STANDARDIZATION OF HERBAL MEDICINE
Herb is a plant that is valued for flavor, scent, or other qualities. Herbs are used in cooking, as medicines, and for spiritual purpose. Medicinal plants, herbs, spices and herbal remedies are known to Ayurveda in India since long times. The value of medicinal plants, herbs and spices as herbal remedies is being lost due to lack of awareness, and deforestation. The result is many valuable medicinal herbs are becoming rare and precious information is lost. Less pollution we make, more ecological balance we maintain, will add to happiness of humankind. Preserve the knowledge of medicinal plants, herbs, spices and herbal remedies, which humankind has received from the past generations, for posterity. Infusions are steeping herbs or spices, with parts like leaves and flowers with boiling water for some time. Filtered or unfiltered use this water extracts of spices as herbal remedies. Decoction is boiling roots, bark and hard parts of herbs and spices with water for along time. Infusion and decoction both are known as herbal teas. Some times essential oil of herbs and spices are also used as herbal remedies. Action of herbal remedies may vary from human to human and care should be observed in using it. Herbs have a variety of uses including culinary, medicinal, or in some cases even spiritual usage. Culinary herbs Culinary use of the term “herb” typically distinguishes between herbs, from the leafy green parts of a plant, and spices, from other parts of the plant, including seeds, berries, bark, root, fruit, and even occasionally dried leaves or roots. Medicinal herbs Plants contain phytochemicals that have effects on the body.. For instance, some types of herbal extract, such as the extract of St. John’s-wort (Hypericum perforatum) or of kava (Piper methysticum) can be used for medical purposes to relieve depression and stress Sacred herbs Herbs are used in many religions – such as in Christianity myrrh and frankincense which was used to honor kings. In Hinduism a form of Basil called Tulsi is worshipped as a goddess for its medicinal value since the Vedic times. Pest control Herbs are also known amongst gardeners to be useful for pest control. Mint, Spearmint, Peppermint, and Pennyroyal are a few of such herbs
INTRODUCTION ON HERBAL STANDARDIZATION
Standardized Herbal Drug: It means the manufacturer has verified that the active ingredient believed to be present in the herb is present in the preparation and that the potency and the amount of active ingredient are assured in the preparation.
The Herbal Standardization Process
Over the past years, recognized world authorities on botanical alternative medicine have defined, and established, specific standards of excellence for herbal extracts. Most importantly, we should standardize for the individual key compounds which have been empirically and scientifically proven to be the most advantageous for the human system.Our standardization process should guarantee a consistent and appropriate level of each plant’s medicinal elements within each of the product formulations we sell.
Standardization Standardization of herbal products is a controversial issue. On one hand, herbalists sometimes feel that highly purified and standardized extracts don’t genuinely represent all the best qualities of herbs and can sometimes lead to safety issues, especially when they are highly concentrated and purified. On the other hand, when herbs are harvested and shipped overseas to faraway places and then made into commercial products such as capsules or tablets, it is very difficult to follow what happens to those herbs along the way. For instance, how long ago were those herbs harvested, how long they have been stored in the warehouse, and what adverse environmental conditions such as excessive heat could have contributed to the degradation in the quality of the herbs.
Modern Testing Today, we have highly sensitive analytical equipment such as high-pressure liquid chromatography (HPLC) to ensure proper identification, levels of active constituents, and purity of the finished product. This can be accomplished without materially altering the internal balance of the original herb. Many modern standardized products today do follow a philosophy that takes the whole plant as the best standard for quality, not isolated and purified individual constituents, though these types of products also are sold. Look at the label, and if you see products where the active constituent is 40 or 50%, even up to 80% of the total weights of the product, then you have a highly purified standardized extract. Need of Standardizations In the global perspective, there is a shift towards the use of medicine of herbal origin. As the dangers and the shortcoming of modern medicine have started getting more apparent, majority of Ayurvedic formulation are prepared from herbs. It is the cardinal responsibility of the regulatory authorities to ensure that the consumers get the medication, which guarantee purity, safety, potency and efficacy. Herbal product has been enjoying renaissance among the customers throughout the world. However, one of the impediments in the acceptance of the Ayurvedic formulation is the lack of standard quality control profile. The quality of herbal medicine i.e. the profile of the constituents in the final product has implication in efficacy and safety. Standardization and Quality Control of Herbal Crude Drugs
According to WHO, it is the process involving the physicochemical evaluation of crude drug covering the aspects, as selection and handling of crude material, safety, efficacy and stability assessment of finished product, documentation of safety and risk based on experience, provision of product information to consumer and product promotion.
?Macro and Microscopic Examination: For Identification of right variety and search of adulterants. ?Foreign Organic Matter: Remove of matter other than source plant to get the drug in pure form. ?Ash Values: It is criteria to judge the identity and purity of crude drug – Total ash, sulfated ash, water soluble ash and acid insoluble ash etc. ?Moisture Content: To check moisture content helps prevent degradation of product. ?Extractive Values: These are indicating the approximate measure of chemical constituents of crude drug. ?Crude Fiber: To determine excessive woody material Criteria for judging purity. ?Qualitative Chemical Evaluation: It covers identification and characterization of crude drug with respect to phytochemical Constituent. ?Chromatographic Examination: Include identification of crude drug based on use of major chemical constituent as marker. ?Qualitative Chemical Evaluation: Criteria to estimate amount the major class of constituents. ?Toxicological Studies: Pesticide residue, potentially toxic elements, and Microbial count approach to minimize their effect in final product.
