Pharmaceutical Standardization and Preliminary Analytical Evaluation of Rasasindura prepared using an Electric Muffle Furnace

Kanchan Swami¹, Asha Kumari², Sanath Kumar S³, Sakhitha K.S.⁴, Anupam Srivastava⁵

¹PhD Scholar, Department of Rasashastra and Bhaishajya Kalpana NIA-Jaipur, Rajasthan, Indai.

²MD Scholar, Department of Rasashastra and Bhaishajya Kalpana NIA-Jaipur, Rajasthan, Indai.

³MD Scholar, Department of Rasashastra and Bhaishajya Kalpana NIA-Jaipur, Rajasthan, Indai.

⁴Assistant Professor, Department of Rasashastra and Bhaishajya Kalpana NIA-Jaipur, Rajasthan, Indai.

⁵Professor and Head, Department of Rasashastra and Bhaishajya Kalpana NIA-Jaipur, Rajasthan, Indai.

*Corresponding Author E-mail: drras2008@gmail.com

ABSTRACT:

Introduction: Rasasindura is an important mercurial formulation extensively used in Ayurvedic therapeutics and is prepared through the Kupipakwa process. Conventionally, Rasasindura is manufactured using the Valuka Yantra in a classical Bhatti. With advancements in pharmaceutical technology, the Electric Muffle Furnace (EMF) offers a potential alternative. The present study aimed to evaluate and standardize the preparation of Rasasindura using EMF. Methods: Rasasindura was prepared in three batches using Shuddha Parada and Shuddha Gandhaka, and Kajjali was formed, followed by processing through the Kupipakwa method in an Electric Muffle Furnace. A controlled heating pattern was adopted, corresponding to classical stages of mild, moderate and intense heating. The final product collected from the neck of the Kupi was evaluated for yield and organoleptic characteristics. Results: All three batches showed uniform observations throughout the heating process. The yield of Rasasindura ranged from 51.33% to 53.33%, with no significant inter-batch variation. Organoleptic evaluation revealed similar characteristics across all batches, indicating reproducibility and consistency of the EMF method. Discussion: The EMF method provided precise temperature control, reduced energy consumption, minimized human effort and ensured a pollution-free working environment compared to the traditional bhatti method. Standardization of the heating pattern using EMF facilitated consistent pharmaceutical outcomes. Conclusion: Preparation of Rasasindura using an EMF is a reliable, efficient and reproducible method. EMF proves to be a suitable alternative to the conventional puta method and can be effectively adopted for the preparation and standardization of Rasasindura and other Kupipakwa Rasayana.

KEYWORDS: Kupipakwa Rasayana, Rasasindura, Standardization.

1. INTRODUCTION:

Rasashastra a branch of Ayurveda deals with pharmaco-therapeutic aspects of metals and minerals. Judicious combinations of herbs with metals and minerals form organometallic compound formulations known as Rasaushadhies which accomplish quick desired effects in smaller doses¹. Kupipakwa Rasayana is a unique process to prepare formulations like Makaradhwaja, Rasasindura etc², where processing is done in a glass bottle with gradual intermittent rise in temperature i.e. mild (150-250°C), moderate temperature (250-450°C), high temperature (450-600°C)³. The traditional furnace used to manufacture Rasasindura is known as Bhatti and fuel used is either hard or soft coal. Difficulty in controlling the temperature, large amount of fuel consumption, exposure of the personnel to heat and air pollution are seen in the traditional method. With advancement in pharmaceutics, replacement of the fuel and instrument by more efficient instrument such as the electric muffle furnace (EMF) may be considered, which has benefits like ease of handling, temperature control, control of air pollution and reduction in human effort. The above points can prove the edge of EMF over the traditional method, but the real facts can only be revealed by a detailed comparative study. Rasasindura is prepared by combining Parada and Gandhaka to form Kajjali (black lustreless compound) and processed with Kupipakwa method. Thus formed final product collected at the neck of the bottle is said to have unique properties to treat and cure diseases such as diabetes, fistula, fever, loss of appetite, anaemia, oedema and many other diseases⁴. Standardization is an important factor for establishing reproducibility and verifying the classical guidelines. Hence present study attempts for standardization of manufacturing process for preparation of Rasasindura by EMF method.

