BP105T Unit 4 – Primary & Secondary Metabolites in Plants
Unit 4 focuses on pharmacopoeial standardization of natural raw materials. It explores commercial drug adulteration mechanisms and the five comprehensive evaluation disciplines: Organoleptic, Microscopic (Stomatal Index, Vein-Islet Number, Palisade Ratio, Lycopodium Spore Method), Physical (Ash values, Extractive values, Moisture content), Chemical, and Biological evaluations.
📋 Prescribed Syllabus Topics
📖 Detailed Lecture Notes & Solved Examples
11. Types and Methods of Commercial Drug Adulteration
Dedicated Webpage➔Adulteration is the debasement of an article of commerce. In crude drugs, adulteration involves fraudulent substitution or accidental addition of an impure, spurious, deteriorated, or inert substance to an authentic drug. Adulteration is classified into: (1) Substitution with substandard/inferior commercial varieties (e.g., substituting true Senna with Arabian or Dog Senna), (2) Substitution with exhausted drugs from which active chemical constituents have been extracted (e.g., exhausted Tea leaves colored with iron salts, exhausted Clove or Ginger), (3) Substitution with superficially similar inferior natural substances (e.g., Ailanthus leaves for Belladonna; Saffron adulterated with dried safflower florets), (4) Substitution with artificially manufactured synthetic materials (e.g., compressed paraffin wax colored yellow to simulate Beeswax), and (5) Contamination with toxic foreign matter (e.g., lead shot added to Opium packages to increase gross weight).Adulteration ka matlab hai munafa kamane ke liye dawai me milawat karna. Iske 5 tareeqe hote hain: (1) Ghatiya variety milana, (2) Exhausted drugs (jinse pehle hi tel/ras nikal liya gaya ho) milana, (3) Milti-julti sasti patti milana, (4) Nakli synthetic cheez milana (jaise paraffin wax ko peela karke beeswax banana), aur (5) Wajan badhane ke liye patthar ya ret milana.
▶Classic Pharmacopoeial Adulteration Examples
Authentic crude drugs and their commercial counterfeit substitutes.
- •Deliberate (Intentional) Adulteration: Motivated by commercial profit and supply shortage.
- •Inadvertent (Accidental) Adulteration: Due to careless collection by untrained tribals, faulty drying, or confusing regional vernacular names.
- •Exhausted Drugs: Completely devoid of active therapeutic metabolites; identified by low alcohol/water extractive values and low volatile oil content.
22. Microscopic Evaluation & Quantitative Microscopy Parameters
Dedicated Webpage➔Microscopic evaluation involves examining transverse sections (T.S.) or powdered samples of crude drugs under compound light microscopes to identify diagnostic histological markers (calcium oxalate crystal types, trichomes, stomata, starch grains). Quantitative Microscopy measures diagnostic numerical histological indices to identify adulterants even in finely powdered mixtures where gross morphology is destroyed.Microscope se Transverse Section (T.S.) dekh kar असली dawai pehchani jaati hai. Stomatal Index ka formula hota hai I = [S / (E + S)] * 100. Ye number har ped ki species ke liye fixed rehta hai (jaise Indian Senna me 17-20), chahe patti kitni bhi purani kyu na ho. Palisade ratio se Belladonna aur Datura me farq kiya jata hai.
▶Key Quantitative Microscopic Parameters & Formulas
Standard pharmacopoeial numerical parameters for leaf drug standardization.
| Diagnostic Parameter | Definition / Unit | Mathematical Formula | Diagnostic Drug Example |
|---|---|---|---|
| Stomatal Index (I) | % of epidermal cells forming stomata | I = [S / (E + S)] * 100 | Distinguishes Indian Senna (17-20) from Alexandrian (10.8-13) |
| Palisade Ratio | Palisade cells under one epidermal cell | Count under 4 continuous cells / 4 | Distinguishes Belladonna (6-10) from Datura (4-7) |
| Vein-Islet Number | Vein islets per mm² leaf surface | Counted under clearing camera lucida | Digitalis purpurea (2-5.5) vs Digitalis lutea (8.5-16) |
| Lycopodium Method | Quantitative weight % of foreign powder | Based on 94,000 spores/mg | Assaying powdered Ginger or Cardamom starch purity |
- •Stomatal Index ($I$) is independent of leaf age and environmental growth conditions, making it an infallible diagnostic criterion.
- •Calcium Oxalate Crystal Types: Prisms (Senna), Rosette aggregates (Rhubarb, Arjuna), Microsphenoidal sand (Belladonna), Acicular needles (Squill, Cinnamon).
- •Trichome Types: Non-glandular uniseriate (Digitalis), Unicellular warty (Senna), Glandular with multicellular head and stalk (Mint, Cannabis).
33. Physical Evaluation: Ash Values, Extractive Values & Moisture Content
Dedicated Webpage➔Physical evaluation determines specific physical constants of crude drugs to detect adulteration, exhausted extraction, or soil contamination. Ash values determine the amount of inorganic mineral residue (carbonates, silicates, phosphates, calcium) remaining after incinerating the drug at 450-500°C. Extractive values determine the amount of chemical constituents extracted by specific solvents (Water, Alcohol, Ether).Physical testing me Total Ash nikalne ke liye powder ko 450°C par jalate hain. Acid-Insoluble Ash se ret aur mitti (silica) ki milawat pakdi jaati hai (Ginger me max 1.5% limit). Water aur Alcohol Extractive values se pata chalta hai ki dawai me active chemicals bache hain ya use pehle hi nichod liya gaya hai.
▶Pharmacopoeial Ash and Extractive Value Standards
Analytical procedures and clinical diagnostic significance.
- •Loss on Drying (LOD): Moisture content determined by heating at 105°C in oven (Must be $< 10\%$ to prevent fungal mold growth).
- •Volatile Oil Estimation: Distillation using the official Clevenger Apparatus.
- •Swelling Index: Volume in mL occupied by 1g of mucilage-containing drug (Ispaghula husk swelling index $> 40$).
- In a 10-mark question on Evaluation of Crude Drugs, cover all 5 methods: Organoleptic, Microscopic (Stomatal Index, Palisade ratio), Physical (Ash values, Extractive values), Chemical, and Biological.
- Define Stomatal Index and write its mathematical formula with example.