Question

The applicability of Noyes-Whitney's equation is to describe _______

• A. \( \text{Dissolution rate} \)
• B. \( \text{Zero order degradation kinetics} \)
• C. \( \text{Mixed order reaction kinetics} \)
• D. \( \text{Rate of excretion} \)

Hint:

Remember "dissolution" when you see "Noyes-Whitney equation." It's a key concept in pharmaceutics related to how drugs dissolve.

Answer 1

The Correct Option is A

The Noyes-Whitney equation describes the rate of dissolution of a solid drug in a liquid medium. The equation is: $$ \frac{dC}{dt} = \frac{DA(C_s - C)}{h} $$ where: - \( \frac{dC}{dt} \) is the dissolution rate - \( D \) is the diffusion coefficient of the drug in the dissolution medium - \( A \) is the surface area of the dissolving solid - \( C_s \) is the solubility of the drug in the dissolution medium - \( C \) is the concentration of the drug in the bulk dissolution medium at time \( t \) - \( h \) is the thickness of the diffusion layer Therefore, the Noyes-Whitney equation is fundamental in describing the dissolution rate of drugs, which is a critical factor in their absorption and bioavailability.