2. MATERIALS AND METHODS:

Collection of raw materials - Parada (Mercury), Gandhaka (Sulphur), Sudha choorna (Lime stone), Saindhava Lavana (Rocksalt), and Nistusha Lashuna (Allium sativum L.) were procured from the GMP certified Nageshwara pharmacy National Institute of Ayurveda, Deemed university Jaipur. Vatankura (Ficus benghalensis L.) were collected from herbal garden of National Institute of Ayurveda, Deemed University Jaipur and Godugdha (Cow’s milk) was procured from saras dairy Jaipur. Gomutra (Cow’s urine) was procured from a local cow husbandry, Jaipur.

Method: The preparation of Rasasindura is divided into three stages, namely, preoperative (Purvakarma), operative (Prdhanakarma) and postoperative (Paschatkarma) stages-

Purvakarma: Parada Shodhana⁵ and Gandhaka Shodhana⁶were done according to Rasa Tarngini. Shodhita Parada and Shodhita Gandhaka were taken in an equal ratio and triturated till the whole mixture was converted into a fine black lusterless Kajjali⁷. This mixture was further triturated three times with Vatankura swarasa⁸. Then Kajjali was filled upto 1/3 of the Kupi (glass bottle coated with seven layers of mud-smeared cotton cloth, capacity: 750 mL) and placed in the center of EMF (EMF inner hearth - length: 15 cm, breadth: 15 cm, depth: 30 cm, max. temp. capacity: 1000°C), in such a way that the Kupi could receive equal distribution of heat. (Figure 1.1, 1.2 and 1.3)

Pradhankarma: In the preparation of Rasasindura by EMF, Observations were recorded and in the same way, three Batches were prepared to ensure a standard manufacturing process. Initially four hours of Mridu (150-250 ⁰C) and Madhyam agni (250-450 ⁰C) and lastly, Teevra agni (450-650 ⁰C) was given. A red hot iron rod was repeatedly inserted in the neck of the bottle so as to burn any accumulated sulphur there. After observation of the confirmative test like, Sheeta Shalaka test, Copper coin test, Red hot bottom etc. Then mouth of the kupi was corked and the temperature was gradually increased to facilitate sublimation of the final product inside the neck of the Kupi. The EMF was switched off and kept for self-cooling. Rasasindura was prepared in three batches of 300 g of Kajjali in each. (Figure 1.4 and 1.5) (Figure 2)

Pashchat karma: On the next day, after self-cooling, the bottle was carefully scraped, broken and the product deposited at the neck was collected of all three Batches (Figure 1.6,1.7,1.8 and1. 9). Rasasindura procured from all the batches were weighed and calculated for the percentage of yield and also subjected to various organoleptic characters.

Table 2: Observations during preparation of 3 batches of Rasasindura

S. No	Observations	Batch 1	Batch 2	Batch 3
1.	Appearance of white fumes	At 176⁰C after 1.5 h of heating	At 180⁰C after 1.5 h of heating	At 180⁰C After 1.5 h of heating
2.	Initiation of Kajjali melting	At 220⁰C after 2 h	At 240⁰C after 2 h	At 240⁰C after 3 h
3.	Appearance light yellow fumes	At 240⁰C after 2.5h	At 240⁰C after 3 h	At 250⁰C after 3.5 h
4.	Kajjali converted to semi-liquid state	At 350⁰C after 4.5 h	At 370⁰C after 5.5 h	At 350⁰C after 5 h
6.	Kajjali completely liquefied	At 420⁰C after 6 h	At 400⁰C after 6 h	At 430⁰C after 6 h
7.	Accumulation of Gandhaka at the neck of Kupi	At 475⁰C after 7 h	At 460⁰C after 7.5 h	At 460⁰C after 7.5 h
8.	Appearance of dense yellow fumes	At 480⁰C after 7.5 h	At 470⁰C after 8 h	At 472⁰C after 8.5 h
9.	Appearance of blue flame started (Blue colour)	At 490⁰C after 9 h	At 480⁰C after 8 h 50 min	At 490⁰C after 8 h 40 min
10.	Increase in flame height and change to red-orange flame after hot Shalaka insertion	8-10 inches at 500⁰C	6-8 inches at 490⁰C	8-9 inches at 490⁰C
11.	Disappearance of flame	At 510⁰C	At 505⁰C	At 510⁰C
12.	Corking of Kupi	At 520⁰C after 10.5 h (Red hot bottom, copper coin test and sheet shalaka test positive)	At 510⁰C after 10.5 h (copper coin test and sheet shalaka test positive)	At 520⁰C after 11 h (Red hot bottom, copper coin test and sheet shalaka test positive)
13.	Furnace switched off	At 600⁰C	At 600⁰C	At 600⁰C
14.	Total duration of heating	12h 30min	12 h 35min	12h 30min

