A medicinal tablet provides a means for delivering pharmaceutically active ingredients to patients in a measured fashion. This solid unit dosage form consists of active ingredients and excipients compressed or moulded into a solid substance. Tablet comes in different shapes, sizes, and colours to aid accurate administration, typically through oral ingestion. Their design allows for convenient and controlled delivery of medications. Coatings or scoring are added to some tablets to facilitate swallowing and permit dosage adjustments. The formulation of tablets can vary to meet specific therapeutic needs, making them a versatile drug delivery method widely used in medicine. This solid form allows for tailored and widespread distribution of treatments to address health requirements.¹

These tablets are designed to supplement the nutritional intake and address specific deficiencies, ensuring the body receives an adequate supply of vital nutrients for overall health and well-being. These kinds of tablets are usually made with a blend of vitamins and minerals, including calcium, iron, zinc, B vitamins (like folic acid and B12), vitamin A, vitamin C, vitamin D, and others.² These tablets are designed to disperse or dissolve in water before administration, these tablets are particularly useful for individuals who have difficulty swallowing whole tablets. These tablets are designed to disintegrate rapidly in water, forming a homogeneous suspension or solution.³ These types of pharmaceutical formulation are designed to rapidly break down in the mouth without the need of water, allowing for smooth administration. These tablets are particularly useful for people who might find it difficult to swallow regular tablets or capsules.⁴

Herbal tablets are evaluated using in vitro tests, physicochemical characterization. The results of this study may further our understanding of herbal formulas and have implications for the broader pharmaceuticals. This might result in the creation of innovative oral treatments with potential applications in the therapeutic fields that are inspired by nature_.

MATERIALS AND METHODS

Plant materials

The fresh roots of Ashwagandha, Amla fruits and Ginger rhizomes were collected from the medicinal plant garden, Bengal School of Technology, Hooghly, West Bengal, an eastern region in India. Medicinal plant gardens are primarily focused on the conservation, cultivation, research and educational activities related to authenticated herbal plant species known for medicinal purposes.

The plants specimens were identified from Central National Herbarium (Botanical Survey of India, Kolkata, certificate No. CNH/Tech.II/2023/174 issued on 08-11-2023). The plants identified are as following Table1.

TABLE 1: SPECIMEN NUMBER CORRESPONDING TO IDENTIFIED PLANT SPECIMEN

Chemicals

Microcrystalline cellulose (MCC) was purchased from Merck Specialities Pvt. Ltd., Mumbai, India Sodium starch glycolate (SSG) was purchased from Loba Chem Pvt Ltd, Mumbai, India and croscarmellose sodium (CCS) was purchased from ResearchLab Pvt. Ltd., Mumbai, India. Magnesium stearate (MgSt.)  was purchased from Loba Chem Pvt Ltd, Mumbai, India and saccharin was purchased from Qualikems Fine Chem Pvt. Ltd, Vadodara, India. All the chemicals used, including the solvents, were of analytical grade.

Preparation of herbal powders of Ashwagandha, Amla and Ginger

Ashwagandha roots were cleaned and washed with water. It was then air dried and powdered into small particles using a mixer grinder. The powder was sieved using sieve number 22. Amla fruits were washed and the pulp was kept for air drying, subsequently in hot air oven at 40⁰C. After drying, it was size reduced in a mixer grinder and was sieved through sieve number 22. Ginger rhizomes were washed and sliced into small pieces of about 1-3 mm in thickness and left for air drying and subsequently in hot air oven at 40⁰C. After that it was size reduced to a powder using mixer grinder and sieved through sieve number 22. All the powders were stored in an air-tight plastic containers.⁵

Determination of moisture content of herbal powders

Herbal powder of 2g was taken and put in the cleaned plate of IR moisture balance. The balance was run for 2 hours at 150^OC till the sample shows constant weight. The change in weight was noted from the scale present in the instrument. The moisture content was noted as percentage.⁶

Determination of ash content of herbal powders

For total ash content, silica furnace crucibles were weighed and 2 g of each herbal powder was weighed and transferred separately. Then the crucibles were put in a muffle furnace. The furnace was run at 550^OC, for 2 hours. After 2 hours, the crucibles were removed from the furnace carefully and cool it in a desiccator to room temperature and weight again.

