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 Table of Contents  
ORIGINAL ARTICLE
Year : 2022  |  Volume : 7  |  Issue : 2  |  Page : 97-104

First-order kinetic study-based comparative shelf-life assessment of Raw Vetas (Salix alba L. stem bark) and Vetas Ghana (a semisolid form of Salix alba L. stem bark aqueous extract)


1 Department of Chemistry, Central Ayurveda Research Institute, Jhansi, Uttar Pradesh, India
2 Department of Microbiology, Central Ayurveda Research Institute, Jhansi, Uttar Pradesh, India
3 Department of Ayurveda, Central Ayurveda Research Institute, Jhansi, Uttar Pradesh, India
4 Department of Chemistry, Central Council for Research in Ayurvedic Sciences, New Delhi, India
5 Department of Ayurveda, Central Council for Research in Ayurvedic Sciences, New Delhi, India

Date of Submission24-Jan-2022
Date of Acceptance06-Feb-2022
Date of Web Publication14-Sep-2022

Correspondence Address:
Dr. Vijay Kumar
Department of Chemistry, Central Ayurveda Research Institute, Jhansi 284003, Uttar Pradesh
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jdras.jdras_10_22

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  Abstract 

BACKGROUND: Shelf-life is an important aspect of raw as well as finished drugs. Recently, shelf-life parameters have been included in the Ayurvedic Pharmacopeia of India (API). The aim of this study to evaluate the comparative long-term shelf-life study of Raw Vetas (Salix alba stem bark) and Vetas Ghana (a semisolid form of Salix alba Stem bark aqueous extract). METHODS: A stability chamber with environmental conditions 30°C ± 2°C/60% RH ± 5% was used for the long-term shelf-life study of Raw Vetas and Vetas Ghana. Physicochemical parameters like loss on drying, pH, total ash, acid insoluble ash, water extractive value, and alcohol extractive value were evaluated at a regular frequency (0th, 3rd, 6th, 9th, and 12th months). RESULTS: There are significant changes that have been observed w.r.t. physicochemical parameters analysis. Physicochemical parameters revealed that the shelf-life of Raw Vetas ranged from 31 to 66 months and the shelf-life of Vetas Ghana ranged from 38 to 62 months. CONCLUSIONS: The average shelf-life of Raw Vetas and Vetas Ghana was 41.83 and 47.50 months, respectively. This study may help to understand the shelf-life of various Ayurvedic formulations consisting of Raw Vetas and Vetas Ghana.

Keywords: API, Salix alba, shelf-life, Vetas, Vetas Ghana


How to cite this article:
Verma R, Jain V, Rawat H, Kushwaha V, Gandhi Y, Mishra SK, Kumar V, Tandon S, Charde V, Jagtap C, Babu G, Singh A, Singh R, Sharma BS, Srikanth N. First-order kinetic study-based comparative shelf-life assessment of Raw Vetas (Salix alba L. stem bark) and Vetas Ghana (a semisolid form of Salix alba L. stem bark aqueous extract). J Drug Res Ayurvedic Sci 2022;7:97-104

How to cite this URL:
Verma R, Jain V, Rawat H, Kushwaha V, Gandhi Y, Mishra SK, Kumar V, Tandon S, Charde V, Jagtap C, Babu G, Singh A, Singh R, Sharma BS, Srikanth N. First-order kinetic study-based comparative shelf-life assessment of Raw Vetas (Salix alba L. stem bark) and Vetas Ghana (a semisolid form of Salix alba L. stem bark aqueous extract). J Drug Res Ayurvedic Sci [serial online] 2022 [cited 2022 Sep 25];7:97-104. Available from: http://www.jdrasccras.com/text.asp?2022/7/2/97/356049

Ravi Verma, Vipin Jain, Hemant Rawat, Vikram Kushwaha, Yashika Gandhi, Sujeet K. Mishra, Vijay Kumar, Smriti Tandon, Vaibhav Charde, Chandrashekar Jagtap; Equal contribution





