Question

Titanium dioxide in gelatin mass components of capsule is a

• A. Tonicity contributor
• B. Viscosity inducer
• C. Opacifier
• D. Preservative

Hint:

Titanium dioxide is used in capsules primarily as an opacifier, giving them a white, opaque appearance to protect the contents from light.

Answer 1

The Correct Option is C

Step 1: Understanding the role of titanium dioxide in capsules.
Titanium dioxide is commonly added to gelatin capsules to make them opaque. This is done to protect the contents of the capsule from light and to make the capsule more visually appealing.
Step 2: Analyzing the options.
(A) Tonicity contributor: This is incorrect, as titanium dioxide does not influence the tonicity of the capsule.
(B) Viscosity inducer: This is not correct; titanium dioxide does not affect the viscosity of the capsule material.
(C) Opacifier: Correct — Titanium dioxide is an opacifier, meaning it makes the capsule opaque by blocking light.
(D) Preservative: Titanium dioxide is not a preservative; it is not used to preserve the drug.
Step 3: Conclusion.
The correct answer is (C) Opacifier because titanium dioxide is used to make capsules opaque.

Answer 2

Excipients added to a gelatin capsule shell each serve a specific formulation purpose, so matching titanium dioxide's known physical property (it is a bright white, highly light-scattering pigment) to the right functional category settles the question.

1. Tonicity contributor: Tonicity relates to the osmotic pressure of a solution (relevant to injectables or ophthalmic products) and has nothing to do with the optical or physical properties of a solid capsule shell.
2. Viscosity inducer: Viscosity-modifying agents change how thick or flowable a liquid or gel is; titanium dioxide's role is not about altering the flow properties of the gelatin mass but about its optical appearance.
3. Opacifier: Titanium dioxide is a white pigment with a very high refractive index, which scatters light strongly. When added to the gelatin mass, it blocks light from passing through the capsule shell, making it opaque, which protects light-sensitive contents and gives the capsule a uniform appearance.
4. Preservative: Preservatives prevent microbial growth or degradation in a formulation; titanium dioxide has no antimicrobial or stabilizing chemical action of that kind.

Only the optical light-blocking function correctly matches titanium dioxide's known role.

Therefore, the correct answer is Opacifier.