Acid insoluble ash is determined by dissolving ash in 40% hydrochloric acid. The liquid filtered through an ashless filter paper and thoroughly washed with hot water. The filter paper is then ignited at about 500 °C to constant weight in the original dish, cooled and weighed. Water soluble ash is determined by boiling the ash for 5 minutes with 25 ml of distilled water. Insoluble matter was collected in a crucible or ash less filter paper and washed with hot water, ignited and weighed.⁷

Preparation of herbal tablet

The direct compression method was utilized to prepare the tablets. All the herbal drugs and excipients were mixed in order of Ashwagandha, Amla, Ginger, microcrystalline cellulose (MCC), sodium starch glycolate (SSG) and croscarmellose sodium (CCS). All the ingredients were mixed properly by using a blender. After that, sodium saccharin and magnesium stearate (MgSt.) were mixed and again blended. Finally, camphor was added and mixed. Then the powder blends were compressed into tablet on rotary tablet punching machine (Rimek, Mini-Press II) using 12 mm oblong punch set. Thickness and weight were adjusted during punching for complete consolidation of powder blends into tablet and ejection of tablets from the die cavity. The tablets were collected and stored in air tight containers and labeled accordingly.⁸ Table 2 provides the composition of all ingredients used for the preparation of the formulations.

Table 2: Formulation ingredients of herbal tablet (weights in mg)

Statistical optimization

3² full factorial design (2 factors and 3 levels) was used for the formulation design optimization of the herbal tablet (Design Expert Software Trial version13.0.5). The amount of SSG and CCS (disintegrating agent) were selected independent variable (factor), at each of three levels. Dispersion time(sec) and hardness (Kg) were selected as dependent variables (response) for optimization of herbal tablet formulation.⁹

Preformulation studies

Preliminary phytochemical screening

Phytochemical screening was performed by following Mayer's test , Hager's test,  Dragendorff test , Foam test, Salkowski test , Molisch's test, Benedict's test ,Modified Brontrager's test ,Keller Kiliani test,  Xanthoproteic test _, Modified Brontrager's test and  Keller Kiliani test.¹⁰

Carr’s compressibility index

The Carr's compressibility index, also known as the Carr’s index, is a parameter to characterize the compressibility of a powder. The Carr’s index is defined by the following formula:

Where, = tapped density, the density of the powder after tapping, and   = bulk density of the initial untapped powder sample

Hausner ratio

Hausner ratio, is another parameter used to assess the powder flow properties. It is defined by the ratio of tapped bulk density to untapped bulk density and is calculated using the following formula:

Angle of Repose

The angle of repose is typically measured by slowly pouring the powder or granular material onto a flat surface until a cone or mound is formed. The angle between the surface and the slope of the cone is then measured to determine the angle of repose.¹¹

Where, h= height of the cone and r= radius of the cone.

Drug excipients interaction study

Attenuated total reflectance infrared (ATR-IR) (Bruker Alpha II) spectroscopy was used as an effective analytical method for evaluation of interactions between drugs and excipients.¹²

EVALUATION OF TABLETS

Physical Evaluation

Hardness: 5 tablets were taken randomly from each batch and hardness was tested using Monsanto hardness tester. The average of five reading was noted. Unit was expressed in Kg.

Thickness:  5 tablets were taken randomly and, their thickness was noted by using a Vernier calipers. The tablets were placed diametrically. The average of the reading was noted. Unit was expressed in mm.

Friability: 20 tablets were taken from a batch and their initial weights were taken. Then they were run in a Roche friabilator for 4 minutes at 25 revolutions per minute (RPM) i.e., 100 cycles. % Friability was calculated as the following formula

                      % Friability = (W₁ – W₂ ) / W₁ X 100

        Where, W₁  = Initial weight of tablets, W₂  = Final weight of tablets

Weight Variation

According to USP, each of the 20 tablets were weighed separately, and the average weights were determined. Subsequently, the percentage of weight variation was calculated by comparing each weight to the average weight.

