Divya Kaushik*, Manoj K. Pandey and Alok Sharma

Transcription

1 Research in Plant Biology, 4(5): 57-64, 2014 ISSN : Review Article Current issues in Authentication and Quality control of Natural Products Divya Kaushik*, Manoj K. Pandey and Alok Sharma Department of Phytopharmaceuticals, Indian Pharmacopoeia Commission, Ministry of Health & Family Welfare, Sector 23, Raj Nagar, Ghaziabad, (U.P.), India In the last decades, the use of products of natural origin has remarkably increased in the global market, because of consumers becoming more health-conscious, herbal medicines are considered safe by consumers and these products are generally less expensive than allopathic medicines. Only a limited percentage is represented by the category of Herbal Medicinal Products (HMPs) whose purity, safety, potency and efficacy is guaranteed by the regulatory authorities. In fact, many case of toxicity have been reported, in some cases due to errors in species identification that is, or should be, one of the first steps in herbal quality control protocol. Established methodical processes are necessary to standardize herbal medicines to produce consistent and reproducible products. Herbal Medicines pose significant standardization and quality control challenges due to their innate phytochemicals complexity and interspecies variability. Standardization and quality control involves inter alia the authentication of plants followed by the quantification of identified biomarkers and the selection and cultivation of the chemotype with the desired characteristics. The aim of this paper was to review the current issues, trends in authentication and Quality control of Natural Products. Keywords: HMP, Pharmacopoeias, WHO, Phytopharmaceuticals, GMP etc. Natural products are gaining popularity worldwide. Beyond the use as food and supplement, natural products have been given more serious consideration as complementary and alternative medicine. Instead, FDA requires a combination of tests and controls to ensure the identity, purity, quality, strength, potency, and consistency of botanical drugs. One important objective of these tests and controls is for quality control of herbal raw materials. At the time of the positive development, natural products are also facing the challenge of product quality and safety. Several incidents which involved natural products became the targets of negative media attention. In these incidents, wrong herbs were mixed with or used in place of the intended plant species, which resulted in dire consequences. The use of Herbal Medicine due to toxicity and side effects of allopathic medicines, hassled to sudden increase in the number of herbal drug manufactures. Herbal Medicines as the major remedy in traditional system of medicine have been used in medical practices since antiquity; because of its biomedical benefits as well as place in cultural beliefs in many parts of world have made a great contribution towards maintaining human health. Many herbs have been traditionally used for multiple purposes, presumably due to multiple bioactivities conferred by the