Physical evaluation: Each monograph contains detailed botanical, macroscopic and microscopic descriptions of the physical characteristics of each plant that can be used to insure both identity and purity.
Microscopic evaluation Full and accurate characterization of plant material requires a combination of physical and chemical tests. Microscopic analyses of plants are invaluable for assuring the identity of the material and as an initial screening test for impurities. Most manufacturers of herbal products lack the quality control personnel to accurately assess plant identity and purity microscopically. Ideally, submitted materials should be in their whole or semi-whole form for microscopic assessments.
Chemical evaluation A chemical method for evaluation covers the isolation, identification and purification. The chemical tests include colour reaction test, these tests help to determine the identity of the drug substance and possible adulteration.
Biological evaluation Pharmacological activity of certain drugs has been applied to evaluate and standardize them. The assays on living animal and on their intact or isolated organs can indicate the strength of the drug or their preparations. All living organism are used, these assays are known as Biological assays or Bioassay.
Analytical Methods Critical to compliance with any monograph standard is the need for appropriate analytical methods for determining identity, quality, and relative potency. There are a plethora of analytical methods available. However, it is often difficult to know which is the most appropriate to use.
Chromatographic Characterization
Chromatography Chromatography is the science which is studies the separation of molecules based on differences in their structure, composition. Chromatographic separations can be carried out using a variety of supports, including immobilized silica on glass plates (thin layer chromatography), very sensitive High Performance Thin Layer Chromatography (HPTLC), volatile gases (gas chromatography), paper (paper chromatography), and liquids which may incorporate hydrophilic, insoluble molecules (liquid chromatography).
Purity Determination Each monograph includes standards of purity and other qualitative assessments which include when appropriate: foreign matter, ash, acid-insoluble ash, moisture content, loss of moisture on drying, and extractives.
Quantitative Analysis The primary goal of the method is to provide validated methods to be used for the quantization of the compound most correlated with pharmacological activity or qualitative markers as determined by the primary pharmacological literature, constituent declaration in product labeling, and a survey of experts.. In this context, validation consists minimally of a two-lab validation using the same procedures, samples, and reference standards. Primary factors for considering a method as appropriate include accuracy of the findings, speed, basic ruggedness, applicability to a large segment of the manufacturing community, and avoidance of the use of toxic reagents and solvents. In an attempt to promote harmonization, primary consideration is given to those methods which are already accepted in official pharmacopoeias. When necessary, comparative tests shall be conducted to determine which of the available method is most appropriate. The validation process minimally includes: standard precision, linearity, sample precision using replicate samples, sample linearity, selectivity , retention times, and limits of detection..
Difference between a herbal extract and standardized herbal extract “Herbal extract” is sometimes also referred to as a tincture, or liquid herbal extract. This is a preparation where a whole herb is steeped in alcohol, water or a combination. A “standardized herbal extract” is a measurable marker substance that is extracted from the herb. This marker may be an active ingredient, or just one that is easily determined, but often, it is a compound that has been used in scientific research.
HPTLC ANALYSIS ON HERBS HPTLC is the most simple separation technique today available to the analyst. HPTLC is a qualitative tool for separation of simple mixtures where speed, low cost and simplicity are required and it is also a tool for quantitative analysis . High-Performance Thin-Layer Chromatography for the analysis of medicinal plants presents the theoretical and technical information needed to perform reliable and reproducible results in order to establish the identity, purity, quality, and stability of raw materials, extracts, and finished botanical products.
Major features High performance thin layer chromatography (HPTLC) is valuable quality assessment tool for the evaluation of botanical materials. It allows for the analysis of a broad number of compounds both efficiently and cost effectively. Additionally, numerous samples can be run in a single analysis thereby dramatically reducing analytical time. With HPTLC, the same analysis can be viewed using different wavelengths of light thereby providing a more complete profile of the plant than is typically observed with more specific types of analyses.
APPLICATIONS OF SPECTROFLUORIMETRY ON HERBS When a beam of light is incident on certain substances, they emit visible light or radiations. This phenomenon is known as fluorescence. In fluorescence measurement two wavelengths are involved i.e. the excitation wavelength (?ex) and emission wavelength (?em).The fluorescence phenomenon involves the absorption of excitation radiation by molecule which then loses energy by internal conversion processes, before emitting a photon of radiation at lower energy. The excitation wavelength maximum (?ex) is lower than the wavelength of maximum fluorescence emission (?em) Advantage High Sensitivity Substances that are reasonably fluorescent in the herbals like flavonoids, tannins, steroids, etc. may be determined at concentrations up to 1000 times lower than those required for absorption spectrophotometry.
Selectivity The facility to vary independently the wavelength of excitation and the wavelength of fluorescence allow the analyst to select the optimum combination of wavelength for the analyte and to reduce interference from other fluorescing species in the sample.