Wetting Time:

A piece of double-folded tissue paper was placed in a petri dish (internal diameter 10-cm) containing 6 ml phosphate buffer of pH 6.8. The tablet was placed on the paper and the time for complete wetting of the tablet was measured in seconds.      

In vitro Dispersion Time

10 ml of pH 6.8 phosphate buffer was placed in a petri dish (internal diameter 10-cm). The tablet was then carefully placed in the center of the petri dish and the time required for the tablet to completely disintegrate into fine particles was noted. Measurements were carried out in replicates of six tablet (n = 6) and mean SD values were recorded.

Swelling Index:

Tea bag method was used to measure the swelling index. The empty tea bag was measured.  The specified amount of powder of different formulations was placed in an empty tea bag and the bag was dipped in an excessive amount of distilled water. Then the tea bag was placed on a dry tissue paper and gently wiped with another dry tissue paper to remove excess water and weakly bound water. Then the tea bag was weighed.

Swelling Index =  ×100

Where, W₂= Weight of powder formulation after swelling, W₁= Weight of powder before immersion.

Antioxidant activity study:

The DPPH (1,1 diphenyl-2-picrylhydrazyl) assay is a method for evaluating the antioxidant activity of a substance. Specified weight of herbal tablets was dissolved in 25 ml of 99% methanol which was taken in a conical flask. The flask was sealed using aluminum foil and sonicated in a bath sonicator for 30 minutes. The sample was then centrifuged for 30 minutes at 5000 RPM. The sample was filtered using a whatman filter paper.¹³

The DPPH solution was prepared in methanol and added the reagent to the samples for the evaluation. Absorbance of samples were measured at 517nm by spectrophotometric method using methanol as blank. % radical scavenging activity (%RSA) values were calculated as the following formula.

× 100%

Field emission scanning electron microscopy (FE-SEM):

Field emission scanning electron microscopy (FE-SEM) (Zeiss, Sigma300) was used to study the surface morphology and microstructure of the prepared herbal formulation of tablet.¹⁴

X-ray diffraction (XRD):

Powder X-ray diffraction (XRD) (Bruker D8 Advance) was used for determination of the crystal structure of the herbal powders and the herbal formulation.

High-Performance Thin-Layer Chromatography:

High-Performance Thin-Layer Chromatography (HPTLC) is a chromatographic method for separating, identifying, and quantifying constituents in mixtures_.

HPTLC (Camag, Linomat 5) was performed for qualification and quantification of the active constituents present in the herbal formulations (ISF Analytical Laboratory, ISF College of Pharmacy, Moga, Punjab, India). For the analysis, CAMAG Linomat 5 linked with winCATS software was used as sample application device. Silica gel 60, F254, 10 x 10 cm HPTLC plates were used for this experiment. Benzene: ethyl acetate (9:1) was used as mobile phase for the detection of Ashwagandha. Ethyl Acetate: formic acid: methanol (3:3:0.8:0.2) was used as mobile phase for the detection of Amla and hexane: ethyl acetate (6:4) was used as mobile phase for the detection of Ginger.¹⁵

Results and discussion

Figure 1:   Moisture content of herbal powders

Phytochemical screening was employed which was found to contain alkaloids, saponins, flavonoids, phenols, phytosterols, carbohydrates, glycosides, amino acids, and tannins. Notably, the analysis also revealed that the mixture did not contain any steroidal compounds.¹⁶

Figure 2 Acid-insoluble and water-soluble ash content of herbal powders

Ash value helps to determine the quality and purity of crude drug, and these values are important qualitative standards. The values for total ash content were 8%, 7% and 4%, acid-insoluble ash content were 18.391%, 19.444% and 10.256%, and water-soluble ash content were 25%, 20.588% and 13.599% for Ashwagandha, Amla and Ginger respectively. The crude drugs had a moisture content of less than 3.1%, 1.8% and 2.2% respectively.^17,18 Figure1-2.