2 various chemical constituents. As an example, Sanqi (P. notoginseng) has used for promoting blood circulation, removal of blood stasis, induction of blood clotting, relief of swelling and alleviation of pain. It bears oestrogen activity and activity of sensitizing an experimental tumor to ionizing radiation. Many of these bioactivities have been attributed to different saponins. If only one bioactivity or component is used for authentication and quality control, other components and bioactivities are then not taken into consideration. The safety of herbs is affected by intrinsic toxicity of some components. It is also affected by the presence of toxic heavy metals, and agrichemicals such as herbicides/ insecticides. DNA profiling, including PCR based techniques and DNA sequencing, can reveal differences in genomic DNAs of living organisms including plants, and their results are generally independent of the environment and developmental stages. Such techniques can distinguish plants from different families, genera and even closely related cultivars. The different techniques vary in setting up terms of cost, throughput, operation cost and reliability. The two most popular techniques are amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR or microsatellite) because of their high level of resolution and robustness. DNA sequencing is also widely used in differentiating herbs at higher taxonomic levels. Correct identification and quality assurance of the starting material is, therefore, an essential prerequisite to ensure reproducible quality of Herbal Medicine, which contributes to its safety and efficacy (Peter, 2001). Selection of chemical markers is crucial for the quality control of Herbal Medicines, including authentication of genuine species, harvesting the best quality raw materials, evaluation of post harvesting handling, assessment of intermediates and finished products, and detection of harmful or toxic ingredients (Pulok, 2006). Chemical fingerprinting has been demonstrated to be a powerful technique for the quality control of Herbal Medicines (Bhutani, 2000). According to regulatory guidelines and pharmacopoeias macroscopic and microscopic evaluation and chemical profiling of the botanical materials is used for quality control and standardization (Indian Herbal Pharmacopoeia, 2002 and British Herbal Pharmacopoeia, 1996). Thin layer chromatography (TLC) and High Performance Thin Layer Chromatography (HPTLC) are valuable tools for qualitative determination of small amounts of impurities. Many analytical techniques such as Volumetric Analysis, Gravimetric Determinations, Gas Chromatography, Column Chromatography, High Performance Liquid Chromatography and Spectrophotometric methods are also frequently used for quality control and standardization (Quality control methods, 1998). Variations in Botanicals Consistency in composition and biological activity are essential requirements for the safe and effective use of therapeutic agents. However, botanical preparations rarely meet this standard, as a result of problems in identifying plants, genetic variability, variable growing conditions, differences in harvesting procedures and processing of extracts, and the lack of information about active pharmacologic principles (Donald and Arthur, 2012). Environmental conditions such as sunlight, rainfall, altitude, temperature, soil, storage conditions as well as different harvesting procedures, time and method of collection, manufacturing processes such as selecting, drying, purifying, extracting, and genetic variability can create substantial variability in product quality and in the concentration of plant chemicals within different products. Ecological conditions like insect feeding; microbial infections may affect secondary metabolites and in turn chemical 58

3 composition of the plant. Also different parts of same plant (example roots, stem and leaves) contain different concentration of chemical constituents. At the same time diurnal variations (for example paclitaxel, opium alkaloids) and seasonal changes also account for variability in Herbal Medicines. The therapeutic or toxic components of plant vary depending on the part of the plant used as well as stages of ripeness (Anna and Stephen, 1997). Products from different manufacture vary considerably and it is not possible to control all the factors that affect the plants chemical composition (Michael, 1999). Consistency in composition and biological activity is essential requirement for the safe and effective use of therapeutic agent. As botanicals are prone to contamination and deterioration there may be batch to batch variation in composition. Each herb contains large number of diverse compounds and it is not possible to analyze for presence or absence for all compounds. Modern chromatographic techniques use chemical markers, which may not be therapeutically active. Due to over exploitation of certain plants, habitat loss and fragmentation of the forest, many medicinal plants have reached to the level of the endangered or rare species. These and many other factors (like cost of raw material) cause problem for availability of genuine drug, which encourages the adulteration of plant by substitution with inferior commercial varieties, artificially manufactured substances, exhausted drugs or cheaper plant or by another vegetative part (Mukherjee, 2002). Several reports suggest that many herbal products contain undisclosed pharmaceuticals and heavy metals (Robert, 2004). The intentional use of pharmaceutical adulterant is possible. Agrochemicals are used to protect the plant from infections and insects, which occur as contaminant in the crude plant material. More over mechanism of action, pharmacokinetics and drug-drug interactions of many herbs are still in infancy. At the same time growing number of reports about fatal or adverse effects of herbal preparations intensifies need for national regulation and registration of Herbal Medicines and establishment of safety monitoring. Clinicians should not prescribe or recommend herbal remedies without wellestablished efficacy as if they were medications that had been proved effective by rigorous study. However, these products continue to have great appeal to patients, and this reality cannot be ignored. Thus, it is imperative to ask patients. This also signifies real need for quality control of botanicals (Peter, 2002). Quality Control of Herbal Medicines and Related Areas The quality control standardization of Herbal Medicine emphasises the standardization of herb medicinal substances, cut crude drug and preparations and that of Herbal Medicine substance. The morphological identification and microscopic identification are utilized to determine the authenticity of Herbal Medicine s whereas the physical and chemical characters are used to evaluate the quality of herbs in the existing quality standards. But by all above methods, the complexity of Herbal Medicine s cannot be elaborated, yet the chromatographic fingerprinting analysis was featured by the fundamental attributions which can chemically represent the characteristics of the Herbal Medicine investigated (Xie, 2001 as cited in Liang et al., 2004). In recent years, the combination of qualitative fingerprint profiles and quantitative multi-compounds detection was proposed and was applied into the quality control of Herbal Medicine s (Kong et al., 2009; Fan et al., 2009; Su et al., 2008). So far, during the production and circulation of Herbal Medicines, there is no comprehensive and integrated quality control measure to reflect the variations of Herbal Medicine products, and to effectively control the quality in the whole process. The research 59

