The validation of herbal products
The validation of herbal products is a major public health concern both in devel-
oped and resource-poor countries, where a fake businesses selling adulterated her-
bal medicines are common. In this regard, there is no control by the government
agencies, despite the existence of certain guidelines in some individual countries
38 2 Quality Control, Screening, Toxicity, and Regulation of Herbal Drugs
and those outlined by the WHO. If the herbal products are marketed as therapeu-
tic agents, and irrespective of whether the products really have any positive effects
to cure and reduce the severity of the disease, it is necessary to ensure scientific val-
idation and periodic monitoring of the quality and efficacy by drug control admin-
istrators.
It is feasible that the introduction of scientific validation would control the pro-
duction of impure or adulterated herbal products and would eventually ensure
their rational use. This could also lead to the regulation of the industry so that on-
ly qualified physicians and health providers are allowed to prescribe the medica-
tion.
Several of the principal pharmacopeias contain monographs outlining standards
for herbal drugs. The major advantage of an official monograph published in a
pharmacopeia is that standards are defined and available, and that the analytical
procedures used are fully validated. This is of major importance, since validation
can be a rather time-consuming process.
By definition, validation is the process of proving that an analytical method is ac-
ceptable for its intended purpose for pharmaceutical methods. Guidelines from
the United States Pharmacopeia (USPC, 1994–2001), the International Conference
on Harmonization (ICH), and the US Food and Drug Administration (FDA) pro-
vide a framework for performing such validations. In general, validation investiga-
tions must include studies on specificity, linearity, accuracy, precision, range, de-
tection, and quantitative limits, depending on whether the analytical method used
is qualitative or quantitative [80]. Also of utmost importance is the availability of
standards. For macroscopic and microscopic procedures in general this means
that reliable reference samples of the plant must be available. A defined botanical
source (e.g. voucher specimens) will normally solve this problem. Standards for
chromatographic procedures are less easy to obtain. Characteristic plant constitu-
ents, either active or markers, are seldom available commercially. Sometimes an
LC/MS approach can be referred to as a mode of characterization. Going one step
further, after isolation of such a compound, elucidations to prove its definite struc-
ture will not be easy. The method often employed is to use readily available com-
pounds that behave similarly in the chosen chromatographic systems, and to cal-
culate retention values and/or times towards these compounds as a standard.
Qualitative chemical examination is designed to detect and isolate the active in-
gredient(s). TLC and HPLC are the main analytical techniques commonly used. In
cases when active ingredients are not known or too complex, the quality of plant ex-
tracts can be assessed by a “fingerprint” chromatogram [81–87].
The validation of herbal products is a major public health concern both in devel-
oped and resource-poor countries, where a fake businesses selling adulterated her-
bal medicines are common. In this regard, there is no control by the government
agencies, despite the existence of certain guidelines in some individual countries
38 2 Quality Control, Screening, Toxicity, and Regulation of Herbal Drugs
and those outlined by the WHO. If the herbal products are marketed as therapeu-
tic agents, and irrespective of whether the products really have any positive effects
to cure and reduce the severity of the disease, it is necessary to ensure scientific val-
idation and periodic monitoring of the quality and efficacy by drug control admin-
istrators.
It is feasible that the introduction of scientific validation would control the pro-
duction of impure or adulterated herbal products and would eventually ensure
their rational use. This could also lead to the regulation of the industry so that on-
ly qualified physicians and health providers are allowed to prescribe the medica-
tion.
Several of the principal pharmacopeias contain monographs outlining standards
for herbal drugs. The major advantage of an official monograph published in a
pharmacopeia is that standards are defined and available, and that the analytical
procedures used are fully validated. This is of major importance, since validation
can be a rather time-consuming process.
By definition, validation is the process of proving that an analytical method is ac-
ceptable for its intended purpose for pharmaceutical methods. Guidelines from
the United States Pharmacopeia (USPC, 1994–2001), the International Conference
on Harmonization (ICH), and the US Food and Drug Administration (FDA) pro-
vide a framework for performing such validations. In general, validation investiga-
tions must include studies on specificity, linearity, accuracy, precision, range, de-
tection, and quantitative limits, depending on whether the analytical method used
is qualitative or quantitative [80]. Also of utmost importance is the availability of
standards. For macroscopic and microscopic procedures in general this means
that reliable reference samples of the plant must be available. A defined botanical
source (e.g. voucher specimens) will normally solve this problem. Standards for
chromatographic procedures are less easy to obtain. Characteristic plant constitu-
ents, either active or markers, are seldom available commercially. Sometimes an
LC/MS approach can be referred to as a mode of characterization. Going one step
further, after isolation of such a compound, elucidations to prove its definite struc-
ture will not be easy. The method often employed is to use readily available com-
pounds that behave similarly in the chosen chromatographic systems, and to cal-
culate retention values and/or times towards these compounds as a standard.
Qualitative chemical examination is designed to detect and isolate the active in-
gredient(s). TLC and HPLC are the main analytical techniques commonly used. In
cases when active ingredients are not known or too complex, the quality of plant ex-
tracts can be assessed by a “fingerprint” chromatogram [81–87].
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