Organoleptic tests of all the four samples of Gandhaka Rasayana, i.e. G.R.A., G.R.K., G.R.I. and G.R.G. were performed .
There was a slight color and taste variation between sample 3 (11 Bhavana) and the other samples. This sample had a cream color with mild astringent taste, while the others had a dark green color with an astringent taste, indicating a lower concentration of Bhavana dravya in this sample.
All the samples had a specific odor of Adraka and Shunthi, but the G.R.G. sample did not have any specific odor. This may be due to a loss of the volatile aromatic components of Bhavana dravya during the pharmaceutical processing of Ghana formation.
A considerable difference was found in the values of some of the physicochemical parameters of Gandhaka Rasayana. Both the water- and the methanol-soluble extractive increased in the G.R.K sample and in the G.R.G sample as compared with the G.R.A and the GRK-I samples, but the G.R.A sample had an increased value of both factors as compared with the GRK-I sample. There was not much variation in the pH, which ranged from 3.84 to 4.65. This reveals that a more concentrated form or more water- and methanol-soluble content may not affect the pH of the samples. Loss on drying in Gandhaka Rasayana GRK-I (5.35%) was more than that of the Gandhaka Rasayana Arka sample (G.R.A) (2.75–3.66%), indicating the presence of more moisture in GRK-I, whereas the Gandhaka Rasayana kwatha and the Ghana sample did not show much of a difference in the L.O.D. ranging between 1.24 and 1.80. The ash value in GRK-I was found to be lower (1.46%) as compared with the three other samples, ranging between 4.55 and 5.90%. The ash value indicates the presence of inorganic contents in the sample. Test for acid-insoluble ash indicates the percentage of insoluble inorganic content or the therapeutic efficacy. It indicates the physiological availability of the drug after passing through the gastric solution. There was not much variation in the acid-insoluble ash, which ranged between 0.230 and 0.395%. This reveals that the method of preparation and media does not affect the physiological availability of the drug, especially in case of Gandhaka Rasayana. The CS2-soluble extractive value was found to be increased in GRK-I (22.27%) in comparison with the G.R.G. sample (12.4–13.0%), but in the G.R.K. and G.R.A. samples, it was found to be between 8.4 and 9.7%. These values show the percentage of free sulfur in the samples. In GRK-I, it is higher because the concentration of Bhavana dravya is less in comparison with the other samples. In the G.R.G. sample, the concentration of free sulfur was found to be 2–3% increased when compared with the G.R.K. and G.R.A. samples. The reason for this may be that the G.R.K. and G.R.A. samples were levigated 88 times with kwatha/SwaRasa/arka of different bhavana dravya. Thus, there may be some possibility of compound formation with free sulfur, and this possibility is only 2–3% as sulfur is water-insoluble .
Particle size distribution
Ninety percent of the particles are below 41.45 μm in size in G.R.A. Ninety percent of the particles are below 26.92 μm in size in G.R.K .
Particle size distribution of all the three samples
Ninety percent of the particles are below 40.81 μm in size in GRK-I.
Ninety percent of the particles are below 93.65 μm in size in G.R.G.
The above data indicate that the G.R.A. and G.R.K. groups are more microfined although the particle size distribution is quite varying in spite of the same number of Bhavana.
Given a general observation, the elements like Cu, V, Cr, Mn, Pb, Co, Zn, Ni, As, Se, Sr, Mo, Ag, Cd, Sb, Ba and Hg are expressed in mg/kg concentration .
From all the suppositions for transitions in the content of the Gandhaka Rasayana prepared using different media and methods, it is clear that an absence or presence of a particular element in prior stage and its changed concentration in the final stages or from the original suddha Gandhaka to the final Gandhaka Rasayana through all the intermediate steps (lavigation) is only by virtue of a direct addition or subtraction of the amount of that trace element present in the Bhavana dravya. It may be actually in the form of some conversion or addition–subtraction phenomenon. These changes may be occurring as such on much subtler levels.
When the surface anatomy of Gandhaka Rasayana
was studied, only C, H and O peaks were observed at the surface having sulfur particles in the core. In case of sample 88, the Bhavana
surface was found to be uniform and even, but in the sample without Bhavana
, i.e. the G.R.G. sample, the surface observed was not uniform. As the penetration power of the XPS analyzer was only 100A°, it was not possible to see the structure of beyond this range. Therefore, by this study, it can be proved that Gandhaka Rasayana
is a herbo-mineral compound having sulfur particle in the core and overlapping of Bhavana dravya
on it, or it may be that our acharya used sulfur as a vehicle for uniform distribution of the extracts of herbal drugs having Rasayana
or other similar properties.[9