Quality Control of Ayurvedic Medicines

Introduction

When the expression “quality” is used in the context of a medicinal product, people usually think in terms of an excellent product that fulfills or exceeds their expectations. The quality of a product is dependent on several factors, like the raw materials used in its production, equipment used, the expertise of the personnel in charge of the operations, manufacturing process, analytical methods, packing and hygiene. Quality control is the application of techniques and measures to achieve and sustain at a constant rate the quality of a product or service. Quality improvement is the use of tools to continually make the product or service unbeatable (Besterfield 2013).

The quality of ayurvedic preparations is achieved through the development of procedures and practices designed to ensure conformity to specifications. Disciplines like botany, chemistry, pharmacology and pharmacognosy are vital to the implementation of these activities (Malone 1983; Dentali 2009). Factors like identification and collection of good constituent herbs, aspects of contamination, adulteration and substitution of herbs, the chemical profile of the herbs, manufacturing process, robust analytical methods and stability define the quality of these medicines (Yau et al. 2015).

Quality Control Measures in Ancient Times

Ayurveda was conceived and developed in a very remote era, when science, as we know it today, had no influence on the society. However, in their own modest way, the ancient masters made sure that the quality of the system was maintained. As the inclusion of the right herb is essential for the therapeutic quality of medicinal formulae, Ayurveda texts give advice on how to identify medicinal plants. For example, Caraka says that goatherds, shepherds, cowherds and other forest-dwellers know medicinal plants by their name and form (Sharma 1981). Susruta also gives similar advice. He instructs that medicinal plants should be recognized and identified with the help of cowherds, hermits, huntsmen and others who trek the forest as well as with the help of those who collect and eat edible roots and fruits of the forests (Murthy 2017a). Therefore, a student or practitioner of Ayurveda in those days used to learn from these sources.

The physicians of ancient India were aware of the factors that can influence the quality of medicinal products. Instructions are available in Ayurveda texts regarding the procurement of herbs. For example, Sarngadhara Samhita, considered to be the best book on ayurvedic pharmacy, gives valuable advice on this subject. With purity of mind the physician himself should collect the herbs, and while doing so, he should avoid herbs growing on anthills, dirty places, marshy land, burial grounds and salty soil. He should discard herbs infested with worms or affected by fire and snow. The root bark is to be collected in the case of large roots, while the entire root should be collected in the case of smaller ones. While the outer bark of large trees like Nyagrodha (Ficus benghalensis) is collected, the heartwood of smaller trees like BTjaka (Pterocarpus marsupium) is preferred (Murthy 2017b).

Instructions are available on the choice of medicinal ingredients. As far as possible, only fresh herbs should be used in the preparation of medicines. However, exceptions to this rule are Vidanga (Embelia ribes), Krsna (Piper longum), Guda (jaggery), Dhanya (Coriandrum sativum), Ajya (clarified butter) and Mdksika (honey). Their medicinal qualities improve with age (Murthy 2017b). Ingredients like GudUci (Tinospora cordifolia), Kutaja (Holarrhene antidysenterica), Vasa (Adhatoda vasica), Kusmanda (Benincasa cerifera), Satavari (Asparagus racemosus), Asvagandha (Withania somnifera), Sahacara (Barleria cristata), Satapuspa (Anethus graveeolens) and Prasarini (Uraria logopoiedes) are always to be used in fresh condition (Murthy 2017b).

If Candana is included in a recipe of ciirna, taila, ghrta or asava, only Svita candana (Santalum album) should be used. However, in the preparation of kvatha or lepa (pastes), Rakta candana (Pterocarpus santalinus) is traditionally used. Interestingly, Sarngadhara Samhita sheds light on the shelf-life of major dosage forms. Ciirna stays potent for two months, guUka and avaliha for one year and ghrta or taila for four months. Asava is said to become more potent as they age (Murthy

2017b). The exact procedures of preparing various dosage forms are not explained in the classical Ayurveda texts, as they are passed down from one generation to another via the master-pupil tradition. However, Sarngadhara Samhita provides clear instructions to prepare kvatha, avaliha, ghrta, taila, gulika and arista- asava (Murthy 2017c).

Present State of Quality Control of Ayurvedic Medicines

Stringent quality control (QC) measures are essential for exporting ayurvedic medicines to Europe and North America. Therefore, the Department of A.Y.U.S.H. (Government of India) assigned Pharmacopeial Laboratory for Indian Medicine, Ghaziabad, to develop protocols for testing ayurvedic products. The laboratory prepared a draft document, circulated it among various experts of the field and, after the consideration of their comments, published it as a volume entitled Protocol for Testing Ayurvedic, Siddha & Unani Medicines (Lohar 2008). This work provides analytical specifications of various ayurvedic dosage forms like kvatha (decoctions), curna (powders), taila (medicated oils), ghrta (medicated clarified butter) and lihva (electuaries). Additionally, methods for testing the parameters are also included.