Table 3: Compressibility index and Hausner ratio of powder blends

Table 4: Angle of repose of powder blends

Angle of repose for selected formulations (F6, F7) were found to be less than 30° which indicate free flowing powder. Carr’s index was found to be less than 25% indicating good flowability. The Hausner ratio was found to be less than 1.34 indicating good flowability. The angle of repose, Carr’s index and Hausner ratio of selected formulations were found to be 28.65°, 10% and 1.11 respectively. This indicates good flow property of the powders. Table 3-4

Figure 3: ATR-IR Spectra of (a) Ashwagandha, (b) Ginger, (c) Amla, (d)Microcrystalline cellulose, (e) Sodium starch glycolate, (f) Croscarmellose sodium and (g) Formulation.

In the ATR-IR analysis of the powders, the characteristic functional groups were shown. In the spectra for Ashwagandha, various stretching and bending like C-O carboxylic Acid stretching, C=O unsaturated ketonic bending, C-O alkoxy stretching were observed. This correspond to the presence of withanolides which are steroidal lactones, hentriacontane which is a acyclic alkane, dulcitol, etc. In the spectra of Amla powder, C=O ketonic bending, C=C cyclic alkene stretching, O-H alcoholic stretching, C-O and N-O stretching corresponds to the presence of amino acids like alanine, aspartic acid, lysine which had C=O, O-H groups in them. Gallic acid and vitamin-C can also be confirmed from the spectra. In the spectra for Ginger, N-H stretching, C=C stretching, C=O stretching along with various others are present. Those type of functional groups are present in α-curcumene, 6-gingerol, zingiberene. The spectra were also recorded for microcrystalline cellulose, sodium starch glycolate, croscarmellose sodium and the formulation. Thus, the study report revealed that there were no major changes in the stretching or bending of major functional groups of the herbal drugs with all excipients. So, incompatibility between herbal drugs and excipients was not observed. Figure 3

The post-compression parameters like thickness, hardness, friability, wetting time, dispersion time of tablets were described. The thickness varied from 4.94 ± 0.05-5.18 ± 0.05 mm for various formulations and did not show much variations amongst each other of the formulations. Table 5

The hardness varied from 3.22 ± 0.33-3.68  ± 0.51 kg. The values of standard deviation indicate that the hardness of all the formulation was almost uniform and the tablets possessed good mechanical strength to withstand packaging, handling, and transportation without breaking. Figure 4

The friability was found to be range of 0.79-0.89% . All the values were below 1% indicating that the tablets possessed good mechanical strength , showing ability to withstand handling, packaging, and transportation without breaking or crumbling. Table 5

The weight variation of all formulations were given in Table5. The formulations passed weight variation test since the results obtained were within the pharmacopoeia limit.

Table 5: Thickness, Average weight and % Friability of herbal tablet formulations

Figure 4: Hardness of each formulation (Data given in Mean ± SD, n=3)

Figure 5: Wetting time and Dispersion time of herbal formulations (Data given in Mean ± SD, n=3)

Study showed shortest dispersion time, clocking in at 58.7 seconds, indicating rapid dispersibility. Figure 5 The swelling index results were depicted in Figure 6. The results showed good swelling property which reached upto 57.41%.

Figure 6: Swelling index of herbal formulations (Data given in Mean ± SD, n=3)

Figure 7 : XRD Spectra of the physical mixture of herbal powder and herbal tablet

Table 6: Average particle size from XRD Spectra of herbal formulations (using Scherrer Equation)

The absence of distinct sharp peak of herbal powders suggest that the powders are amorphous in nature. The absence of distinct sharp peak revealed no perfect crystalline structure in the powder grind of the formulation while presence of MCC in the powder grind sample denoted a broad amorphous hump in the 16-22° 2Ɵ range and a crystalline peak at 26°. Figure 7 For the calculation of average particle size, Scherrer Equation was employed and particle size was found to be 7.956 nm. Table 6

FIGURE 8 : 3D RESPONSE SURFACE PLOT FOR (A) DISPERSION TIME AND (B) HARDNESS

3D response curves were plotted against the SSG and CCS (independent variables). This response curve denoted that the amount of the SSG and the amount of the CCS might have effect on dispersion time. Figure 8. Response surface methodology has been reported to be an effective tool for the optimization of a process when the independent variables have a combined effect on the desired response.

