Question

Match the following: 
I. True density            (P) Reciprocal of bulk density 
II. Granule density     (Q) Graduated cylinder method 
III. Bulk density         (R) Helium Pycnometer 
IV. Bulkiness             (S) Mercury displacement method

• A. (I)-(S), (II)-(P), (III)-(Q), (IV)-(R)
• B. (I)-(Q), (II)-(S), (III)-(P), (IV)-(R)
• C. (I)-(R), (II)-(S), (III)-(Q), (IV)-(P)
• D. (I)-(S), (II)-(R), (III)-(Q), (IV)-(P)

Hint:

Bulk density and true density are crucial parameters in powder flow, compression behavior, and dosage form uniformity.

Answer 1

The Correct Option is C

Each type of density in pharmaceutical powders is determined using specific techniques: - I. True density refers to the density of the solid material excluding pores and voids. It is accurately measured using a Helium Pycnometer because helium gas can penetrate even the smallest voids in the sample. \hfill $\Rightarrow$ (R)
- II. Granule density (also called apparent or particle density) includes intra-particle pores and is often measured using the mercury displacement method, as mercury does not enter small pores. \hfill $\Rightarrow$ (S)
- III. Bulk density is the mass of a powder divided by its bulk volume (including voids). It is typically measured using the graduated cylinder method, where the powder is poured into a cylinder without tapping. \hfill $\Rightarrow$ (Q)
- IV. Bulkiness is the inverse of bulk density, i.e., volume occupied per unit mass of the powder. \hfill $\Rightarrow$ (P)
Thus, the correct matching is: I-(R), II-(S), III-(Q), IV-(P)