BP105T • Unit 4Topic 3 of 3⏱ 5 Min Read

3. Physical Evaluation: Ash Values, Extractive Values & Moisture Content

💡 Core Concept & Clinical Context:

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).

Clinical Scenarios & Pharmacopoeial Examples:

1Pharmacopoeial Ash and Extractive Value Standards

Analytical procedures and clinical diagnostic significance.

Step-by-Step Breakdown:

•1. Total Ash Value:

•- Complete incineration of 2g powdered drug in a tared silica crucible at 450°C until white/carbon-free.

•- Measures both physiological ash (minerals native to plant tissues) and non-physiological ash (sand, soil, grit adhering to surface).

•2. Acid-Insoluble Ash:

•- Total ash boiled with 25 mL 2M Hydrochloric Acid (HCl); filtered through ashless filter paper, ignited and weighed.

•- Measures specifically siliceous earth, silica, and sand contamination (IP limit for Ginger is max 1.5%).

•3. Water-Soluble Ash:

•- Total ash boiled with water; water-soluble inorganic salts filtered out. The difference in weight represents water-soluble ash (Detects exhausted drugs).

•4. Extractive Values:

•- Water-Soluble Extractive: Indicates glycosides, tannins, gums, sugars (Senna not less than 30%).

•- Alcohol-Soluble Extractive: Indicates resins, alkaloids, flavonoids (Asafoetida not less than 50%).

📋Key Takeaways & Exam Highlights

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 $> 40$).

🇮🇳 हिन्दी व्याख्या (3. Physical Evaluation: Ash Values, Extractive Values & Moisture Content)

टोटल ऐश (Total Ash) दवा को 450°C पर जलाकर राख का वजन नापना है। एसिड-इनसॉल्युबल ऐश (Acid-Insoluble Ash) से मिट्टी और रेत की मिलावट पकड़ी जाती है। पानी और अल्कोहल एक्सट्रैक्टिव वैल्यू से यह पता चलता है कि दवा से उसका रस पहले ही तो नहीं निकाल लिया गया।