FIGURE 9: FIELD EMISSION-SCANNING ELECTRON MICROSCOPY(FE-SEM) IMAGE OF HERBAL FORMULATIONS

In the image of scanning electron microscopy, the surface morphology of the herbal ingredients, namely Amla, Ashwagandha, and Ginger, were precisely identified and observed, with cylindrical structures indicative of Ashwagandha, larger rocky particles likely representing Amla, and sharp, rough structures characteristic of Ginger. Figure 9

FIGURE 10: %RADICAL SCAVENGING ACTIVITY OF HERBAL FORMULATIONS (DATA GIVEN IN MEAN ±SD, N=3)

The in vitro antioxidant study utilizing DPPH radical scavenging activity revealed a notably high efficacy in neutralizing free radicals. The phytoconstituents that exhibit antioxidant activity, include; Ashwagandha contains withanolides, Amla contains ascorbic acid, and Ginger contains gingerols, shogaols. Figure 10

Figure 11: PEAK FOR RETENTION FACTOR AND AREA UNDER CURVE OF ASHWAGANDHA

Table 7: RETENTION FACTOR AND AREA UNDER CURVE FOR EACH PEAK OF ASHWAGANDHA

Figure 12: PEAK FOR RETENTION FACTOR AND AREA UNDER CURVE OF AMLA

Table 8: RETENTION FACTOR AND AREA UNDER CURVE FOR EACH PEAK OF AMLA

Figure 13: PEAK FOR RETENTION FACTOR AND AREA UNDER CURVE OF GINGER

Table 9: RETENTION FACTOR AND AREA UNDER CURVE FOR EACH PEAK OF GINGER

In the chromatogram for the high-performance thin-layer chromatography (HPTLC) of herbal drug of Ashwagandha, the range of retention factor (Rf) spanned between start Rf 0.97 to end Rf 1.38 for the two extremes. This indicates the diversity of compounds present within the sample. Similarly, for the powdered tablet, the start Rf and end Rf were recorded as 0.98 and 1.36 respectively, showcasing a comparable range of compounds. The starting Rf, approximately 0.97, suggests the presence of alkaloids. Table 7 & Figure 11 Similarly, in the chromatogram for Amla, the range of retention factor extended from start Rf 0.22 to end Rf 0.59. Gallic acid and ascorbic acid exhibited standard Rf values of approximately 0.33 and 0.5-0.6 respectively, affirming the presence of these vital medicinal compounds within both the Amla powder and the herbal tablet formulation. Table 8 & Figure 12 Moving to the chromatogram of HPTLC of Ginger powder, the start Rf was noted at about 0.21 and end Rf at 0.55, denoting a broad spectrum of compounds present. Standard Rf values for specific compounds within Ginger, such as eugenol (0.21), 6-gingerol (0.4), and shogaol (0.5), further confirm the presence of these compounds within both the crude Ginger powder and the herbal tablet formulation. Table 9 & Figure 13 Thus, the chromatogram analysis strongly suggests that the herbal compounds are present in herbal tablet formulations.

In the quantitative analysis, drug content for Amla, Ashwagandha, Ginger was calculated to be 104.760 mg, 110.093 mg, and 76.905 mg respectively. The result of this assay concludes that drug was incorporated in the herbal tablet formulations.

Conclusion

Through a comprehensive examination of various studies and analyses, a holistic understanding emerges regarding the formulation and characterization of herbal tablet formulation containing Ashwagandha, Amla, and Ginger. With its diverse array of bioactive compounds, favourable physical properties, and potent antioxidant activity, the formulation holds promise as a therapeutic agent with potential applications in various health conditions. Continued research and refinement will undoubtedly further enhance our understanding and utilization of this herbal formulation in clinical practice.

ACKNOWLEDGEMENT

The authors would like to acknowledge Bengal School of Technology, Sugandha, Delhi Road, Hooghly-712102, West Bengal, India.

FUNDING

The research work was supported by the Institutional research fund, Bengal School of Technology, Sugandha, Delhi Road, Hooghly-712102, West Bengal, India.

CONFLICT OF INTERESTS

The authors report no conflicts of interest in this research work.