  Introduction Top


Salix alba L. is a medicinal plant widely used in the treatment of musculoskeletal and inflammation-related diseases.[1],[2],[3] In Ayurveda, the stem bark of Salix alba L. is considered to be a medicinally important part. In Ayurveda, Salix alba L. is known as Vetas and a semisolid form of Salix alba (Stem bark) aqueous extract is known as Vetas Ghana (VG). VG is an intermediate or precursor of various Ayurvedic formulations.[4] The phytochemicals like salicin, isosalicin, salicylic acid, catechin, epicatechins are the major constituents of Salix alba L. responsible for biological activities including anti-obesity, anti-migraine, anti-inflammation, cardiovascular potency, antioxidant, anti-acetylcholinesterase, anti-rheumatoid arthritis, anti-cancer, etc.[5],[6],[7],[8],[9],[10]

Shelf-life is termed as Virya, which means the potency of any drug.[11] Shelf-life and expiry date are different concepts, but these terms are interrelated to each other. Expiry of any drug depends upon the shelf-life of the product. In classical literature, it is in practice since the twentieth century AD.[11] To maintain the safety regulations, International Conference on Harmonisation (ICH) has issued the shelf-life guidelines.[12],[13],[14],[15],[16],[17] Recently, in 2016, the Indian government amended Drugs and Cosmetics (Amendment) Rules, 1940 to meet the international standards and shelf life of various dosage forms used in Ayurveda have been introduced in the regulatory provisions for ASU drugs.[18] The basic parameters for shelf-life studies included in API were evaluation of physicochemical parameters and biological testing. The examination of shelf-life of traditional or herbal drugs is a tedious and cumbersome job. The Shelf-life of a polyherbal formulation (tablet (vati), and powder (churna) consisting of more than three ingredients may depend on various factors. One contaminated ingredient, having contamination such as microbial load, aflatoxins, pesticide residues, or heavy metal, may spoil the whole formulation. Microbial contaminations (microbial load or aflatoxins) exert a prime effect on the shelf-life of herbal drugs. Environmental factors including temperature and humidity, storage, handling, and transportation play a vital role in the shelf-life of any product.[19],[20],[21],[22]

There is no report on the shelf-life study of Vetas and VG available yet which is the aim of this study. The aim of this study was to evaluate the comparative long-term shelf-life study of Raw Vetas (RV) (Salix alba stem bark) and VG (a semisolid form of Salix alba Stem bark aqueous extract).


  Experimental Top


Materials and methods

Standards of metal ions lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg) of analytical grade and purity >98% were purchased from Merck Ltd India. Agar (MacConkey, Bismuth sulfite, Mannitol Salt, and Soyabean casein) and standard chloramphenicol were of AR grade purchased from HiMedia. The microorganisms with MTCC numbers were purchased from CSIR – Institute of Microbial Technology Chandigarh, India. The authentic material of RV (Salix alba L. stem bark) was collected from Kashmir, India by the Botanist of Kashmir University (Herbarium Number: 3160-KASH). VG was prepared in the in-house pharmacy of Central Ayurveda Research Institute Jhansi.

Long term shelf-life studies

The dried RV and VG samples were packed in seal packs in December 2020 and were kept in food grade HDPE containers. The containers were placed in a stability chamber for long term shelf-life studies at 30°C ± 2°C/65% RH ± 5% RH.[14] A control sample was kept in a deep freezer at 0°C.

Quality control parameters assessment

Quality control parameters like loss on drying (LOD), pH, total ash, acid insoluble ash, water extractive value, and ethanol extractive value were performed at a regular frequency (0th, 3rd, 6th, 9th, and 12th months) as per the protocols mentioned under the API.[23],[24],[25]

Kinetic analysis

The results of quality control parameters were fitted in first-order kinetic model =by plotting log Ct vs. time (t) and a straight line was observed. The differential and integrated rate law for first-order-kinetics is represented by





The 10% degradation time, t0.9 (where Ct = 0.9C0) was calculated from the first-order integrated rate law. The equation for time required for 10% decomposition is as follows:





The rate constant (kobs) is the slope obtained from the linear plot of log Ct vs. time (t).

