Step 1: What are pharmacopoeial quality parameters?
Pharmacopoeias define several tests to check the identity, purity, and quality of crude drugs. Each test detects a different type of impurity or characteristic.
Step 2: What is total ash and acid-insoluble ash?
Total ash is the residue left after burning the crude drug. It represents all inorganic material. Acid-insoluble ash is the part of total ash that does not dissolve in dilute hydrochloric acid. This acid-insoluble residue is mainly silica from sand and soil particles, which are foreign inorganic contaminants.
Step 3: Why are the other tests wrong?
Assay for active principle measures the potency of the drug, not foreign matter. Loss on drying measures moisture and volatile material, not foreign inorganic material. TLC profile checks chemical identity and purity, not physical inorganic contaminants.
Step 4: Practical significance.
A high acid-insoluble ash value means the drug is adulterated with sand or soil. This directly detects foreign inorganic material that cannot be removed by acid.
Step 5: Conclude.
Total ash and acid-insoluble ash are the standard pharmacopoeial parameters specifically designed to detect foreign inorganic matter.
Answer: Option (3) — Total ash and acid-insoluble ash