4 and establishment of fingerprints contributed much to solving the problem. It can evaluate the integrative and holistic properties of Herbal Medicines by comparing the similarity and correlation of the analytes among the whole producing process, such as manufacture, processing and storage of raw materials for preparation, intermediate products, finished products and distribution products. The fingerprint analysis has been internationally accepted as one of the efficient methods to control the quality of Herbal Medicines (Liang et al., 2004). Chemical fingerprint is used to analyze the chemical constituents in Herbal Medicines, consisting chromatographic fingerprint, such as thin layer chromatography (TLC), high performance liquid chromatography (HPLC), gas chromatography (GC), capillary electrophoresis (CE) and spectral fingerprint, for instance, UV, IR, MS, X-ray and so on, and their hyphenated techniques. The biological fingerprints mainly refer to genomics fingerprints. Since genetic composition is unique for each individual, DNA methods for Herbal Medicines identification are less affected by age, physiological conditions, environmental factors, harvest, storage and processing methods. Genomic fingerprint has been used widely for the differentiation of plant individual, genus, homogeneity analysis, and detection of adulterants (Cheng et al., 1997; Huang et al., 2002; Wang et al., 2007). Standardization and Quality Control of Herbal Crude Drugs Accounting 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. Foreign Organic Matter for Remove of matter other than source plant to get the drug in pure form. Ash Value (total ash, sulfated ash, water soluble ash and acid insoluble ash etc) is criteria to evaluate the identity and purity of crude drug of which moisture level to check moisture content helps prevent degradation of product. Extractive Values for indicating the approximate measure of chemical constituents of crude drug. Qualitative Chemical Evaluation covers identification and characterization of crude drug with respect to phytochemicals Constituent. Chromato-graphic Examination includes identification of crude drug based on use of major chemical constituent as marker. Qualitative Chemical Evaluation categorises the criteria to the estimated amount of the major class of constituents. Toxicological studies involve pesticide residue, potentially toxic elements, and microbial count approach to minimize their effect in final product. Biochemical variations in the drug, deterioration due to treatment and storage, substitution and adulteration as a result of carelessness, ignorance or fraud or variability caused by differences in growth, geographical location, and time of harvesting needs a confirmation of its identity and determination of quality and purity of the herbal drug and hence, the need of drug evaluation. The different types of evaluations are Organoleptic evaluation (morphological evaluation), microscopic evaluation, chemical evaluation, physical, biological evaluation etc. The Analytical Evaluation of Herbal Drugs are carried out by different modern techniques such as Hyphenation procedure, LC-IR, LC-MS, LC-NMR, GC-MS, HPLC DAD, HPLC MS and others. DNA-based molecular markers (SCAR, AP-PCR, RAPD and RFLP) have proved their utility in fields like genetic variation/genotyping, authentication of medicinal plants, marker assisted selection of desirable chemotypes, medicinal plant breeding, applications in food and nutraceuticals in the field of taxonomy, 60

