Industrial Manufacture of Traditional Ayurvedic Medicines

Introduction

In the olden days, manufacture of ayurvedic medicines was carried out on a small scale, often by the physician himself, helped by his assistants. Herbs were mostly procured locally, with some exotic ones like guggul gum, silajit and saffron coming from faraway places. Commercial production of ayurvedic medicines was first attempted by Vaidya Gangadhar Ray, a Kaviraja of Bengal. He was inspired by the increasing demand for ayurvedic medicines and set up a large-scale manufacturing unit in 1884. He called it N.N. Sen and Company (Gupta 1976). Vaidya Gangadhar Ray was followed by the physician- entrepreneur Dr S.K. Burman (1856-1907), who was affectionately called Daktar Burman by his clientele. In 1884, he set up the company Dabur (the name derived from the Da of Daktar and Bur of Burman) in a small house in Calcutta. After 133 years the company founded by him is today India’s most trusted name and the world’s largest manufacturer of ayurvedic medicines, with a portfolio of over 381 products (Anonymous 2018). By the turn of the 20th century, the demand for ayurvedic medicines had increased sufficiently to occupy a fair share in the country’s medicine market (Kumar 2001).

Large-scale manufacture of traditional ayurvedic medicines was started in southern India by P.S. Variar (1869-1944), a visionary physician and philanthropist of the province of Kerala. The humble enterprise started by him in 1902 as a village clinic has now grown into a million-dollar business (Vellodi 1987). In recognition of the various services rendered by him to the development of Ayurveda, the colonial government of India conferred on him in 1933 the title of Vaidyaratnam (Gem of a physician). Arya Vaidya Sala was the first ayurvedic manufacturing facility in Kerala, processing ayurvedic drugs using modern methods. Moreover, P.S. Variar was the first person who introduced kvdtha preserved in bottles without spoilage for any length of time. The success of Arya Vaidya Sala of Kottakkal inspired several others like Kesari Kuteeram Ayurveda Ousadhasala in Madras, Andhra Ayurveda Pharmacy Ltd, Sivagnana Siddha Vaidya Salai at Koilpatti and the Siddha Vaidya Agastya Asramam in Tanjore (Kanagarathinam 2016). At present Kerala has the second largest number of ayurvedic manufacturing units (12% of total manufacturing units) next to Uttar Pradesh (Harilal 2009). Table 3.1 lists the important companies in India manufacturing traditional ayurvedic medicines.

Procurement of Herbal Raw Material

India’s domestic herbal industry consists of 8610 licensed herbal units engaged in the manufacture of herbal formulations under different streams of Indian systems of medicine. They are grouped into large, medium, small and very small enterprises depending on their annual turnover. Analysis of their consumption data reveals that the industry consumes nearly 195,000 metric tons of crude drugs derived from 907 plant species. Of these, more than two-thirds are consumed by the large and medium units (Goraya et al. 2017b).

Most of these herbs are collected from forests, agricultural farms, fallow lands, sides of roads and railway tracks, banks of canals, ponds, lakes and waste lands (Goraya et al. 2017c). The trade of medicinal plants takes place in India in mandis (large yards); the like of which in Neemuch, Unjha and Sojat are famous internationally for the trade of cultivated herbs like asvagandha (Withania somnifera), isabgol (Plumbago ovata) and mehendi (Lawsonia inermis) (Figures 3.1-3.4). The one at Khari Baoli in Delhi is the largest spice market in Asia and the largest conventional crude drug mandi in the country (Goraya et al. 2017a). Medicinal herbs and other forest produce are offered for sale by some of the forest development corporations in the country. The major corporations are listed in Table 3.2.

Storage of Raw Materials

Herbs and other raw materials arriving from traders are stored in properly designated storage rooms under conditions that prevent contamination and deterioration (Figures 3.5 and 3.6). While dealing

TABLE 3.1

Leading Manufacturers of Traditional Ayurvedic Medicines

with the storage of chamomile flowers, Boettcher and Guenther (2005) recommend certain storage conditions. Though described in the context of the storage of the German chamomile (Matricaria chamomilla), the desirable storage conditions and the characteristics of the storage room listed by Boettcher and Guenther (2005) are equally relevant to any other herb. Based on that report the following storage conditions can be adapted for ayurvedic herbs: moisture content of stored product: 8-10%; relative humidity of ambient air: <50%; room temperature: 25°C; lighting: largely in a darkened room; stock pests: free from living larvae and insects (Boettcher and Guenther 2005).

By storing dried herbs in these conditions, almost all quality deteriorations can be prevented or reduced. The entry of insects should be prevented by permanently covering all windows, walls, and ventilation openings with 1-2 mm mesh wide wire netting. All doors should be kept automatically closed. The continuous operation of electrical UV insect traps in the storage room is an effective measure. These will attract all insects flying in and kill them with the current. If pests are detected in the store, disinfestation must be carried out immediately. The stored products must be regularly inspected to determine their water content, external quality traits and infestation with stock pests. These checks, including the quality control analyses, must be repeated every 4 to 6 months. Stored herbs can be kept in this condition with minimal deterioration (Boettcher and Guenther 2005).

FIGURE 3.1 Mandi at Delhi - herbs in sacks. Photo courtesy: Janak Raj Rawal, Rawal Medherbs Consultants LLP. Delhi-110 052.