Safety and toxicological parameter analysis

Heavy metal analysis

Heavy metals like lead (Pb), cadmium (Cd), mercury (Hg), and arsenic (As) were analyzed by using the inductively coupled plasma-optical emission spectrometry (ICP-OES) instrument (Agilent 5800, USA). The samples were digested by using an automatic microwave sample digestor (Microwave 130000 Multiwave GO Plus 50Hz).

Microbial load, specific pathogens

Microbial assay like microbial load and specific pathogens (Aspergillus niger,  Escherichia More Details coli, Pseudomonas aeruginosa,  Salmonella More Details typhi, and Staphylococcus aureus) were analyzed as per protocols mentioned in API and were found to be within limits.

Pesticides residues analysis and Aflatoxin analysis

The analysis of aflatoxins (B1, B2, G1, and G2) and pesticide residues (organochlorine, organophosphate, and pyrethroid pesticides) were carried by Delhi Test House, Delhi. The gas chromatography tandem mass spectrometry (GC-MS/MS) based QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure was used to analyze the pesticides residues.[26] The quantification of aflatoxins was done by using the high-performance liquid chromatography (HPLC) method.[21]


  Results and Discussion Top


The results of the long-term shelf-life study of RV and VG are mentioned in [Table 1] and shown in [Figure 1]. [Figure 1] shows that, in RV, after 12 months, pH, LOD, water extractive value (WEV), ethanol extractive value (EEV), total ash (TA), and acid insoluble ash (AIA) were changed by 4.34%, 8.69%, 8.59%, 7.66%, 6.77%, and 9.43%, respectively. In the case of VG, after 12 months, 6.16%, 7.96%. 4.70%, 8.25%, 6.57%, and 5.13% changes were noticed for pH, LOD, WEV, EEV, TA, and AIA parameters. After 12 months, significant changes (at P < 0.001) were observed as compared to the initial day (0th month) results.
Table 1: Shelf-life data of raw Vetas (RV) and Vetas Ghana (VG)

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Figure 1: % change in parameters of Raw Vetas (RV) and Vetas Ghana (VG) with time (months) (LOD = loss on drying, WEV = water extractive value, EEV = ethanol extractive value, TA = total ash, AIA = acid insoluble ash)

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The toxicity and safety parameters of RV and VG were analyzed and have been mentioned under [Table 2] and [Table 3]. The microbial load (cfu/g) w.r.t. total bacterial count (TBC) and total fungal count (TFC) was increased as compared to initial day (0th month) results [Table 2]. The observed TBC values for RV and VG changed from 112 to 436 cfu/g and from 32 to 387 cfu/g, respectively. Similarly, TFC values for RV and VG changed from 123 to 311cfu/g and from 21 to 287cfu/g, respectively. Specific pathogens viz. A. niger, E. coli, Salmonella, S. aureus, and P. aeruginosa were not observed in RV and VG samples throughout the examination period, that is, from 0th to 12th month. The aforementioned results were quite within limits as per prescribed limits of API as well as the World Health Organization (WHO). The observed results for aflatoxins B1, B2, G1, and G2 were well within tolerance limits as none of the aflatoxin was detected in the whole period of shelf-life analysis [Table 2]. The analysis for heavy metals and pesticides residues were done at the initial day (0th month) where no pesticide residues and heavy metals were detected [Table 4]. The analysis of pesticide residues and heavy metals was carried out as numerous reports on heavy metal toxicity and pesticides contaminations of herbs or raw drugs have been published till date.[21],[22],[27],[28] In this study, RV was collected from natural resources and that might be the reason that there is no heavy metal toxicity and pesticides residue detected in RV.
Table 2: Microbial load and test for specific pathogens in Raw Vetas (RV) and Vetas Ghana (VG)