Figure 2. Comparative Temperature – Time profile of three batches during Kupipakwa heating process

Table 3: Weight and yield in % of Rasasindura

S. No.	Batch	Weight of Kajjali	Weight of Rasasindura	Yield %
1.	Batch I	300 g	156 g	52%
2.	Batch II	300 g	154 g	51.33%
3.	Batch III	300 g	160 g	53.33%

Table 4: Result of organoleptic characters of three Batches of Rasasindura

S. No	Parameters	Batch 1	Batch 2	Batch 3
1.	Appearance	Compact	Compact	Compact
2.	Texture	Crystalline	Crystalline	Crystalline
3.	Colour	Vermillion (Brick red)	Vermillion (Brick red)	Vermillion (Brick red)
4.	Taste	Tasteless	Tasteless	Tasteless
5.	Smell	Indistinct	Indistinct	Indistinct

Table 5: Result of physicochemical analysis of three Batches of Rasasindura

S.N.	Parameter	Batch 1	Batch 2	Batch 3
1.	pH	7	6.9	7.2
2.	Loss on drying (at 110⁰C)	0.25%	0.45%	0.30%
3.	Total ash (at 650⁰C) w/w%	0.50%	0.30%	0.40%
4.	Acid insoluble ash in w/w%	0.13%	0.12%	0.12%
5.	Alcohol soluble extractive	0.40	0.30	0.20
6.	Water soluble extractive	0.20	0.15	0.10

5. DISCUSSION:

Rasashastra is a specialized branch of Ayurvedic therapeutics that emphasizes on the development of potent, fast-acting formulations. With its advent, the therapeutic application of metals, minerals and herb-mineral preparations became well established through defined pharmaceutical procedures. Among these, Kupipakwa Rasayana preparations require meticulous execution of Parada Shodhana, Gandhaka Shodhana, Kajjali preparation and a regulated heating pattern to ensure quality, maximum yield and safety of the final product. In the present study, changes were observed at various stages of Rasasindoora preparation. During Parada Shodhana, an initial weight of 600 g was reduced to 500 g, corresponding to a loss of 100 g (16.66%). This reduction may be attributed to handling loss and elimination of impurities through Jalgati and Malgati, as described in classical Rasashastra texts.¹⁰ The post-Shodhita Parada exhibited a smooth texture and lustrous appearance, indicating effective purification and removal of dosha. Gandhaka Shodhana resulted in a weight reduction from 500 g to 457 g, showing a loss of 43 g (8.6%). This loss is likely due to the removal of physical and chemical impurities during the Shodhana process. The role of Godugdha in detoxifying Gandhaka is significant, as its lipid components facilitate the dissolution of fat-soluble sulphur impurities. The observed change in the colour of Godugdha from white to yellowish-cream, along with the characteristic sulphur odour. Repetition of the Shodhana process three times ensured thorough detoxification and elimination of residual dosha. During Kajjali preparation, equal quantities of Shodhita Parada and Shodhita Gandhaka were triturated in Khalva Yantra. The weight decreased marginally from 900 g to 886 g, indicating a loss of 14 g (1.5%). This minor loss can be attributed to fine particle dispersion, adherence of material to the mortar and pestle and minimal handling loss during prolonged trituration. The formation of a uniform, smooth and lustreless Kajjali signifies proper amalgamation of mercury and sulphur. Subsequently, three Bhavana of Vatankura Swarasa (Ficus benghalensis) were triturated to the Kajjali, resulting in a weight gain from 886 g to 900 g (1.5%). This increase reflects the absorption and retention of liquid media within the Kajjali mass. Bhavana is known to enhance physicochemical characteristics such as colour, texture and homogeneity, while also imparting additional therapeutic attributes from the herbal juice to the final formulation. In the EMF method after a hour of mild temperature, light white fumes were observed initially that gradually became dense. Probing with an iron rod was done to maintain the patency of bottle mouth. It was observed that the Kajjali started melting at around 220⁰C. During moderate temperature, dense yellow fumes were observed and the bottom of the Kupi was not seen. On gradually increases of the temperature, the Kajjali started to boil and Gandhaka accumulation was observed at the neck of Kupi. Dense fumes were observed at a range of 472-480⁰C, respectively followed by flame. With the increase in temperature and after insertion of hot Shalaka, the height of the flame increased by 6-10 inches. Duration of the flame was for 1.5-2 hours in three batches. Confirmatory tests like disappearance of flame, Sheeta Shalaka test (dry appearance of iron spoke inserted into the Kupi and taken out), copper coin test (completion of product formation confirmed by placing a copper coin which is determined by colour changes on it), appearance of red-hot bottom at around 510-520°C respectively, in three batches. Disappearance of flame and Sheeta Shalaka test (+ve) during the process indicates that no free sulphur was available inside the Kupi. Reddish color at the bottom of the Kupi indicated that material was converted into compound form. The copper coin test (+ve) is also one parameter of free sulphur test. The time required to complete the procedure was almost 13 hours. Although Kramagni¹¹ is mentioned in the classics which is interpreted as intermittent gradual rise of temperature and equal amount of heat at all three stages of heating, mild and moderate stages are for three hours each and increased heat for six hours to facilitate enough time for digestion of sulphur and to avoid delaying of the procedure. Practically, moderate and intense stages are more essential in the heating process, as in this stage, maximum chemical reaction and compound formation take place. In the EMF, there is equal distribution of temperature from bottom to neck, which may result in dissociation of some product at the neck at high temperatures (beyond sublimation), if not controlled appropriately.