FIGURE 3.2 Mandi at Delhi - traders with samples of herbs. Photo courtesy: Janak Raj Rawal, Rawal Medherbs Consultants LLP. Delhi-110 052.

The characteristics of the storage room also influence successful storage. The store room should be cleaned and disinfected before products are taken into storage. It should be airy and cool, with a constant curve of temperature. The openings of buildings should be sealed with wire netting to prevent the entry of harmful insects, pests, birds and pets. Proper fire prevention measures should be taken. Toxic drugs are to be stored separately. To make the movement of stock easier, larger storage rooms should have mechanical stacking devices (Boettcher and Guenther 2005). Requirements of good manufacturing practices are generally implemented in the storage of herbs, raw materials and manufacture of the products (Anonymous 2014).

FIGURE 3.3 Mandi at Neemuch - heaps of herbs. Photo courtesy: Janak Raj Rawal, Rawal Medherbs Consultants LLP, Delhi-110 052.

FIGURE 3.4 Mandi at Neemuch - buyers inspecting herbs. Photo courtesy: Janak Raj Rawal, Rawal Medherbs Consultants LLP, Delhi-110 052.

Pre-processing of Raw Materials

Cleaning of Herbs

At the time of harvest or collection, most herbs are likely to contain contaminants. Ferrous and non-ferrous metals, filings, soil, stones, animal hair, bone and excreta are the common contaminants found in consignments of herbs. Therefore, it is necessary to perform operations of cleaning to ensure that herbs with uniformly high quality are made available for subsequent processing. It

TABLE 3.2

Major Sources of Forest Produce

FIGURE 3.5 Sacks of raw materials stored in the herb store of an Ayurveda medicine manufacturing facility. Photo courtesy: Nagarjuna Herbal Concentrates Ltd, Kerala (www.nagarjunaayurveda.com).

is not possible to produce high-quality ayurvedic medicines from substandard raw' materials, and, therefore, these cleaning procedures carried out in the beginning are a method of improving the quality of the raw material (Fellows 2000).

Wet cleaning is effective for removing soil from root crops. Dry cleaning procedures are used for raw materials that are smaller, like grains, seeds, nuts, rhizomes, fruits and their pericarps, which possess greater mechanical strength and have a lower moisture content. Dry procedures involve smaller and cheaper equipment than wet procedures. In addition to this, plant cleaning is easier. The major equipment used for dry cleaning is air classifiers, magnetic separators and separators based on screening. Classifiers use a moving stream of air to separate contaminants from foods by differences in their densities. They are used in the separation of heavy contaminants like stones and lighter contaminants like dust, leaves, stalks and husks. Metal fragments are common contaminants in consignments of herbs and pose a potential hazard in medicine manufacturing. Ferrous metals are removed by magnets or electromagnets (Fellows 2000).

Sieving or screening is used in the separation of pieces of herbs into two or more fractions on the basis of differences in size. Screens w'ith fixed or variable apertures are used for size sorting. The screen may be stationary or rotating or vibrating. Fixed aperture screens are commonly used for sorting turmeric, nutmeg, cumin, black cumin and so on (Fellows 2000).

FIGURE 3.6 Sacks of herbs stored in the herb store of another manufacturing facility. Photo courtesy: Rajah Healthy Acres, Kerala (www.ayurvedichospital.com).

Size Reduction of Herbs

Size reduction or comminution is a process by which raw materials such as roots, leaves, bark, heartwood and seeds are reduced to powders that can pass through sieves of different mesh sizes. Pulverizing equipment is selected according to the material that is to be powdered. Chunks of heart- wood are first minced before being fed into pulverizers (Figure 3.7). These mincing machines chop the wood lengthwise and crosswise, reducing it to small pieces, which are fed into hammer mills. Hammer-like solid metal blocks fixed to the shaft of the machine swing at high speed and pow'der the pieces of wood dropped into the chamber of the hammer mill. The number of hammers varies with different models. The particle size of the powder is dependent on the perforated screen that is fixed to the wall of the chamber (Kumar 2016).

Another equipment, called the knife mill, has sets of sharp knives fixed to a rotor. These knife mills are suitable for powdering leaves, roots, and barks. Herbs are also pulverized using a pin mill (teeth mill, impact mill). This equipment has a circular row of pins (teeth) fixed inside the chamber. Bits of herbs that are dropped into it are powdered through the beating, shearing, crushing and colliding that the material undergoes during the process (Kumar 2016).

Large-sized pin mills have a screw feeder with a variable speed drive, ensuring the uniform feeding of the herb into the mill. Other types of comminution equipment such as the shredding mill, ball mill, slow-speed attrition mill, micromill and air-swept mill are also used in the pulverization of herbs (Kumar 2016).

Different pulverization processes are applied to different herbs. Herbs with more stems and stalks need shredding or cutting mills, while hammer mills are suitable for hard and brittle materials like

FIGURE 3.7 Pulverizer for size reduction of herbs. Photo courtesy: Nagarjuna Herbal Concentrates Ltd, Kerala (www.nagarjunaayurveda.com).

resins, and leafy plants such as senna and Adhatoda vasica. Hard materials like cinnamon bark and dry ginger rhizomes can be pulverized in a two- or three-stage process combining cutting, shredding and pulverization in hammer or pin mills. Pulverization needs to be carried out carefully, so that the herb is not damaged due to the generation of heat (Anonymous 2001a; Kumar 2016).