5 physiology, embryology, genetics, etc. 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 the evaluation parameters viz. physical, microscopic, biological, chemical, analytical, chromatographic characterisation, purity and qualitative assessments on the basis accepted in official pharmacopoeias. Drug adulteration The adulteration and substitution of herbal drugs is the burning problem in herbal industry and it has caused a major effect in the commercial use of natural products. Adulteration in market samples is one of the greatest drawbacks in promotion of herbal products. Adulteration it is a practice of substituting the original crude drug partially or fully with other substances which is either free from or inferior in therapeutic and chemical properties or addition of low grade or spoiled drugs or entirely different drug similar to that of original drug substituted with an intention of enhancement of profits done by adulteration may be mixing or substituting the original drug material with other spurious, inferior, defective, spoiled, useless other parts of same or different plant or harmful substances or drug which do not confirm with the official standards (Ansari, 2003; Kokate, 2004). Adulteration may takes place by two ways. - Direct or intentional adulteration- with artificially manufactured materials or substitutes, inferior quality materials marketed as adulterants, exhausted material as a substituent for the genuine drug, foreign matter used as synthetic chemicals to enhance the natural character of the drug, harmful / fictitious substances, the wastes from market are collected and admixed with authentic drugs particularly for liquids or unorganized drugs. Assessment of Quality Quality control for the efficacy and safety of herbal products is essential. The quality control of phytopharmaceuticals is the status of a drug which is determined either by identity, purity, content and other chemical, physical or biological properties or by the manufacturing process. Compared with Synthetic drugs, the criteria and the approach for herbal drugs are much more complex. Accounting 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. Phytopharmaceuticals are always mixtures of many constituents and are therefore very variable and difficult to characterize. The quality criteria for herbal drugs are based on a clear scientific definition of the raw material. Depending on the type of preparation, morphological property, physical constants, moisture, ash value, solvent residues and adulterations have to be checked to prove identity and purity. Microbiological contamination and foreign materials, such as heavy metals, pesticide residues, aflatoxins and radioactivity, also need to be tested for. To prove the constant composition of Herbal preparations, appropriate analytical methods have to be applied and different concepts have to be used in order to establish relevant criteria for uniformity. Quality assurance Quality assurance, individually or collectively influence the quality of a product. It is the totality of the arrangements made with the object of ensuring that pharmaceutical products are of the quality 61

6 required for their intended use. Quality assurance therefore incorporates GMP and other factors, including those outside the scope of this guide such as product design and development. The system of quality assurance appropriate to the manufacture of pharmaceutical products should ensure that: (a) pharmaceutical products are designed and developed in a way that takes account of the requirements of GMP and other associated codes such as those of good laboratory practice (GLP)1 and good clinical practice (GCP); (b) production and control operations are clearly specified in a written form and GMP requirements are adopted; (c) managerial responsibilities are clearly specified in job descriptions; (d) arrangements are made for the manufacture, supply and use of the correct starting and packaging materials; (e) all necessary controls on starting materials, intermediate products, and bulk products and other in-process controls, calibrations, and validations are carried out; (f ) the finished product is correctly processed and checked, according to the defined procedures; (g) pharmaceutical products are not sold or supplied before the authorized persons have certified that each production batch has been produced and controlled in accordance with the requirements of the marketing authorization and any other regulations relevant to the production, control and release of pharmaceutical products; (h) satisfactory arrangements exist to ensure, as far as possible, that the pharmaceutical products are stored by the manufacturer, distributed, and subsequently handled so that quality is maintained throughout their shelf-life. The manufacturer must assume responsibility for the quality of the pharmaceutical products to ensure that they are fit for their intended use, comply with the requirements of the marketing authorization and do not place patients at risk due to inadequate safety, quality or efficacy. The attainment of this quality objective is the responsibility of senior management and requires the participation and commitment of staff in many different departments and at all levels within the company, the company s suppliers, and the distributors. To achieve the quality objective reliably there must be a comprehensively designed and correctly implemented system of quality assurance incorporating GMP and quality control. It should be fully documented and its effectiveness monitored. Conclusion Herbal drug standardization is massively wide and deep. Strict guidelines have to be followed for the successful production of a quality herbal drug. Among them are proper botanical identification, phytochemical screening, and standardization. Quality control and the standardization of herbal medicines involve several steps. The source and quality of raw materials, good agricultural practices and manufacturing processes are certainly essential steps for the quality control of herbal medicines and play a pivotal role in guaranteeing the quality and stability of herbal preparations. Standardization of herbal drugs comprises total information and controls to essentially guarantee consistent composition of all herbals including analytical operations for identification, markers and assay of active principles. There is no legal control model over medicinal plants. Different countries define medicinal plants or products derived from them in different ways and have adopted different approaches to licensing, dispensing, manufacturing and trading to ensure their safety, quality and efficacy. Fingerprinting of herbal medicines is utilized for the authenticity and quality control of herbal medicines and herbal preparations. Chemical fingerprints obtained by chromatographic, spectroscopic, thermo gravimetric analysis, capillary electrophoresis and polarography techniques have become the most potent tools for quality control of 62