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Table 3: Pesticides residues and heavy metals in Raw Vetas (RV) and Vetas Ghana (VG)

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Table 4: Kinetics study data of Raw Vetas (RV) and Vetas Ghana (VG)

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Kinetic results of the shelf-life study are tabulated under [Table 4] and shown in [Figure 2]. Various kinetic models were applied to the obtained data and finally, first-order kinetics was found to be the most suited where linear plot of log Ct vs time (t) with regression coefficient r2 > 0.95 was observed [Figure 2]. The shelf-life period w.r.t. 10% degradation was calculated. The shelf-life period of RV w.r.t. LOD, pH, WEV, EEV, TA, and AIA parameters was calculated to be 34, 66, 35, 39, 46 and 31 months, respectively. Similarly, shelf-life period of VG w.r.t. LOD, pH, WEV, EEV, TA, and AIA parameters was calculated to be 39, 44, 62, 38, 44 and 58 months, respectively.
Figure 2: Linearity plot log (Ct) vs. time (t in months) of shelf-life data of Raw Vetas (RV) and Vetas Ghana (VG) (LOD = loss on drying, WEV = water extractive value, EEV = ethanol extractive value, TA = total ash, AIA = acid-insoluble ash)

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Recently, a number of studies on the shelf-life study of herbal drugs have been reported by few researchers, which shows the keenness of scientific community on herbal drugs shelf-life study. Few shelf-life reports on Ayurvedic drugs like churna, avaleha, ghrita, kwath churna, and herbo-minerals have been reported.[21],[24-26],[29–35] It has been observed that herbal or polyherbal drugs contain a wide class of phytochemicals and act as good inhibitors for microbes and aflatoxins.[21],[24-26],[29-35] For the better understanding of shelf-life, the terms like “true shelf life,” “estimated shelf life,” “supported shelf life,” “maximum shelf life,” and “labelled shelf life” have been well mentioned in literature.[36] Few researchers have experimentally claimed that shelf-life and expiry are even more than 10 years as labelled shelf-life.[37] This shows that potency of drug does not depend upon a single parameter or single phytochemical. The average shelf-life of RV and VG was found to be 41.83 and 47.50 months, respectively. The lower shelf-life of RV as compared to VG might be due to preparation of VG in controlled conditions. VG was prepared in pharmacy and packed for shelf-life study whereas RV was used as collected from natural resources. Stem bark sample of RV might contain high moisture content and high microbial load which attributes to lower shelf-life period. To obtain the highest level of homogeneity in results and global acceptance of herbal drug, it is important to follow the same methodology as prescribed by ICH[38] and followed by Govt. of India. For the better understanding of shelf-life of herbal drugs, the shelf-life of raw drugs and intermediate is an importance aspect that needs to be covered by researchers while performing their shelf-life study experiments.


  Conclusions Top


This is the first kinetics-based shelf-life study where an Ayurvedic raw drug and its intermediate was assessed. Overall, first-order kinetic model was fitted to shelf-life experiments of RV and VG. Good linearity was maintained with r2 more than 0.95. The average shelf-life of RV and VG was found to be 41.83 and 47.50 months, respectively. This study may help to understand the shelf-life of various Ayurvedic formulations consisting of RV and VG.

Acknowledgement

DG-CCRAS is highly acknowledged for funding and facilities at CARI, Jhansi (Uttar Pradesh). RARI, Jammu is highly acknowledged to collect Salix alba L. stem bark sample from Kashmir University.

Financial support and sponsorship

This work was supported by the CCRAS, Ministry of Ayush under IMR Project.

Conflicts of interest

There are no conflicts of interest.

Ethics approval and consent to participate

Not applicable.





 
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    Figures

  [Figure 1], [Figure 2]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4]



 

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