T Y BSc. Botany (Sem V)

VSC- Herbal Quality Control and Analytical Techniques (Practical)

TY BSc Botany VSC                                                           Sem V

External Practical 

Practical No. 1: Determination of Swelling Index and Foaming Index of Herbal Drugs

Introduction: Quality control of herbal drugs involves the determination of various physicochemical parameters that help establish identity, purity, and quality. Among these parameters, Swelling Index and Foaming Index are important indicators used for evaluating herbal materials rich in mucilage and saponins respectively.

The swelling index measures the capacity of a plant material to absorb water and swell, whereas the foaming index provides an estimate of the saponin content by measuring the foam produced by an aqueous decoction under standardized conditions. These parameters are widely employed in pharmacognostic evaluation and herbal drug standardization.

A. Determination of Swelling Index

Aim: To determine the Swelling Index of a mucilage-containing herbal material.

Principle:  Certain herbal materials contain polysaccharides such as mucilage, pectin, and hemicellulose that absorb water and swell considerably without dissolving. The swelling index is defined as the volume (mL) occupied by the swollen material obtained from 1 g of herbal drug under specified conditions.

Materials Required

Distilled water

Plant Material: Isabgol (Plantago ovata), Fenugreek (Trigonella foenum-graecum), or Linseed (Linum usitatissimum)/ Sabja/Tukmaria (Ocimum basilicum).

Apparatus:  25 mL glass-stoppered measuring cylinder, Analytical balance, Glass rod, Stopwatch and Measuring pipette. 

Requirements

Parameter Specification

Sample Weight 1.0 g

Water Volume 25 mL

Shaking Duration 1 hour

Standing Time 3 hours

Temperature Room Temperature (25 ± 2°C)

Procedure

1. Accurately weigh 1.0 g of herbal sample.

2. Transfer it into a clean, dry 25 mL glass-stoppered measuring cylinder.

3. Add 25 mL distilled water.

4. Stopper the cylinder securely.

5. Shake thoroughly to disperse the material.

6. Shake again every 10 minutes during the first hour.

7. After 1 hour, allow the cylinder to stand undisturbed for 3 hours at room temperature.

8. Observe the final volume occupied by the swollen mass including any mucilage layer and record the volume in mL.

9. Perform three independent replicate / determinations.

Observation Table

Replicate Weight of Sample (g) Initial Volume (mL) Final Swollen Volume (mL)

I 1.0 25

II 1.0 25

III 1.0 25

Calculation

Swelling Index (SI)

B. Determination of Foaming Index

Aim: To determine the Foaming Index of a saponin-containing herbal crud drug.

Principle: Saponins possess surface-active properties and produce stable foam when shaken in aqueous solution. The foaming index is determined by preparing an aqueous decoction of the herbal material and measuring the height of the foam produced after standardized shaking. The result indirectly indicates the saponin content of the sample.

Materials Required

Distilled water

Plant Material Powdered herbal sample like Liquorice (Glycyrrhiza glabra), or Soapnut (Sapindus mukorossi), or Shatavari (Asparagus racemosus).

Apparatus: Analytical balance, 500 mL conical flask, Water bath, Filter paper , Funnel , 100 mL volumetric flask , Ten stoppered test tubes , Measuring cylinder , Ruler .

Requirements

Parameter Specification

Sample Weight 1 g

Boiling Water 100 mL

Boiling Time 30 min

Standing Time After Shaking 15 min

Shaking Rate 2 shakes/sec

Procedure

1. Accurately weigh 1 g of powdered herbal crud drug sample. Transfer into a 500 mL conical flask and add 100 mL boiling distilled water.

2. Boil gently for 30 minutes for making decoction and cool the mixture.

3. Filter into a 100 mL volumetric flask and make up the volume to 100 mL using distilled water.

4. Take ten stopper test tune and mark each test tube with 10 ml level and 1cm Above 10ml marking.

6. Stopper all test tubes.

7. Shake each tube vigorously in a lengthwise motion for 15 seconds at approximately 2 shakes per second.

8. Allow the tubes to stand undisturbed for 15 minutes.

9. Measure the height of the foam in each tube using a ruler and 15 minutes.

10. Identify the tube showing exactly 1 cm foam height (As in Fig Tube no 07).