7 traditional herbal medicines and standards of Pharmacopoeias. Moreover, all herbal products manufacturers must follow WHO guidelines for quality control. Further, the combination of qualitative fingerprinting and quantitative multicomponent analysis is a novel and rational method to address the key issues of quality control of herbal medicines. The advancement of analytical techniques will serve as a rapid and specific tool in the herbal research, thereby, allowing the manufacturers to set quality standards and specifications so as to seek marketing approval from regulatory authorities for therapeutic efficacy, safety and shelf life of herbal drugs. The applications of hightechnology oriented advanced hyphenated techniques will serve as a rapid and unambiguous tool in the herbal research, thereby, benefiting the entire pharmaceutical industry. Quality control of Herbal Medicines has not only to establish reasonable analytical methods for analyzing the active constituents in Herbal Medicine s, but many other factors should be concerned, such as pesticides residue, aflatoxine content, the heavy metals contamination, good agricultural practice (GAP), good manufacturing practice (GMP), etc. There is need for development of techniques which includes both traditional methods of evaluation and modern methods of evaluation. This will improve the quality of the drug and also motivates the practitioners to get more involved in the standardization process. Overcoming the various problems, the vast knowledge of the important herbs found in India and widely used in Ayurvedic formulation should be explored in collaboration with the new standardization techniques. Advancement on this path will help us authenticate quality of traditionally important herbs thereby reducing further problems. Quality if ensured at the starting point will eliminate all problems in quality control of herbal formulations to obtain better formulations. Moreover the society will be benefitted with safer drugs at affordable price, leading to the Goal of WHO Health for All. References Anna KD, Stephen PM. 1997, Safety issues in herbal medicine: implications for the health professions. Med J Aust., 166: Ansari SH Essentials of Pharmacognosy, Birla Publications Pvt. Ltd, Bhutani. KK 2000, Finger-Printing of Ayurvedic Drugs, The Eastern Pharmacist, British Herbal Pharmacopoeia, 1996, British Herbal Medicine Association. Cheng KT, Chang HC, Su CH, & FL Hsu. 1997, Identification of dried rhizomes of coptis species using random amplified polymorphic DNA. Bot. Bull. Acad. Sinica, 38: Donald MM, Arthur PG. 2002, Botanical medicines the need for new regulations. N Engl J Med. 347 (25): EMEA. 1998, Quality of Herbal Medicinal Products. Guidelines. European Agency for the Evaluation of Medicinal Products (EMEA), London. Fan L, Zhao HY, Xu M, Zhou L, Guo H, Han J, Wang BR, Guo DA Qualitative evaluation and quantitative determination of 10 major active components in Carthamus tinctorius L. by highperformance liquid chromatography coupled with diode array detector. J. Chromatogr. A. 1216: Gupta MK and Sharma PK. 2007, Test Book of Pharmacognosy, Ayurvedic formulations, Pragati Prakashan Meerut Vol II, Ist edition. Huang Y, Qin MJ, Yang G, Xu LS and Zhou KY 2002, Identification of Belamcanda Chinensis and related Chinese material medica of Irid L.by RAPD analysis. Chin Tradit Herb Drugs, 33(10):

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