The pH of Rasasindura Batch 1 and Batch 3 was 7.1, while Batch 2 showed a slightly lower pH of 6.9. This indicates that all three batches are nearly neutral in nature. The loss on drying was almost similar in all batches; however, it was slightly higher in Batch 2 (0.45%) compared to Batch 1 (0.25%) and Batch 3 (0.30%), suggesting marginally higher moisture content in Batch 2. The total ash value was highest in Batch 1 (0.50%), followed by Batch 3 (0.40%) and Batch 2 (0.30%), indicating comparatively higher inorganic content in Batch 1. Acid-insoluble ash was also slightly higher in Batch 1 (0.13%) than in Batch 2 and Batch 3 (0.12% each). It might be due to the impurity of silica particles during the process and this shows that all three batches are largely soluble in gastric juice, with Batch 2 and Batch 3 being relatively more soluble than Batch 1. The water-soluble and alcohol-soluble extractive values of all three Rasasindura batches indicating, that the all batches were slightly soluble in both water and alcohol.

6. CONCLUSION:

Three different batches of Rasasindura prepared by EMF with almost 13 hours of heating yields 51.33-53.33%. Almost all three batches exhibited comparable organoleptic characteristics and physicochemical parameters, indicating uniformity and reproducibility in the preparation process. Based on these findings, it can be concluded that Kupipakwa Rasayana prepared using an Electric Muffle Furnace (EMF) yields consistent and satisfactory results. The use of EMF provides better ease of handling and precise temperature control throughout the procedure. Furthermore, it offers advantage in terms of pollution control compared to the traditional furnace method. The EMF demonstrates several practical benefits, including accurate maintenance of temperature, energy efficiency, cost-effectiveness and reduced human effort. It was found to be a convenient and reliable method for the preparation of Rasasindura and may be effectively adopted for the standardized manufacturing of Kupipakwa Rasayana formulations.

7. REFERENCES:

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Received on 30.03.2026 Revised on 02.05.2026

Accepted on 01.06.2026 Published on 04.07.2026

Available online from July 30, 2026

Asian J. Research Chem.2026; 19(4):299-303.

DOI: 10.52711/0974-4150.2026.00046

This work is licensed under a Creative Commons Attribution-Non Commercial-Share Alike 4.0 International License. Creative Commons License.

S. No.	Name of process	Initial weight (in grams)	Final weight after process (in grams)	Weight loss ↓/ weight gain ↑
1.	Parada Shodhana	600 g	500 g	100 g ↓ (16.66%)
2.	Gandhaka Shodhana	500 g	457 g	43 g ↓ (8.6%)
3.	Kajjali preparation	900 g	886 g	14g ↓ (1.5%)
4.	Bhavana in Kajjali	886 g	900 g	14g ↑ (1.5%)