Shelf life is the time period during which a drug product is expected to remain within the approved life specification, provided that it is stored under the conditions defined on the container label. Shelf life is the time required for 10% of the material to disappear; it is the time at which molar concentration of the reactant has decreased to 90% of its initial concentration. In ayurvedic literature, shelf life is known as Saviryata Avadhi refers to the time period during which a drug remains potent. The information regarding the concept of shelf life for different dosage forms is found scattered in Brihatrayi like Shelf life of Vati (tablet) and Churna (powder) is one Prahara (3 hours) and 2-3 months respectively. Acarya Caraka explained that a aushdhi (drug) can be utilized for treatment purposes until it maintains its fragrance, color, taste etc. After that Acarya Sharangadhara opines that the Avaleha start to lose their therapeutic potency after a year, while Yogaratnakara opines the period as six months. Trivrit Avaleha (TA) is composed of Trivrit (Operculina turpethum Linn.), Trijata (Cinnamomum tamala Nees and Eberm., Cinnamomum zeylanicum Breyn., Elettaria cadamomum Maton.), Madhu (honey) and Khandasarkarā (sugar candy). It is an important formulations used frequently to induce Virecana (therapeutic purgation) by ayurveda physicians. However, no stability profiles of this formulation are available till date. Considering this, an attempt has been made to evaluate shelf life of TA with the help of modern analytical techniques.
Materials and methods
Collection of raw materials
All the herbal drugs, Madhu (honey) and Khandaśarkarā (sugar candy) were procured from the Pharmacy, IPGT & RA, Jamnagar. All the herbal drugs were authenticated in the Pharmacognosy Laboratory, IPGT & RA, Jamnagar. Composition formulation is placed at Table 1.
Pharmaceutical preparation of formulation
Avaleha is prepared by following classical guidelines of Avaleha.
Shelf life evaluation
Sample quantity and packing
Samples were supplied in four transparent airtight food grade plastic containers plastic bottles with transparent screw cap. Each bottle contains 100 grams of TA.
Accelerated stability study was conducted as per International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) Guidelines Q1A (R2). Samples were stored at 40±2°C and Relative Humidity 75±5%.
Basic analytical parameters including moisture %, ash value and water soluble extractive were evaluated at intervals specified earlier. Test for microbial contamination was done initially and at the end of six months of storage by following standard guidelines. Chromatographic profiles (HPTLC) were evaluated under 254, 366 and 540 nm initially and after six months of storage. Accurately weighed 5g of sample was individually soaked in 10 ml methanol on a Vortex for 10 min, heated for 10 min, filtered through Whatman filter paper no. 1 and then concentrate it on water bath up to 2ml. Drying Mode, Temp. & Time: TLC Plate Heater Preheated at 100± 5°C for 3 minutes; Application Mode: CAMAG Linomat 5 - Applicator; Filtering System: Whatman filter paper No.1; Stationary Phase: MERCK - TLC / HPTLC Silica gel 60 F254 on Aluminum sheets; Application (X axis) Start Position: 10mm; Development (Y axis) End Position: 90mm from plate base; Space Between Band: 10mm; Sample Application Volume: 06μL; Development Mode: CAMAG TLC Twin Trough Chamber; Chamber Saturation Time: 30 minutes; Mobile Phase (MP): Toluene: Ethyl acetate: Formic acid (7:3:0.1); Visualization: @254nm, @ 366nm and @ 540 nm (after derivatization); Spray reagent: Anisaldehyde Sulphuric acid reagent; Derivatization mode: CAMAG - Dip tank for about 1 minute.
Results and discussion
The organoleptic characters of the TA are shown in Table 2. No changes in organoleptic characters were found in the formulation at different levels of storage. Physico-chemical characters of TA at initial, 1, 3, 6months interval are shown in Table 2. Microbial growth was found below prescribed limits by the end of 6thmonths (Table 3). Heavy metals were also found to be within the permissible limits at the end of 6th months (Table 4). HPTLC showed 2spots at 254 nm, 4 spots at 366 nm and 4 spots at 540 nm (Figure 1). Rf values recorded were same for both samples (0, 6 months) (Table 5).
No changes in organoleptic characters were found at different levels of storage. TA was found to be brownish black in color with characteristic odor and taste. Color of drug was due to its components. Insignificant differences were observed in basic physico-chemical profiles in the drugs at different stages of analysis. Physicochemical standards such as total ash value and water soluble extractive value are useful in identification and authentication of the plant material. The total ash is particularly important in the evaluation of purity of drugs, i.e. the presence or absence of inorganic matter and also helps in determining both physiological ash and non-physiological ash. Extractive values help in determining the amount of active constituents and is done on plant materials in particular solvent for which as yet no suitable chemical or biological assay exists. Presence of more moisture content in a sample can create preservation problem. The moisture content was found to be increasing gradually with storage. Microbial count and Heavy metals were within the permissible limits indicating safety and quality of the product.
|Organism||Initial||6 months||Permissible Limits|
|Total plate count (cfu/g)||<10 cfu/g||<10 cfu/g||105/g|
|Total Yeast and Mould Count||Ab||Ab||103/g|
|Heavy metals||TA||Permissible limits|
|Arsenic||0.425 ppm||3 ppm|
|Drug||Spot||Rf at 254 nm||Rf at 366 nm||Rf at 540 nm|
|Track1 (0 month)||Track2 (6 month)||Track1 (0 month)||Track2 (6 month)||Track1 (0 month)||Track2 (6 month)|
|Loss on Drying||10.063||1.010|
|Water Soluble Extractive||75.63||0.76|
|Parameters||Initial||10% Degradation||Approximate Months required for 10% degradation|
|Loss on drying||10.94||9.846||0.21|
|Water soluble extractive||74.67||67.203||11.09|
|Drug||Mean Months for 10% degradation||Multiplication Factor||Months||Shelf life Years|
|Trivrit Avaleha||6.93333||3.33||23.088||1 year 11 months|
Shelf life of Avaleha according to classical texts varies from 6 to 12 months, while Rule 161-B of Drugs and Cosmetics Act mentioned it as three years. In current study; Shelf life of TA is found to be 1 year and 11 months. Earlier study, Shirishāvaleha showed 2 years 6 months (with Kanji) and 1 year 4 months (with water), Kamsaharitaki Avaleha showed 1 year 6 months, Shirishashwagandhadi Avaleha showed 8 years 7 months. Findings of earlier studies make corroborate to results of TA except Shirishashwagandhādi Avaleha that is found more stable, possibly due to the presence of metallic components in that. This indicates that the shelf life of Avalehas with metallic composition will be comparatively higher than the ones with pure herbal part (Table 6 to 8).
On extrapolation of the observations the Shelf life of TA is found to be 1 year and 11 months. Findings of earlier studies are in support of current observations. Similar RF values obtained in HPTLC analysis of TA initially and after six months showed minimum deterioration of the product. Studies involving other Avalehas are needed to substantiate the observations of the current study. The current work is preliminary in nature involving a few parameters. Extensive studies may be taken-up to revalidate current observations.