale-up process. The importance
of prep-HPLC in pharmaceutical production as a purifi cation tool has been
increasing. Chromatographic separation can remove impurities of different
polarity and can reduce the content of an enantiomer in a racemic mixture.
In both of these instances, crystallization may be used to prepare the pure
product. Bench to pilot scale production of natural products needs some
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