REFERENCES

1. Balekundri A, Shahapuri A, Patil M. Poly-herbal tablet formulation by design expert tool and in vitro anti-lipase activity. Futur J Pharm Sci. 2020 Dec;6(1).
2. Dhone PG, Gundawar N, Zopate P, Agrawalla D. Development and characterization of hydralazine mouth dissolving tablet. Int J Health Sci (Qassim). 2022 Aug 8;7459–69.
3. Paul S, Dey T, Koirala P, Tamang S, Bhattacharya S, Das R. Formulation and evaluation of Polyherbal tablet by using Neem, Tulsi, Turmeric and Ginger extract. Journal of Drug Delivery and Therapeutics. 2023 Jul 15;13(7):46–51.
4. CV A, HA P. Development and Evaluation of Sucrose Free Herbal Orally Disintegrating Tablets of Ginger. J Bioanal Biomed. 2017;09(06).
5. Kaushal M, Kaushik R, Vaidya D, Gupta A, Dhiman S. Development and Characterization of Functional Ginger Powder Tablets. Int J Curr Microbiol Appl Sci. 2019 Jan 20;8(01):2918–25.
6. Saraf S, Ajazuddin. Evaluation of physicochemical and phytochemical properties of Safoof-E-Sana, a Unani polyherbal formulation. Pharmacognosy Res. 2010;2(5):318.
7. Pande J, Padalia H, Donga S, Chanda S. DEVELOPMENT OF QUALITY CONTROL PARAMETERS FOR THE STANDARDIZATION OF AEGLE MARMELOS (ROXB.) SEED. Int J Pharm Sci Res 2018;9(6):2387.
8. Basu B, Bagadiya A, Makwana S, Vipul V, Batt D, Dharamsi A. Formulation and evaluation of fast dissolving tablets of cinnarizine using superdisintegrant blends and subliming material. J Adv Pharm Technol Res. 2011;2(4):266–73.
9. Oh E, Kim U, Lee BJ, Moon C. Multivariate statistical optimization of tablet formulations incorporating high doses of a dry herbal extract. Pharmaceutics. 2019 Feb 1;11(2).
10. Deka s, Prasad s, Lalhlenmawia h, Roy Pkr. Phytochemical profile, fabrication, and evaluation of herbal tablets. Int J Curr Pharm Res. 2022 May 15;58–63.
11. Paul S, Dey T, Koirala P, Tamang S, Bhattacharya S, Das R. Formulation and evaluation of Polyherbal tablet by using Neem, Tulsi, Turmeric and Ginger extract. Journal of Drug Delivery and Therapeutics. 2023 Jul 15;13(7):46–51.
12. Jozanikohan G, Abarghooei MN. The Fourier transform infrared spectroscopy (FTIR) analysis for the clay mineralogy studies in a clastic reservoir. J Pet Explor Prod Technol. 2022 Aug 1;12(8):2093–106.
13. Parvez MS, Jashin N, Yesmin MT, A Reza MS, Akter N. Proximate, Phytochemical and Antioxidant Activity of Amla Powder and Amla Candy. J Environ Sci & Natural Resources. 2020;13(2):82–6.
14. Gnanamoorthy P, Karthikeyan V, Prabu VA. Field emission scanning electron microscopy (FESEM) characterisation of the porous silica nanoparticulate structure of marine diatoms. Journal of Porous Materials. 2014;21(2):225–33.
15. Attimarad M, Mueen Ahmed KK, Aldhubaib BE, Harsha S. High-performance thin layer chromatography: A powerful analytical technique in pharmaceutical drug discovery. Pharm Methods. 2011 Apr;2(2):71–5.
16. Singh P, Khosa RL, Srivastava S, Mishra G, Jha KK, Srivastava S, et al. Pharmacognostical study and establishment of quality parameters of aerial parts of Costus speciosus-a well known tropical folklore medicine. Asian Pac J Trop Biomed. 2014;4(6):486–91.
17. Prakash A, Janmeda P, Pathak P, Bhatt S, Sharma V. Development and standardization of quality control parameters of different parts of Trianthema portulacastrum L. SN Appl Sci. 2019 Sep 1;1(9).
18. Natikar NA, Shalavadi M, Killer S, Kolli S, VM C, HL R. PHARMACOGNOSTIC EVALUATION OF CURCUMA VAMANA. Int J Res Ayurveda Pharm. 2019 Sep 12;10(4):68–75.