Question:
Equipment used in structured breakdown of thixotropy
Equipment used in structured breakdown of thixotropy
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Thixotropy is essential in pharmaceutical formulations like suspensions and gels, ensuring ease of application during use and stability at rest.
Updated On: Jul 14, 2026
- Viscometer
- Planimeters
- Rotameters
- Orifice meter
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The Correct Option is A
Approach Solution - 1
Thixotropy is a time-dependent shear-thinning property. A thixotropic material becomes less viscous over time when shear is applied and recovers its viscosity when the shear is removed.
- This behavior is common in colloidal systems, gels, and suspensions, where structural breakdown occurs under stress and rebuilds when at rest.
- A viscometer is an instrument used to measure the viscosity of a fluid. In the study of thixotropy, viscometers help observe how viscosity decreases over time under constant shear—indicating structural breakdown.
- Brookfield viscometer and rotational viscometers are widely used for studying thixotropic flow behavior in pharmaceuticals.
Other options: - Planimeters (option b) are used to measure the area on a two-dimensional plane and are not relevant to rheology.
- Rotameters (option c) measure fluid flow rate, not viscosity.
- Orifice meters (option d) are also flow-measuring devices used in process industries.
Hence, the correct equipment for measuring the structural breakdown in thixotropy is the viscometer.
- A viscometer is an instrument used to measure the viscosity of a fluid. In the study of thixotropy, viscometers help observe how viscosity decreases over time under constant shear—indicating structural breakdown.
- Brookfield viscometer and rotational viscometers are widely used for studying thixotropic flow behavior in pharmaceuticals.
Other options: - Planimeters (option b) are used to measure the area on a two-dimensional plane and are not relevant to rheology.
- Rotameters (option c) measure fluid flow rate, not viscosity.
- Orifice meters (option d) are also flow-measuring devices used in process industries.
Hence, the correct equipment for measuring the structural breakdown in thixotropy is the viscometer.
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Approach Solution -2
This question asks which instrument is used to study the structural breakdown that defines thixotropic behavior. Checking what each instrument actually measures against what thixotropy requires shows which one fits.
- Viscometer: Thixotropy shows up as a drop in a material's resistance to flow the longer or harder it is sheared, followed by a slow recovery at rest. A viscometer measures exactly this resistance to flow, or shear stress at a given shear rate, over time, which lets it track the structural breakdown and rebuilding that defines thixotropic behavior directly.
- Planimeters: A planimeter traces the outline of a flat shape to calculate its area. It has no way to apply or measure shear on a fluid, so it cannot record how a material's structure breaks down.
- Rotameters: A rotameter reads how fast a fluid is flowing through a tube, using a float that rises with flow rate. It reports flow rate, not the resistance or structural changes within the fluid, so it does not capture thixotropic breakdown.
- Orifice meter: An orifice meter also measures flow rate, this time from the pressure drop across a narrowed opening in a pipe. Like the rotameter, it is built for flow measurement in process piping, not for tracking how a material's internal structure changes under shear.
Only an instrument that can apply a controlled shear and record the resulting resistance over time can capture the breakdown and recovery cycle of a thixotropic material, which is exactly what a viscometer does.
So the correct answer is Viscometer.
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