Rheology in Pharmaceutical Sciences

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What is the term Rheology derived from?

Greek words meaning 'to flow' and 'science' (correct)

Latin and Greek words meaning 'to deform'

French words meaning 'to measure' and 'fluids'

English words meaning 'to study' and 'material'

Which type of deformation is reversible according to the text?

Elastic deformation (correct)

Plastic deformation

Permanent deformation

Irreversible deformation

What is the material response to a stress known as?

Plasticity

Elasticity

Rheology (correct)

Viscoelasticity

Shearing stress is applied in which manner to the surface of a body?

Tangentially Signup and view all the answers

Which of the following is a concept related to rheology according to the text?

Viscosity Signup and view all the answers

What type of stress is applied perpendicularly to the surface of a body?

Tensile stress Signup and view all the answers

What is viscosity?

The ability of a liquid to resist flow Signup and view all the answers

How does viscosity change with temperature?

Decreases with rise in temperature Signup and view all the answers

What unit is used to measure viscosity in the C.G.S system?

Dyne-second/square centimeter Signup and view all the answers

Why are ophthalmic preparations made viscous?

To prolong the contact time of the drugs Signup and view all the answers

How are paints affected when made more viscous?

They remain in contact with skin for a long time Signup and view all the answers

Why are certain pharmaceutical formulations standardized based on viscosity?

To maintain consistency and quality Signup and view all the answers

What type of flow is typically exhibited by polymers in solution?

Pseudo-plastic flow Signup and view all the answers

How is the consistency curve for a pseudo-plastic material represented?

It starts at the origin or approaches it at low shear rates. Signup and view all the answers

What happens to the viscosity of a pseudo-plastic material as shear stress is increased?

It cannot be expressed by any single value. Signup and view all the answers

What effect does shearing stress have on molecules in a pseudo-plastic material?

It aligns their long axes in the direction of flow. Signup and view all the answers

Which of the following is NOT an application of materials exhibiting pseudo-plastic flow?

Concrete Signup and view all the answers

What causes the curved Rheogram for pseudo-plastic materials?

Shearing action on long chain molecules Signup and view all the answers