INTRODUCTION:
Excipients are any substances included in the manufacturing process or in a final product other than drug or prodrug, as defined by International Pharmaceutical Excipients Council [1]. These excipients used in a particular dosage form can control or alter the physicochemical properties of drugs and leads to alteration in therapeutic activity [2]. Excipients can be obtained from synthetic or natural sources. Synthetic excipients have many demerits like toxicity, non biodegradable, expensive and their synthesis cause environmental pollution. Natural excipients have many advantages like economical, biocompatible, and readily available [3]. Gums are pathological products formed by injuring the plant or by breakage of cell walls. Mucilages are metabolic products formed by intracellular metabolic processes [4]. In recent years, interest in utilizing gums and mucilage of natural sources has gained tremendously. Fenugreek seeds are known as methi in Hindi. The seeds are obtained from Trigonella foenum graecum L., an herbaceous plant of leguminaceae or fabaceae family. The seeds are also used as spice in vegetables and act as preservatives in pickles. It has demonstrated many activities like immunostimulatory, antidiabetic, antihypertensive, and cholesterol-lowering activities as reported in literature [5]. The aim of this research work is to extract and evaluate mucilage from fenugreek seed and conduct physiochemical and phytochemical studies.
MATERIALS AND METHODS:
The fenugreek seeds were collected from local market. Ethanol was procured from SD Fine Ltd., India. All other chemicals were of analytical grade.
Extraction of mucilage
Fenugreek seeds were procured from local market. The seeds were washed with double distilled water to remove any adherent material. The seeds were pulverized and about three times its volume of water was added and kept aside with occasional stirring using mechanical stirrer (Remi, India). This was continued for about 5 hours until the slurry was prepared. The viscous solution was then filtered through eight fold muslin cloth. The process was repeated 4 times with the residue on the muslin cloth. All the filtrate was added together. Then the filtrate was precipitated in about three times its volume of ethanol with continuous stirring with mechanical stirrer. The precipitate was washed for three times with ethanol and dried at 40±1°C. The dried material was ground by a mechanical grinder and passed through # 60 mesh sieve and kept in a desiccator till further use
Phytochemical Examination
The extracted mucilage was subjected to phytochemical examination. Presence of carbohydrate, protein, saponins, tannins, alkaloids, glycosides, flavonoids were qualitatively determined.
Physicochemical Characterization
i. Solubility test: Solubility of extracted mucilage was determined in water, ethanol, acetone, and chloroform as per Indian Pharmacopoeia.
ii. Loss on drying: 10g mucilage was weighed and dried at 105°C until constant weight of sample was obtained. Loss on drying was calculated.
iii. pH: pH of mucilage solution (5%w/v) was determined was using pH meter.
iv. Angle of repose: Angle of repose was determined by funnel method [6]
v. Bulk and tap density: Bulk and tapped density was determined as per reference [6]
vi. Hausner ratio: Hausner ratio was calculated by using the following formula
vii. Compressibility index: Compressibility was calculated by
viii. % Yield: This was calculated by using the formula
Swelling properties
5 g of mucilage was placed in 50 ml cylinder. 20 ml of distilled water was added and the content was vigorously shaken for 15 minutes and then the solution was allowed to stand for 5 hours without any disturbance. The test was performed in triplicate and swelling index was calculated using the following formulation
Where, Vf= Final volume occupied by mucilage, V0= Initial Volume of the mucilage
Moisture sorption studies
2 g of mucilage was taken in petridish and placed in dessicator containing distilled water in its reservoir for 5 days. The sample was weighed daily and increase in weight, indicates the amount of water sorbed, was calculated.
Viscosity
Solution of different concentration of mucilage (2%, 4%, 6%, 8%, 10% w/v) was prepared by using distilled water. The solutions were kept overnight at room temperature. Viscosity of the solution was then measured using Brookfield Viscometer (Brookfield, USA) using spindle 4 at shear rate of 20 rpm.
Fourier transform-infra red (FTIR)
The infra – red spectrum of the mucilage was recorded using FTIR (IR – Affinity, Shimadzu, Japan). Mucilage was compressed with potassium bromide and transformed into disk. Disk was applied to the centre of the sample holding device and scanned between 4000 – 400 cm – 1 at a resolution of 4 cm – 1.
RESULTS AND DISCUSSION:
Mucilages are polysaccharides hydrocolloids and are found commonly in many higher plants. These polysaccharides are responsible for reducing the release of drug from dosage form [7]. Mucilage from fenugreek seed was extracted by precipitating the viscous dispersion of seed with ethanol. The yield was found to be 24.8%. The precipitated mucilage was subjected to various phytochemical and physicochemical tests. The mucilage shows the presence of carbohydrates, reducing sugar and confirms the presence of mucilage, whereas alkaloids, steroids, glycosides, tannins were absent.
The mucilage was found to be soluble in distilled water. Low moisture content suggests that the mucilage is suitable to be used in formulations containing moisture sensitive drugs. Angle of repose compressibility suggests that mucilage has good flow properties with moderate compressibility. Bulk and tapped densities gives an indication about the packing and arrangement of particles and the compaction. The swelling index of mucilage shows that it can absorb water (Table 1). Moisture sorption by the mucilage is shown in figure 1 which shows that the mucilage absorbed substantial amount of moisture over the period of 5 days. The viscosity of mucilage was found to be dependent on concentration. Viscosity of the mucilage solution was found to be increasing with the concentration of solution (figure 2).
FTIR spectrum was recorded (figure 3) and the mucilage shows characteristic peaks at 1328.95, 1375.25, 1500.62, 2943.37, 3527.80 suggesting the presence of C – H bend, C – H rock, N – O stretch, C – H stretch, O – H stretch