Ayurvedic Pharmacopoeia of India

The Ayurvedic Pharmacopoeia of India is a unique compendium of standards defining the quality, purity and strength of selected medicinal preparations that are manufactured, distributed and sold by licensed manufacturers in India. It was developed in two parts. Part I consists of monographs on medicinal substances of natural origin, and Part II includes selected compound formulations sourced from books listed in the First Schedule of the Drugs and Cosmetics Act, 1940. The first part of The Ayurvedic Formulary of India was published in 1978, and, thereafter, The Ayurvedic Pharmacopoeia of India Part I, Volume I was published in 1989 (Joshi et al. 2017). So far nine volumes of The Ayurvedic Pharmacopoeia of India Part I (Anonymous 2001a, 2001b, 2001c, 2004, 2006a, 2008a, 2000b, 201 la, 2016a) and four volumes of The Ayurvedic Pharmacopoeia of India Part II (Anonymous 2007, 2009a, 2010, 2017a) have been published. Three volumes of The Ayurvedic Formulary of India are also available (Anonymous 2000, 2003, 2011b). The Ayurvedic Pharmacopoeia of India Part I provides for each herb the following pharmacopeial information: Synonyms, names of the herb in regional languages, description, information on powder microscopy, identification by T.L.C., quantitative parameters, limits of contaminants, assay by H.P.L.C., storage conditions, labeling requirements and reference standards; and method of preparation, identification by T.L.C., and assay by H.P.L.C. of hydro-alcoholic and water extracts.

The Ayurvedic Pharmacopoeia of India Part II gives the following pharmacopeial information on medicinal formulations: Definition, composition and method of preparation of the formulation, description, identification by T.L.C., physicochemical parameters, the assay of the major bioactive compound, limits of contaminants, storage conditions, therapeutic uses and dose.

The Ayurvedic Formulary of India provides definitions, textual sources, methods of preparation, general precautions, characterization and preservation of various ayurvedic dosage forms like asava, arista, arka, avaliha, рака, kvatha curna, guggulu, taila, ghrta, ciirna and so on. Detailed formulae of these medicines are also given. This voluminous work provides lists of single drugs of animal, mineral and herbal origin, with detoxification-cum-potentiation protocols of the toxic ingredients. The Ayurvedic Pharmacopoeia of India and The Ayurvedic Formulary of India are useful to the Ayurveda industry of India for controlling the quality of crude drugs and finished products.

Factors That Influence the Quality of Ayurvedic Medicines

These A.Y.U.S.H. specifications are valuable to assess the quality of the final products. However, considering the inherent complexity of naturally growing medicinal herbs, quality assurance of ayurvedic medicines calls for testing of herbal raw materials, their storage and validation of the manufacturing processes similar to those adopted for European herbal medicines (EMA 2011). Characteristics that define the quality of the herbal substance/preparations and herbal medicinal products should be identified. There are several critical aspects that need to be monitored.

Good Agricultural and Collection Practices

The Government of India published Guidelines on Good Field Collection Practices for Indian Medicinal Plants in 2009 to address issues associated with harvesting and post-harvest management of medicinal plants collected in the wild. The objective of these guidelines among several others is to ensure consistency in the quality of crude drugs having a bearing on the safety and efficacy of herbal formulations, minimize the direct and indirect negative impact on the environment due to wanton collection from the wild and ensure equitable returns to the herb collectors and other stakeholders (Anonymous 2009b). This document provides guidelines on compliance with regulatory requirements, harvesting of medicinal plant produce, post-harvest management, packing and storage of the produce and guidelines for the collection and post-harvest management of various categories of medicinal plant parts like roots, stem bark, wood, leaves, fruits, gums and so on. Adherence to these guidelines ensures sustainable harvesting of herbs used in Ayurveda.

Similarly, the Government of India has published Good Agricultural Practices for Medicinal Plants (Anonymous 2009c). Adapted from the WHO Guidelines on Good Agricultural and Collection Practices (G.A.C.P.), this document is intended to suit the policy framework on environment and health in India. It describes soil, climatic conditions, seeds, propagation material, precautions and crop management. Good agricultural practices can alleviate the problem of herb misidentification and ensure that the quality of the starting herbal ingredients is reproducible through good practices for cultivation, harvesting and post-harvesting processes. Contamination and product safety can also be controlled in this way.

 
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